ORALS

Polypropylene based nanocomposite membrane with a self-assembled coating for seawater treatment via membrane distillation Rajesha Kumar1, Mansour Ahmed1, Garudachari Bhadrachari1, Jibu Thomas1 1Water Research Center, Kuwait Institute for Scientific Research, P.O. Box, 24885, 13109 Safat, Kuwait, Tel: +965 97920482 * e-mail: rajeshakumar15@yahoo.com Abstract. A novel approach of self-assembly techniques has been used for the coating of superhydrophobic layer over the microporous polypropylene (PP) support. The hydrophobic fluorinated silica nanoparticles were synthesized and isolated by reacting tetraethyl orthosilicate (TEOS) with excess heptadeca- fluoro-1,1,2,2-tetrahydrodecyl) triethoxysilane. The hydrophobic silica particles (HSP) were dispersed in the coating solution consisted of trimesoyl chloride, trimethylamine and hexane compositions. The coating layer thickness was limited to 100-150 I�m by selecting the proper compositions of the TEA and TMC. The coating layer with HSP was effectively formed over the PP support via self-assembly of the hydrolyzed TMC molecules (trimesic acid (TMA) molecules). The high dispersion of HSP particles was achieved in the coating solution consisted of TMA leading to smooth and superhydrophic membrane surfaces with a contact angle of >150A�. The porosity of the surface was well in control with an average pore size of ~0.2 I�m. The application of membranes was tested for membrane distillation application in direct contact membrane distillation (DCMD) configuration. The hot feed of 35 g/L aqueous sodium chloride solution, and cold deionized water as permeate. The maximum transmembrane permeate flux of 46.7 kg/m2h with >99% salt rejection was obtained at 80 A�C demonstrating the future potential application towards seawater desalination. Keywords: seawater treatment, nanocomposite membrane, membrane distillation, self-assembly

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References
Behera, D, Banthia, AK, (2007) BisGMA/TiO2 organic-inorganic hybrid nanocomposite. Polymer-plastics Technology and Engineering 26(1):10-12. DOI: 10.1080/03602550701575821
Rittigstein, P, Priestley RD, Broadbelt, LJ, Torkelson JM, (2007) Model polymer nanocomposites with known interlayer spacing provide understanding of confinement effects in real nanocomposites. Nature Materials 6(1):278-282. DOI: 10.1038/nmat1870
Hongxia W, Jian F, Tong C, Jie D, Liangti Q, Liming D, Xungai W, Tong L, (2008) One-step coating of fluoro-containing silica nanoparticles for universal generation of surface superhydrophobicity. Chemical Communications 0 (2008) 877a��879. DOI: 10.1039/B714352D