(60ck) Effect of Short-Term Contact with C1–C4 Monohydric Alcohols on the Water Permeance of MPD-TMC Thin-Film Composite Reverse Osmosis Membranes

Effect of Short-Term Contact with C1–C4
Monohydric Alcohols on the Water Permeance of MPD-TMC Thin-Film Composite
Reverse Osmosis Membranes

Jaime A. Idarraga-Mora ¹, Michael A. Lemelin ¹,
Steven T. Weinman ² and Scott M. Husson ¹*

¹ Department of Chemical and
Biomolecular Engineering, Clemson University, 127 Earle Hall, Clemson, SC
29634, USA

² Department of Chemical and
Biological Engineering, The University of Alabama, Box 870203, Tuscaloosa, AL
35487, USA

In this paper, we discuss the effect of alcohol contact on
the transport properties of thin-film composite reverse osmosis membranes. Five
commercial membranes were studied to quantify the changes in water permeance
and sodium chloride rejection from contact with five C1–C4 monohydric alcohols.
Water permeance generally increased without decreasing rejection after
short-term contact. The extent of these changes depends on the membrane and
alcohol used. Young′s modulus measurements showed decreased stiffness of
the active layer after contacting the membranes with alcohol, suggesting
plasticization. Data analysis using a dual-mode sorption model identified
positive correlations of the initial water permeance, as well as the change in
free energy of mixing between water and the alcohols, with the increase in
water permeance after alcohol contact. We suggest that the mixing of water with
the alcohols facilitates alcohol penetration into the active layer, likely by
disrupting inter-chain hydrogen bonds, thus increasing the free volume for
water permeation. Our studies provide a modeling framework to estimate the
changes in transport properties after short-term contact with C1–C4 alcohols.