Aqueous solution

Chemistry

Materials science

Optoelectronics

Engineering

Lyotropic

Composite material

Mesophase

Biochemistry

Nanostructure

Nanotechnology

Organic chemistry

Membrane

Nanofiltration

Monomer

Polymerization

Interfacial polymerization

Chemical engineering

Liquid crystal

Liquid crystalline

Polymer

Science Advances

Self-assembled materials are attractive for next-generation membranes. However, the need to align self-assembled nanostructures (e.g. cylinders, lamellae) and the narrow stability windows for ordered bicontinuous systems present serious challenges. We propose and demonstrate a novel approach that circumvents these challenges by exploiting size-selective transport in the water-continuous medium of a nanostructured polymer templated from a self-assembled lyotropic H1 mesophase. Optimization of the mesophase composition enables high-fidelity retention of the H1 structure on photoinduced cross-linking. The resulting material is a mechanically robust nanostructured polymer possessing internally and externally cross-linked nanofibrils surrounded by a continuous aqueous medium. Fabricated membranes show size selectivity at the 1- to 2-nm length scale and water permeabilities of ~10 liters m-2 hour-1 bar-1 μm. Moreover, the membranes display excellent antimicrobial properties due to the quaternary ammonium groups on the nanofibril surfaces. These results represent a breakthrough for the potential use of polymerized lyotropic mesophase membranes in practical water purification applications.

Precise nanofiltration in a fouling-resistant self-assembled membrane with water-continuous transport pathways