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

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 ~500Da, a size range challenging to achieve with current membranes, while achieving a large improvement in permeability (~65 L m^−1 h^−1 bar^−1 compared with 4^–7 L m^−2 h^−1 bar^−1) over similarly rated commercial membranes.

Yue-xiao Shen, Woochul C. Song, D. Ryan Barden, Tingwei Ren, Chao Lang, Hasin Feroz, Codey B. Henderson, Patrick O. Saboe, Daniel Tsai, Hengjing Yan, Peter J. Butler, Guillermo C. Bazan, William A. Phillip, Robert J. Hickey, Paul S. Cremer, Harish Vashisth and Manish Kumar
Nature Communications
Volume: 9
Number: 2294
Date: August, 2018
ICB Affiliated Authors: Guillermo C Bazan