Desalination, Vol.379, 108-117, 2016
Reverse osmosis membranes surface-modified using an initiated chemical vapor deposition technique show resistance to alginate fouling under cross-flow conditions: Filtration & subsequent characterization
The surface of commercial reverse osmosis (RO) membranes was mortified by the deposition of 2-hydroxyethyl methacrylate-co-perfluorodecyl actylate (HEMA-co-PFDA) copolymer films using an initiated chemical vapor deposition (iCVD) technique. Antifouling characteristics of the modified and unmodified membranes were evaluated under cross-flow permeation conditions using sodium alginate as a model organic foulant. The permeate flux decline was lower in the surface-modified membranes as compared to the virgin ones while salt rejection remained almost unaltered in both virgin and coated membranes. The presence of the HEMA-co-PFDA copolymer on the fouled membrane surface is confirmed by simultaneous analyses with Attenuated Total Reflectance-Fourier Transform Infra-Red (ATR-FTIR) and X-ray Photoelectron Spectroscopy. Field Emission Scanning Electron Microscopy (FESEM) images showed a dense and continuous foulant layer on the virgin samples as opposed to a porous and discontinuous one for the coated membranes. The water contact angle values for the coated membranes registered a decrease indicating the more hydrophilic nature of the adsorbed alginate. To conclude, although fouling appears inevitable, it is considerably slowed down by this surface modification strategy. (C) 2015 Elsevier B.V. All rights reserved.