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dc.contributor.advisorPeinemann, Klaus-Viktor
dc.contributor.authorAli, Ola
dc.date.accessioned2013-06-19T07:22:38Z
dc.date.available2013-06-19T07:22:38Z
dc.date.issued2013-05
dc.identifier.doi10.25781/KAUST-25BE5
dc.identifier.urihttp://hdl.handle.net/10754/294156
dc.description.abstractRegenerated cellulose (RC) membranes are extensively used in medical and pharmaceutical separation processes due to their biocompatibility, low fouling tendency and solvent resistant properties. They typically possess ultrafiltration and microfiltration separation characteristics, but recently, there have been attempts to widen their pool of applications in nanofiltration processes. In this work, a novel method for preparing high performance composite RC membranes was developed. These membranes reveal molecular weight cut-offs (MWCO) of less than 250 daltons, which possibly put them ahead of all commercial RC membranes and in competition with high performance nanofiltration membranes. The membranes were prepared by acidic hydrolysis of dip-coated trimethylsilyl cellulose (TMSC) films. TMSC, with a degree of silylation (DS) of 2.8, was prepared from microcrystalline cellulose by reaction with hexamethyldisilazane under the homogeneous conditions of LiCl/DMAC solvent system. Effects of parameters, such as coating solution concentration and drying rates, were investigated. It was concluded that higher TMSC concentrations as well as higher solvent evaporation rates favor better MWCOs, mainly due to increase in the selective layer thickness. Successful cross-linking of prepared membranes with glyoxal solutions, in the presence of boric acid as a catalyst, resulted in MWCOs less than 250 daltons. The suitability of this crosslinking reaction for large scale productions was already proven in the manufacturing of durable-press fabrics. For us, the inexpensive raw materials as well as the low reaction times and temperatures were of interest. Moreover, the non-toxic nature of glyoxal is a key advantage in medical and pharmaceutical applications. The membranes prepared in this work are strong candidates for separation of small organic solutes from organic solvents streams in pharmaceutical industries. Their hydrophilicity, compared to typical nanofiltration membranes, offer high fouling resistance and higher fluxes in aqueous applications.
dc.language.isoen
dc.subjectCellulose
dc.subjectMembranes
dc.subjectNanofiltration
dc.subjectGlyoxal
dc.subjectCrosslinking
dc.subjectComposite
dc.titleHigh Performance Regenerated Cellulose Membranes from Trimethylsilyl Cellulose
dc.typeThesis
dc.contributor.departmentPhysical Sciences and Engineering (PSE) Division
thesis.degree.grantorKing Abdullah University of Science and Technology
dc.contributor.committeememberHilke, Roland
dc.contributor.committeememberNunes, Suzana Pereira
thesis.degree.disciplineChemical and Biological Engineering
thesis.degree.nameMaster of Science
refterms.dateFOA2014-06-12T00:00:00Z


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