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

Abstract

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.

Smectic Liquid Crystalline Polymer Membranes with Aligned Nanopores in an Anisotropic Scaffold

“…This would make this membrane competitive with commercial membranes such as the Dow FILMTEC NF90-400, which has a permeability of roughly 10–15 L m –2 h –1 bar –1 . 38 However, the presence of a possible thin top layer, vide supra, is not taken into account. The optimization toward an LC layer in the range of nanometers could be realized with industrially applied thin-film fabrication techniques such as flexography, spin coating, or spray coating.…”

Fabrication of desalination membranes by interfacial polymerization: history, current efforts, and future directions

“…59 Such insights may lead to new approaches for making high-performance membranes. Notably, advances in materials science related to thin-film fabrication techniques (e.g., self-assembly, 62 atomic layer deposition, 63 and surface-initiated polymerization 64 ) can provide new approaches for the design of novel IP strategies.…”

Ultrahigh Adsorption Capacity and Kinetics of Vertically Oriented Mesoporous Coatings for Removal of Organic Pollutants

“…[ 28–31 ] However, most of previously developed MCs generally have prevailing 2D channels parallel to substrates and/or 3D interpenetrated ones, which greatly prevent the diffusion of organic molecules into the internal surfaces. [ 32–36 ] Therefore, MCs with vertical channels have been extensively explored. [ 37–39 ] For example, Su et al.…”