Effects of surface coating process conditions on the water permeation and salt rejection properties of composite polyamide reverse osmosis membranes

Handle URI:
http://hdl.handle.net/10754/561577
Title:
Effects of surface coating process conditions on the water permeation and salt rejection properties of composite polyamide reverse osmosis membranes
Authors:
Louie, Jennifer Sarah; Pinnau, Ingo ( 0000-0003-3040-9088 ) ; Reinhard, Martin
Abstract:
The application of polymer surface coatings to improve the fouling resistance of reverse osmosis membranes tends to increase flow resistance across the membrane. This paper presents a systematic analysis on how membrane properties and performance are impacted by the coating process steps, and investigates how such effects could contribute to lower water flux. On one hand, simply pre-soaking dry aromatic polyamide composite membranes in aliphatic alcohols results in a significant increase in water flux, which is attributed to wetting of pores in the selective polyamide layer and to changes in the polymer structure. This flux increase was not readily reversible, based on a 300-h water permeation test. Conversely, drying a wetted membrane led to a decrease in water flux, which we hypothesize is caused by increased interchain hydrogen-bonding in the selective layer. This drop in water flux was not permanent; higher flux was observed if the same wetted/dried membrane was then re-soaked in ethanol prior to the water permeation experiment. An ethanol pre-soaking step also increased water flux of a PEBAX-coated membrane by nearly 70%. In contrast to the reduction in water flux caused by the specific treatment sequence of ethanol-swelling followed by drying, this same sequence actually increased gas transport. The eight- to ten-fold increase in Knudsen diffusion-based gas permeance after this pre-treatment was attributed to an increase in the number or size of membrane defects. © 2010 Elsevier B.V.
KAUST Department:
Advanced Membranes and Porous Materials Research Center; Physical Sciences and Engineering (PSE) Division; Chemical and Biological Engineering Program
Publisher:
Elsevier
Journal:
Journal of Membrane Science
Issue Date:
Feb-2011
DOI:
10.1016/j.memsci.2010.10.067
Type:
Article
ISSN:
03767388
Sponsors:
This work was funded by the Santa Clara Valley Water District (Agreement A2727A), the Metropolitan Water District (Agreement 41808), the California Department of Water Resources, the WateReuse Foundation (WRF-06-020) and Singapore Economic Development Board. Membranes used for this study were generously donated by Hydranautics (Oceanside, CA). Membrane Technology and Research, Inc. is gratefully acknowledged for providing water and gas permeation equipment.
Appears in Collections:
Articles; Advanced Membranes and Porous Materials Research Center; Physical Sciences and Engineering (PSE) Division; Chemical and Biological Engineering Program

Full metadata record

DC FieldValue Language
dc.contributor.authorLouie, Jennifer Sarahen
dc.contributor.authorPinnau, Ingoen
dc.contributor.authorReinhard, Martinen
dc.date.accessioned2015-08-02T09:14:36Zen
dc.date.available2015-08-02T09:14:36Zen
dc.date.issued2011-02en
dc.identifier.issn03767388en
dc.identifier.doi10.1016/j.memsci.2010.10.067en
dc.identifier.urihttp://hdl.handle.net/10754/561577en
dc.description.abstractThe application of polymer surface coatings to improve the fouling resistance of reverse osmosis membranes tends to increase flow resistance across the membrane. This paper presents a systematic analysis on how membrane properties and performance are impacted by the coating process steps, and investigates how such effects could contribute to lower water flux. On one hand, simply pre-soaking dry aromatic polyamide composite membranes in aliphatic alcohols results in a significant increase in water flux, which is attributed to wetting of pores in the selective polyamide layer and to changes in the polymer structure. This flux increase was not readily reversible, based on a 300-h water permeation test. Conversely, drying a wetted membrane led to a decrease in water flux, which we hypothesize is caused by increased interchain hydrogen-bonding in the selective layer. This drop in water flux was not permanent; higher flux was observed if the same wetted/dried membrane was then re-soaked in ethanol prior to the water permeation experiment. An ethanol pre-soaking step also increased water flux of a PEBAX-coated membrane by nearly 70%. In contrast to the reduction in water flux caused by the specific treatment sequence of ethanol-swelling followed by drying, this same sequence actually increased gas transport. The eight- to ten-fold increase in Knudsen diffusion-based gas permeance after this pre-treatment was attributed to an increase in the number or size of membrane defects. © 2010 Elsevier B.V.en
dc.description.sponsorshipThis work was funded by the Santa Clara Valley Water District (Agreement A2727A), the Metropolitan Water District (Agreement 41808), the California Department of Water Resources, the WateReuse Foundation (WRF-06-020) and Singapore Economic Development Board. Membranes used for this study were generously donated by Hydranautics (Oceanside, CA). Membrane Technology and Research, Inc. is gratefully acknowledged for providing water and gas permeation equipment.en
dc.publisherElsevieren
dc.subjectCoatingen
dc.subjectGas permeationen
dc.subjectPebaxen
dc.subjectPolyamideen
dc.subjectRO membranesen
dc.subjectWettingen
dc.titleEffects of surface coating process conditions on the water permeation and salt rejection properties of composite polyamide reverse osmosis membranesen
dc.typeArticleen
dc.contributor.departmentAdvanced Membranes and Porous Materials Research Centeren
dc.contributor.departmentPhysical Sciences and Engineering (PSE) Divisionen
dc.contributor.departmentChemical and Biological Engineering Programen
dc.identifier.journalJournal of Membrane Scienceen
dc.contributor.institutionDepartment of Civil and Environmental Engineering, Stanford University, Environment and Energy Building, 473 Via Ortega, Stanford,CA,94305-4020, United Statesen
kaust.authorPinnau, Ingoen
All Items in KAUST are protected by copyright, with all rights reserved, unless otherwise indicated.