Chapter 1 Introduction

Nanomaterials:Synthesis,PropertiesandApplicationsTel:18353108833E-mail:[e-mail]boratoryWashington,DCandR.C.CammarataDepartmentofMaterialsScienceandEngineeringJohnsHopkinsUniversityBaltimore,MDReferencebooks1、曹茂盛，官长斌，《纳米材料导论》，哈工大出版社，20022、张立德，《纳米材料和纳米结构》，科学出版社，20013、K.J.克莱邦德主编，陈建峰等译，《纳米材料化学》，化学工业出版社，20044、许炳社，《纳米材料及应用技术》，化学工业出版社，20045、刘吉平，郝向阳，《纳米科学与技术》，科学出版社，20026、刘吉平，孙洪强，《碳纳米材料》，科学出版社，20047、图书馆可以检索到的所有相关书籍、综述性文献CourseFinalGradeDiscussioninclassandattendance10%Homework20%FinalExamination70%LectureHours：24hHowtostudythislesson?BelieveyourselfandyouarethebestSettleddowntostudyinearnestSkimthebookListencarefullyWritedownthenoteDoschoolworkintimePrefaceIntroduction(2)FormationofClustersandNanoparticlesfromaSupersaturatedvapor(2)ParticleSynthesisbyChemicalRoutes(2)Formationof-NanostructuresbyMechanicalAttrition(2)ProcessingofNanostructuredSol–gelMaterials(2)ConsolidationofNanocrystallineMaterialsbyCompactionandSintering(6)ChemicalProperties(4)MechanicalProperties(2)Synthesis,Structure,andPropertiesofFullerenes(2)KeywordsNanomaterialsScanningTunnelingMicroscope(STM)Zero(one,two,three)-dimensionSizeEffect-Kubotheory(1)Quantumsizeeffect(2)SmallsizeeffectSurfaceeffectCoulombblockadeandQuantumtunnelingeffectDielectricconfinementeffectIntroductionWhatareNanoandNanomaterials?★“Nano”–FromtheGreekwordfor“dwarf”andmeansfor10-9,oronebillionth.Inthiscaseitrefersto10-9meters,or1nanometer(nm).1nmisabout3atomslong.★Nanomaterials–Materialshavingacharacteristiclengthscalelessthanaboutahundrednanometers.Thislengthscalecouldbeaparticlediameter,grainsize,layerthickness,orwidthofaconductinglineonanelectronicchip.Startwithacentimeter.Nowdivideitinto10equalparts.Nowdividethatinto10equalparts.Nowdividethatinto100equalparts.Nowdividethatinto10equalparts.Finallydividethatinto100equalparts.Acentimeterisaboutthesizeofabean.Eachpartisamillimeterlong.Aboutthesizeofaflea.Eachpartis100micrometerslong.Aboutthesize(width)ofahumanhair.Eachpartisamicrometerlong.Aboutthesizeofabacterium.Eachpartisa100nanometerslong.Aboutthesizeofavirus.Eachpartisananometer.Aboutthesizeofasmallmolecule.Howsmallisananometer?(andothersmallsizes)1cm1mm100mm1mm100nm1nmWhyStudyNanomaterials?Oneistheneedtofabricatenewmaterialsonaneverfinerscaletocontinuedecreasingthecostandincreasingthespeedofinformationtransmissionandstorage.Anotheristhatnanomaterialsdisplaynovelandoftenenhancedpropertiescomparedtotraditionalmaterials,whichopensuppossibilitiesfornewtechnologicalapplications.BriefHistory1.NatureNanomaterialsarefoundinbothbiologicalandman-madestructures.Magnetotacticbacteria;Ferritin;MolluscanteethCandleash2.Scientificwork1861BritishchemistcoinedthetermColloid1930Langmuir-Blodgettmonolayerfilms1960UyedausedEMstudyindividualparticle1970magnetictape1980studyclusterscontaining100atoms1985SmalleyandKrotofoundC601991Iijimareportedcarbontubefilament1991-nanocompositedesign;nanostructureassemblysystem理查德·费曼（R.P.Feynman)(1918～1988）ANobelprizewinningphysicistwhodescribednanotechnologyinhis1960presentationThere’sPlentyofRoomattheBottom.RichardP.Feynman(1960)“Whenwegettothevery,verysmallworld…wehavealotofnewthingsthatwouldhappenthatrepresentcompletelynewopportunitiesfordesign…”Hediscussedtheadvantagesthatcouldbeprovidedbysuchcontrol.Forexample,hepointedoutthatifabitofinformationrequiresonly100atoms,thenallthebookseverwrittencouldbestoredinacubewithsides0.02inch.Whichinstrumentscanbeused?SPM-ScanningProbeMicroscopeSTM-ScanningTunnelingMicroscopeSFM-ScanningForceMicroscopeAFM-AtomicForceMicroscopeMFM-MagneticForceMicroscopeLFM-LateralForceMicroscopeEFM-ElectrostaticForceMicroscopeNSOM-Near-fieldscanningopticalmicroscopeG.BinnigH.RohrerSTMTheSTMpictureofC60AFMDonEigler–XenononNickelAnSTMcanmanipulateindividualatomsExerciseHowmanylibrariescanbestoredinacircularplatewithadiameterof2cmand0.1cmthickness?Assumption:awordrequires100atoms,radiusofFeatomis1.26×10-8cm,3×105wordsinabook,1×107booksinthelibrary.Three-dimensionNanomaterials(Zeolite)Two-dimensionfilm,superlatticeOne-dimensionnanowire,nanotubeZero-dimensionparticle,cluster★classificationaccordingtodimensionsThree-dimensionTwo-dimensionOne-dimensionOne-dimensionOne-dimensionOne-dimensioncarbonnanotubeGraphite★Basictheoryofnanoparticles1.SizeEffect-Kubotheory(1)Smallsizeeffect(2)QuantumsizeeffectTkdeWB2134VNEF31dTkB3dVFormationofazero-dimensioal(0D)quantumdotbytheformalreductionofdimensions,correlatingwiththecontinuingdiscretizationoftheenergystates.2.Surfaceeffectd(nm)S(m2g-1)atominsurfaceSurfaceenergy(J•mol-1)1006.65.9×1022010%106620%5.9×103540%280%166099%5.9×1043.CoulombblockadeandQuantumtunnelingOnekindofsingle-electrondeviceisbasedonthechangeintheCoulombicenergywhenanelectronisaddedorremovedfromaparticle.TheuseofCoulombicrepulsioniscalledCoulombblockade.CoulombicblockadeenergyblockstheflowofotherelectronsCeEC22QuantumtunnelingCeEVeC222CeVTkCeB)2(24.DielectricconfinementeffectBrusformula12222]11