Polyamide thin-film composite membranes based on carboxylated polysulfone microporous support membranes for forward osmosis

Abstract

/npsi/ctrl?lang=en http://nparc.cisti-icist.nrc-cnrc.gc.ca/npsi/ctrl?lang=fr Access and use of this website and the material on it are subject to the Terms and Conditions set forth at http://nparc.cisti-icist.nrc-cnrc.gc.ca/npsi/jsp/nparc_cp.jsp?lang=en NRC Publications Archive Archives des publications du CNRCThis publication could be one of several versions: author's original, accepted manuscript or the publisher's version. / La version de cette publication peut être l'une des suivantes : la version prépublication de l'auteur, la version acceptée du manuscrit ou la version de l'éditeur. For the publisher's version, please access the DOI link below./ Pour consulter la version de l'éditeur, utilisez le lien DOI ci-dessous.http://dx.doi.org/10.1016/j.memsci.2013.06.003 Science, 445, pp. 220-227, 2013-06-13 Polyamide thin-film composite membranes based on carboxylated polysulfone microporous support membranes for forward osmosis Cho, Young Hoon; Han, Jungim; Han, Sungsoo; Guiver, Michael D.; Park, Ho Bum Journal of Membrane AbstractDue to its simple process and low energy consumption, forward osmosis (FO) has gained significant attention in the fields of emergency drinks, desalination, landfill leachate treatment, and brine concentration. However, current state-of-the-art reverse osmosis (RO) membranes show relatively low water fluxes in FO processes due to high internal concentration polarization (ICP) and high mass transfer resistance in commercially available microporous support membranes. In this study, carboxylated polysulfones (CPSFs) were synthesized via direct polysulfone (PSF) functionalization and considered as moderately hydrophilic, mechanically stable microporous support membranes. The incorporation of hydrophilic groups into hydrophobic polymer backbones often reduces mechanical strength due to excessive water swelling. However, the mechanical properties of CPSFs (degree of substitution, DS=0.45~0.85) were similar to those of pristine PSF, and they retained their hydrophilic nature. Microporous CPSF membranes were prepared in various conditions, and FO water fluxes and salt passages of polyamide thin-film/CPSF composite membranes were measured and compared with each other. CPSF-based FO membranes showed significantly higher water fluxes than PSF-based FO membranes at the same membrane formation conditions, which might be due to enhanced hydrophilicity and reduced ICP.

Preparation of graphene oxide modified polyamide thin film composite membranes with improved hydrophilicity for natural organic matter removal

“…2. Both pure PA TFC and GO modified TFC membranes displayed ridge-valley surface structure, similar to the structure observed on the surfaces of other TFC and thin film nanocomposite (TFN) membranes [17,[30][31][32]. Furthermore, the surface of the GO modified TFC membranes appeared to be denser than that of the pure PA TFC membrane.…”

Water desalination by forward (direct) osmosis phenomenon: A comprehensive review

“…Thin-film composite (TFC) polyamide membranes have been fabricated in both flat sheet [136,[142][143][144]146,147,150,151,155,159,161,163,164,170,[172][173][174] and hollow fiber [133,134,171] configurations for application in FO desalination. Almost all of these membranes have been fabricated using the conventional technique for preparing TFC polyamide RO membranes, i.e., phase inversion (for porous substrate preparation) followed by interfacial polymerization (for formation of polyamide active layer).…”

“…However, in this case, the zeolite loading requires optimization since high loading can reduce the water flux. Later on, amine functionalized multi-walled carbon nanotubes (MWCNTs) were incorporated in the 18 [161] polyamide active layer of the TFC membranes [159]. Compared to ordinary TFC FO membranes, the addition of amine functionalized MWCNTs in the active layer resulted in much higher water flux.…”

“…Therefore, recent membrane fabrications have focused on the membrane support layer for water flux enhancement and ICP effect mitigation. For example, hydrophilic carboxylic acid groups were incorporated in the hydrophobic PSf substrate which resulted in higher water permeation rates (18 L/m 2 h using deionized water feed and 1 M MgCl 2 draw solution) compared to PSf-based membranes [161]. However, in this case, the mechanical stability of the membrane was compromised at higher concentration of draw solution.…”

Progress in Forward Osmosis Membrane Separation Process

“…into either membrane substrates [54] or membrane surfaces [55,56] may leak out after a long-term operation as a result of no affinitive interaction between the added materials and membrane. Unlike physical modification, chemical modification is conducted on either membrane surface [57][58][59][60] or membrane polymer prior to the membrane fabrication [61][62][63][64][65] via chemical reactions between materials to enhance membrane hydrophilicity. Chemical modification on membrane or functionalization on membrane polymers (eg.…”