学科分类
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6 个结果
  • 简介:TheinfluenceofNa2SO4ontheformationofZnOwhiskerswasinvestigatedinthispaper.ZnOwhiskerswithaspectratiosofupto50weresynthesizedbydissolvingε-Zn(OH)2precursorinNaOH/Na2SO4solutionatroomtemperature,followedbyagingoftheresultingsolutionat140℃for6h.Fouriertransforminfraredspectroscopy,Ramanspectroscopy,andX-rayphotoelectronspectroscopyanalysesrevealedthatSO42-ionswereprimarilyadsorbedonthe(100)planeoftheZnOwhiskersviaanouter-spherecomplexconfiguration(O-H…O),therebypromotingtheone-dimensionalgrowthofZnOwhiskersalongthec-axis.

  • 标签: 氧化锌晶须 硫酸钠溶液 水热合成 X射线光电子能谱分析 傅立叶变换红外光谱 ZnO晶须
  • 简介:PureAl2O3-2SiO2powderswerepreparedbysol-gelandcoprecipitationmethods,andtheiralkaliactivationreactivitieswerecompared.Thealkali-activationreactivityofthepowderpreparedbythesol-gelmethodwashigherthanthatofthepowderpreparedbythecoprecipitationmethod.Thepowderswereinvestigatedby27AIand29Simagic-anglespinningnuclearmagneticresonancespectroscopy(MASNMR)tounderstandtherelationshipbetweentheirstructureandalkali-activationreactivity.The27AlMASNMRdatashowedthatthefive-coordinateAIcontentofthepowderpreparedbythesol-gelmethodwashigherthanthatofthepowderpreparedbycoprecipitation.Thehighercontentoffive-coordinateAlcorrespondedtohigheralkali-activationreactivity.The29SiMASNMRdatashowedthatforthepowderpreparedbythesol-gelmethod,siliconwasreplacedbyaluminumatsecondarycoordinationsitesofthecentralSiatomsduringcalcination.However,forthepowderpreparedbysingle-batchcoprecipitation,themainchangewasfromalowdegreeofpolycondensationtoahighdegreeofpolycondensation.

  • 标签: 魔角旋转核磁共振 活化反应 固体碱 核磁共振光谱 粉末 化学合成
  • 简介:Commerciallyavailablelatticescontainvariouskindsofmorphologicalimperfectionswhichresultingreatdegradationinlattices’mechanicalproperties,therefore,toobtainimperfectioninsensitivelatticestructureisobviouslyapracticalresearchsubject.Hierarchicalstructurematerialswerefoundtobeaclassofpromisinganti-defectmaterials.Thispaperbuildshierarchicallatticebyaddingsoftadhesiontolattice’scelledgesandnumericalresultsshowthatitsimperfectionsensitivitytomissingbarsisminorcomparedwiththeclassiclattice.Softadhesionwithappropriatepropertiesreinforcecelledge’sbendingstiffnessandthusreducethebendingdeformationinlatticecausedbymissingbarsdefect,whichisconfirmedbystatisticalanalysisofnormalizednodedisplacementsofimperfectlatticesunderhydrostaticcompressionandshearloads.

  • 标签: 敏感性 缺陷 晶格结构 二维 结构材料 力学性质
  • 简介:Thereisaneedtostandardizemethodsassociatedwiththedispersionofnanomaterialsinnano(eco)toxicologicalinvestigations.Thefirststeptowardthisgoalistounderstandthedegreeofvariabilitythatexistsinnanomaterialdispersionspreparedbyusingdifferentprotocols.Usingtwocasestudies,thedegreeofvariabilityinTiO2nanomaterialdispersionswasassessedbydifferentialcentrifugalsedimentation(DCS)methods.Casestudy1addressesthevariabilitythatarisesfromvariationswithinoneprotocol,investigatingtheeffectsofdispersionaging,sonicationexposuretime,sonicationinthepresence/absenceofanicebath,materialsubsampling,particleconcentrationandhavingapre-wettingstep.Casestudy2addressesthevariabilitybetweenfourdifferentprotocolsdevelopedthroughpastresearchactivitiesandprojects.Theresultsindicatethatthereisalargedegreeofvariability(relativestandarddeviation(RSD)ofmeanparticlediameter=26%)inthedispersionofTiO2nanomaterialsbetweenthefourdifferentprotocolsstudiedandthatseveralstepsinadispersionprotocolarepotentialsourcesofvariation,withfinalparticleconcentrationbeingthemostsignificant.Theimplicationofthisstudyisclear:forthepurposeofdatacomparability,thereisaneedtoprovidetheexactdetailsofallstepsinvolvedinadispersionprotocol.

  • 标签: 分散体 协议 粒度分布 TIO2 纳米材料 相对标准偏差
  • 简介:Afacilemethodforthesynthesisofsilver-silica(Ag-SiO2)Janusparticleswithfunctionalitiessuitablefortextileapplicationsisreported.SilicananoparticlespreparedbytheStobermethodwerefunctionalizedwithepoxy,amine,andthiolgroups,whichwereconfirmedbyFouriertransforminfraredanalysis.ThefunctionalizedsilicananoparticleswereusedtoproducePickeringemulsions,andtheexposedsurfacewasusedfortheattachmentofsilvernanoparticles(AgNPs)viathelow-temperaturechemicalreductionmethod.ThemorphologyandstructureoftheAg-SiO2Janusparticleswerecharacterizedbyscanningelectronmicroscopy,scanningtransmissionelectronmicroscopy,high-resolutiontransmissionelectronmicroscopy,energy-dispersiveX-rayanalysis,andUV-visspectroscopy.Becauseoftheirspecificfunctionalities,theseAg-SiO2Janusparticlesareproposedforapplicationsontextilesubstrates,astheycanovercomeseveraldrawbacksofdirectapplicationofAgNPsontextiles,suchasleaching,agglomeration,andinstabilityduringstorage.

  • 标签: 硅纳米颗粒 纺织应用 原位合成 环氧树脂 纺织品 二氧化硅纳米粒子
  • 简介:Nanostructuredtransitionmetaloxidesarepromisingalternativeanodesforlithiumionbatteries.Li-ionstorageperformanceisexpectedtoimproveifhighpackingdensityenergyparticlesareavailable.Herein,Mn2O3microsphereswithaca.18μmdiameterandatappeddensityof1.33g/cm3weresynthesizedbyafacilesolvothermal-thermalcoversionroute.SphericalMnCO3precursorswereobtainedthroughsolvothermaltreatmentandtheydecomposedandconvertedintoMn2O3microspheresatanannealingtemperatureof700C.TheMn2O3microspheresconsistedofMn2O3nanoparticleswithanaverage40nmdiameter.TheseporousMn2O3microspheresallowgoodelectrolytepenetrationandprovideanionbufferreservoirtoensureaconstantelectrolytesupply.TheMn2O3microsphereshavereversiblecapacitiesof590and320mAh/gat50and400mA/g,respectively.Wethusreportanefficientrouteforthefabricationofenergyparticlesforadvancedenergystorage.

  • 标签: MN2O3 锂离子电池 溶剂热合成 负极材料 微球 过渡金属氧化物