UPDATE 16.08.2019

Precise 2D‐patterned Incompatible Catalysts for Reactions in One‐pot

M. O. Pretscher, T. Chen, G. Sitaru, S. Gekle, J. Ji, S. Agarwal

Precise 2D‐patterned Incompatible Catalysts for Reactions in One‐pot, Chem., 2019.


We show precise and direct two‐dimensional (2D) printing of the incompatible polymer acid‐base catalysts and their utility in one‐pot two‐step reactions. Multi‐step catalytic reactions using incompatible catalysts in a one‐pot reaction cascade require special methods and materials for isolation of catalysts from each other. This, in general is a tedious process requiring special polymer architectures as catalysts’ carrier for preserving the activity of otherwise incompatible catalysts. We propose the immobilization of incompatible polymer catalysts, such as polymer acid and base catalysts, on a substrate in variable sizes and amounts by precise 2D printing. The copolymers with a basic (4‐vinylpyridine) and acidic (styrene sulfonic acid) functionality and methacryloyl benzophenone as a UV cross‐linking unit were used for 2D printing. The printed meshes were immersed together in a reaction solution containing (dimethoxy methyl)‐benzene and ethyl cyanoformate, resulting in a two‐step acid‐base catalyzed cascade reaction, i.e. deacetalization followed by carbon‐building reaction. The time‐dependent consumption of (dimethoxymethyl)‐benzene to the intermediate benzaldehyde and the product was monitored, and a kinetic model was developed to investigate the underlying reaction dynamics. The complexity of multi‐step Wolf‐Lamb‐type reactions was generally significantly decreased using our approach due to the easy polymerization and immobilization procedure.

Hyperbranched Fractal Nanocarbons for Bright Photoluminescence in Solid State

Wang, Y.‐L., Liu, B., Yang, J.‐L., Cao, X.‐H., Yang, Y.‐Z., Yang, Q., Greiner, A., Xu, J.‐T., Zhang, X.‐H.

Hyperbranched Fractal Nanocarbons for Bright Photoluminescence in Solid State. Advanced Optical Materials 2019, 1900659.


Nanocarbons with diverse structures have great potential applications in biomedicine, energy conversion, and catalysis owing to their unique photoelectric properties. This work describes bottom‐up synthesis of hyperbranched fractal nanocarbons (HFNs), using trimethylolpropane tri(cyclic carbonate) ether and ethylenediamine as the precursors. HFNs are formed by self‐assembly of in situ generated carbonized polymer dots (CPDs), driven by their low surface ζ‐potentials. Of significance, both CPDs and HFNs possess graphitized carbon core and functionalized shell with core edge layer, thus emit bright solid‐state luminescence with an absolute quantum yield of 11.7% at room temperature and strong phosphorescence at 77 K. The carbonyl cluster of these nanocarbons is mainly responsible for the strong photoluminescence emission. The application of HFNs is demonstrated for energy conversion, using them as single phosphor for fabricating multicolor light‐emitting diodes. This work outlines a fundamental principle to prepare HFNs with bright photoluminescence in solid state.

Mesostructured Nonwovens with Penguin Downy Feather‐Like Morphology—Top‐Down Combined with Bottom‐Up

M. Burgard,  D. Weiss,  K. Kreger,  H. Schmalz,  S. Agarwal,  H.‐W. Schmidt,  A. Greiner

Adv. Funct. Mater. 2019, 1903166. doi: 10.1002/adfm.201903166


Polymer fibers play an important role in nature and technical systems. Fiber morphologies with off‐standing branches, as found in nature, e.g. in penguin downy feathers, provide unique properties but are unknown for man‐made polymer fiber systems. We discovered that it is possible to initiate seeded growth from trisamide seeded polystyrene fibers, prepared by core‐shell electrospinning, to form off‐standing supramolecular trisamide branches similar to penguin downy feathers but in polymer nonwovens and in nanoscale. Resulting mesostructured nonwovens show unique properties. For example, air filtration efficiency of 99.8% for the filtration of 0.3 µm aerosol particles, being significantly higher compared to neat electrospun polystyrene nonwovens as bench‐mark, showing only an efficiency of about 52.6%. Most remarkably, the pressure drop observed in filtration tests and thus, the energy consumption during filtration, did not increase up to a certain content of off‐standing supramolecular fibrils. This is a unique behavior, as higher filtration capabilities are typically connected to higher energy consumptions and pressure drops. Hence, branching electrospun fibers with supramolecular fibrils paves the way to new mesostructured nonwovens with unique morphologies, property profiles and applications in filtration, catalysis, and energy storage/harvesting, exploiting nature's concepts.


Chengzhang XU and Qiang GAO received the poster award for best posters at the 6th international Electrospin 2019 conference, Shanghai, China, June 19th-21st, 2019
We congratulate Chengzhang and Qiang – very well done!


Prof. Andreas Greiner, Prof. Seema Agarwal, Chengzhang Xu und Qiang Gao participated on the conference Electrospin 2019 in Shanghai, Donghua University on June 19th-21st, 2019 with about 400 participants and presented lectures and posters.

Air‐Blowing‐Assisted Coaxial Electrospinning toward High Productivity of Core/Sheath and Hollow Fibers

Duan, G., Greiner, A.

Macromol. Mater. Eng. 2019, 304, 1800669.


Coaxial electrospinning is an attractive technology to produce core/sheath and hollow fibers. However, until now, the relatively low productivity has limited its broad applications. In this work, coaxial electrospinning with air‐blowing‐assistance is applied to improve the productivity of core/sheath and hollow fibers. Different core and shell materials are used for this electrospinning. The flow rate and air‐blowing rate during electrospinning are optimized. SEM and TEM are used to confirm the core/sheath and hollow structure of fibers. The results show that air‐blowing‐assisted electrospinning technology can be successfully applied for the large‐scale production of core/sheath and hollow fibers which open the path to new applications of this promising class of materials.

Sustainable Approach to Superhydrophobic Surfaces Based on Water‐Born Electrospinning

M. Doimoto, A. Greiner

Macromol. Mater. Eng. 2018, 303, 1700621.


Superhydrophobic surfaces are obtained by a sustainable approach by electrospinning of water‐based acrylate dispersion followed by mild silanization and removal of template polymer. The resulting nonwovens show very high superhydrophobicity and very low roll angle. In contrast to many other approaches, pores provide the required morphology to achieve superhydrophobicity. This new material provides a new approach to electrospun nonwoven coatings which can be of interest for textile applications.

Preparation of Biocomposite Microfibers Ready for Processing into Biologically Active Textile Fabrics for Bioremediation

P. Kaiser, S. Reich, A. Greiner, R. Freitag

Kaiser, P., Reich, S., Greiner, A., Freitag, R., Macromol. Biosci. 2018, 18, 1800046.



Biocomposites, i.e., materials consisting of metabolically active microorganisms embedded in a synthetic extracellular matrix, may find applications as highly specific catalysts in bioproduction and bioremediation. 3D constructs based on fibrous biocomposites, so‐called “artificial biofilms,” are of particular interest in this context. The inability to produce biocomposite fibers of sufficient mechanical strength for processing into bioactive fabrics has so far hindered progress in the area. Herein a method is proposed for the direct wet spinning of microfibers suitable for weaving and knitting. Metabolically active bacteria (either Shewanella oneidensis or Nitrobacter winogradskyi (N. winogradskyi)) are embedded in these fibers, using poly(vinyl alcohol) as matrix. The produced microfibers have a partially crystalline structure and are stable in water without further treatment, such as coating. In a first application, their potential for nitrite removal (N. winogradskyi) is demonstrated, a typical challenge in potable water treatment.

Wolf–Lamb-type Catalysis in One Pot Using Electrospun Polymeric Catalyst Membranes

M. Pretscher, S. Gekle, S. Agarwal

Macromolecular Rapid Communication, 2019, 1900148



Multistep catalytic transformations using incompatible catalysts (Wolf–Lamb‐type) in a one‐pot reaction cascade require site isolation of different catalysts by compartmentalization. In this work, the use of different electrospun catalytic membranes in a modular way as individual compartments is shown for one‐pot Wolf–Lamb‐type reaction cascades. The data are presented for one‐pot cascade reaction sequences catalyzed by acidic and basic membranes made by electrospinning polymeric acid (poly(styrene‐co‐styrene sulfonic acid‐co‐4‐methacryloyl‐oxybenzophen)) and basic (poly(styrene‐co‐4‐vinylpyridine‐co‐4‐methacryloyl‐oxybenzophen)) catalysts, respectively. The two‐step, one‐pot system used is the acidic catalyzed deacetylation of dimethoxybenzylacetale to benzaldehyde, which reacts with ethyl cyanoformate to result in a high yield of product (over 90%) under base‐catalyzed conditions. The reaction kinetics are further monitored and evaluated by using differential equations, showing the necessity of a parameter Δt to represent a retarded start for the second reaction step. The concept provides an easy and upscalable approach for use in Wolf–Lamb‐type systems.

Synthesis and self-assembly of biobased poly(limonene carbonate)-block-poly(cyclohexene carbonate) diblock copolymers prepared by sequential ring-opening copolymerization

Bailer, J.; Feth, S.; Bretschneider, F.; Rosenfeldt, S.; Drechsler, M.; Abetz, V.; Schmalz, H.; Greiner, A.

Green Chem. 2019, 21, 2266. doi: 10.1039/C9GC00250B


Polycarbonate diblock copolymers with a biobased poly(limonene carbonate) (PLimC) and a poly(cyclohexene carbonate) (PCHC) block were prepared via -diiminate zinc catalysed living ring-opening copolymerization (ROCOP) of CO2 and trans-limonene oxide and cyclohexene oxide, respectively. Trans-limonene oxide can be readily obtained from limonene, a renewable non-food source, that can be found in the peel of many citrus fruits and is the main component of orange oil. The block formation was realised by sequential addition of the epoxide monomers. The composition of the resulting amorphous poly(limonene carbonate)-block-poly¬(cyclohexene carbonate) (PLimC-b-PCHC) diblock copolymers was analysed by 1H NMR spectroscopy. The self-assem¬bly of the diblock copolymers into well-defined bulk mor¬pholo¬gies was studied by transmission electron microscopy (TEM) and small angle X-ray scattering (SAXS). Depending on the composition and molecular weight the formation of cylindrical, lamellar, and hexagonally perforated lamellar morphologies was observed.


Filter‐Through Method of Making Highly Efficient Polymer‐Clay Nanocomposite Membranes

J. Zhu, C. Habel, T. Schilling, A. Greiner, J. Breu, S. Agarwal

Macromol. Mater. Eng. 2019, 1800779.


Electrospun filter with hierarchical pore structure and variable pore diameter is used for the first time in making a flexible, strong, and high gas‐barrier membrane. A versatile, technical, benign processing method for the fabrication of highly filled (>25 wt%) efficient gas‐barrier polymer membrane with perfectly aligned synthetic high‐aspect ratio layered silicate (clay) of variable and considerable thickness (up to 5 µm) is presented. This process combines advantageous features of an electrospun substrate like high porosity, variable pore size (typically <5 µm), thermoplasticity and of an aqueous suspension of a synthetic clay consisting of single 1 nm thick layers with a huge median lateral extension (>10 µm) in a layered structure. By simple and fast filtration, a gas‐barrier self‐assembled layer of variable and appropriate thickness is obtained on a mechanically stable thermoplastic electrospun filter support that subsequently can be laminated adhesively or via hot pressing, even in a multilayer structure, if required. The resulting composite membranes are flexible, strong, transparent, and show enhanced gas‐barrier properties.


High‐Temperature Spray‐Dried Polymer/Bacteria Microparticles for Electrospinning of Composite Nonwovens

S. Reich, P. Kaiser, M. Mafi, H. Schmalz, D. Rhinow, R. Freitag, A. Greiner

 Macromol. Biosci. 2019, 1800356.


Living Micrococcus luteus (M. luteus) and Escherichia coli (E. coli) are encapsulated in poly(vinyl alcohol), poly(vinylpyrrolidone), hydroxypropyl cellulose, and gelatin by high‐temperature spray drying. The challenge is the survival of the bacteria during the standard spray‐drying process at temperatures of 150 °C (M. luteus) and 120 °C (E. coli). Raman imaging and transmission electron microscopy indicate encapsulated bacteria in hollow composite microparticles. The versatility of the spray‐dried polymer bacteria microparticles is successfully proved by standard polymer solution–processing techniques such as electrospinning, even with harmful solvents, to water‐insoluble polyacrylonitrile, polystyrene, poly(methyl methacrylate), and poly(vinyl butyrate) nanofiber nonwovens, which opens numerous new opportunities for novel applications.

Gradient-Structured Nonflammable Flexible Polymer Membranes

J. Zhu, J. Breu, H. Hou, A. Greiner, S. Agarwal

ACS Applied Materials & Interfaces 2019 11 (12), 11876-11883


Herein, we report the formation and properties of a rare example of high-performance composite membranes from polybisbenzimidazobenzophenanthroline-dione (BBB) that do not sustain a flame or burn with smoke nor show melt dripping. In addition, this material possesses a low density and very high thermal stability (char yield as high as 80–94%), strength, and flexibility. Such membranes are highly desirable for battery separators, protective clothing, construction, and automobiles. Because BBB is an insoluble and infusible polymer, the composite membranes were made using a bottom-up vacuum-assisted self-assembly method with an aqueous dispersion of short BBB fibers and Hec. The use of water as the solvent, upscalability, and excellent flame retardancy in combination with low density, flexibility, and low thermal conductivity of the composite membranes make the preparation method and membranes highly promising for future use in real applications.

Electrospun Bacteria‐Gold Nanoparticle/Polymer Composite Mesofiber Nonwovens for Catalytic Application

S.Reich, S. Agarwal, A. Greiner

 Macromol. Chem. Phys. 2019, 1900007.


Polymer composite nonwovens with living Micrococcus luteus (ML), a very common gram‐positive bacterium present on human skin, are prepared by electrospinning followed by coating via the chemical vapor deposition (CVD) of poly(p‐xylylene) (PPX). The encapsulated living ML convert Au(III) ions to gold nanoparticles (AuNPs) when the composite nonwovens are dipped in an aqueous chloroauric acid solution. As a result of this process, AuNPs are formed on the ML. The ML‐immobilized AuNPs can be used for catalytic reactions with acetone as the solvent at a very low gold concentration. Despite the presence of acetone, ML survive the catalytic reaction. Interestingly, the catalytic reactions are possible only when the ML in the nonwovens are alive. In contrast, nonwovens with dead ML do not show any significant catalytic activity.

Controlled-Release LCST‐Type Nonwoven Depots via Squeezing-Out Thermal Response

F. Käfer, R. Vilensky, G. Vasilyev, E. Zussman, S. Agarwal

Macromol. Mater. Eng. 2018, 1800606.


A novel thermoresponsive fibrous matrix as controlled release depots upon heating is described. The matrix is composed of electrospun fibers of a lower critical solution temperature (LCST)‐type poly(methacrylamide‐co‐N‐tert‐butylacrylamide‐co‐4‐acryloylbenzophenone) P(MAAm‐NtbAAm‐ABP) copolymer. Spherical particles, simulating depots of drugs, are embedded with liquid‐filled inter‐fiber spaces (pores). On heating above 25 °C up to 45 °C, the nanofibers undergo a contraction of about 40%. This solid deformation is attributed to the LCST transition. Fibrous matrix contraction drives expulsion of depots and water solution stored in the pores of the matrix, as evidenced by in situ observations. The liquid flow in the deformable porous medium demonstrates liquid drainage from the matrix as a function of temperature. Experimental results reveal that 70% of the particles are expelled from the matrix upon heating to 45 °C from room temperature. The presented particles encapsulation and release model system using LCST‐type fibrous matrix can be used as a transdermal patch.

Synthesis and properties evaluation of quaternized polyurethanes as antibacterial adhesives

P. Hu, A. Greiner, S. Agarwal

J. Polym. Sci. Part A: Polym. Chem., 2019, doi:10.1002/pola.29321


We present new side‐chain quaternized polyurethanes as antibacterial adhesives made by polyaddition polymerization followed by quaternization for different time intervals. The degree of quaternization of N‐diol units in the polymer is changed from 13.6 to 99.0 mol % (almost complete) for tuning the antibacterial action (leaching/contact type) and studying effect on adhesive strength. The degree of quaternization of about 26 mol % provided the nonleaching antibacterial effect with adhesive strength more than 60 N cm−2 on aluminum and glass substrates. The increase in the degree of quaternization enhanced polymer polarity shifting nonleaching (contact type) antibacterial behavior to the leaching type but maintaining the high adhesive strengths.

Interpenetrating thermophobic and thermophilic dual responsive networks

F. Käfer, Y.Hu, Y. Wang, Z. Wu, S. Agarwal

J. Polym. Sci. Part A: Polym. Chem., 2019, 57: 539-544.


Poly(N‐acryloyl glycinamide) (PNAGA)/poly(N‐isopropyl acrylamide) (PNIPAAm) interpenetrating network (IPN) hydrogels were made by UV‐light initiated radical polymerization in two‐steps. The IPN hydrogels showed a double thermoresponsive behavior due to the combination of PNIPAAm (thermophobic) and PNAGA (thermophilic) networks. Increasing the content of the thermophobic PNIPAAm network leads to a change from a broad thermophilic volume phase transition temperature of PNAGA to a thermophilic–thermophobic‐type dual transition for the prepared IPN. Due to the double thermoresponsive character of the IPN gels, the mechanical properties are dependent upon temperature as demonstrated by performing tensile tests in water at 15 and 50 °C. Furthermore, the IPN hydrogels were characterized using turbidity measurements, SEM, and the determination of the equilibrium swelling ratio.

Redispersible Gold Nanoparticle/Polymer Composite Powders Ready for Ligand Exchange Reactions

J. Kronawitt, Z. Fan, M. Schöttle, S. Agarwal, A. Greiner

ChemNanoMat. 2018 doi:10.1002/cnma.201800517


Dry powders embedded with gold nanoparticles (AuNPs) are produced by spray-drying technique from an aqueous AuNP dispersion in a poly(vinyl alcohol) (PVA) or poly(vinyl pyrrolidone) (PVP) matrix. The prepared powders consist of AuNPs stabilized in hollow capsules of PVA (PVA@AuNP) or PVP (PVP@AuNP) with an average diameter of several micrometers. The AuNP powders are dispersible in water and no agglomeration triggered by the spray drying process of AuNPs is observed. The PVA@AuNP powders are coextruded with polycaprolactone to demonstrate the industrial application of dry‐state AuNPs. With PVP@AuNP the incorporation of AuNP into other stabilizing polymers via ligand exchange method is facilitated. After each step, the active surface of the AuNPs was tested by catalytic studies.

Progress in the Field of Water- and/or Temperature-Triggered Polymer Actuators

S. Agarwal, S. Jiang, Y. Chen

Macromol. Mater. Eng., 2018, 1800548


Water- and/or temperature-triggered polymer actuators have great potential in robotics, microfabrication and micromanipulation, cell culture, artificial scaffolds, muscles, and motors. In the past few years, a large amount of work has been carried out, and several innovative concepts have been proposed to address challenges such as actuation with large-scale displacement in a very short time, actuation of large-sized samples, complex 3D shaping, directional control, multiresponsive actuation, and strong actuators. Herein, the progress made in the field of actuators triggered by water, temperature, and a combination of both is presented, emphasizing the new concepts of fast and direction-controlled actuation, the corresponding mechanisms, the associated challenges, and future tasks and perspectives.

A fluorescein-centered polymer as a phosphor for fabricating pure white light-emitting diodes

B. Liu,  H. Duan,  Y. Wang,  B. Du,  Q. Yang,  J. Xu,  Y. Yang,  A. Greiner  and  X. Zhang

Mater. Horiz., 2018,5, 932-938


White light-emitting diodes (LEDs) are very important energy-saving lighting devices. It is still a big challenge to fabricate pure white LEDs using low-cost, easy-to-process and environment-friendly phosphors. Herein, we report a pure white LED fabricated by combining rationally designed fluorescein-centered polymers with a blue LED chip. Pure white LEDs with Commission International de L’Eclairage (CIE) coordinates of (0.33, 0.33), a satisfactory color rendering index (CRI) of 82 and a correlated color temperature (CCT) of 5230 K were achieved. Covalently embedding fluorescein into the center of the polymer chain realized molecular dispersion of fluorescein. Of significance, by varying the types of the side groups of the polymer, the fluorescence properties of the embedded fluorescein unit can be regulated. The performance parameters (i.e., emission spectra, CIE coordinates, CRI and CCT) of the as-fabricated LEDs could also be tailored by varying the working voltages, and the types and amounts of fluorescein-centered polymers.

Anisotropic microfibres of a liquid-crystalline diketopyrrolopyrrole by self-assembly-assisted electrospinning

M. Hechta, B. Soberats, J. Zhuc, V. Stepanenkoa, S. Agarwal, A. Greiner and F. Würthner

Nanoscale Horiz., 2018, Advance Article.


Electrospinning is a well-established technique for the preparation of nanofibres from polymer solution or melt, however it is rarely applied for small molecules. Here we report a unique example of a liquid-crystalline (LC) diketopyrrolopyrrole (DPP) dye that was successfully used for electrospinning. Micrometric fibres with anisotropic alignment of DPP dye were produced by this process as shown by polarized optical microscopy and selected area electron diffraction. This newly designed DPP dye self-assembles in solution by hydrogen bonding and π–π-interactions and forms columnar LC phases in the bulk. X-ray scattering and polarized FT-IR studies in the LC state revealed a hierarchical arrangement of DPP molecules into columnar structures. The successful preparation of anisotropic microfibers by electrospinning is attributed to the hydrogen bond-directed supramolecular polymerization of the new DPP dye in solution and its LC properties.

Strategies for the selective loading of patchy worm-like micelles with functional nanoparticles

J. Schöbel; C. Hils; A. Weckwerth; M. Schlenk; C. Bojer; M. C. A. Stuart; J. Breu; S. Förster; A. Greiner; M. Karg; H. Schmalz

Nanoscale 2018, in print.


Block copolymer self-assembly in solution paves the way to the construction of well-defined compartmentalized nanostructures. These are excellent templates for the incorporation and stabilisation of nanoparticles (NPs), giving rise to highly relevant applications in the field of catalysis or sensing. However, the regio-selective incorporation of NPs in specific compartments is still an issue, especially concerning the loading with different NP types. Using crystallisation-driven self-assembly (CDSA), functional worm-like crystalline-core micelles (wCCMs) with a tailor-made, nanometre-sized patchy corona were prepared as versatile templates for the incorporation and stabilisation of metal and metal oxide NPs.

Preparation of Biocomposite Microfibers Ready for Processing into Biologically Active Textile Fabrics for Bioremediation

P. Kaiser, S. Reich, A. Greiner, R. Freitag 

Macromol. Biosci. 2018, 1800046


Biocomposites, i.e., materials consisting of metabolically active microorganisms embedded in a synthetic extracellular matrix, may find applications as highly specific catalysts in bioproduction and bioremediation. 3D constructs based on fibrous biocomposites, so‐called “artificial biofilms,” are of particular interest in this context. The inability to produce biocomposite fibers of sufficient mechanical strength for processing into bioactive fabrics has so far hindered progress in the area. Herein a method is proposed for the direct wet spinning of microfibers suitable for weaving and knitting. Metabolically active bacteria (either Shewanella oneidensis or Nitrobacter winogradskyi (N. winogradskyi)) are embedded in these fibers, using poly(vinyl alcohol) as matrix. The produced microfibers have a partially crystalline structure and are stable in water without further treatment, such as coating. In a first application, their potential for nitrite removal (N. winogradskyi) is demonstrated, a typical challenge in potable water treatment.

 2018 WITec Paper Award for Outstanding Scientific Publications


Our work on “Tailoring the morphology of responsive bioinspired bicomponent fibers”, published in Macromol. Mater. Eng. 2018, 303, 1700248 (DOI. 10.1002/mame.201700248), received the WITec Silver Paper Award 2018. Mimicking biological structures with interesting functional features is a thriving field of research. In our work we were inspired by biological fibers and developed new fibers with distinct structures, utilizing side-by-side electrospinning of a thermo-responsive polymer and a methacrylate-based copolymer. By changing the spinning solvents the fiber morphology could be easily switched between side-by-side and coaxial bead-on-string fibers, as proven by correlative Raman imaging, atomic force microscopy and scanning electron microscopy.

Combining 3D Printing with Electrospinning for Rapid Response and Enhanced Designability of Hydrogel Actuators

T. Chen, H. Bakhshi, L. Liu, J. Ji, S. Agarwal

Adv. Funct. Mater. 2018, 1800514


Porous structures have emerged as a breakthrough of shape-morphing hydro-gels to achieve a rapid response. However, these porous actuators generally suffer from a lack of complexity and diversity in obtained 3D shapes. Herein, a simple yet versatile strategy is developed to generate shape-morphing hydrogels with both fast deformation and enhanced designability in 3D shapes by combining two promising technologies: electrospinning and 3D printing. Elaborate patterns are printed on mesostructured stimuli-responsive electrospun membranes, modulating in-plane and interlayer internal stresses induced by swelling/shrinkage mismatch, and thus guiding morphing behav-iors of electrospun membranes to adapt to changes of the environment. With this strategy, a series of fast deformed hydrogel actuators are constructed with various distinctive responsive behaviors, including reversible/irrevers-ible formations of 3D structures, folding of 3D tubes, and formations of 3D structures with multi low-energy states. It is worth noting that although poly(N-isopropyl acrylamide) is chosen as the model system in the present research, our strategy is applicable to other stimuli-responsive hydrogels, which enriches designs of rapid deformed hydrogel actuators.

Composite Polymeric Membranes with Directionally Embedded Fibers for Controlled Dual Actuation

L. Liu, H. Bakhshi, S. Jiang, H. Schmalz, S. Agarwal

Macromol. Rapid Commun. 2018, 1800082


In this paper, preparation method and actuation properties of an innovative composite membrane composed of thermo‐ and pH‐responsive poly(N‐isopropylacrylamide‐co‐acrylic acid) fibers (average diameter ≈ 905 nm) embedded within a passive thermoplastic polyurethane (TPU) matrix at different angles with degree of alignment as high as 98% are presented. The composite membrane has a gradient of TPU along the thickness. It has the capability of temperature‐ and pH‐dependent direction‐, and size‐controlled actuation in few minutes. The stresses generated at the responsive fiber and nonresponsive matrix provide actuation, whereas the angle at which fibers are embedded in the matrix controls the actuation direction and size. The temperature has no effect on actuation and actuated forms at pH 7 and above, whereas the size of the actuated forms can be controlled by the temperature at lower pH. The membranes are strong enough to reversibly lift and release ≈426 times weight of their own mass (2.47 g metal ring is lifted by a 5.8 mg membrane). Soft actuators are of interest as smart scaffolds, robotics, catalysis, drug release, energy storage, electrodes, and metamaterials.

Ling-Peng defense

Congratulations Ling Peng for successfully defending  PhD work and wish you good luck for the future.

Ultraporous, Compressible, Wettable Polylactide/Polycaprolactone Sponges for Tissue Engineering

M. Mader, V. Jérôme, R. Freitag, S. Agarwal, A. Greiner

Biomacromolecules, 2018, DOI: 10.1021/acs.biomac.8b00434


Ultraporous, degradable sponges made of either polylactide or of blends of polylactide/poly(ε-caprolactone) are prepared by freeze-drying of dispersions of short electrospun fibers and subsequent thermal annealing. The sponges feature ultrahigh porosity (99.6%), a hierarchical cellular structure, and high reversible compressibility with fast recovery from deformation in the dry as well as in the wet state. The sponge properties depend on the fiber dispersion concentration and the annealing temperature. Sponge characteristics like fiber density (2.5–20 mg/cm3), size, shape, crystallinity, mechanical strength, wetability, and structural integrity are user adjustable. Cell culture experiments were successfully performed with Jurkat cells with Confocal Laser Scanning Microscopy and MTT staining showing rapid cell proliferation. Live/Dead staining demonstrated high viability of the seeded cells. The sponge characteristics and modifications investigated and presented here reveal that these sponges are highly promising for tissue engineering applications.

Low Density, Thermally Stable, and Intrinsic Flame Retardant Poly(bis(benzimidazo)Benzophenanthrolinedione) Sponge

J. Zhu, S. Jiang, H. Hou, S. Agarwal and A. Greiner

Macromol. Mater. Eng. 2018, 1700615.

Jian Zhu Macromolmateng

Low density (≤13.9 mg cm−3), compressible poly(bis(benzimidazo)benzophenanthroline-dione) (BBB) sponges with high temperature resistance are reported. The processing of BBB is limited due to its insolubility in organic solvents and infusibility. Therefore, the sponges are made in two steps: first, the BBB fibers are prepared by electrospinning the starting monomers with a template polymer followed by polycondensation of monomers on solid fibers at high temperature. In the second step, the BBB fibers are mechanically cut and self-assembled from a dispersion during freeze-drying. The use of poly(vinyl alcohol) is critical in getting self-assembled hierarchically double-pore-structured, mechanically stable sponges. The sponges show very high pyrolytic stability, high compressibility (more than 92% recovery after 50% compression), very low thermal conductivity (0.028–0.038 W mK−1), and high oil absorption capacity.

Polymer nanofibre composite nonwovens with metal-like electrical conductivity

Steffen Reich, Matthias Burgard, Markus Langner, Shaohua Jiang, Xueqin Wang, Seema Agarwal, Bin Ding, Jianyong Yu & Andreas Greiner

npj Flexible Electronics (2018) 2:5 ; doi:10.1038/s41528-017-0018-5.

Bildschirmfoto 2017-02-13 um 13.43.17

Bendable and breathable polymer nanofibre nonwovens with metal-like electrical conductivity are required for lightweight electrodes and electric shielding design with applications in batteries, functional textiles, sensors, cars, aerospace, constructions, mobile phones, and medical devices. Metal-like conductivity in polymer nonwovens has not been achieved till now due to the limitation of the existing processing techniques. We show here, the metal-like electrical conductivity of 750,000 S/m in polyacrylonitrile (PAN), poly(ε-caprolactone) (PCL) nonwoven using very low content of silver nanowires (AgNW; 3.35 vol%). The key to the high conductivity was the homogenous distribution of AgNW in nonwoven made by wet-laid process using short electrospun fibre and AgNW dispersion. Above a threshold of 0.36 vol% AgNW, the conductivity of the nonwoven increased by seven orders of magnitude, which we attribute to the onset of percolation of the AgNW. Our nonwoven-AgNW composites show fast heating and cooling within a few seconds at a voltage of 1.1 V, which is in the range of portable devices. These composites are also breathable and bendable. The electrical conductivity was independent of the bending angle of the composite, which is important for applications mentioned above and would help other scientists to design new conductive materials in the future.

Highly Efficient Reusable Sponge-Type Catalyst Carriers Based on Short Electrospun Fibers

Gaigai Duan, Melissa Koehn-Serrano, Andreas Greiner

Macromol. Rapid Commun. 2017, 38, 1600511.


This study reports on gold nanoparticles (AuNPs) immobilized in a sponge made of short electrospun fibers (Au-sponge), which show surprisingly high reaction rates at extremely low gold amount. Au-sponges are made by freeze-drying of dispersions of short electrospun fibers with preimmobilization of AuNPs. The resulting Au-sponges show very low densities around 7 mg cm−3 corresponding to a pore volume of about 150 mL g−1, but low surface area and very low amount of AuNPs in the range of 0.29–3.56 wt%. In general, catalysts with immobilized AuNPs show much low reaction rates compared to systems with dispersed AuNPs. By contrast, the Au-sponge catalyst with immobilized AuNPs is discerned here as an extremely efficient catalyst even superior to other systems with dispersed AuNPs. The fidelity of the Au-sponges after reactions is good enough for manifold use and thereby provides a sustainable catalyst design as well.

Mesostructured ZnO/Au nanoparticle composites with enhanced photocatalytic activity

Carina Bojer, Judith Schobel, Thomas Martin, Thomas Lunkenbein, Daniel R. Wagner, Andreas Greiner, Josef Breu, Holger Schmalz

Polymer 2017, 128, 65-70.


Ease of catalyst separation from reaction mixtures represents a significant advantage in heterogeneous photocatalytic wastewater treatment. However, the activity of the catalyst strongly depends on its surface-to-volume ratio. Here, we present an approach based on cylindrical polybutadiene-block-poly(2-vinylpyridine) polymer brushes as template, which can be simultaneously loaded with zinc oxide (ZnO) and gold (Au) nanoparticles. Pyrolytic template removal of the polymer yields in mesostructured ZnO/Au composites, showing higher efficiencies in the photocatalytic degradation of ciprofloxacin and levofloxacin (generic antibiotics present in clinical wastewater) as compared to neat mesostructured ZnO. Upscaling of the presented catalyst is straightforward promising high technical relevance.

Spin-Crossover Iron(II) Coordination Polymer with Fluorescent Properties: Correlation between Emission Properties and Spin State

Charles Lochenie, Konstantin Schötz, Fabian Panzer, Hannah Kurz, Bernadette Maier, Florian Puchtler, Seema Agarwal, Anna Köhler and Birgit Weber

J. Am. Chem. Soc., 2018, 140 (2),700–709.


A spin-crossover coordination polymer [Fe(L1)(bipy)]n (where L = a N2O22– coordinating Schiff base-like ligand bearing a phenazine fluorophore and bipy = 4,4′-bipyridine) was synthesized and exhibits a 48 K wide thermal hysteresis above room temperature (T1/2↑ = 371 K and T1/2↓ = 323 K) that is stable for several cycles. The spin transition was characterized using magnetic measurements, Mössbauer spectroscopy, and DSC measurements. T-dependent X-ray powder diffraction reveals a structural phase transition coupled with the spin transition phenomenon. The dimeric excerpt {(μ-bipy)[FeL1(MeOH)]2}·2MeOH of the coordination polymer chain crystallizes in the triclinic space group P1̅ and reveals that the packing of the molecules in the crystal is dominated by hydrogen bonds. Investigation of the emission properties of the complexes with regard to temperature shows that the spin crossover can be tracked by monitoring the emission spectra, since the emission color changes from greenish to a yellow color upon the low spin-to-high spin transition.

Nanofibre preparation of non-processable polymers by solid-state polymerization of molecularly self-assembled monomers

Jian Zhu, Yichun Ding, Seema Agarwal, Andreas Greiner, Hean Zhang Haoqing Hou

Nanoscale, 2017, 9, 18169–18174.


Polybisbenzimidazobenzophenanthroline-dione (BBB) is a high-performance polymer which is characterized by very high mechanical strength in combination with exceptional thermal stability, but it cannot be processed to electrospun fibres for any useful applications due to its insolubility and infusibility. We overcame all obstacles in the electrospinning of BBB by a new bottom-up, and facile approach for the solid-state polymerization of self-assembled monomer precursors. Key to this new strategy is the incorporation of a high molecular weight sacrificial polymer to aid in fibre formation. The resulting electrospun BBB fibres and belts prepared thereof according to this new approach are very strong and show excellent thermal stability. We envisage that this procedure could be applied to other classes of non-processable high-performance polymers for the preparation of electrospun fibres for applications such as filtration, sound insulation, battery separation, electrodes, fire protection, and reaction engineering under demanding conditions.

Disputation Viola Buchholz

Congratulation Viola to your successful defense of your Ph. D. thesis on October 20th, 2017. We wish her all the best for her future and look for to close contacts between her and us.

Exploration of the Electrical Conductivity of Double-Network Silver Nanowires/Polyimide Porous Low-Density Compressible Sponges

S. Jiang, S. Reich, B. Uch, P. Hu, S. Agarwal, A. Greiner

Appl. Mater. Interfaces 2017, 9(39), 34286-34293.


Stress-responsive, highly flexible, and breathable nanocomposite sponges show an electrical conductivity from 1.7 to 166.6 S/cm depending on the applied stress. Key for the responsive electrical conductivity of the sponges is the change of percolation of the silver nanowires. These sponges made of short electrospun fibers and silver nanowires could be applied without any amplifier for the operation of automobile bulbs and as an efficient Joule heater. The time required for electric heating (current on) and cooling is very short. Interestingly, the maximum temperature reached by electric heating depends on the compression status. The higher the compression status, the lower is the maximum temperature, which is in accordance with the understanding of Joule heaters. It is noteworthy that these sponges are thermally, chemically, and mechanically very stable. These conductive sponges will open a new area for novel conductive devices with relevance for real-world applications.

Ultralight, Thermally Insulating, Compressible Polyimide Fiber Assembled Sponges

S. Jiang, B. Uch, S.Agarwal, A. Greiner

ACS Appl. Mater. Interfaces, 2017, 9 (37), pp 32308–32315.


Tunable density, thermally and mechanically stable, elastic, and thermally insulating sponges are required for demanding applications. Hierarchically structured sponges with bimodal interconnected pores, porosity more than 99%, and tunable densities (between 7.6 and 10.1 mg/cm3) are reported using polyimide (PI) as high temperature stable polymer. The sponges are made by freeze-drying a dispersion of short PI fibers and precursor polymer, poly(amic acid) (PAA). The concept of “self-gluing” the fibrous network skeleton of PI during sponge formation was applied to achieve mechanical stability without sacrificing the thermal properties. The sponges showed initial degradation above 400 and 500 °C in air and nitrogen, respectively. They have low thermal conductivity of 0.026 W/mK and thermal diffusivity of 1.009 mm2/s for a density of 10.1 mg/cm3. The sponges are compressible for at least 10 000 cycles and good thermal insulators even at high compressions. These fibrous PI sponges are promising candidates for potential applications in thermal insulation, lightweight construction, high-temperature filtration, sensors, and catalyst carrier for high-temperature reactions.

Exploration of Macroporous Polymeric Sponges As Drug Carriers

G.Duan, A.Reza Bagheri, S.Jiang, J.Golenser, S.Agarwal, A. Greiner

Biomacromolecules 2017 DOI: 10.1021/acs.biomac.7b00852


Achieving high drug loading capacity and controlling drug delivery are two main challenges related to drug carriers. In this study, polymeric macroporous sponges with very high pore volume and large porosity are introduced as a new-type of drug carrier. Due to the high pore volume (285 and 166 cm3/g for the sponges with densities of 3.5 and 6.0 mg/cm3, respectively), the sponges exhibit very high drug loading capacities with average values of 1870 ± 114 and 2697 ± 73 mg/g in the present study, which is much higher than the meso and microporous drug carriers (<1500 mg/g). In order to control the release profiles, an additional poly(p-xylylene) (PPX) coating was deposited by chemical vapor deposition on the drug loaded sponge. Consequently, Artemisone (ART) release in the aqueous medium could be retarded, depending on the density of the sponge and the thickness of the coating. In future, the new 3D polymeric sponges would be highly beneficial as drug carriers for the programmed release of drugs for treatment of chronic diseases.

Our article „ Fate of So-Called Biodegradable Polymers in Seawater and Freshwater“ has been highlighted on news website

Defense Ph. D. thesis Gaigai Duan 26 July 2017

On July 26th, 2017 Gaigai accomplished successfully the defense of her Ph. D. thesis. We sincerely congratulate her and wish all the best for a happy future.

Hyperbranched polyesters as biodegradable and antibacterial additives

H. Bakhshi and S. Agarwal

J. Mater. Chem. B, 2017, DOI:10.1039/C7TB01301A

Hyperbranchend polyesters-HB

Herein, we present novel hyperbranched poly(amino-ester)s functionalized with quaternary ammonium salts (QAS-HPAEs). These materials can be used as antibacterial and biodegradable additives for mixing with non-active polymers. The chemical structure and thermal properties of the HPAEs were studied. All QAS-HPAEs were stable until 192 °C, which makes their thermal blending with other polymers possible. Blending polycaprolactone (PCL) as a biodegradable polymer with QAS-HPAEs improved its surface and bulk hydrophilicity, while partially decreasing its elastic modulus and tensile strength. Mixing 10 wt% of QAS-HPAEs in PCL resulted in a film with high contact-killing activity against E. coli and B. subtilis and faster degradability in the presence and absence of esterase. The activity of esterase was inhibited in the presence of a higher content of QAS-HPAEs (20 wt%).

Tailoring the Morphology of Responsive Bioinspired Bicomponent Fibers

M. Gernhardt, L. Peng, M. Burgard, S. Jiang, B. Förster, H. Schmalz, S. Agarwal

Macromol. Mater Eng. 2017 DOI:10.1002/mame.201700248


Nature is an intriguing inspiration for designing a myriad of functional materials. However, artificial mimicking of bioinspired structures usually requires different specialized procedures and setups. In this study, a new upscalable concept is presented that allows to produce two bioinspired, bicomponent fiber morphologies (side-by-side and coaxial bead-on-string) using the same electrospinning setup, just by changing the employed spinning solvent. The generated fiber morphologies are highly attractive for thermoresponsive actuation and water harvesting. Another challenge solved in this work is the compositional characterization of complex fiber morphologies. Raman imaging and atomic force microscopy is introduced as a powerful method for the unambiguous characterization of complex bicomponent fiber morphologies. The work opens the way for the construction of heterostructured fiber morphologies based on different polymers combinations, offering high potential for applications as actuators, smart textiles, water management, drug release, and catalysis.

Electrogenic Single-Species Biocomposites as Anodes for Microbial Fuel Cells

P. Kaiser, S. Reich, D. Leykam, M. Willert-Porada, A. Greiner, R Freitag 

Macromol. Biosci. 2017, 17, 1600442


Integration of electrogenic microorganisms remains a challenge in biofuel cell technology. Here, synthetic biocomposites (“artificial biofilms”) are proposed. Bacteria (Shewanella oneidensis) are embedded in a hydrogel matrix (poly(vinyl alcohol)) via wet- and electrospinning, creating fibers and nonwoven gauzes. The bacteria remain viable and metabolically active. The performance is compared to S. oneidensis suspension cultures and “natural” biofilms. While lower than with the suspension cultures, the power output from the fuel cells with the artificial biofilms is higher than with the natural one. Handling, reproducibility, and stability are also better. Artificial biofilms can therefore contribute to resolving fundamental issues of design, scale up, and monosepsis in biofuel cell technology.

Fate of So-Called Biodegradable Polymers in Seawater and Freshwater

A. R. Bagheri, C. Laforsch, A. Greiner, S. Agarwal 

Global Challenges 2017, 1700048.

TOC-seawater Abagheri

The stability of polymers with C[BOND]C and stable C[BOND]heteroatom backbones against chemicals, hydrolysis, temperature, light, and microbes has challenged society with the problem of accumulation of plastic waste and its management worldwide. Given careless disposal of plastic waste, large amounts of plastic litter accumulate in the environment and disintegrate into microplastics. One of the questions frequently raised in the recent times is if so-called biodegradable polymers can substitute conventional polymers for several applications and help to tackle this challenge. The answer is not so simple as biodegradability is a certified property occurring only under certain environmental conditions and therefore requires systematic study. As a first step, this study focusses on comparative degradation studies of six polymers (five taken from the so-called biodegradable polyesters, including poly(lactic-co-glycolic acid) (PLGA), polycaprolactone (PCL), polylactic acid (PLA), poly(3-hydroxybutyrate) (PHB), Ecoflex, and one well-known non-degradable polymer poly(ethylene terephthalate) (PET) in artificial seawater and freshwater under controlled conditions for 1 year. Only amorphous PLGA shows 100% degradation as determined by weight loss, change in molar mass with time, NMR, electron microscopy, and high-performance liquid chromatography. This is a step forward in understanding the degradability of polyesters required for the design of environmentally friendly novel polymers for future use.

New Review coauthored by Shaohua Jiang, Seema Agarwal and Andreas Greiner published in Angewandte Chemie

"Low-density open cellular sponges as functional materials''



Congratulations Amanda for successfully defending  PhD work and wish you good luck for the future.

Advanced Science News highlights our work about biobased polycarbonate as BREATHING GLASS (Biobased Polycarbonate as a Gas Separation Membrane and “Breathing Glass” for Energy Saving Applications, O.Hauenstein, Md. M.Rahman, M.Elsayed, R. Krause-Rehberg, S.Agarwal, V. Abetz and A. Greiner Adv. Mater. Technol. 2017, 1700026).


For details please see:

Breathing Glass: How To Save The Environment With Polymers

Elimination of Schistosoma mansoni in infected mice by slow release of artemisone

D. Gold, M. Alian, A. Domb, Y. Karawani, M. Jbarien, J. Chollet, R. K. Haynes, H. N. Wong, V. Buchholz, A. Greiner, J. Golenser International Journal for Parasitology: Drugs and Drug Resistance, 2017, 7, 241-247.


The current treatment of schistosomiasis is based on the anti-helminthic drug praziquantel (PZQ). PZQ affects only the adult stages of schistosomes. In addition, resistance to PZQ is emerging. We suggest a drug, which could serve as a potential alternative or complement to PZQ, and as a means of treating infections at earlier, pre-granuloma stage. Derivatives of the peroxidic antimalarial drug artemisinin have been indicated as alternatives, because both plasmodia and schistosomes are blood-feeding parasites. The mechanism of action of artemisinins is related to oxidative effects of the artemisinins on intracellular reductants leading to formation of cytotoxic reactive oxygen species. We used artemisone, which has improved pharmacokinetics and anti-plasmodial activity, and reduced toxicity compared to other artemisinins in clinical use against malaria. We infected adult mice by subcutaneous injection of S. mansoni cercariae (about 200) and treated them at various times post infection by the following methods: i. artemisone suspension administered by gavage (400–450 mg/kg); ii. subcutaneous injection of a gel containing a known concentration of artemisone (115–120 mg/kg); iii. subcutaneous insertion of the drug incorporated in a solid polymer (56–60 mg/kg); iv. intraperitoneal injection of the drug solubilized in DMSO (115–120 mg/kg). Drug administration in polymers was performed to enable slow release of the artemisone that was verified in vivo and in vitro bioassays using drug-sensitive malaria parasites. We found superior strong anti-schistosome effects up to a total reduction of worm number, mainly following repetitive treatments with the drug absorbed in the polymers (73.1% and 95.9% reduction in mice treated with artemisone in gel 7 and 14, and 21, 28 and 35 days post infection, respectively). The results indicate that artemisone has a potent anti-schistosome activity. Its main importance in this context is its effectiveness in treating hosts harboring juvenile schistosomes, before egg-deposition and induction of deleterious immune responses.

Poly(amino acid)-Based Gel Fibers with pH Responsivity by Coaxial Reactive Electrospinning

K. Molnar, A. Jedlovszky-Hajdu, M. Zrinyi, S. Jiang, S. Agarwal Macromol. Rapid Commun. 2017, DOI: 10.1002/marc.201700147.


Electrospinning is a well-known technique for the preparation of scaffolds for biomedical applications. In this work, a continuous electrospinning method for gel fiber preparation is presented without a spinning window. As proof of concept, the preparation of poly(aspartic acid)-based hydrogel fibers and their properties are described by using poly(succinimide) as shell polymer and 2,2,4(2,4,4)-trimethyl-1,6-hexanediamine as cross-linker in the core of the nozzle. Cross-linking takes place as the two solutions get in contact at the tip of the nozzle. The impact of solution concentrations and feeding rates on fiber morphology, proof of the presence of cross links as well as pH sensitivity after the transformation of the poly(succinimide)-based material to poly(aspartic acid) is presented.

Unlocking Nanocarriers for the Programmed Release of Antimalarial Drugs

A. R. Bagheri, S. Agarwal, J. Golenser, A. Greiner Global Challenges 2017, DOI: 10.1002/gch2.201600011.


A programmable release system with wide range of release profiles of the antimalarial artemisone (ART) from fibrous nanocarriers (NFN) is presented. This is achieved following a new paradigm of using ART-loaded NFN in infusion system of hydrophobic drug eluting nanocarriers, adapted to clinical applications. Very importantly, under these conditions ART did not degrade as it was observed in solution.

Biobased Polycarbonate as a Gas Separation Membrane and “Breathing Glass” for Energy Saving Applications

O.Hauenstein, Md. M.Rahman, M.Elsayed, R. Krause-Rehberg, S.Agarwal, V. Abetz and A. Greiner Adv. Mater. Technol. 2017, 1700026.


The biobased poly(limonene carbonate) (PLimC) synthesized by catalytic copolymerization of trans-limonene oxide and CO2 unifies sustainability, carbon capture and utilization of CO2 in one material. Films of PLimC show surprisingly high gas permeation and good selectivity. Additionally, it is not only very permeable to gases, but also to light, while simultaneously being a good heat insulator and mechanically strong, representing a novel type of material that is defined here as “breathing glass.” Hence, this study investigates the gas permeation and the selectivity in detail. The selectivity of PLimC for CO2 can be understood by its high fractional free volume, which is determined by positron annihilation lifetime spectroscopy supported by simulations. The CO2 permeability of PLimC at 30 °C is 68 barrer, while the CO2/N2 selectivity is ≈19, which places PLimC in a promising position in the Robeson plot and makes it unique due to its excellent transparency and processability under ambient conditions. Based on the high permeability of PLimC to gases and light, this study discusses here a completely new potential application of light transparent, gas-permeable polymer films as “breathing glass.”

Ultralight sponges of poly(para-xylylene) by template-assisted chemical vapour deposition

Tobias Moss,Ilka E. Paulus, Daniel Raps,Volker Altstädt, Andreas Greiner e-polymers, 2017, DOI: 


Particle foams and open cell sponges play nowadays an important role in academia and industrial research. The fabrication of new high-performance foams is one of the challenges. Until now, it is impossible to visualise the quality of particle foams, and the quantification is only possible with expensive analytical methods like scanning electron microscopy. In this work, we demonstrate a simple method for the visualisation of void sizes and defects inside particle foams on the basis of expanded polystyrene. The concept was transferred to porous materials, which work as templates for the formation of ultralight poly(para-xylylene) foams with stunning properties.

Compaction and Transmembrane Delivery of pDNA: Differences between l-PEI and Two Types of Amphiphilic Block Copolymers

A.Raup, H. Wang, C.V. Synatschke, V.Jérôme, S.Agarwal, D.V. Pergushov, A. Müller and R.Freitag Biomacromolecules 2017, 18 (3), pp 808–818.


Polycations are popular agents for nonviral delivery of DNA to mammalian cells. Adding hydrophobic, biodegradable, or cell-penetrating functions could help to improve their performance, which at present is below that of viral agents. A crucial first step in gene delivery is the complexation of the DNA. The characteristics of these “polyplexes” presumably influence or even determine the subsequent steps of membrane passage, intracellular traveling/DNA release, and nuclear uptake. Herein, polyplexes formed with linear poly(ethylenimine) (l-PEI) are compared to complexes generated with functionalized diblock copolymers. While l-PEI interacts only electrostatically with the DNA, interaction in the case of the diblock polymers may be mixed-mode. In certain cases, transfection efficiency improved when the polyplexes were formed in hypertonic solution. Moreover, whereas conventional PEI-based polyplexes enter the cells via endocytosis, at least one of the diblock agents seemed to promote entry via transient destabilization of the plasma membrane.

Spongy Gels by a Top-Down Approach from Polymer Fibrous Sponges

S. Jiang, G. Duan, U. Kuhn, M. Mörl, V. Altstädt, A. L. Yarin, A. Greiner Angew.Chem. Int.Ed. 2017, 56,3285 –3288.


Ultralight cellular sponges offer a unique set of properties. We show here that solvent uptake by these sponges results in new gel-like materials, which we term spongy gels. The appearance of the spongy gels is very similar to classic organogels. Usually, organogels are formed by a bottom-up process. In contrast, the spongy gels are formed by a top-down approach that offers numerous advantages for the design of their properties, reproducibility, and stability. The sponges themselves represent the scaffold of a gel that could be filled with a solvent, and thereby form a mechanically stable gel-like material. The spongy gels are independent of a time-consuming or otherwise demanding in situ scaffold formation. As solvent evaporation from gels is a concern for various applications, we also studied solvent evaporation of wetting and non-wetting liquids dispersed in the sponge.

Self-Rolled Porous Hollow Tubes Made up of Biodegradable Polymers

Ling Peng, Jian Zhu and Seema Agarwal Macromol. Rapid Commun. 2017, DOI: 10.1002/marc.201700034


A tubular highly porous scaffold of polylactide (PLA) and poly-ε-caprolactone (PCL) is fabricated by self-rolling of a 2D fibrous bilayer of PLA and PCL in water without use of any classical thermo-/pH-responsive polymers. The self-rolling and diameter of the tube are dependent upon the bilayer thickness and temperature. A 75 µm thick 2D bilayer (PLA = 25 µm; PCL = 50 µm) rolls to a hollow tube of diameter around 0.41 mm with multilayered wall at 40 °C within 5 min. The tubes keep their form and size in water at all temperatures once they are formed. The interesting properties of the hollow tubes, that is, permeation of gases through the walls and flow of water without leakage under tested conditions in combination with good mechanical stability, use of only biodegradable polymers, and easy and reproducible fabrication method, allow them to be promising candidates for future studies as scaffolds for tissue engineering.

Controlled release of artemisone for the treatment of experimental cerebral malaria

J. Golenser, V. Buchholz, A.Bagheri, A.Nasereddin, R. Dzikowski, J. Guo, N. H. Hunt, S. Eyal, N. Vakruk and A.Greiner 
Parasites & Vectors, 2017, 10:117.

Cerebral malaria (CM) is a leading cause of malarial mortality resulting from infection by Plasmodium falciparum. Treatment commonly involves adjunctive care and injections or transfusion of artemisinins. All artemisinins that are in current use are metabolized to dihydroxyartemisinin (DHA), to which there is already some parasite resistance. We used artemisone, a derivative that does not convert to DHA, has improved pharmacokinetics and anti-plasmodial activity and is also anti-inflammatory (an advantage given the immunopathological nature of CM).We examined controlled artemisone release from biodegradable polymers in a mouse CM model. This would improve treatment by exposing the parasites for a longer period to a non-toxic drug concentration, high enough to eliminate the pathogen and prevent CM. The preparations were inserted into mice as prophylaxis, early or late treatment in the disease course.

The most efficient formulation was a rigid polymer, containing 80 mg/kg artemisone, which cured all of the mice when used as early treatment and 60% of the mice when used as a very late treatment (at which stage all control mice would die of CM within 24 h). In those mice that were not completely cured, relapse followed a latent period of more than seven days. Prophylactic treatment four days prior to the infection prevented CM. We also measured the amount of artemisone released from the rigid polymers using a bioassay with cultured P. falciparum. Significant amounts of artemisone were released throughout at least ten days, in line with the in vivo prophylactic results.


On February 1st, 2017 Oliver has mastered the defense of his Ph. D. thesis on biobased Polylimonenecarbonate. This topic covered aspects from synthesis, engineering, and application, which opened a new challenging research field for the chair. Thank you Oliver for your excellent work and congratulations to your great accomplishment. We wish you all the best for your next carrier step and please keep in touch.


We congratulate Paul on successfully defending his PhD work and wish him good luck for the future.


On December 2016 the members of the chair of Macromolecular Chemistry II enjoyed a very nice Christmas party as obvious from the photo taken at an early stage of the party. The party was organized by a wonderful team! Thank you very much for doing this.


Ziyin has passed her Ph. D. examination very successfully. Well done Ziyin! Her topic was on complex macromolecular architectures on metal nanoparticles, which was demanding for synthetic macromolecular chemist as well as for materials scientist. Ziyin has mastered all perfectly. We all wish her success and happiness for the future and look forward to future interaction with the people of MC II.

Disp Hui

Hui has successfully defended her Ph. D. thesis on biodegradable and antimicrobial polymers. We wish Hui all the best for her future endeavors and challenges. Good luck and all the best Hui. 

Bottom-Up Meets Top-Down: Patchy Hybrid Nonwovens as an Efficient Catalysis Platform

Judith Schöbel, Matthias Burgard, Christian Hils, Dr. Roland Dersch, Dr. Martin Dulle, Kirsten Volk, Prof. Dr. Matthias Karg, Prof. Dr. Andreas Greiner, Dr. Holger Schmalz

Angew. Chem. Int. Ed. 2017, 56, 405-408.


Heterogeneous catalysis with supported nanoparticles (NPs) is a highly active field of research. However, the efficient stabilization of NPs without deteriorating their catalytic activity is challenging. By combining top-down (coaxial electrospinning) and bottom-up (crystallization-driven self-assembly) approaches, we prepared patchy nonwovens with functional, nanometer-sized patches on the surface. These patches can selectively bind and efficiently stabilize gold nanoparticles (AuNPs). The use of these AuNP-loaded patchy nonwovens in the alcoholysis of dimethylphenylsilane led to full conversion under comparably mild conditions and in short reaction times. The absence of gold leaching or a slowing down of the reaction even after ten subsequent cycles manifests the excellent reusability of this catalyst system. The flexibility of the presented approach allows for easy transfer to other nonwoven supports and catalytically active NPs, which promises broad applicability.

Biosorption of copper from aqueous environments by Micrococcus luteus in cell suspension and when encapsulated

Ilya Letnik, Ron Avrahami, Rafi Port, Andreas Greiner, Eyal Zussman, J. Stefan Rokem, Charles Greenblatt International Biodeterioration & Biodegradation, 116, (2017) 64-72.


The ability to sequester or tolerate copper has been described for a number of bacteria. It was shown that Micrococcus luteus tolerates copper, and possible mechanisms of uptake for this bacterium have been proposed. Using a count live of M. luteus (CFU), 10% survived a copper concentration of 370 ppm. Maximum sorption capacity was 59 mg of Cu2+/g of dry cells at pH 6. Several proteins of M. luteus with copper affinity were identified by enrichment on a metal-chelating resin followed by LC-MS/MS to identify the metallome. Use of SEM/EDX showed how copper concentrated on the bacterial surface, whereas TEM indicated that copper was found also inside the cells. The enhanced capability of M. luteus to bind copper was tested using three configurations: free cells on an agar surface and cells encapsulated in alginate or in electrospun polymer composites. The latter showed the highest capability to bind copper (∼76 mg Cu2+/g dry cells). Such polymer composites may potentially be used in various water-based applications such as treatment of wastewater with a high concentration of copper or other heavy metals.

Tunable, concentration-independent, sharp, hysteresis-free UCST phase transition from poly(N-acryloyl glycinamide-acrylonitrile) system

Florian Käfer, Arne Lerch, Seema Agarwal


Poly(N-acryloylglycinamide-co-acrylonitrile) (poly(NAGA-AN)) copolymers were synthesized using reversible-addition-fragmentation transfer polymerization. In contrast to poly(NAGA) the thermoresponsive behavior of poly(NAGA-AN) shows a narrow cooling/heating hysteresis in water with a tunable cloud point, depending on the acrylonitrile amount in polymer. Furthermore, we showed that there is no significant effect of the solution concentration on the cloud point and stable phase transition behavior in electrolyte solutions, which is presumable controlled by forming stable micellar like structures as a result of the block/graft-copolymer structure. This is in contrast to poly(NAGA) which shows a strong concentration dependent cloud point in aqueous solution with a broad cooling/heating hysteresis.

One-Component Dual Actuation: Poly(NIPAM) Can Actuate to Stable 3D Forms with Reversible Size Change

Li Liu, Ali Ghaemi, Stephan Gekle, Seema Agarwal
Advanced Materials, 201628 (44), 9792-9796.

ToC 5

The work provides a rare example of a one-component dual actuator with irreversible change in shape by rolling on contact with water and reversible size change on changing the temperature. The actuator has a bilayer structure with aligned and randomly oriented fibers of poly (N-isopropyl acrylamide). A combination of anisotropic E modulus and temperature dependent swelling/shrinkage provides the dual actuation.

Tensile versus AFM Testing of Electrospun PVA Nanofibers: Bridging the Gap from Microscale to Nanoscale

Benedikt R. Neugirg, Matthias Burgard, Andreas Greiner, Andreas Fery JOURNAL OF POLYMER SCIENCE, PART B: POLYMER PHYSICS, 2016, 54 (23), 2418-2424.


Design and application of mechanically extraordinary nanofibers requires their full comprehension, based on conclusive testing methods. Electrospun polymer nanofibers, for instance, show a progressive and pronounced increase in their Young's moduli when diameters decrease below the µm scale. Measurement of mechanical properties in this diameter range is challenging and in the vast majority of reports, two classes of methods are commonly used: highly sensitive tensile testing and atomic force microscopy three-point deformation testing. Despite the methods' inherent dissimilarity, we resolve their conformity for the first time, with respect to the determination of Young's moduli. Here, we benchmark them against each other for electrospun polyvinyl-alcohol nanofibers, a well-defined model system. Our results provide an experimental basis for a comprehensive understanding of nanofiber structures and its implications on their mechanical properties.

Polyimide Nanofibers by “Green” Electrospinning via Aqueous Solution for Filtration Applications

Shaohua Jiang, Haoqing Hou, Seema Agarwal and Andreas Greiner ACS Sustainable Chem. Eng., 2016 4(9), 4797-4804.


The use of large amounts of environmentally unfriendly, toxic, and flammable organic solvents in electrospinning of polymers puts demand on the development of new methods and formulations for making water stable hydrophobic nanofibers from water-soluble precursor solution. Electrospun polyimide (PI) nanofibers are of particular interest for a variety of applications due to their extraordinary thermal and chemical stability. However, the intermediate precursor of polyimide, the polyamic acid (PAA) has to be electrospun from harmful solvents like dimethylformamide (DMF) which is a serious obstacle for technical applications of electrospun PI. This work highlights the formation of PI nanofibers by “green” electrospinning of ammonium salts of PAA from water. The high temperature used for imidization in the second step also removed ammonia and the template polymer by sintering giving PI nanofibers with diameter 295 ± 58 nm. The thus obtained PI nanofibers by “green” electrospinning were defined as “green” PI nanofibers. Aerosol filtration of “green” PI nanofibers showed a performance that was very similar to PI nanofibers obtained by electrospinning of PAA from DMF. Additionally, it has been shown that the “green” PI nanofibers were suitable for the filtration of hot oil as well.

Wie Mikroorganismen und Elektroden interagieren

Uwe Schröder, Andreas Greiner, Miriam A. Rosenbaum and Falk Harnisch Nachrichten aus der Chemie, 2016, 64(7-8), 732-737.

Die Verknüpfung von Elektrochemie und Mikrobiologie ist Forschung mit Anwendungspotenzial: von der Energiegewinnung aus Abwasser bis zur Synthese von Chemikalien. Wichtige Rollen spielen Elektrochemie, Mikrobiologie und Materialwissenschaften.

Assembly of Gold Nanoparticles on Gold Nanorods Using Functionalized Poly(N-isopropylacrylamide) as Polymeric “Glue”

Ziyin Fan, Moritz Tebbe, Andreas Fery, Seema Agarwal and Andreas Greiner Particle & Particle Systems Characterization,2016 33(9), 698-702.

zyin-toc- parsyn

A telechelic thermoresponsive polymer, α-amino-ω-thiol-poly(N-isopropylacrylamide) (H2N-PNiPAM-SH), is used as the polymeric glue to assemble gold nanoparticles (AuNPs) around gold nanorods (AuNRs) into a satellite structure. Prepared by reversible addition-fragmentation chain transfer polymerization followed by hydrazinolysis, H2N-PNiPAM-SH is able to interlink the two types of the gold building blocks with the thiol-end grafting on AuNRs and the amine-end coordinating on the AuNP surface. The density of the grafted AuNPs on AuNRs can be tuned by adjusting the molar ratio between AuNPs and AuNRs in the feed. The resulted satellite-like assembly exhibits unique optical property that was responsive to temperature change.

Dendrons as active clicking tool for generating non-leaching antibacterial materials

Hadi Bakhshi and Seema Agarwal Polymer Chemistry,2016 7, 5322-5330.


We show a novel concept of using dendrons as a tool for making non-active materials antibacterial in a simple way. A dendron is a part of a dendrimer with the advantage of having many peripheral functional groups and a focal point. We used this structural advantage in making an antibacterial polymeric tool for clicking to other non-active polymers and surfaces. We show the success of the concept by making new antibacterial poly(urethane-biuret) dendrons containing quaternary ammonium salts (QASs) on the periphery and a primary hydroxyl group as the focal point in one pot. The chemical structure and thermal properties of the dendrons were fully studied. All quaternized dendrons were stable until above 200 °C. The newly synthesized dendrons show high activity against Escherichia coli (E. coli) and Bacillus subtilis (B. subtilis) as tested by the determination of MIC, MBC values and the Kirby–Bauer assay. The hydroxyl group enabled the attachment of the dendrons to a cotton mat and PU foam, as a reactive additive, bringing them non-leaching fast bactericidal activity. The interaction of urethane and biuret bonds in the dendrons’ backbone led to a transparent non-leaching bactericidal coating on the treated glass slides

Protection of Vine Plants against Esca Disease by Breathable Electrospun Antifungal Nonwovens

Viola Buchholz, Melanie Molnar, Hui Wang, Steffen Reich, Seema Agarwal, Michael Fischer, and Andreas Greiner Macromolecular Bioscience, 2016, 16(9), 1391-1397.


The harmful Esca disease in vine plants caused by wood-inhabiting fungi including Phaeomoniella chlamydospora (Pch) is spreading all across the world. This disease leads to poor vine crops and a slow decline or to a sudden dieback of the vine plants. The pruning wounds of vine plants are the main entry point for Pch. While model experiments with aerosol particles recommend electrospun nonwovens as a suitable barrier to block Pch, tests with living spores show clearly that only electrospun fibrous nonwovens do not prevent Pch invasion. However it is found, that with antifungal additives electrospun nonwovens could be applied successfully for blocking of Pch to infect the substrate. Thereby, a highly useful concept for the protection of vine plants against Esca disease is provided which could also serve as a concept for related plant diseases.

Structural Exploration of Phantom Oligoguanidine from Asymmetric Diamine and Guanidine Hydrochloride

Hui Wang, Christian Benke, Markus Hermann, Gernot Frenking and Seema Agarwal Macromolecular Chemistry and Physics,2016, 217 (16), 1834-1841.


Condensation reaction of asymmetric triamine (spermidine) with guanidine hydrochloride provides a phantom structure with selective formation of rings in the repeat unit. The intermolecular condensation between amine and guanidine hydrochloride can provide either a linear structure or six- or seven-membered rings in the repeat unit by elimination of one or three molecules of ammonia, respectively, per repeat unit. The preference of formation of rings and mechanistic aspects are studied by matrix-assisted laser desorption/ionization time-of-flight mass spectrometry, 1D, 2D NMR, and quantum chemical calculations.

Bio-based polycarbonate as synthetic toolbox

Oliver Hauenstein, Seema Agarwal, Andreas Greiner

Nature Communications, 2016, 7, Article number: 11862.

PLimC Platform Polymer highRes

Completely bio-based poly(limonene carbonate) is a thermoplastic polymer, which can be synthesized by copolymerization of limonene oxide (derived from limonene, which is found in orange peel) and CO2. Poly(limonene carbonate) has one double bond per repeating unit that can be exploited for further chemical modifications. These chemical modifications allow the tuning of the properties of the aliphatic polycarbonate in nearly any direction. Here we show synthetic routes to demonstrate that poly(limonene carbonate) is the perfect green platform polymer, from which many functional materials can be derived. The relevant examples presented in this study are the transformation from an engineering thermoplastic into a rubber, addition of permanent antibacterial activity, hydrophilization and even pH-dependent water solubility of the polycarbonate. Finally, we show a synthetic route to yield the completely saturated counterpart that exhibits improved heat processability due to lower reactivity.

Biodegradable Aliphatic–Aromatic Polyester With Antibacterial Property

Hui Wang, Markus Langner and Seema Agarwal Polymer Engineering and Science, 201656(10), 1146-1152.

huiwang toc biodeg

Fast acting antibacterial property was introduced to aliphatic–aromatic polyester in the present work without sacrificing its compostability, thermal stability, and mechanical properties. Antibacterial poly(hexamethylene guanidine) hydrochloride (PHMG) was melt mixed with poly(butyleneadipate-co-terephthalate) (PBAT, also called Ecoflex) using a twin-screw extruder in different amounts. The non-reactive blending and uniform mixing was confirmed by nuclear magnetic resonance, gel permeation chromatography, scanning electron microscopy, and energy-dispersive X-Ray spectroscopy analysis. The influence of antibacterial agent on compostability, mechanical properties, and thermal stability was studied. The presence of PHMG changed slightly the degradation profile of Ecoflex retaining the extent of degradation almost the same. The antibacterial PBAT showed high thermal stability (degradation starts around 330°C), stress at break 17–20 MPa, modulus 89–127 MPa, and elongation at break more than 700% depending upon the amount of PHMG. The combination of antibacterial activity with biodegradability makes this material a very interesting candidate for many different applications including packaging. POLYM. ENG. SCI., 2016. © 2016 Society of Plastics Engineers.

Photo-polymerizable, low shrinking modular construction kit with high efficiency based on vinylcyclopropanes

Paul Pineda Contreras and Seema Agarwal  Polym. Chem., 20167, 3100-3106.

paulpineda polychem 2016

The successful development of a universal hydrogen bond (H-bond) concept, specific for bi-functional vinylcyclopropane (VCP) ester–amide derivatives is reported here. Thereby, uniformity within the intermolecular hydrogen bond strength as investigated by variable temperature NMR and FT-IR measurements provides an excellent control of high reactivity, nearly regardless of the chosen spacer-unit, offering the system a possible application as a modular construction kit for cross-linked networks with varied properties. Two entirely diversified VCP ester–amide systems were prepared. The performance benchmark of a flexible, high molar mass macro-monomer VCPPPG2000, implementing a polypropyleneglycol Genamine D01/2000 macro-spacer, and two rigid, low molar mass monomers VCP-m-phenyl and VCP-p-phenyl outlined significantly the strength of the system. Extremely low volume shrinkages between 1.4–4.5% and a wide range of E-moduli could be achieved. An easy control of adjusting final characteristics by varying the co-monomer content in co-networks was shown, especially without obtaining any significant disadvantage in the curing behavior. The VCP ester–amides offer the possibility to replace some currently used dimethacrylate resins within several high-end applications, especially where low volume shrinkage and high polymerization efficiency are required.

New book coauthored by Seema Agarwal, Matthias Burgard, Andreas Greiner and Joachim Wendorff

Electrospinning: A Practical Guide to Nanofibers (De Gruyter Textbook)

ISBN-13: 978-3110331806 ISBN-10: 3110331802

buch e-spinning agarwal, burgard

Ultralight open cell polymer sponges with advanced properties by PPX CVD coating

Gaigai Duan, Shaohua Jiang, Tobias Moss, Seema Agarwal and Andreas Greiner Polym. Chem., 20167, 2759-2764.

gaigaidun polymerchem16

Ultralight polyacrylate sponges were prepared from dispersions of short electrospun polymer fibres by freeze drying and coated with poly(p-xylylene) (PPX) by chemical vapour deposition (CVD). The PPX coating of the sponges increased the compression strength, the water contact angle, and the solvent resistance significantly without significant alteration of the sponge morphology.

Patchy Wormlike Micelles with Tailored Functionality by Crystallization-Driven Self-Assembly: A Versatile Platform for Mesostructured Hybrid Materials

Judith Schöbel, Matthias Karg, Dominic Rosenbach, Gert Krauss, Andreas Greiner and Holger Schmalz Macromolecules, 2016, 49(7), 2761-2771.


One-dimensional patchy nanostructures are interesting materials due to their excellent interfacial activity and their potential use as carrier for functional nanoparticles. Up to now only wormlike crystalline-core micelles (wCCMs) with a nonfunctional patchy PS/PMMA corona were accessible using crystallization-driven self-assembly (CDSA) of polystyrene-block-polyethylene-block-poly(methyl methacrylate) (SEM) triblock terpolymers. Here, we present a facile approach toward functional, patchy wCCMs, bearing tertiary amino groups in one of the surface patches. The corona forming PMMA block of a SEM triblock terpolymer was functionalized by amidation with different N,N-dialkylethylenediamines in a polymer analogous fashion. The CDSA of the functionalized triblock terpolymers in THF was found to strongly depend on the polarity/solubility of the amidated PMMA block. The lower the polarity of the amidated PMMA block (increased solubility), the higher is the accessible degree of functionalization upon which defined, well-dispersed wCCMs are formed. Interestingly, also the structure of the patchy corona can be tuned by the composition/chemistry of the functional patch, giving rise to spherical patches for R = methyl, ethyl and rectangular patches for R = isopropyl. Patchy wCCMs were successfully used as template for the selective incorporation of Au nanoparticles within the amidated corona patches, showing their potential as versatile platform for the construction of functional, mesostructured hybrid materials.

pH dependent thermoresponsive behavior of acrylamide–acrylonitrile UCST-type copolymers in aqueous media

Beatriz A. Pineda-Contreras, Holger Schmalz, Seema Agarwal Polym. Chem., 2016,7, 1979-1986.


There are only a few non-ionic polymers known for showing thermoresponsivity of UCST-type. Copolymers of acrylamide (AAm) and acrylonitrile (AN) represent one of such thermoresponsive polymers. The present work shows pH-dependent UCST-transitions of this copolymer system. Herein, systematic studies were carried out to show hydrolytic stability and retention of UCST of the copolymer under various conditions. Regeneration of lost UCST-type transitions under extreme pH conditions could be achieved by changing pH, and by addition of electrolytes. Reversible addition fragmentation chain transfer (RAFT) was employed as a tool to synthesize copolymers of AAm and AN. Hydrolysis reactions were carried out intentionally under acidic and alkaline conditions, in order to analyze the chemical stability of the synthesized copolymers as well as to introduce carboxylic groups into the polymer structure. The obtained results showed high tolerance of poly(AAm-co-AN) samples under acidic conditions even after long periods of storage (25 days at pH 3) or after use of pH 0 and increased temperatures (40 °C). In the case of base catalyzed hydrolysis, the thermoresponsive behavior was significantly influenced during hydrolysis in buffer solution of pH 9. Loss and regeneration of the phase transition temperature of these copolymers could be achieved by changing the pH from basic to acidic. Meanwhile, hydrolysis at pH 14 at 40 °C influenced the thermoresponsive behavior and the chemical stability of the polymer, increasing the phase transition temperature over 30 °C. Further, we observed that additives, e.g. formamide can act as a sacrificial agent for providing stable UCST-type transitions even under alkaline conditions as well as at high temperatures (85 °C).

"“Patchy” Carbon Nanotubes as Efficient Compatibilizers for Polymer Blends"

Gegenhuber, T.; Krekhova, M.; Schöbel, J.; Gröschel, A. H.; Schmalz, H. ACS Macro Letters 20165(3), 306-310.

ACS macro letters 2016

Surface-modified carbon nanotubes (CNTs) have become well-established filler materials for polymer nanocomposites. However, in immiscible polymer blends the CNT-coating is selective toward the more compatible phase, which suppresses their homogeneous distribution and limits harnessing the full potential of the filler. In this study, we show that multi-walled CNTs with a patchy polystyrene/poly(methyl methacrylate) (PS/PMMA) corona disperse equally well in both phases of an incompatible PS/PMMA polymer blend. Unlike polymer-grafted CNTs with a uniform corona, the patchy CNTs are able to adjust their corona structure to the blend phases by selective swelling/collapse of respective miscible/immiscible surface patches. Importantly, the high interfacial activity of patchy CNTs further causes a significant decrease in PMMA droplet size with increasing filler content. The combined effect of compatibilization and homogeneous distribution makes patchy CNTs interesting materials for polymer blend nanocomposites, where next to the compatibilization a homogenous filler distribution is important to gain the desired materials property (e.g. reinforcement).

Polymerkäfige als universelles Hilfsmittel für die präzise Bottom-up-Synthese metallischer Nanopartikel

Ziyin Fan, Xuelian Chen, Melissa Köhn Serrano, Holger Schmalz, Sabine Rosenfeldt,
Stephan Förster, Seema Agarwal und Andreas Greiner Angew. Chem.,2015, 127, 14747 –14752.

TOC-zyin fan angewandte

Eine neue, Templat-gestützte Synthese monodisperser Nanopartikel stellt keine Anforderungen an die Selbstorganisation und ist hoch reproduzierbar. Hierzu werden maßgeschneiderte Polymerkäfige für die Synthese von Nanopartikeln verwendet, die aus vernetzten Makromolekülen mit Thiolendgruppen bestehen. Goldnanopartikel (AuNPs) wurden in verschiedenen Verhältnissen von Polymerkäfig zu Gold in situ in den Polymerkäfigen synthetisiert. Die Polymerkäfige zeichneten sich dabei durch eine definierte Beladungskapazität aus, mit exzellenter Kontrolle über Form und Größe. Dagegen zeigten Kontrollversuche mit linearen Diblockcopolymeren einen linearen Anstieg der Partikelgrößen mit steigendem Goldanteil. Das unterschiedliche Wachstumsverhalten der AuNPs wird durch die Vernetzungsgrad-abhängige Flexibilität der Polymerketten erklärt. Des Weiteren wird die Polymerkäfig-gesteuerte In-situ-Synthese auf Silber- (AgNPs), Palladium- (PdNPs) und Platinnanopartikel (PtNPs) übertragen.

Quantitative Comparison of the Antimicrobial Efficiency of Leaching versus Nonleaching Polymer Material

Joerg Bruenke, Ingolf Roschke, Seema Agarwal, Thomas Riemann and Andreas Greiner, Macromolecular Bioscience, 2016, 16(5), 647-654.


New antimicrobial materials will be more and more in the focus for hygienic and clinical disease control. Antimicrobial materials have to be distinguished in leaching and nonleaching materials. For many applications of antimicrobial materials on implants the use of nonleaching materials is essential. Therefore, the antimicrobial efficiency of leaching and nonleaching polymers has been investigated quantitatively in vitro in direct comparison on a highly relevant implant of central venous catheters (CVCs) using a well-established called Certika test. This test is especially designed to test antimicrobial properties of leachable and nonleachable materials. This contribution demonstrates that newly developed nonleaching antimicrobial CVCs are equivalent to conventional leaching CVC systems in their antimicrobial performance against gram-positive and gram-negative bacteria, as well as Candida species. The use of new nonleaching antimicrobial polymers as shown here for CVCs represents a different mode of action with the aim to prevent infections also with antibiotic-resistant strains and reduced side effects.

Wet-Laid Meets Electrospinning: Nonwovens for Filtration Applications from Short Electrospun Polymer Nanofiber Dispersions

Markus Langner, Andreas Greiner, Macromolecular Rapid Communications 2016, 37 (4), 351-355.

ML macrorepcom16

Dispersions of short electrospun fibers are utilized for the preparation of nanofiber nonwovens with different weight area on filter substrates. The aerosol filtration efficiencies of suspension-borne nanofiber nonwovens are compared to nanofiber nonwovens prepared directly by electrospinning with similar weight area. The filtration efficiencies are found to be similar for both types of nonwovens. With this, a large potential opens for processing, design, and application of new nanofiber nonwovens obtained by wet-laying of short electrospun nanofiber suspensions.

Giving Direction to Motion and Surface with Ultra-Fast Speed Using Oriented Hydrogel Fibers

Li Liu, Shaohua Jiang, Yue Sun, and Seema Agarwal, Adv. Funct. Mater. 2016, 26(7), 1021-1027.


Thermoresponsive hydrogel fibrous membranes showing directionally controlled movements and surface change with ultra-fast speed are presented for the first time. They show reversible coiling, rolling, bending, and twisting deformations in different controllable directions for many cycles (at least 50 cycles tried) with inside-out change in surfaces and shapes. Speed, reversibility, large-scale deformations and, most importantly, control over the direction of deformation is required in order to make synthetic actuators inspired from natural materials or otherwise. A polymeric synthetic material combining all these properties is still awaited. This issue is addressed and provide a very simple system fulfilling all these requirements by combining porosity and asymmetric swelling/shrinking via orientation of hydrogel fibers at different angles in a fibrous membrane. Electrospinning is used as a tool for making membranes with fibers oriented at different angles.

Self-Organization of Gold Nanoparticle Assemblies with 3D Spatial Order and Their External Stimuli Responsiveness

Melissa S. Köhn Serrano, Tobias A. F. König, Johannes S. Haataja,  Tina I. Löbling, Holger Schmalz, Seema Agarwal, Andreas Fery, Andreas Greiner, Macromol. Rapid Commun., 201637(3), 215-220.


Gold nanoparticles (AuNP) with pyridyl end-capped polystyrenes (PS-4VP) as “quasi-monodentate” ligands self-assemble into ordered PS-4VP/AuNP nanostructures with 3D hexagonal spatial order in the dried solid state. The key for the formation of these ordered structures is the modulation of the ratio AuNP versus ligands, which proves the importance of ligand design and quantity for the preparation of novel ordered polymer/metal nanoparticle conjugates. Although the assemblies of PS-4VP/AuNP in dispersion lack in high dimensional order, strong plasmonic interactions are observed due to close contact of AuNP. Applying temperature as an external stimulus allows the reversible distortion of plasmonic interactions within the AuNP nanocomposite structures, which can be observed directly by naked eye. The modulation of the macroscopic optical properties accompanied by this structural distortion of plasmonic interaction opens up very interesting sensoric applications.

On the occasion of a visit for the preparation of future close cooperation of macromolecular science with the Donghua University Prof. Bin Ding (on the left) and Prof. Xianfeng Wang (on the right) received the mascot of the UBT. Prof. Greiner and Prof. Agarwal were appointed by the dean of the college of engineering to visiting professors of Donghua University.

Dr. Natalia ZvukovaIMG_2236IMG_2237

We congratulate  Melissa Köhn (l) and Yinfeng Shi (r) for defending successfully their PhD work on 18th and 19th November 2015 and and wish them all the best and success in the future.

Melissa  (2)Shi (2)

Chemical vapour deposition of soluble poly(p-xylylene) copolymers with tuneable properties

Ilka E. Paulus, Markus Heiny, V. Prasad Shastribc and Andreas Greiner  Polym. Chem,. 20167(1), 54-62.

GA Ilka E Paulus

Chemical vapour deposition (CVD) is a technique widely applied for the synthesis of thin and highly conformal polymer coatings. The copolymerization of poly(1,4-xylylene)s (PPX), with 2-hydroxyethyl methacrylate (HEMA) via CVD revives a hardly investigated field of PPX chemistry. The use of alkyl substituted [2.2]paracyclophanes leads to soluble PPX-copolymers. Proof of copolymerization was obtained by correlation of both monomer units in 1H,13C-HMBC 2D-NMR spectra. Next, insoluble p(PX-N-co-HEMA) copolymers were synthesized in a modified commercially available SCS Labcoater. The availability of the hydroxy ester functionality of HEMA on the film surface was indirectly confirmed by the reduction of water contact angles down to 65°. Preliminary studies using human umbilical vein endothelial cells (HUVEC) indicate the cytocompatibility of as deposited p(PX-N-co-HEMA) films.

Living Composites of Electrospun Yeast Cells for Bioremediation and Ethanol Production

Ilya Letnik, Ron Avrahami, J. Stefan Rokem, Andreas Greiner, Eyal Zussman, and Charles Greenblatt, Biomacromolecules, 2015, 16 (10), 3322–3328.

paper letnik

The preparation of composites of living functional cells and polymers is a major challenge. We have fabricated such “living composites” by preparation of polymeric microtubes that entrap yeast cells. Our approach was the process of coaxial electrospinning in which a core containing the yeast was “spun” within a shell of nonbiodegradable polymer. We utilized the yeast Candida tropicalis, which was isolated from olive water waste. It is particularly useful since it degrades phenol and other natural polyphenols, and it is capable of accumulating ethanol. The electrospun yeast cells showed significant activity of bioremediation of phenol and produced ethanol, and, in addition, the metabolic processes remained active for a prolonged period. Comparison of electrospun cells to planktonic cells showed decreased cell activity; however, the olive water waste after treatment by the yeast was no longer toxic for Escherichia coli, suggesting that detoxification and prolonged viability and activity may outweigh the reduction of efficiency.

The joint paper with the Greenblatt, Zussman, Greiner, and Rokem groups on bioremediation with yeast were recently discussed in an interview with Chemical Engineering News by Neil Savage which can be found under

Bio-based polycarbonate from limonene oxide and CO2 with high molecular weight, excellent thermal resistance, hardness and transparency

O. Hauenstein, M. Reiter, S. Agarwal, B. Rieger and A. Greiner Green Chemistry, 2015 ,18, 760-770.

TOC Oliver-Hauenstein

Completely bio-based, high molecular weight (>100 kDa) poly(limonene carbonate) (PLimC) with attractive thermal (glass transition temperature, Tg = 130 °C) and optical properties (transmission 94%, haze 0.75%) was prepared by coupling bio-based limonene oxide (LO) and carbon dioxide (CO2) using a β-diiminate zinc catalyst (bdi)Zn(OAc). The molar mass of the polymer could be controlled by changing the ratio of catalyst and monomer, keeping molar mass dispersities low. The synthesis of the LO with very high content (>85%) of trans-isomer and absence of impurities with hydroxyl functionality was also established, which was necessary to obtain a high molar mass of polymer and almost quantitative conversion of epoxide during polymerisation. The upscaled syntheses of both the monomer and the polymer (>1 kg per batch) were readily realised, suggesting an easy transfer to pilot plant scale. The polymerisation kinetics were studied suggesting a second order dependence on LO concentration, wherefrom a mechanism is proposed with an alternating insertion of LO and CO2. The effect of chain-ends on the thermal stability of PLimC was studied with a thermal desorption unit coupled with gas chromatography-mass spectrometry (GC-MS) experiments. PLimC with thermal stability as high as 240 °C could be achieved using appropriate end-capping agents. PLimC is characterised by excellent transparency and hardness.

Synthesis and Enzymatic Degradation of Soft Aliphatic Polyesters

Viola Buchholz, Seema Agarwal and Andreas Greiner Macromolecular Bioscience, 2016, 16(2), 207-213.

TOC Viola Buchholz

Novel aliphatic enzymatically degradable polyesters with short alkyl side chains for tuning crystallinity are presented in this work. The intrinsic problem of aliphatic polyesters is their brittleness and tendency to crystallize. This was modulated by the synthesis of random copolyesters based on aliphatic linear monomers, adipic acid, 1,5-pentanediol and monomers with aliphatic branches, such as 2-butyl-2-ethyl-1,3-propanediol by polycondensation. The resulting copolyesters were crystalline, wax-like or had liquid texture with varied mechanical properties and enzymatic degradability depending upon the copolymer composition. Such polyesters are of significant interest for a wide range of possible applications such as controlled drug delivery, agricultural applications and as packing materials

Our work on Universal Template for Controlled Size and Surface Modification of Metal Nanoparticles was presented as poster by Ziyin Fan at the Bayreuth Polymer Symposium (BPS2015) from 20th-22nd Sept. 2015. At the same conference the work on Highly Porous and Highly Conductive Metallized Polymer Sponges with Low Density by Wet Chemical Metal Deposition was presented by Markus Langer. Both contributions were judged best among the Bayreuth poster award category by the attendees. The awards were handed over by Prof. Hans-Werner Schmidt. Congratulations to the whole team working on nanoparticles and sponges and specifically to Ziyin and Markus for the international recognition and encouragement for future outstanding scientific accomplishments.

IMG_9976 (3)

Large Multipurpose Exceptionally Conductive Polymer Sponges Obtained by Efficient Wet-Chemical Metallization

Markus Langner, Seema Agarwal, André Baudler, Uwe Schröder and Andreas Greiner Advanced Functional Materials 2015, 25(39), 6182-6188.


Exceptionally conductive (250 S cm−1), very fast electrically heatable, thermally insulating, antimicrobial 3D polymeric sponges with very low density (≈30 mg cm−3), superhydrophobicity, and high porosity, their method of preparation, and manifold examples for applications are presented here. The electrical heatability is reversible, reaching 90 °C with 4.4 W in about 19–20 s and cooling immediately on switching off the voltage. The sponges show high contact angles >150° against water on the sponge surface as well as inside the sponge. Water droplets injected into the sponges are ejected. A facile wet-chemical method established for macroscopic melamine–formaldehyde sponges is the key for the thorough in-depth surface metallization of the sponges. The coating thickness and uniformity depend on the metallization formulation, conditions of metallization, and the type of metal used. A scanning electron microscope is used for morphology characterization. A reduced metallization rate in air is highly critical for the in-depth uniform coating of metals. The resulting metallized sponges could be highly interesting for heating as well as insulation devices in addition to oil/water separation membranes.

Enzymatically Degradable Polyester-Based Adhesives

Yinfeng Shi, Peiran Zhou, Valérie Jérôme, Ruth Freitag, and Seema Agarwal ACS Biomater. Sci. Eng., 2015, 1(10), 971-977.

TOC-ACS Biomater. Sci

A designed 3,4-dihydroxyphenylalanine (DOPA) mimetic enzymatic degradable synthetic adhesive with good adhesion to soft tissue and metals made by a simple two-step reaction is presented in this article. This adhesive has degradable polycaprolactone-type of repeat units together with glycidyl methacrylate (GMA) and oligo(ethylene glycol) methacrylate (OEGMA) on the polymer backbone. Radical initiated copolymerization of 2-methylene-1,3-dioxepane (MDO), glycidyl methacrylate (GMA) and OEGMA followed by immobilization of catechol group on epoxy rings of GMA provided the adhesive material. Fe(acac)3 was proved to be the most effective cross-linking agent with lap shear strength of 13.13 ± 1.74 kPa and 218.4 ± 16.0 kPa on soft tissue (porcine skin) and metal (aluminum), respectively. The cross-linked adhesive showed good adhesion stability in pH 7 PBS buffer at 37 °C for at least 1 week. Because of the high adhesive strength, enzymatic degradability, and low toxicity, the material is a promising candidate for future studies as medical glue.

Two-in-One Composite Fibers With Side-by-Side Arrangement of Silk Fibroin and Poly(l-lactide) by Electrospinning

Ling Peng, Shaohua Jiang, Maximilian Seuß, Andreas Fery, Gregor Lang, Thomas Scheibel and Seema Agarwal Macromolecular Materials and Engineering, 2016, 301(1), 48-55.

TOC new color

1D fibers of Bombyx mori silk fibroin (SF) and poly(l-lactide) (SF-s-PLLA) with side-by-side parallel arrangement of the two components in a single fiber made by electrospinning are presented. The side-by-side arrangement in both randomly oriented and aligned two-in-one fibers was confirmed by scanning electron and confocal laser scanning microscope studies. The molecular orientation and secondary structure of SF and PLLA were dependent on the fiber alignment and annealing conditions. The two sides retained their individual secondary structure before and after annealing without affecting each other in a significant way. The two-in-one fibers after post treatment with methanol and heat at 80 °C showed tensile strength 16.5 ± 1.4 MPa, modulus 205 ± 20.6 MPa, and an elongation at break of 53 ± 8%.

LCST and UCST in One: Double Thermoresponsive Behavior of Block Copolymers of Poly(ethylene glycol) and Poly(acrylamide-co-acrylonitrile)

Florian Käfer, Fangyao Liu, Ullrich Stahlschmidt, Valérie Jérôme, Ruth Freitag, Matthias Karg, and Seema Agarwal Langmuir 2015, 31(32), 8940-89466.

 Langmuir KF-1

The change in thermoresponsive behavior from a single phase transition of upper critical solution temperature (UCST)-type of an acrylamide-acrylonitrile copolymer (AAm-co-AN) to a double responsive behavior (LCST-UCST-type (LCST, lower critical solution temperature)) in water by the introduction of a poly(ethylene glycol) (PEG) block is highlighted in the present work. The polymer is synthesized in a simple way by free-radical polymerization of acrylamide and acrylonitrile using a poly(ethylene glycol) (PEG) macro-azoinitiator. The dual thermoresponsive behavior was observed in a wide range of concentrations repeatable for many cycles with very small hysteresis depending upon the ratio of AAm, AN and PEG. Static light scattering (SLS) and dynamic light scattering (DLS) together with turbidity photometry and transmission electron microscopy confirmed a unique phase transition behavior due to the temperature dependent change in the morphology from micelles to agglomerates. The low cytotoxicity and two-in-one thermoresponsive behavior makes the polymer promising for biomedical applications in the future.

Peter Disputation

Peter has passed the defense of his Ph. D. thesis successfully on July 31st, 2015. He has undertaken a very successful challenge with his Ph. D. thesis and will have more challenges in the near future. We wish Peter all the best for a good future.

Renaissance for low shrinking resins: all-in-one solution by bi-functional vinylcyclopropane-amides

Paul Pineda Contreras, Christian Kuttner, Andreas Fery, Ullrich Stahlschmidt,
Valérie Jérôme, Ruth Freitag and Seema Agarwal Chem. Commun., 2015, 51, 11899-11902

PP ChemComm

A low volume shrinking vinylcyclopropane (VCP) monomer, showing both a high reactivity and a low viscosity, was obtained by applying a sterically hindered and isomeric spacer element, incorporating intermolecular amide hydrogen bonds. The resulting properties locate this VCP system in a pronounced range that so far no other efficient and radical polymerizable resin could enter.

Selective Template Removal by Thermal Depolymerization to Obtain Mesostructured Oxycarbide

Martin Schieder, Thomas Lunkenbein, Carina Bojer, Martin Dulle, Julia vom Stein, Gudrun Auffermann, Tina Löbling, Judith Schöbel, Holger Schmalz and Josef Breu Z. Anorg. Allg. Chem. 2015, 641(10), 1829-1834.

 Fangyao defense

We congratulate Fangyao on passing PhD  examination and wish him all the best and success in the future.

Does it have to be carbon? Metal anodes in microbial fuel cells and related bioelectrochemical systems André Baudler, Igor Schmidt, Markus Langner, Andreas Greiner, Uwe Schröder Energy Environ. Sci., 2015,8, 2048-2055 DOI: 10.1039/C5EE00866B


Copper and silver are antimicrobial metals, on whose surface bacteria do not grow. As our paper demonstrates, this commonly reported antimicrobial property does not apply to electrochemically active, electrode respiring bacteria. These bacteria readily colonize the surface of these metals, forming a highly active biofilm. Average anodic current densities of 1.1 mA cm−2 (silver) and 1.5 mA cm−2 (copper) are achieved – data that are comparable to that of the benchmark material, graphite (1.0 mA cm−2). Beside the above metals, nickel, cobalt, titanium and stainless steel (SUS 304) were systematically studied towards their suitability as anode materials for microbial fuel cells and related bioelectrochemical systems. The bioelectrochemical data are put in relation to physical data of the materials (specific conductivity, standard potential) and to basic economic considerations. It is concluded that especially copper represents a highly promising anode material, suitable for application in high-performance bioelectrochemical systems.


Our work about Ultralight 3D Electrospun Nanofiber Sponge for tissue engineering was presented in Shanghai (China) on the Fiber Society’s Spring 2015 Conference in conjunction with the 2015 International Conference on Advanced Fibers and Polymer Materials, Shanghai (China) from 24th-27th May 2015 by Mrs. M.Sc. Gaigai Duan. The work was awarded with the Outstanding Poster Presentation Award Congratulations to the whole team working on ultralight sponges and specifically to Gaigai for the international recognition and encouragement for future outstanding scientific accomplishments.

Polymer/Nanoparticle Hybrid Materials of Precise Dimensions by Size-Exclusive Fishing of Metal Nanoparticles
Z. Fan, M. Köhn Serrano, A. Schaper, S. Agarwal A. Greiner
Adv. Mater.2015, 27(26), 3888.

Polymer cages prepared by etching of gold nanoparticles from polymer templates by the “grafting around” method are designed for selective separation of metal nanoparticles. The separation process is demonstrated as a fast biphasic ligand exchange reaction. The high separation efficiency and size selectivity of the polymer cage is verified by comparison with the linear block copolymer.


We congratulate Holger on passing PhD  examination and wish him all the best and success in the future.

Reversible Gold Nanorod Alignment in Mechano-Responsive Elastomers
H. Pletsch, M. Tebbe, M. Dulle, B. Förster, A. Fery, S. Förster, A. Greiner, S. Agarwal
Polymer; 2015, 66, 167-172.

Highways for ions in polymers - 3D–imaging of electrochemical interphase formation
V. Wesp, J. Zakel, M. Schäfer, I. Paulus, A. Greiner, K.-M. Weitzel
Electrochim. Acta; 2015;170, 122-130.

Agarwal S. (2015) Functional (bio)degradable polyesters by radical ring-opening polymerization. In: Stoyko Fakirov (ed.) Biodegradable polyesters, pp. 25, Wiley-VCH.

(2015) Functional (bio)degradable polyesters by radical ring-opening polymerization. In Stoyko Fakirov (ed.) Biodegradable polyesters, pp. 25, Wiley-VCH.

Living composites of bacteria and polymers were utilized for sequestration of gold from aqueous hydrogen tetrachloraureate solution and for the bioconversion of nitrite.


For more details see:

Living Composites of Bacteria and Polymers as Biomimetic Films for Metal Sequestration and Bioremediation
C. Knierim, M. Enzeroth, P. Kaiser, C. Dams, D. Nette, A. Seubert, A. Klingl, C. L. Greenblatt, V. Jérôme, S. Agarwal, R. Freitag, A. Greiner
Macromol. Biosci.2015, 15(8), 1052-1059.

On March 15th-April 5th, Maysa Jbarien, a master student from Hebrew university of Jerusalem in Prof. Golenser’s group, visited our research labs for learning new techniques for fabrication of drug loaded nanofibrous scaffolds based on electrospinning.

amir gip

Ultralight, Soft Polymer Sponges by Self-Assembly of Short Electrospun Fibers in Colloidal Dispersions
G. Duan, S. Jiang, V. Jérôme, J. H. Wendorff, A. Fathi, J. Uhm, V. Altstädt, M. Herling, J. Breu, R. Freitag, S. Agarwal, A. Greiner
Adv. Funct. Mater.; 2015; 25, 2850-2856 (pdf)

Antibacterial 45S5 Bioglass®-based scaffolds reinforced with genipin cross-linked gelatin for bone tissue engineering
W. Li, H. Wang, Y. Ding, E.C. Scheithauer, O.-M. Goudouri, A. Grünewald, R. Detsch, S. Agarwal, A. R. Boccaccini
J. Mater. Chem. B2015, 3(16), 3367-3378.

Synthesis of liquid crystalline thioether-functionalized hydroxypropyl cellulose esters
P. Ohlendorf, A. Greiner
Polym. Chem.2015, 6(14), 2734-2739.

Thermophilic films and fibers from photo cross-linkable UCST-type polymers
F. Liu, S. Jiang, L. Ionov, S. Agarwal
Polym. Chem.2015, 6(14), 2769-2776.

Low volume shrinkage of polymers by photopolymerization of 1,1-bis(ethoxycarbonyl)-2-vinylcyclopropanes
P. Pineda Contreras, P. Tyagia, S. Agarwal
Polym. Chem.; 2015, 6(12), 2297-2304.


Our work about UCST (upper critical solution temperature) in water and electrolytes was presented in Tsukuba (Japan) on the 10th SPSJ International Polymer Conference (IPC 2014) organized by the Society of Polymer Science, Japan (SPSJ) from 2nd - 5th Dec 2015 by Mr. Fangyao Liu. The work was highly appreciated and got the best young scientist poster award. Congratulations to the whole team working on UCST polymers and specifically to Mr. Fangyao Liu for this achievement.

Thermoresponsive Gold Nanoparticles with Positive UCST-Type Thermoresponsivity
F. Liu, S. Agarwal,
Macromol. Chem. Phys.; 2015, 216(4), 460-465.

Preparing a pseudo-solid by the reinforcement of a polydentate thioether using silver nanoparticles
H. Pletsch, A. Greiner, S. Agarwal,
Nanoscale2015, 7(5), 1977-1983.

Preparation of Conductive Gold Nanowires in Confined Environment of Gold-Filled Polymer Nanotubes
F. Mitschang, M. Langner, H. Vieker, A. Beyer, A. Greiner,
Macromol. Rapid Commun.2015, 36(3), 304-310.

One-Step Preparation of Reduction-Responsive Biodegradable Polymers as Efficient Intracellular Drug Delivery Platforms
T. Cai, Y. Cheng, Y. Wang, H. Wang, X. Liu, Q. Jin, S. Agarwal, J. Ji,
Macromol. Chem. Phys.2014, 215(19), 1848-1854.

Functional 2-methylene-1,3-dioxepane terpolymer: a versatile platform to construct biodegradable polymeric prodrugs for intracellular drug delivery
T. Cai, Y. Cheng, Y. Wang, H. Wang, X. Liu, Q. Jin, S. Agarwal, J. Ji,
Polym. Chem.; 2014, 5(13), 4061-4068.

Solvent-Free Aqueous Dispersions of Block Copolyesters for Electrospinning of Biodegradable Nonwoven Mats for Biomedical Applications
K. Bubel, D. Grunenberg, G. Vasilyev, E. Zussman, S. Agarwal, A. Greiner,
Macromol. Mater. Eng.; 2014; 299, 1445-1454.


Fabian has passed his defense of his Ph. D. thesis successfully on August 6th, 2014. Fabian is the first Ph. D. student of the Greiner group who defended his thesis in Bayreuth and hopefully the start of a long sequence of further defenses. We wish Fabian all the best for a good future.

Design of Soft Materials from Liquid Triblock Co-Oligomers and Metal Nanoparticles
H. Pletsch, M. J. Schnepf, S. Agarwal,
Chem. Mater.; 2014, 26(16), 4805-4811.

shaohua phd

Shaohua Jiang has passed the defense of his Ph.D. thesis successfully on June 30th, 2014. Shaohua is the first Ph. D. student of the Agarwal group who defended his thesis in Bayreuth. Friends from Bayreuth as well as the whole MC2 group joined his examination and the after-examination party. We wish you all the best for your future.

A Non-ionic Thermophilic Hydrogel with Positive Thermosensitivity in Water and Electrolyte Solution
F. Liu, J. Seuring, S. Agarwal
Macromol. Chem. Phys.; 2014; 215, 1466-1472.

Template Assisted Change in Morphology from Particles to Nanofibers by Side-by-Side Electrospinning of Block Copolymers
S. Jiang, Q. Jin, S. Agarwal,
Macromol. Mater. Eng.; 2014, 299(11), 1298-1305.

Oligomeric dual functional antibacterial polycaprolactone
H. Wang, C. V. Synatschke, A. Raup, V. Jérôme, R. Freitag, S. Agarwal
Polym. Chem.; 2014, 5, 2453-2460.

A Rare Example of the Formation of Polystyrene-Grafted Aliphatic Polyester in One-Pot by Radical Polymerization
Y. Shi, Z. Zheng, S. Agarwal
Chem. Eur. J.; 2014, 20 (24), 7419-7428.

Highly Flexible and Tough Concentric Triaxial Polystyrene Fibers
S. Jiang, G. Duan, E. Zussman, A. Greiner, S. Agarwal,
ACS Applied Materials & Interfaces; 2014, 6(8), 5918-23.

Tea-Bag-Like Polymer Nanoreactors Filled with Gold Nanoparticles
F. Mitschang, H. Schmalz, S. Agarwal, A. Greiner,
Angew. Chem. Int. Ed.; 2014, 53, 4972–4975.

Importance of compositional homogeneity of macromolecular chains for UCST-type transitions in water: Controlled versus conventional radical polymerization
B. A. Pineda-Contreras, F. Liu, S. Agarwal,
J. Polym. Sci. Part A: Polym. Chem.; 2014, 52, 1878-1884.

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