%0 journal article %@ 0009-2665 %A Müller, M., Abetz, V. %D 2021 %J Chemical Reviews %N 22 %P 14189-14231 %R doi:10.1021/acs.chemrev.1c00029 %T Nonequilibrium Processes in Polymer Membrane Formation: Theory and Experiment %U https://doi.org/10.1021/acs.chemrev.1c00029 22 %X Porous polymer and copolymer membranes are useful for ultrafiltration of functional macromolecules, colloids, and water purification. In particular, block copolymer membranes offer a bottom-up approach to form isoporous membranes. To optimize permeability, selectivity, longevity, and cost, and to rationally design fabrication processes, direct insights into the spatiotemporal structure evolution are necessary. Because of a multitude of nonequilibrium processes in polymer membrane formation, theoretical predictions via continuum models and particle simulations remain a challenge. We compiled experimental observations and theoretical approaches for homo- and block copolymer membranes prepared by nonsolvent-induced phase separation and highlight the interplay of multiple nonequilibrium processes—evaporation, solvent–nonsolvent exchange, diffusion, hydrodynamic flow, viscoelasticity, macro- and microphase separation, and dynamic arrest—that dictates the complex structure of the membrane on different scales.