Additive manufacturing of ultrafiltration membranes from block copolymer nanowires

Precise manipulation of the structure and performance of separation membranes holds immense significance for realizing highly efficient separations in ultrafiltration applications. Herein, we demonstrate an additive manufacturing approach to ultrafiltration membranes by controlled deposition of block copolymer nanowires on macroporous substrates via spray coating. The nanowires with a high concentration and good dispersibility are synthesized through in situ crosslinking polymerization-induced self-assembly. The nanowire morphology can be adjusted by changing the block ratio, enabling the selection of an optimal configuration for membrane preparation. By controlling the concentration and volume of deposited nanowires, intact separation layers composed of stacked nanowires can be formed. The thickness of the nanowire layer is directly correlated with the spraying parameters, and it shows great tunability within the range of approximately 100 nm–3 μm. This tunable thickness imparts adjustable separation performance to the resultant membranes. Furthermore, the strategy presented herein demonstrates exceptional up-scalability in the fabrication of ultrafiltration membranes, paving the way for industrial applications.