Understanding and Improving Self-Assembled Block Copolymer Membranes with Aligned Cylindrical Nanopores

Block copolymers are capable of self-assembling into films comprising densely-packed arrays of monodisperse cylindrical nanopores providing ideal structures for filtration membranes. In theory, aligned cylinders formed through nanostructuring of block copolymers can enable a fully polymeric analog to theorized aquaporin and aligned nanotube membranes, while maintaining ease and economy of large-scale polymeric membrane fabrication. Herein, we use these materials as ideal models of ultrafiltration membrane structures to probe the validity of a newly developed structure-performance model relating solvent and solute transport. The transport model accounts for hindered diffusion, hindered convection, and solvent/solute-membrane affinity as well as the range of solute/solvent-membrane affinity interactions relative to the pore dimension. Our work provides new insight into the potential performance enhancements that may be achieved with block copolymer membrane materials and also provides new insight from a new mechanistic perspective.