静电纺丝技术PPT课件

.,1,J.Am.Chem.Soc.2014,136,1671616719,.,2,静电纺丝技术,将前驱体溶液带上高压静电，带电的聚合物液滴在电场的作用力下于毛细管的Taylor锥顶点被加速。当电场力足够大时，聚合物液滴可克服表面张力形成喷射细流。细流在喷射过程中溶剂挥发或固化，最终落在接受装置上，形成类似非织造布状的纤维毡。,.,3,纳米纤维定义：美国国家科学基金会(NSF)定义纳米纤维为至少在一维空间尺度上小于100nm的纤维。无纺布工业一般认为直径小于1m的纤维就是纳米纤维。,特点：在微观上表现为纳米结构，具有纳米材料具有的一切特性；而在宏观上表现为网毡结构，可以在重力作用下自然沉降而分离。,.,4,ACSAppl.Mater.Interfaces2011,3,369377,Nanolett2004,4,933,Nanolett2004,4,933,.,5,实验部分：,纺丝液：PVP(K-30)、TBOT(钛酸丁酯，钛源)、DIPA(偶氮二羧酸二异丙酯，发泡剂)；无水乙醇、醋酸作溶剂。,静纺,TiO2nanofibers,PVP/TBOT/DIPAfibers,煅烧,DIPA,分子式为C8H14N2O4，在160左右完全分解为气相CO2、NO2、H2O。,.,6,Fig.1(a-b)TypicalSEMimagesoftheas-spunpolymerprecursorofSampleA1underdifferentmagnifications.(c-e)TheelementmappingsofTi,OandNwithinasingleprecursorfiberunderSEM.,.,7,Fig.2(a,b)SEMimagesoftheTiO2mesoporousnanofibers.(c)TEMimageofasinglemesoporousTiO2nanofiber.(d)XRDpatternofSampleA1aftercalcination.(e)NitrogenadsorptiondesorptionisothermoftheTiO2mesoporousnanofibers.(f)Correspondingporesizedistribution.,.,8,Fig.3(a-b)SEMimagesoftheelectrospunpolymerfibersofSampleA2.(c-d)SEMimagesofthecalcinedproductsofSampleA2.(e)XRDpatternrecordedfromthecalcinedproductsSampleA2.(f)Nitrogenadsorption-desorptionisothermofthecalcinedproductsofSampleA2.,.,9,Table1.SurfacepropertiesoftheTiO2mesoporousnanofibersofSampleA1andA2aswellasP25,.,10,Fig.4(a)Hydrogenproductionphotocatalyzedbytheas-fabricatedmesoporousTiO2nanofibers,solidTiO2nanofibers,andP25underdifferentirradiationtime.(b)ResultsofreusabilityexperimentsforphotocatalyticH2generationusingthepresentthreephotocatalysts.(c)Schematicillustrationofmesoporousfiberswithenhancedphotocatalyticactivities.,.,11,Fig.5AverageH2evolutionratesoftheas-fabricatedmesoporousTiO2fibers,solidTiO2fibersandP25.,.,1