A novel ultrafiltration (UF) membrane with controllable selectivity for protein separation

Anovelultrafiltration(UF)membranewithcontrollableselectivityforproteinseparationQianLi,Qiu-yanBi,Han-HanLin,Li-XiaBian,Xiao-LinWangnBeijingKeyLaboratoryofMembraneMaterialsandEngineering,DepartmentofChemicalEngineering,TsinghuaUniversity,Beijing,100084,PRChinaarticleinfoArticlehistory:Received3July2012Receivedinrevisedform3September2012Accepted4September2012Availableonline27September2012Keywords:ProteinseparationUltrafiltrationmembraneControllableselectivitySulfobetainepolymerPoly(vinylpyrrolidone)abstractAnovelultrafiltration(UF)membranewithcontrollableselectivityforproteinseparationwasobtainedbyalteringthestructureofthethicksievinglayeronthemembranesurfaceandsubsurface.Poly(vinylpyrrolidone)(PVP)wasfirstcross-linkedon/inthepoly(vinylidenefluoride)(PVDF)hollowfibermicrofiltration(MF)membranetoattractmoresulfobetaine(SB)monomeradjacenttomembraneforsubsequentgraftingpolymerizationandtheformedthicksulfobetainepolymer(PSB)layeronthemembranesurfaceandsubsurfaceactedasthesievinglayerwithenvironmentsensitivity.Afterimmersedin20mmol/LNaClsolutionat601C,thenovelUFmembranewiththesievinglayerof4.8mmshowedhighpermeatecapacitywithawaterfluxof590L/m2handagoodselectivebehaviorwithMWCOof95–110kDa.Theproteinmixture(BSAandLys)couldbeseparatedthroughthenovelUFmembraneefficientlybyisoelectricfocusingofonecomponentwithalargersize(BSA).Bymeansofthesimpleimmersioninpurewater,themembranepermeatedmostofproteinsandthedegreeoffluxdeclinereducedobviously.AfterswelledinNaClsolutionagain,themembranerestoredtheselectivityandtheproteinseparationefficiency.SuchnovelsmartUFmembraneisanattractivecandidateforthebatchseparationofproteinmixtures,expandingthemembraneapplicationinthefieldsofagro-food,biomedicineandotherbio-filtration.&2012ElsevierB.V.Allrightsreserved.1.IntroductionProteinseparationisofgreatimportancefordiversifiedagro-food,biomedicineandotherbio-filtrationapplicationsandresearches[1,2].Manytechniqueshavebeenexploredtoseparateproteinsmixturesinthebiotechindustries,includingproteinadsorben