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22Vol.2No.5200210TheChineseJournalofProcessEngineeringOct.2002Ti(OC4H9)4(201800)-[Ti(OC4H9)4]()(AcAc)(AgNO3)Ti(OC4H9)4−C2H5OH−H2OAgNO3.Ti(OC4H9)4TB43;TB321A1009−606X(2002)05−0435−041.7.1%∼7.9%[1].TiO2..−[2−4].−2070.−..−..[5−7].−..pH(AcAc).21[Ti(OC4H9)4](C2H5OH)(CH3COCH2COCH2).5:20:130minH2OTi(OC4H9)4H2O1:2.PHS−3TC(0.01)pH.30min40oCNDJ−1.1Table1Chemicalreagentsusedinthiswork2002−02−192002−06−14(1974−).ReagentMolecularformulaManufacturerPurityContentAbsoluteethanolCH3CH2OHShanghaiNo.1ZhenxingChemicalCo.CP≥99.7%TitianiumtetrabutoxideTi(OC4H9)4ShanghaiNo.3ReagentsCo.CP≥98.0%SilvernitrateAgNO3ShanghaiChemicalReagentsCo.,ChinaMedicineGroupAR≥99.8%AcetylacetoneCH3COCH2COCH3ShanghaichemicalreagentsCo.,ChinaMedicineGroupCP≥98.5%436233.1-pH.pH.1(a)1(b).−2(1).H+H2OH→++OH−(2)Ti−OC4H9−OC4H9.1(a)pH=7.003.5hpH=3.89500h.H3O+−OR..110100204060800(b)pH7.007.088.36η(×103mPa·s)t(h)110100020406080(a)pH3.984.466.657.00η(×102mPa·s)t(h)1Fig.1Viscosityevolutionunderacid-catalysisandbase-catalysisconditionsat40oC([AcAc]:[Ti(OC4H9)4]=1:5)1(b).OH−.OH−Ti4+OH−OR−.−OR4−OR−OH.pH7.007.083.8h4h.pH8.36175h.3.22.OH−Ti(OC4H9)4OH−.Ti(OC4H9)4.2pH6.36.AcAcR=[AcAc]:[Ti]=0.55Ti(OC4H9)443703006009001200036912R0.30.40.5η(×103mPa·s)t(h)1200hAcAc.AcAcTi(OC4H9)4pHTiO2..AcAc.AcAcR=0.2..2Fig.2Viscosityevolutioninthesystemswithdifferentacetylacetonecontentsat40oC3.33(a)3(b)AgNO3[AgNO3]:[Ti(OC4H9)4]=1:10.3(a)AgNO3500hAgNO3750h..3(b)150hAgNO3AgNO3750h.3(a)3(b)AgNO3.HOU[8]AgNO3.02004006008000481216(b)pHAgNO38.35with8.35withoutη(×103mPa·s)t(h)02004006008000481216(a)pHAgNO34.46with4.33withoutη(×103mPa·s)t(h)3AgNO3Fig.3EffectofAgNO3ontheviscosityevolutioninacid-catalyzedandbase-catalysedsystemsat40oC([AcAc]:[Ti(OC4H9)4]=1:5)3.4[AgNO3]/[Ti(OC4H9)4]=1:10[H2O]/[Ti]=2:1pH=2.6AcAc1500mPa⋅s.K92000r/min30s.0.5h200oC0.5h625oC1h..2.AcAcTiO2[AcAc]/[Ti]=0.2.43822AcAcTiO2Table2ThestateofTiO2thinfilmsatdifferentcontentsofacetylacetoneSample[AcAc]/[Ti][H2O]/[Ti][Ag]/[Ti]pHStateofTiO2thinfilms1020.12.61Seriouslycracked20.0520.12.55Cracked30.1020.12.63Slightlycracked40.1520.12.60Almostnocrack50.2020.12.71Nocrack4(1)Ti(OC4H9)4−C2H5OH−H2OpHpH=73.8hpH=3.89500h.pHpH=8.36175h.(2)pH=6.36[AcAc]/[Ti(OC4H9)4]=3:10100h5:101200h.(3)AgNO3700h..Ti(OC4H9)4−C2H5OH−H2OpH.[1]OreganB,GratzalM.ALow-cost,High-efficiencySolarCellBasedonDye-sensitizedColloidalTiO2Films[J].Nature,1991,353(24):7.[2].TiO2[J].,1996,45(6):1239−1243.[3]SluneckeJ,KosecM,HolcJ,etal.MorphologyandCrystallizationBehaviorofSol−GelDerivedTitania[J].J.Am.Ceram.Soc.,1998,81(5):1121−1124.[4]PedrazaF,VazquesA.ObtentionofTiO2RutileatRoomTemperatureThroughDirectOxidationofTiCl3[J].J.Phys.Chem.Solids,1999,60(4):445−448.[5]SlepynLI.DynamicFactorinImpact,PhaseTransitionandFracture[J].J.Mech.Phys.Solids,2000,48(5):927−960.[6]EdwardJAPOPE,MackenzieJD.TheoreticalModelingoftheStructuralEvolutionofGels[J].J.Non-Cryst.Solids,1988,101:198−212.[7]RomanoSD,KurlatDH.RheologicalMeasurementsinTitaniaGelsSynthesizedfromReverseMicells[J].Chem.Phys.Lett.,2000,323(9):93−97.[8]HOULS,LUOWW.PreparationandPropertiesofMutlifunctionalCoatingsforCar-glassbytheSol−GelProcess[A].ThinSolidFilms(CoatingonGlass)[C].1999.132−134.ViscosityControlintheHydrolysisProcessofTi(OC4H9)4forPreparationofTiO2ThinFilmsZENGXian-cheng,HOULi-song(ShanghaiInstituteofOpticsandFineMechanics,ChineseAcademyofSciences,Shanghai201800,China)Abstract:HydrolysischaracteristicsofTi(OC4H9)4intheTi(OC4H9)4−C2H5OH−H2OsystemwereinvestigatedforthepreparationofTiO2thinfilmsviathesol−gelprocess.Experimentalresultsaregivenabouttheeffectsofthesystemacidity(orbasicity)andtheadditionofacetylacetoneandAgNO3ontheviscosityandgelationtimeofthesystem.ItwasfoundthattheintroductionofAgNO3cangreatlyimprovethestabilityofthesolsandprolongthegelationtimebesidesadjustingpHandaddingacetylacetone.Keywords:Ti(OC4H9)4;hydrolysis;viscosity;TiO2thinfilms