SiO2浓度对反应体系成胶特性及SiO2凝胶粉末性能的影响

:,1963,,;:.3(97150007)33:1999-01-23SiO2SiO2333(450052)(450003),,-.SiO2,.:SiO2,;SiO2,,.;-;TQ127.2,,.,.-,[1][2],,.,,,SiO2,.11.1SiO2301,(3.34)(/SiO2).,.0.5,11pH,AgNO3Cl-.,SiO2.07()JOURNALOFZHENGZHOUUNIVERSITY312(1999,6)Vol.31No.2(1999,6)SiO2pH.SiO2,,Na+,0.580.59molL-1.1.2Hitach2600SiO2,.ASAP22000,10-6mmHg1202.,BET;t-Plot;(asinglecondensationpoint)(0.99).21tsoltgelSiO22.1SiO2,pH,.,,[3],,.[4],tsol.,pH,OH-SiO2,,SiO2Na+[5].[4],tgel.1tsoltgelSiO2.1,tsoltgelSiO2.:Na+,SiO2,SiO2Na2O,[3],,,tsol.SiO2,(2ad),,,,,tgelSiO2.2.2SiO22adSiO20.75,1.0,1.251.5molL-1.,SiO2,SiO2.SiO20.751.25molL-1,30nm.17()JOURNALOFZHENGZHOUUNIVERSITY312(1999,6)Vol.31No.2(1999,6)2SiO2(50000)SiO2(molL-1):0.75(a),1.0(b),1.25(c),1.5(d)2.3SiO23SiO2BET.,BETSiO20.75molL-11.0molL-13SiO2SiO2BET,,4SiO2SiO227SiO2SiO2,;SiO2,SiO21.25molL-1;SiO2.4SiO2SiO2.,SiO2,SiO2,.SiO21.0molL-1,10100nm,5060nm;SiO21.25molL-1,.4,SiO2,.[1]HeleyJR,JacksonD,JamesPF.FineLowDensitySilicaPowdersPreparedbySupercriticalDryingofGelsDerivedfromSiliconTetrachloride.JNon2CrystSolids,1995,186:3036[2],,,.Sol2gel.,1992,(3):4348[3]IlerRK.ColloidalComponentsinSolutionsofSodiumSilicate.In:JamesS,FalconeJ,eds.SolubleSili2cates.WashingtonDC:ACSSymposiumSeries194,1982,95114[4],,.-SiO2.,1998,29(2):131134[5]IlerRK.TheChemistryofSilica.NewYork:JohnWiley&Sons,1979.372383EffectofSiO2ConcentrationontheCharacteristicofSol2GelFormationandthePropertyofSilicaGelPowdersLiZhongjunZhaoJinan(ChemicalandEngineeringCollege,ZhengzhouUniversity)ShenXiaoqing(HenanUniversityofTraditionalChineseMedicine)AbstractUltrafinesilicagelpowderswerepreparedbymeansofsol2gelmethodfromwa2terglassusingethylacetateasalatentacidreagent.Bothoftheeffectofsilicaconcentrationinthesol2gelprocessonthecharacteristicofsilicasol2gelformationandthepropertyofsilicagelpowdersobtainedwereinvestigated.TheproductswerecharacterizedbyTEMandnitrogenad2sorption.Theresultsshowthatwithincreasingsilicaconcentration,thetimeofsilicasol2gelformationisgraduallyreduced,atthesametime,thesizeofsilicagelpowdersobtainedisin2creasedbydegrees,thetotalporevolumedecreasedmontonouslyandtheamountofporesformedbyaggregationofparticlesdiminishedramatically.Keywordssilica;sol2gelprocess;powderpreparation()37()JOURNALOFZHENGZHOUUNIVERSITY312(1999,6)Vol.31No.2(1999,6)