Ln1.5Sr0.5NiO4(Ln=La、Nd)聚偏氟乙烯介電復合材料中期報告

Ln1.5Sr0.5NiO4(Ln=La、Nd)聚偏氟乙烯介電復合材料中期報告Abstract:Polyvinylidenefluoride(PVDF)compositesfilledwithLn1.5Sr0.5NiO4(Ln=La,Nd)werepreparedbyblendingandcompressionmolding.Thedielectricproperties,morphology,andthermalstabilityofthecompositeswerestudied.TheresultsshowedthatthedielectricconstantanddielectriclossofthecompositesweresignificantlyenhancedduetotheadditionofLn1.5Sr0.5NiO4.ThedispersionofLn1.5Sr0.5NiO4inthePVDFmatrixwasfoundtobeuniform.ThecoexistenceoftheferroelectricphaseandtheparaelectricphasewasobservedinthePVDFmatrix.Inaddition,thethermalstabilityofthecompositeswasimprovedbyaddingLn1.5Sr0.5NiO4.Introduction:Polyvinylidenefluoride(PVDF)isapromisingdielectricmaterialduetoitshighthermalstability,excellentchemicalresistance,andgooddielectricproperties.Ithasbeenwidelyusedinthefieldofelectronicmaterials,suchasinsulationmaterials,capacitors,andpiezoelectricmaterials.Ln1.5Sr0.5NiO4(Ln=La,Nd)isaperovskite-typeoxidewithgoodelectricalconductivity,whichmakesitapromisingcandidateasafillerforPVDFcomposites.Inaddition,theadditionofLn1.5Sr0.5NiO4canalsoimprovethethermalstabilityofthecomposites.Inthisstudy,PVDFcompositesfilledwithLn1.5Sr0.5NiO4werepreparedbyblendingandcompressionmolding.Thedielectricproperties,morphology,andthermalstabilityofthecompositeswereinvestigated.Experimental:PVDFpowderwasobtainedfromSolvaySolexis.Ln1.5Sr0.5NiO4powderwassynthesizedbysolid-statereaction.ThePVDF/Ln1.5Sr0.5NiO4compositeswerepreparedbyblendingPVDFandLn1.5Sr0.5NiO4powdersatdifferentweightratios(90/10,80/20,70/30)usingaballmillfor4hours.Theblendedpowderswerethencompressionmoldedat200°Cfor10minutesunderapressureof10MPa.Thedielectricpropertiesofthecompositesweremeasuredusingaprecisionimpedanceanalyzer(AgilentE4980A)overafrequencyrangeof100Hzto1MHz.Themorphologyofthecompositeswasobservedbyscanningelectronmicroscopy(SEM,HitachiS-4800).Thethermalstabilityofthecompositeswasevaluatedbythermogravimetricanalysis(TGA,PerkinElmerTGA4000).ResultsandDiscussion:Dielectricproperties:ThedielectricconstantanddielectriclossofthePVDFcompositesfilledwithLn1.5Sr0.5NiO4areshowninFigure1.ThedielectricconstantofthecompositeswassignificantlyenhancedduetotheadditionofLn1.5Sr0.5NiO4,andthemaximumvaluewasreachedat70/30weightratio.ThedielectriclossofthecompositesalsoincreasedwiththeincreaseofLn1.5Sr0.5NiO4content.Themaximumdielectriclosswasobtainedattheweightratioof80/20.TheincreaseindielectricconstantanddielectriclosscanbeattributedtotheadditionofconductiveLn1.5Sr0.5NiO4,whichcanformconductivepathwaysinthePVDFmatrix.Morphology:SEMimagesofthePVDFcompositesfilledwithLn1.5Sr0.5NiO4areshowninFigure2.ItcanbeseenthatthedispersionofLn1.5Sr0.5NiO4inthePVDFmatrixwasuniform,andnoagglomerationwasobserved.TheuniformdispersionofLn1.5Sr0.5NiO4canimprovetheinterfacialinteractionbetweenthefillerandthematrix,andenhancetheconductivepathwaysinthecomposites.Thermalstability:TheTGAcurvesofthePVDFcompositesfilledwithLn1.5Sr0.5NiO4areshowninFigure3.ItcanbeseenthatthethermalstabilityofthecompositeswasimprovedbyaddingLn1.5Sr0.5NiO4.ThethermaldegradationtemperatureofthecompositesincreasedwiththeincreaseofLn1.5Sr0.5NiO4content.TheimprovementinthermalstabilitycanbeattributedtothegoodthermalstabilityofLn1.5Sr0.5NiO4.Conclusion:PVDFcompositesfilledwithLn1.5Sr0.5NiO4werepreparedbyblendingandcompressionmolding.TheadditionofLn1.5Sr0.5NiO4significantlyenhancedthedielectricpropertiesofthecomposites.ThedispersionofLn1.5Sr0.5NiO4inthePVDFmatrixwasfo