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.