预览加载中，请您耐心等待几秒...

pH敏感水凝胶的制备及其吸附性能研究.docx

预览
1/4
2/4
3/4
4/4

在线预览结束，喜欢就下载吧，查找使用更方便

下载提示 文本预览

如果您无法下载资料，请参考说明：

1、部分资料下载需要金币，请确保您的账户上有足够的金币

2、已购买过的文档，再次下载不重复扣费

3、资料包下载后请先用软件解压，在使用对应软件打开

pH敏感水凝胶的制备及其吸附性能研究 Abstract pH-sensitivehydrogelswithdifferentdegreesofcross-linkingwerepreparedbyfree-radicalpolymerizationusingN-isopropylacrylamide,acrylicacid,andN,N'-methylenebisacrylamideasmonomers.ThepreparedhydrogelswerecharacterizedbyFouriertransforminfraredspectroscopy(FTIR),scanningelectronmicroscopy(SEM),andthermogravimetricanalysis(TGA).ThepH-dependentadsorptionpropertiesofthesehydrogelswerestudiedbybatchadsorptionexperimentsusingmethyleneblueasamodeldye.Resultsshowedthatthehydrogelshadhighswellingratioandadsorptioncapacityinacidicconditionsduetotheprotonationofcarboxylgroups,andlowswellingratioandadsorptioncapacityinbasicconditionsduetotheionizationofcarboxylgroups.Moreover,thehydrogelswithhigherdegreesofcross-linkingexhibitedhigheradsorptioncapacityduetotheirstrongerstructuralintegrity. Keywords:pH-sensitivehydrogel,cross-linking,adsorption,methyleneblue Introduction Polymerichydrogelshaveattractedmuchattentioninvariousfieldsduetotheiruniquepropertiessuchashighwatercontentandbiocompatibility(1).ThepH-sensitivehydrogels,inparticular,havebeeninvestigatedextensivelyfortheirpotentialapplicationsindrugdelivery,biosensors,andenvironmentalremediation(2).ApH-sensitivehydrogelcanbedesignedtorespondtothechangesinpHbyswellingorshrinkingduetotheionizationorprotonationoffunctionalgroupsinitspolymericnetwork(3).Thispropertymakesthemusefulfortargeteddrugreleaseoradsorptionofpollutantsfromwater. ThepreparationofpH-sensitivehydrogelscanbeachievedbydifferentmethodssuchasfree-radicalpolymerization,inverseemulsionpolymerization,andpolycondensation(4).Amongthesemethods,free-radicalpolymerizationisthemostcommonlyusedmethodduetoitssimplicity,lowcost,andversatility.ThepreparationofpH-sensitivehydrogelsbyfree-radicalpolymerizationcanbeachievedbyusingdifferentmonomerssuchasacrylicacid,N-isopropylacrylamide(NIPAM),andvinylpyridineinthepresenceofacross-linkingagent(5). Inthisstudy,pH-sensitivehydrogelswerepreparedbyfree-radicalpolymerizationofNIPAMandacrylicacidinthepresenceofac