Transport in self-assembled polymer membranes with uniform 1 nm transport limiting features

Membranes that exhibit independently tunable solute selectivity and permeance have the potential to transform a number of selective transport applications, with significant implications for water purification, organic solvent separations, and electrochemical device operation. A key but elusive goal is the development of materials with uniform, well-defined pores at the 1 nm scale, the sizes of which can be tuned in small increments with high fidelity. Here, we investigate the fabrication and transport properties of a nanoprous membranes derived from self-assembled liquid crystal mesophases, with the potential to address the aforementioned issues. We highlight the dependence of selectivity on the orientation of the transport vector relative to the nanostructure in membranes derived from direct hexagonal mesophases, and compare the permeability of these systems against membranes produced from double gyroid mesophases. Appropriately normalized, transport in gyroid membranes is demonstrably slower than in direct hexagonal membranes. Good stability in a wide range of conditions and the precision with which the nanostructure can be tuned suggest that these membranes may provide new opportunities for the systematic design of separations with tailored selectivity and permeability, and for understanding and modeling rejection in nanoscale flows.