改性聚偏氟乙烯超滤膜的制备与性能的研究

306Vol.30No.6201012MEMBRANESCIENCEANDTECHNOLOGYDec.2010改性聚偏氟乙烯超滤膜的制备与性能的研究施柳青,卞晓锴,陆晓峰(,,201800):以接枝马来酸酐的改性聚偏氟乙烯(PVDF-g-MAH)为膜材料,采用浸没沉淀相转化方法制备超滤膜.在绘制PVDF-g-MAH-溶剂-水体系的三元相图基础上,研究并讨论铸膜液中溶剂体系聚合物浓度以及添加剂浓度配比对膜性能和结构的影响,比较了接枝前后超滤膜的亲水性和抗污染性.研究结果表明:在聚合物-溶剂二元体系发生相分离过程中,4种溶剂体系所需非溶剂(水)的量的顺序为:DMACNMPDMFDMSO;以DMAC溶剂制备的铸膜液,制得的膜表面相对致密,纯水通量小,截留率高;随着聚合物浓度的提高,膜的通量下降,截留率提高;同时SEM照片也显示了随聚合物浓度的增加,超滤膜表层趋于致密,支撑层指状孔孔径缩小,孔数增多;超滤试验结果表明,在截留率相同的前提下,用PVDF制备的超滤膜纯水通量为104.6L/(m2h),而PVDF-g-MAH制得的超滤膜纯水通量为230L/(m2h),同时对比了连续超滤BSA溶液12h后的膜通量衰减状况,两种膜的通量的衰减率分别为36%和15.4%,表明以改性材料制备的超滤膜的亲水性和抗污染性能均得到提高.:改性聚偏氟乙烯;相转化法;超滤膜;三元相图:TQ028.8:A:10078924(2010)06011206(PVDF),,,[1-3].PVDF,,,.PVDF-g-MAH,PVDF,,,,1.76~1.80,165~172.PVDF-g-MAH,.,,;;;PVDF-g-MAH;(SEM).1实验部分1.1(PVDF),PVDF-g-MAH(ARKEMA-INCDG:0.1%);PEG(Mw=10000)(PVP)N-(NMP)()(DMAC)()(DMF)()(DMSO)()(BSA,Mn=67000)...1.2();TOC-5000A(:20091112;:20100330:(08231200300);:(1968),,,,[e-mail]6:113);(Model1530VP,LEO);(Avatar-370,ThermoNicolet).1.3---,20,(),,,.1.4PVDF-g-MAH,N,N-,,.1.51.5.1,,0.2MPa10min,,(1).F=(Lm-2h-1)(1)1.5.2R(BSA,Mn=67000),,,TOC-5000A,(2)R.R=(1-)100%(2)1.5.3,0.2MPa,0.5g/L,12h,.1.5.4(JGW-360A),.1.5.5,,,.1.5.660,FTIR-ART.2结果及讨论2.1PVDFPVDF-g-MAH,1.:PVDF-g-MAH,1860cm-11790cm-1[4,5],,.1PVDFPVDF-g-MAHFig.1FTIRspectrumofPVDFandPVDF-g-MAHpowder2.2.,[6,7].PVDF-g-MAH-DMAc,PVDF-g-MAH-NMP,PVDF-g-MAH-DMF,PVDF-g-MAH-DMSO4,,,2.2PVDF-g-MAH--(20)Fig.2Ternaryphasediagramat20forPVDF-g-MAH-solventwatersystems11430-,,,.2DMSOPVDF-g-MAH-,,(),.DMACPVDF-g-MAH-,,.2,4:DMACNMPDMFDMSO.:DMSO,,,DMACNMP-,,.2.3,/,.3,PVDF-g-MAH.3PVDF-g-MAHFig.3PurewaterfluxofmembranescastfromPVDF-g-MAHsolutionsindifferentsolvents3,:DMSODMFNMPDMAC.2:PVDF-g-MAH-,PVDF-g-MAH-DMACPVDF-g-MAH-DMSO,,.,,DMAC-,.,,.Kai[8],-;,,,,.2.4,DMACPVDF-g-MAH.,.4.4Fig.4Effectofpolymerconcentrationonmembraneperformance2.55SEM,500.5SEM:DMAC,,,,,.,,,,,.5(e),,.,,/,.,,,.,,6:1155SEMFig.5CrosssectionSEMimagesofmembranesindifferentpolymerconcentration,,.,,.2.66SEM,500.6SEMFig.6CrosssectionSEMimagesofmembranesinadditivedifferentconcentration6,5,PEG,,,7,,,,,6C.,PVDF-g-MAH,PEG,PEG,,,,,,.2.7,.,,,,[9].,,3~7,,1.11630表1添加剂浓度对膜性能的影响*Table1Effectsofmembranepropertiesofadditiveconcentration/(Lm-2h-1)/%3153.595.4523094.0724088.6*0.5g/L,20,0.2MPa.:,,.,,,,,,,.,,,,.2.8PVDF-g-MAHPVDF2.8.1PVDF-g-MAHPVDF,PVDF-g-MAHPVDF,:PVDF-g-MAH,PVDF-g-MAH230L/(m2h),PVDF104.6L/(m2h).2.8.2PVDF-g-MAHPVDFPVDF-g-MAHPVDF,.0.2MPa0.5g/L,12h,.7.7,PVDF-g-MAHPVDF,,PVDF-g-MAHPVDF15.4%36%.,PVDF-g-MAHBSAPVDF.,:0.5g/L,20,0.2MPa7PVDF-g-MAHPVDFFig.7Comparisonoftheanti-pollutionofPVDF-g-MAHandPVDFultrafiltrationmembrane.2.8.3PVDF-g-MAHPVDFPVDF-g-MAHPVDF,2.PVDF-g-MAH.表2PVDF-g-MAH和PVDF超滤膜表面水接触角Table2ThecontactangleofPVDF-g-MAHandPVDFultrafiltrationmembranePVDF-g-MAHPVDF/()59653结论1)PVDFPVDF-g-MAH,1860cm-11790cm-1,PVDF.2)PVDF3-g-MAH-,():DMACNMPDMFDMSO.DMAC,-,.3)PVDF-g-MAH,;,6:117,,;,,.4),PVDF104.6L/(m2h),PVDF-g-MAH230L/(m2h),54%,BSA12h,36%15.4%,.[1]LiK,KongJF,WangDL,etal.TailormadeasymmetricPVDFhollowfibersforsolublegasremoval[J].AIChEJ,1999,45(6):1211-1219.[2]ChabotS,RoyC,ChowdhurylG,etal.Developmentofpoly(vinylidenefluoride)hollowfibermembranesforthetreamentofwater/organicvapormixtures[J].JApplPolymSci,1997,65:1263-1270.[3]JianK,PintauroPN.AsymmetricPVDFhollowfibermembranesfororganic/waterpervaporationseparation[J].JMembSci,1997,135:41-53.[4].[M].:.[5],,,.[J].,2005,18(2):335-339.[6]LauY,GueverMD,MatsuuraT.Phaseseparationinpolysulfone/solvent/waterandpolyethersulfone/solvent/watersystems[J].JMembrSci,1991,59:219-227.[7].PVBMBR[D].:,2005.[8]KaiM,IshiiK,TsugayaH,etal.Developmentofpolyethersulfoneultrafiltrationmembranes[A].MatsuuraT,SourirajanS,Eds.ReverseOsmosisandUltrafiltration,ACSSymposiumSeriesNo.281[C].Washington,DC:AmericanChemicalSociety,1985,Chap2:21-33.[9],.[M].:,1989.PreparationandperformanceofPVDF-g-MAHultrafiltrationmembranesSHILiuqing,BIANXiaokai,LUXiaofeng(ShanghaiInstituteofAppliedPhysics,ChineseAcademyofSciences,Shanghai201800,China)Abstract:PVDFgMAHultrafiltrationmembraneswerepreparedbyusingLSphaseinversiontechniques.Inthispaper,ternaryphasediagramat20forPVDFsolventwatersystemswasplotted,theeffectsofdifferentsolvents,polymerandadditivesconcentrationonthemembranestructureandperformancewerediscussed,hydrophilicityandantifoulingabilityofthePVDFgMAHmembranewerecomparedwithPVDFmembrane.Theternaryphasediagramshowedthatthewidthofthehomogeneousregionforfourdifferentsolventsreducedinthefollowingorder:DMACNMPDMFDMSO.WhenDMACwasusedassolvent,aquickmutualdiffusionbetweenthesolventandwateroccurredduringimmersionstep,whichledtoadensersurfaceofmembrane,lowerwaterfluxandhigherrejectionofBSA.Astheconcentrationofpolymerincreased,thewaterfluxofthemembranedecreasedandtherejectionincreased.TheSEMimagesalsoshowedthedensersurfaceandthesupportlayerofthePVDFgMAHmembraneasthepolymerconcentrationincreased.IntheBSArejectionofthesamepremise,UFexperimentresultshowedthatthewaterfluxofPVDFgMAHmembranewas230L/(m2h),whichwashigherthanthatofPVDFmembraneof104.6L/(m2h).Within12hoursofcontinuousruntime,althoughbothPVDFgMAHmem