Achieving high permeability and enhanced selectivity for Angstrom-scale separations using artificial water channel membranes

Nat Commun. 2018 Jun 12;9(1):2294. doi: 10.1038/s41467-018-04604-y.

Abstract

Synthetic polymer membranes, critical to diverse energy-efficient separations, are subject to permeability-selectivity trade-offs that decrease their overall efficacy. These trade-offs are due to structural variations (e.g., broad pore size distributions) in both nonporous membranes used for Angstrom-scale separations and porous membranes used for nano to micron-scale separations. Biological membranes utilize well-defined Angstrom-scale pores to provide exceptional transport properties and can be used as inspiration to overcome this trade-off. Here, we present a comprehensive demonstration of such a bioinspired approach based on pillar[5]arene artificial water channels, resulting in artificial water channel-based block copolymer membranes. These membranes have a sharp selectivity profile with a molecular weight cutoff of ~ 500 Da, a size range challenging to achieve with current membranes, while achieving a large improvement in permeability (~65 L m-2 h-1 bar-1 compared with 4-7 L m-2 h-1 bar-1) over similarly rated commercial membranes.

Publication types

  • Research Support, Non-U.S. Gov't
  • Research Support, U.S. Gov't, Non-P.H.S.

MeSH terms

  • Aquaporins / chemistry
  • Computer Simulation
  • Detergents / chemistry
  • Lipid Bilayers / chemistry
  • Liposomes / chemistry
  • Membranes, Artificial*
  • Microscopy, Confocal
  • Microscopy, Electron, Transmission
  • Molecular Dynamics Simulation*
  • Molecular Weight
  • Permeability
  • Polymers / chemistry*
  • Porosity
  • Salts / chemistry
  • Water / chemistry*

Substances

  • Aquaporins
  • Detergents
  • Lipid Bilayers
  • Liposomes
  • Membranes, Artificial
  • Polymers
  • Salts
  • Water