Tunable membranes incorporating artificial water channels for high-performance brackish/low-salinity water reverse osmosis desalination
byM. di Vincenzo, A. Tiraferri, V. Musteata, S. Chisca, M. Deleanu, F. Ricceri, D. Cot, S. P. Nunes, M. Barboiu
Year:2021DOI:10.1073/pnas.2022200118
Bibliography
Proceedings of the National Academy of Sciences 2021, 118, e2022200118
Extra Information
Proceedings of the National Academy of Sciences 2021, 118, e2022200118
Abstract
Membrane-based technologies have a tremendous role in water purification
and desalination. Inspired by biological proteins, artificial water
channels (AWCs) have been proposed to overcome the
permeability/selectivity trade-off of desalination processes. Promising
strategies exploiting the AWC with angstrom-scale selectivity have
revealed their impressive performances when embedded in bilayer
membranes. Herein, we demonstrate that self-assembled imidazole-quartet
(I-quartet) AWCs are macroscopically incorporated within industrially
relevant reverse osmosis membranes. In particular, we explore the best
combination between I-quartet AWC and m-phenylenediamine (MPD) monomer
to achieve a seamless incorporation of AWC in a defect-free polyamide
membrane. The performance of the membranes is evaluated by cross-flow
filtration under real reverse osmosis conditions (15 to 20 bar of
applied pressure) by filtration of brackish feed streams. The optimized
bioinspired membranes achieve an unprecedented improvement, resulting in
more than twice (up to 6.9 L⋅m−2⋅h−1⋅bar−1)
water permeance of analogous commercial membranes, while maintaining
excellent NaCl rejection (>99.5%). They show also excellent
performance in the purification of low-salinity water under low-pressure
conditions (6 bar of applied pressure) with fluxes up to 35 L⋅m−2⋅h−1 and 97.5 to 99.3% observed rejection.