High Performance Regenerated Cellulose Membranes from Trimethylsilyl Cellulose

Handle URI:
http://hdl.handle.net/10754/294156
Title:
High Performance Regenerated Cellulose Membranes from Trimethylsilyl Cellulose
Authors:
Ali, Ola
Abstract:
Regenerated 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.
Advisors:
Peinemann, Klaus-Viktor
Committee Member:
Hilke, Roland; Nunes, Suzana Pereira ( 0000-0002-3669-138X )
KAUST Department:
Physical Sciences and Engineering (PSE) Division
Program:
Chemical and Biological Engineering
Issue Date:
May-2013
Type:
Thesis
Appears in Collections:
Theses; Physical Sciences and Engineering (PSE) Division; Chemical and Biological Engineering Program

Full metadata record

DC FieldValue Language
dc.contributor.advisorPeinemann, Klaus-Viktoren
dc.contributor.authorAli, Olaen
dc.date.accessioned2013-06-19T07:22:38Z-
dc.date.available2013-06-19T07:22:38Z-
dc.date.issued2013-05en
dc.identifier.urihttp://hdl.handle.net/10754/294156en
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.en
dc.language.isoenen
dc.subjectCelluloseen
dc.subjectMembranesen
dc.subjectNanofiltrationen
dc.subjectGlyoxalen
dc.subjectCrosslinkingen
dc.subjectCompositeen
dc.titleHigh Performance Regenerated Cellulose Membranes from Trimethylsilyl Celluloseen
dc.typeThesisen
dc.contributor.departmentPhysical Sciences and Engineering (PSE) Divisionen
thesis.degree.grantorKing Abdullah University of Science and Technologyen_GB
dc.contributor.committeememberHilke, Rolanden
dc.contributor.committeememberNunes, Suzana Pereiraen
thesis.degree.disciplineChemical and Biological Engineeringen
thesis.degree.nameMaster of Scienceen
dc.person.id118398en
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