Connecting Solute Diffusion to Pore Morphology in Self-Assembled Triblock Copolymer Membranes

Block copolymers self-assemble a variety of morphologies useful as porous water-treatment membranes. A key challenge is to determine which morphologies maximize the flux of water while selectively rejecting contaminants. Here, we generate equilibrium and nonequilibrium ABC triblock copolymer morphologies using self-consistent field theory (SCFT) and use them in a kinetic Monte Carlo (kMC) model for solute diffusion. Our model excludes transport through the A-block membrane matrix, confining it to the B-block brush that expands when the sacrificial C-block is removed to establish a pore network. These effects are embedded in the SCFT and kMC workflow to examine the roles of mesoscale morphology and internal pore structure in determining solute diffusion rates in porous block copolymer membranes.