Abstract
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.
Highlights
Thin-film composite (TFC) reverse osmosis (RO) membranes comprise a non-woven fabric backing, a porous support layer, and an active layer that typically is produced via interfacial polymerization of a diamine (e.g., m-phenylenediamine, MPD) and a triacyl chloride [1].TFC membranes are the current standard for membrane-based pressure-driven seawater desalination.TFC membranes have been used to develop new osmotically-driven membrane processes such as forward osmosis (FO), pressure-retarded osmosis (PRO), osmotically-assisted reverse osmosis (OARO) [2], and pressure-assisted forward osmosis (PAFO)
Our studies provide a modeling framework to estimate the changes in transport properties after short-term contact with short-chain alcohols that is especially useful when selecting conditions for wetting the support layer of TFC membranes for osmotically-driven membrane processes
We concluded that all the polyamide layers of the membranes used in this study were made by the reaction of m-phenylenediamine (MPD) and trimesoyl chloride (TMC), which would yield a fully aromatic polyamide structure
Summary
Thin-film composite (TFC) reverse osmosis (RO) membranes comprise a non-woven fabric backing, a porous support layer, and an active layer that typically is produced via interfacial polymerization of a diamine (e.g., m-phenylenediamine, MPD) and a triacyl chloride (e.g., trimesoyl chloride, TMC) [1]. The water permeance and salt rejection properties of TFC membranes can change after contact with these alcohols [5,7,8,9,10,11,12,13]. The above-mentioned studies propose that polyamide-alcohol interactions contribute to the improvement in transport properties. This paper contributes to the understanding of the effects of short-chain (C1–C4) monohydric alcohols on the transport properties of commercial TFC RO membranes with an MPD-TMC-based active layer and different initial transport properties. Our studies provide a modeling framework to estimate the changes in transport properties after short-term contact with short-chain alcohols that is especially useful when selecting conditions for wetting the support layer of TFC membranes for osmotically-driven membrane processes
Sign-in/Register to view highlights & summary Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
