Cellulose acetate blend membranes

W.M. King, D.L. Hoemschemeyer and C.W. Saltonstall, Jr, Cellulose Acetate Blend Membranes, in Reverse Osmosis Membrane Research, H.K. Lonsdale and H.E. Podall (eds), Plenum Press, New York, pp. 131-162 (1972). 

The importance of proper RO membrane selection has already been discussed. A review of commercially available RO membranes revealed five different basic membranes that could provide organic recovery. Cellulose acetate and cellulose acetate blends, aromatic polyamide, polyamide thin-film composite, cross-linked polyimine thin-film composite (FT-30), and polybenzimidazole were available when this work was performed. Only the first four types were commercially available. All membranes were available with excellent salt rejection (>97 sodium chloride). Two types of membranes, cellulose acetate and FT-30, have shown short-term (<2-months intermittent use) resistance... 

Most MF, UF, RO, and NF membranes are synthetic organic polymers. NF membranes are made from cellulose acetate blends, cellulose triacetate (CTA), or polyamide composites such as the RO membranes, or they could be modified forms of UF membranes such as sulfonated polysulfone [27]. On the other hand, poly(vinyl alcohol) (PVA) is a significant polymer for nonaqueous applications. Chemical stmctures of a few of the prominent polymers are shown in Figure 42.4. 

Membrane polymer Polyamide Corr5)osite polyamide Cellulose-acetate blend Composite polyamide... 

Boricha, A. G. and Murthy, Z. V. P. 2010. Preparation of N.O-carboxymethyl chitosan/cellulose acetate blend nanofiltration membrane and testing its performance in treating industrial wastewater. Chem. Eng. J. 157 393-400. 

In the woik of Olde Riekerink et al. (2002), one type of UF (cellulose triacetate, CTA) membrane and one type of RO (cellulose acetate blend, CAB) membrane were selected for CO2 plasma modification. CTA ultrafilters are well known for their low fouling properties and CAB membranes are widely used for desalination. CO2 plasma treatment resulted in the gradual etching of the membrane s dense top layer. 

AN, 0-Carboxy methyl chitosan/cellulose acetate blend nano filtration membrane was prepared in acetone solvent. It had been tested to separate chromium and copper fiom effluent treatment. The highest rejection was observed to be 83.40% and 72.60%, respectively (Alka et al., 2010). A chitosan/cellulose acetate/polyethylene glycol ultra filtration membrane was prepared with DMF as solvent. It was focused to be efficient in removing chromium from artificial and tannery effluent wastewater. The highest rejection rate was responding (Sudha et al., 2008).Cross-linked chitosan/polyvinyl alcohol blend beads were prepared and studied for the adsorption capacity of Cd from wastewater. The maximum adsorption of Cd(II) ions was foimd to be 73.75% at pH 6 (Kumar et al., 2009). 

Chun Xiu Liu and Renbi Bai (2006). Adsorptive removal of copper ions with highly porous chi-tosan/cellulose acetate blend hollow fiber membranes. Journal of Membrane Science 284(1 2), 313-322. 

Modification of polymeric membrane materials through incorporation of hydrophi-licity results in membranes with low fouling behavior and high flux. Thus, literature presents sulfonated polysulfone/cellulose acetate blends applied in various compositions for obtaining ultrafiltration membranes, where their performance is improved by the inclusion of polyethyleneglycol into the casting solution as a nonsolvent additive in various concentrations. In this way, total polymer concentration, cellulose acetate, sulfonated polysulfone polymer blend composition, additive concentration, and their compatibility with polymer blends are optimized [133]. 

Han, B. et al.. Preparation and characterization of cellulose acetate/carboxymethyl cellulose acetate blend ultrafiltration membranes. Desalination, 2013.311 80-89. 

Ultrathin (about 400 A thick), polymer-blend membrane prepared from poly(styrenephosphonate diethyl ester) and cellulose acetate Size-quantized CdS particles generated in membranes... 

Asymmetric cellulose acetate membranes were developed in the early 1960s by Loeb and Sourirajan (2). For more than a decade, cellulose acetate and its blends were the only commercially available RO membranes. Improved membranes (with respect to operating pH, biodegradation, compaction, and organic compound rejection) were developed in the early 1970s (3). These membranes used aromatic... 

Figure 9.19 Fraction of benzene in permeate as a function of feed mixture composition for pervaporation at the reflux temperature of a binary benzene/cyclohexane mixture. A 20-qm-thick crosslinked blend membrane of cellulose acetate and polystyrene phosphate) was used [54]. Reprinted with permission from I. Cabasso, Organic Liquid Mixtures Separation by Selective Polymer Membranes, Ind. Eng. Chem. Prod. Res. Dev. 22, 313. Copyright 1983 American Chemical Society...

Chen ZA, Deng MC, Yong C, He GH, Ming W, and Wang JD. Preparation and performance of cellulose acetate/polyethyleneimine blend microfiltration membranes and their applications. J. Membr. Sci. 2004 235 73-86. 

Regenerated cellulose (cellophane), poly(vinyl alcohol) (PVA), cellulose acetate (CA), cellulose triacetate (CTA), two blends of CTA (B1 and B2) with acrylic acid, poly(dimethylsiloxane) (PDMS), and linear low density polyethylene (LLDPE) membrane... 

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