Humidity sensors based on silica nanoparticle aerogel thin films

《Humidity sensors based on silica nanoparticle aerogel thin films》由会员上传分享，免费在线阅读，更多相关内容在学术论文-天天文库。

1、SensorsandActuatorsB107(2005)402410HumiditysensorsbasedonsilicananoparticleaerogelthinfilmsChien-TsungWanga,∗,Chun-LungWua,I-CherngChenb,Yi-HsiaoHuangcaDepartmentofChemicalEngineering,NationalYunlinUniversityofScienceandTechnology,123UniversityRoad,Section3,Touliu,Yunlin640,TaiwanbMaterial

2、sResearchLaboratories,IndustrialTechnologyResearchInstitute,Hsinchu310,TaiwancCenterforEnvironment,SafetyandHealthTechnology,IndustrialTechnologyResearchInstitute,Hsinchu310,TaiwanReceived24June2004;receivedinrevisedform25September2004;accepted29October2004Availableonline15December2004Abs

3、tractHumiditysensorswerefabricatedwiththinfilmsofsilicananoparticlesaerogelongold-patternedaluminasubstratesbysolgelcolloidspincoatingandsupercriticaldrying.Theaerogelsilicapossessesaverageporesizeof20.5nm,particlesizearound30nm,filmthicknesswithin142nm,andspecificsurfaceareaof866m2/g.Bothim

4、pedanceandcapacitanceresponsesofthemesoporousfilmsensorweresensitivetomoistureandoperationtemperatureat40%RHandhigher,andwithahysteresiswithin3.3%RH.Electricalresistancemarkedlydecreasedwithhumidityatlowfrequency.Porosity,surfacehydroxyls,andfilmuniformityofsilicaweredirectlyrelatedtothesen

5、sorsperformance.Theoperationstabilityandreproducibilityovertimemaketheaerogelfilmspotentiallyviableforuseinceramicsintegratedhumiditysensors.©2004ElsevierB.V.Allrightsreserved.Keywords:Humiditysensor;Aerogelfilm;Silicananoparticle;Supercriticaldrying1.Introductionofnotonlyagreatamountofsurf

6、acesilanolsitestotrappolarspeciesthroughhydrogenbondingbutalsoafastdiffusionMesoporousthinfilmsofnanostructuredsilicawithhighmotionforfreemoleculesreversiblyfromexternalenviron-porosityandsurfaceareahavebeenextensivelyinvestigatedmenttothelargesilicapores.formolecularrecognitionapplication

7、sinthefieldsofhu-Structuralpropertiesgenerallyconcludedtoaffectsen-midityandvolatileorganicchemicals.Themaintechnolog-sorperformanceincludeporegeometry(e.g.,surfacearea,icaldevelopmentistoimprovesensitivityandcapabilityofporevolume,poresize,andporeshape),overallporos