Tunable organic solvent nanofiltration in self-assembled membranes at the sub–1 nm scale

Abstract

Organic solvent–stable membranes exhibiting strong selectivity and high permeance have the potential to transform energy utilization in chemical separation processes. A key goal is developing materials with uniform, well-defined pores at the 1-nm scale, with sizes that can be tuned in small increments with high fidelity. Here, we demonstrate a class of organic solvent–stable nanoporous membranes derived from self-assembled liquid crystal mesophases that display such characteristics and elucidate their transport properties. The transport-regulating dimensions are defined by the mesophase geometry and can be controlled in increments of ~0.1 nm by modifying the chemical structure of the mesogen or the composition of the mesophase. The highly ordered nanostructure affords previously unidentified opportunities for the systematic design of organic solvent nanofiltration membranes with tailored selectivity and permeability and for understanding and modeling rejection in nanoscale flows. Hence, these membranes represent progress toward the goal of enabling precise organic solvent nanofiltration.

Stabilizing Differential Interfacial Curvatures by Mismatched Molecular Geometries: Toward Polymers with Percolating 1 nm Channels of Gyroid Minimal Surfaces

“…Recent studies have established the use of polymeric materials derived from polymerized “normal” lyotropic LCs as efficient separation membranes, particularly for organic nanofiltration. − The successful application therefore requires the prepared polymeric films to be able to resist structural collapse in organic solvents. This capability, in principle, is related to the cross-linking density of the polymeric materials.…”

Aperture‐Adjustable and Repairable Metal‐Based MOFs Catalysis Membrane for Water Purification

“…The curves are fitted with a sigmoidal model. [ 35 ] Error bars correspond to 95% confidence interval from a minimum of three replicates.…”

2D Covalent Organic Framework Membranes for Liquid‐Phase Molecular Separations: State of the Field, Common Pitfalls, and Future Opportunities

“…Chemical separations are ubiquitous in industry and currently account for 10–15% of the world's total annual energy consumption. [ 1–3 ] Within industrial separations, nearly 80% of energy use is attributed to heat‐based processes that rely on chemical phase changes, such as distillation or evaporation. [ 1,2 ] By transitioning from thermal separations to membrane‐based alternatives, the required energy input could be reduced by as much as 90%, which would decrease costs and greenhouse gas emissions.…”