Preparation and performance analysis of acrylonitrile based nanocomposite membranes for chromium (VI) removal from aqueous solutions

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2010
Bozkır, Selçuk
Acrylonitrile were copolymerized with 2-ethylhexyl acrylate and hexyl acrylate via one step emulsion polymerization using ammonium persulfate (initiator), 1-dodecanthiol (chain transfer agent) and DOWFAX 8390 (surfactant) in the presence of water at about 68 0C. Poly (acrylonitrile-2ethylhexyl acrylate) and poly (acrylonitrile-hexyl acrylate) copolymers with three different comonomer composition (8, 12 and 16 molar percent) were prepared. FTIR and 1H-NMR were used in order to clarify the chemical structure of copolymers. The comonomer amount incorporated into copolymers was determined by using 1H-NMR spectra. The thermal behavior of copolymers was determined by DSC and TGA. Molecular weights of copolymers were determined by intrinsic viscosity (IV) measurements. IV measurements revealed that both poly (acrylonitrile-2ethylhexyl acrylate) and poly (acrylonitrile-hexyl acrylate) have sufficient molecular weight to form nanoporous filtration membranes. Nanoporous filtration membranes were prepared and tested for chromium (IV) removal. It was observed that chromium (VI) rejections of nanoporous filtration membrane were highly dependent on the concentration and the pH of the solutions. Almost complete removal (99, 9 percent Cr (VI)) rejection was achieved at pHs 2, 5 and 7 for solution containing 50 ppm, chromium (VI) with permeate flux within a range from 177 to 150 L/m2h at 689.5 kPa. Also, chemical structure, swelling ratios, sheet resistivity and fracture morphologies of the nanoporous filtration membrane were studied. It should be noted that the nanoporous filtration membranes were fouling resistant.
Citation Formats
S. Bozkır, “Preparation and performance analysis of acrylonitrile based nanocomposite membranes for chromium (VI) removal from aqueous solutions,” M.S. - Master of Science, Middle East Technical University, 2010.