《导电高分子优秀PPT.ppt》由会员分享，可在线阅读，更多相关《导电高分子优秀PPT.ppt（85页珍藏版）》请在taowenge.com淘文阁网|工程机械CAD图纸|机械工程制图|CAD装配图下载|SolidWorks_CaTia_CAD_UG_PROE_设计图分享下载上搜索。
1、导电高分子你现在浏览的是第一页，共85页Introduction你现在浏览的是第二页，共85页Polymerswerethoughtofaselectrialinsulatorsuntilthediscoverythatiodine-dopedpolyacetylene(聚乙炔)exhibitedelectricalconductivitymanyordersofmagnitudehigherthanneutralpolyacetylene.ThisdiscoverywaspublishedbyShirakawa,H.,Louis,E.,MacDiarmid,A.,Heeger,A.,(197
2、7).Asaresultofthispioneeringwork,theyreceivedthe2000NobelPrizeinChemistry.Introduction你现在浏览的是第三页，共85页Nobel Prize in Chemistry 2000“For the discovery and development of conductive polymers”G.MacDiarmid H.Shirakawa J.Heeger你现在浏览的是第四页，共85页黑格（黑格（Alan J.Alan J.Heeger,1936Heeger,1936 ）美美国国加利福尼亚大学的加利福尼亚大学的
3、著名物理学家，著名物理学家，20002000年年1010月月1010日，因对日，因对导电聚合物的发现导电聚合物的发现和发展而获得诺贝和发展而获得诺贝尔化学奖。尔化学奖。Introduction你现在浏览的是第五页，共85页麦克迪尔米德（麦克迪尔米德（Alan Alan G.MacDiarmidG.MacDiarmid，19371937 ）美国美国宾夕法尼亚大学宾夕法尼亚大学的的著名化学家，著名化学家，20002000年年1010月月1010日，日，因对导电聚合物的因对导电聚合物的发现和发展而获得发现和发展而获得诺贝尔化学奖。诺贝尔化学奖。Introduction你现在浏览的是第六页，共85页白
4、川英树白川英树(Hideki(Hideki ShirakawaShirakawa，19361936 )日本筑波大学的著名日本筑波大学的著名化学家，化学家，20002000年年1010月月1010日，因对导电日，因对导电聚合物的发现和发聚合物的发现和发展而获得诺贝尔化展而获得诺贝尔化学奖。学奖。Introduction你现在浏览的是第七页，共85页ConductivityIntroduction你现在浏览的是第八页，共85页Thediscoveryofconductivepolymersisuniqueinitsaccomplishmentasapossiblesubstitute(替代物替代物
5、)formetallicconductorsandsemiconductors.Scientistsfrommanydisciplinesarenowcombiningexpertise(专门技术)tostudyorganicsolidsthatexhibitremarkableconductingproperties.Alargenumberoforganiccompounds,whicheffectivelytransportchargeareroughlydividedintothreegroupsi.e.chargetransfercomplexes/ionradical(基基)sal
6、ts,organometallicspeciesandconjugatedorganicpolymers.Introduction你现在浏览的是第九页，共85页Electronicallyconductingpolymersdifferfromallthefamiliarinorganiccrystallinesemiconductorsintwoimportantfeaturesthatpolymersaremolecularinnatureandlacklongrangeorder.Akeyrequirementforapolymertobecomeintrinsically(本征本征)e
7、lectricallyconductingisthatthereshouldbeanoverlapofmolecularorbitalstoallowtheformationofdelocalized(离域离域)molecularwavefunction.Besidesthis,molecularorbitalsmustbepartiallyfilledsothatthereisafreemovementofelectronsthroughoutthelattice.Introduction你现在浏览的是第十页，共85页Conductingpolymerscontain-electronbac
8、kboneresponsiblefor(是的原因)theirunusualelectronicpropertiessuchaselectricalconductivity,lowenergyopticaltransitions,lowionizationpotentialandhighelectronaffinity.Thisextended(延长延长)-conjugatedsystemoftheconductingpolymershavesingleanddoublebondsalternatingalongthepolymerchain.Thehighervaluesoftheelectr
9、icalconductivityobtainedinsuchorganicpolymershaveledtothenamesyntheticmetals.Introduction你现在浏览的是第十一页，共85页IntroductionThedevelopmentofpolymerswithconductivitiesequaltosemiconductorsandmetalshavebeenpresentedinTable1andtheircorrespondingstructuresareshowninFig.1.你现在浏览的是第十二页，共85页Introductionisothianaph
10、thene:异硫茚；异硫茚；azulene:甘菊蓝；甘菊蓝；furan:呋喃呋喃你现在浏览的是第十三页，共85页IntroductionPoly-acetylenePolypyrrolePolythiophenePolyanilinePoly-p-phenylenePoly-phenylenevinylenePoly-p-phenylenesulphidePoly-iso-thianaphthene你现在浏览的是第十四页，共85页Historical background of electronically conducting polymers你现在浏览的是第十五页，共85页Historic
11、al background of electronically conducting polymersResearchonconductingpolymersintensified(增强)soonafterthediscoveryofpoly(sulphurnitride)(SN)xin1975whichbecomessuperconductingatlowtemperatures(Greeneetal.,1975).Although,conductingpolymercomplexesintheformoftetracyano(四氰基)andtetraoxalato-platinates(四
12、草酸铂酸盐),theKrogmansaltschargetransfercomplexeshadbeenknownearlier,thesignificanceliesintherediscoveryofPAin1977(initiallydiscoveredbyShirakawaetal.,1977usingaZieglerNattatypepolymerizationcatalyst)byMacDiarmidandHeeger,UniversityofPennsylvania(宾夕法尼亚).重视你现在浏览的是第十六页，共85页Theywereabletoenhancetheelectric
13、alconductivityofPA(109Scm1)byseveralordersi.e.105Scm1bysimpledopingwithoxidizingagentse.g.I2,AsF5,NOPF6(p-doping)orreducingagents(n-doping)e.g.sodiumnapthalide(萘钠).Thishasgeneratedrenewedinterestofthescientificcommunitytowardsthestudyanddiscoveryofnewconductingpolymericsystems.Historical background
14、of electronically conducting polymers你现在浏览的是第十七页，共85页Poly-paraphenylene(对苯基)wassynthesizedbyIvoryetal.(1979).Itformshighlyconductingchargetransfercomplexeswithbothnandptypedopants.DopingwithAsF5increasesitsconductivitytoitsvaluesfrom105to500Scm1.Theoreticalmodelsandelectronspinresonancemeasurementsi
15、ndicatethatthechargetransportinPPPisapolaron(极化子)/bipolaron.PPS(聚苯硫醚)wasthefirstnon-rigid,butnotfullycarbonbackbonelinkedconductingpolymer.Itsdiscoverywasparticularlyexciting,sinceitspropertyofsolutionprocessabilityopenedthedoorforpotentiallyobtainingcommerciallyviableconductingplastics(Raboltetal.,
16、1980).Historical background of electronically conducting polymers你现在浏览的是第十八页，共85页Amongstpolyheterocyclines(聚杂环聚杂环),polypyrrole(PPY)hasbeeninvestigatedthemost.TheelectrochemicaloxidationofpyrroleinaqueousH2SO4canbecarriedoutonplatinumelectrode.TheproductisaconductingpolymerknownasPyrroleBlackKanazawa
17、etal.(1979)producedcoherentfilmsofPPYwithaconductivityof100Scm1andexhibitedexcellentairstability.Butthemainhindrance(障碍)ofitsprocessabilityisinitsinsolubilityinanyorganicsolvents.Historical background of electronically conducting polymers你现在浏览的是第十九页，共85页PTH(聚噻吩)showsremarkablestabilityofbothoxidized
18、(p-doped)conductingformanditsneutral(undoped)insulatingforminbothairandwater.Itshowshighdopinglevelupto50%whichmaybeattributedtoitspartiallycrystallinenaturethathasbeenconfirmedbyX-rayphotoelectronspectroscopystudies.Manyotherconductingpolymerssuchaspolyfuran(聚呋喃聚呋喃),polyindole(聚聚吲哚吲哚),polycarbazole
19、(聚咔唑聚咔唑),polyanilineetc.havealsobeensynthesized.StructuresofsometypicalconductingpolymershavebeenshowninFig.1.Historical background of electronically conducting polymers你现在浏览的是第二十页，共85页Synthesis of conducting polymers你现在浏览的是第二十一页，共85页Thereisnosingularmethodforsynthesisingpolymersthatcanbetransformed
20、intoconductivepolymers,theincorporationofextended(延长延长)-electronconjugation(共轭共轭)isofforemostimportance.Conductivepolymersexceptionomeric(离子交联的)polymersmaybesynthesisedusingstandardmethodsofpolymerisationincludingconventionalaswellasspecificrouteswhichincludeWitting(维狄希),Horner(霍纳)andGrignard(格林尼亚)r
21、eactions,polycondensationprocessesandmetalcatalysedpolymerisationtechniques.Oxidativecoupling(偶合)withoxidisingLewisacidcatalystsgenerallyleadstopolymerswitharomaticorheterocyclicbuildingblocks(构件构件).Synthesis of conducting polymers你现在浏览的是第二十二页，共85页Conductivepolymersmaybesynthesisedbyanyoneofthefollo
22、wingtechniques:1.Chemicalpolymerisation2.Electrochemicalpolymerisation3.Photochemicalpolymerisation4.Metathesis(复分解)polymerisation5.Concentratedemulsion(浓乳液浓乳液)polymerisation6.Inclusion(夹杂)polymerisation7.Solid-statepolymerisation8.Plasma(等离子体)polymerisation9.Pyrolysis(高温分解)10.Solubleprecursor(前体)po
23、lymerpreparationSynthesis of conducting polymers你现在浏览的是第二十三页，共85页Amongalltheabovecategories,chemicalpolymerisationisthemostusefulmethodforpreparinglargeamountsofconductivepolymers,sinceitisperformedwithoutelectrodes.Chemicalpolymerisation(oxidativecoupling)isfollowedbytheoxidationofmonomerstoacation
24、(阳离子)radicalandtheircouplingtoformdicationsandtherepetition(重复)ofthisprocessgeneratesapolymer.Alltheclassesofconjugatedpolymersmaybesynthesisedbythistechnique.Synthesis of conducting polymers你现在浏览的是第二十四页，共85页Electrochemicalpolymerisationisnormallycarriedoutinasingle-ordual-compartment(隔间隔间)cellbyado
25、ptingastandardthree-electrodeconfigurationinasupportingelectrolyte,bothdissolvedinanappropriate(适当的适当的)solvent.Electrochemicalpolymerisationcanbecarriedoutpotentiometricallybyusingasuitablepowersupply(potentiogalvanostat).Synthesis of conducting polymers你现在浏览的是第二十五页，共85页Generally,potentiostaticcondi
26、tionsarerecommendedtoobtainthinfilms,whilegalvanostaticconditionsarerecommendedtoobtainthickfilms.Theelectrochemicaltechniquehasreceivedwiderattentionbothbecauseofthesimplicityandtheaddedadvantageofobtainingaconductivepolymerbeingsimultaneouslydoped.Besidesthis,awiderchoiceofcationsandanionsforuseas
27、“dopantions”isavailableintheelectrochemicalpolymerisationprocess.Free-standing(自由选定自由选定)aswellasself-supportingconductivepolymerfilmsofdesiredthicknessorgeometrycanbeobtained.Synthesis of conducting polymers你现在浏览的是第二十六页，共85页Usingthisnoveltechnique,avarietyofconductivepolymerslikepolypyrrole,polythio
28、phene,polyaniline,polyphenyleneoxidepyrroleandpolyaniline/polymericacidcompositehavebeengenerated.Pyrroleinaqueousacetontrilesolventcontainingtetraethylammoniumtetrafluoroboratewaselectropolymerisedinatwo-electrodeelectrochemicalcell.PolypyrrolecontainingtheBF4-ion(dopant)wasobtainedasafilmdeposited
29、ontheplatinumelectrodesurface.Synthesis of conducting polymers你现在浏览的是第二十七页，共85页Thismethodhasalsobeenusedtopolymericacetylene(乙炔乙炔).Inanelectrolyticcell,consistingofPtascathodeandaNistripasanode,acetylenegasispassedoverasolutioncomprisingNiBr2dissolvedinCH3CN.Onapplicationofvoltagevaryingfrom5to40Vfo
30、rabout50min.polyacetylenefilmscanbeeasilygrownonaPtelectrode.Thedegreeofdopingdependsonthedopantconcentration,voltageappliedandtheamountofchargepassed.Synthesis of conducting polymers你现在浏览的是第二十八页，共85页Synthesis of conducting polymers你现在浏览的是第二十九页，共85页Photochemicalpolymerisationtakesplaceinthepresenceo
31、fsunlight.Thistechniqueutilisesphotonstoinitiateapolymerisationreactioninthepresenceofphotosensitisers.Recently,pyrrolehasbeenphotopolymerisedusingaruthenium(II)complexasphotosensitiser.Underphotoirradiation,Ru(II)isoxidisedtoRu(III)andthepolymerisationisinitiatedbyaone-electrontransferoxidationproc
32、ess.Polypyrrole(PPy)filmsmaybeobtainedbyphotosensitisedpolymerisationofbenzo(C)thiophene(苯并噻吩苯并噻吩)hasbeencarriedoutinacetonitrileusingCCl4andtetrabutylammoniumbromide.Synthesis of conducting polymers你现在浏览的是第三十页，共85页Plasma(等离子体等离子体)polymerisationisatechniqueforpreparingultrathinuniformlayers(500-100)
33、thatstronglyadheretoanappropriatesubstrate.Electricglowdischargeisusedtocreatelow-temperature“cold”plasma.Theadvantageofthistechniqueisthatiteliminatesvariousstepsneededfortheconventionalcoatingprocess.Synthesis of conducting polymers你现在浏览的是第三十一页，共85页Metathesis(复分解)polymerisationisunique,differingfr
34、omallotherpolymerisationsinthatallthedoublebondsinthemonomerremaininthepolymer.Itwasanaturaloutgrowth(发展)ofZiegler-Nattapolymerisationinthatthecatalystsusedaresimilar,andoftenidentical(一样的),i.e.atransitionmetalcompoundplususuallyanorganometallicalkylatingagent(烷基化剂).Metathesispolymerisationisfurther
35、dividedintothreeclasses:ring-openingmetathesisofcyclo-olefins(环状石蜡)(ROMP);metathesisofalkynes(炔烃),acyclic(脂肪族的)orcyclic;andmetathesisofdiolefins(二烯).ByfarthegreatestamountofworkhasbeendoneonROMP.Synthesis of conducting polymers你现在浏览的是第三十二页，共85页Pyrolysis(高温分解)isprobablyoneoftheoldestapproachutilisedt
36、osynthesiseconductivepolymersbyeliminatingheteroatoms(杂原子)fromthepolymerbyheatingittoformextendedaromaticstructures.Theproductofpolymerhydrolysiscanbeafilm,powderorafibredependingontheformandnatureofthestandingpolymer(常规聚合物)includingthepyrolysiscondition.Synthesis of conducting polymers你现在浏览的是第三十三页，
37、共85页Nevertheless,conductivepolymershavealsobeensynthesisedbyothertechniquessuchaschainpolymerisation,step-growthpolymerisation,chemicalvapourdeposition,solid-statepolymerisation,solubleprecursorpolymerpreparation,concentratedemulsionpolymerisationetc.However,mostofthesetechniquesaretime-consumingand
38、involvetheuseofcostlychemicals.Synthesis of conducting polymers你现在浏览的是第三十四页，共85页Conduction mechanism你现在浏览的是第三十五页，共85页Conduction mechanismThemechanismofconductioninsuchpolymersisverycomplexsincesuchamaterialexhibitsconductivityacrossarangeofaboutfifteenordersofmagnitudeandmanyinvolvedifferentmechanis
39、mswithindifferentregimes(情景情景).Conductingpolymersshowenhancedelectricalconductivitybyseveralordersofmagnitudeofdoping.Theconceptofsolitons(光孤子光孤子),polaronsandbipolaronshasbeenusedtoexplaintheelectronicphenomenainthesesystems(Heeger,1986).你现在浏览的是第三十六页，共85页什么是什么是Soliton光孤子是传播时几乎没有能量损失并能保持其形状光孤子是传播时几乎没
40、有能量损失并能保持其形状(即使与即使与其他波相碰撞其他波相碰撞)的的波波，这种现象首先是在水中被观察到的。孤子以光脉，这种现象首先是在水中被观察到的。孤子以光脉冲的形式被用于光纤传输系统以提高距离和性能。光孤子信号按照数字冲的形式被用于光纤传输系统以提高距离和性能。光孤子信号按照数字编码方法编码后进入光缆。基于光孤子的设备发射通过光缆传播而又不编码方法编码后进入光缆。基于光孤子的设备发射通过光缆传播而又不会出现色散的激光短脉冲。会出现色散的激光短脉冲。光弧子是一种特殊的光弧子是一种特殊的ps数量级上的超短光脉冲，由于它在光纤的数量级上的超短光脉冲，由于它在光纤的反常色散区，群速度色散和非线性效
41、应相互平衡，因而经过光纤长距离反常色散区，群速度色散和非线性效应相互平衡，因而经过光纤长距离传输后，波形和速度都保持不变。光弧子通信就是利用光弧子作为载体传输后，波形和速度都保持不变。光弧子通信就是利用光弧子作为载体实现长距离无畸变的通信，在零误码的情况下信息传递可达万里之遥。实现长距离无畸变的通信，在零误码的情况下信息传递可达万里之遥。你现在浏览的是第三十七页，共85页polaron来作用于来作用于电子电子，改变电子的状态与，改变电子的状态与能量能量，并伴随电子通，并伴随电子通过过点阵运点阵运动动。电子及其周围的。电子及其周围的极化场所极化场所构成的构成的总体总体，称，称为为极化子极化子。极
42、化子。极化子是是离子晶体离子晶体中基本的中基本的载流子载流子。极化子。极化子的尺寸由电子周围的尺寸由电子周围畸变畸变场区域场区域的大小确定。当这个区域的大小确定。当这个区域比比晶格常数晶格常数大很多时，称为大极化子，这时大很多时，称为大极化子，这时晶体可作为晶体可作为连续介质连续介质处理处理;当畸变区等于或小于晶格常数时，称为当畸变区等于或小于晶格常数时，称为小极化子，此时必须考虑小极化子，此时必须考虑晶体结构晶体结构的的原子原子性，用晶格模性，用晶格模型处理。型处理。你现在浏览的是第三十八页，共85页Conductivityinconductingpolymersisinfluencedby
43、avarietyoffactorsincludingpolaronlength,theconjugationlength,theoverallchainlengthandbythechargetransfertoadjacentmolecules(Kroschwitz,1988).Theseareexplainedbylargenumberofmodelsbasedonintersoliton(中间光极子中间光极子)hopping,hoppingbetweenlocalizedstatesassistedbylatticevibrations,intra-chainhoppingofbipol
44、arons,variablerangehoppingin3-dimensionsandchargingenergylimitedtunnelingbetweenconductingdomains.Conduction mechanism你现在浏览的是第三十九页，共85页Conductivity improvement techniques你现在浏览的是第四十页，共85页Theconductivityofapolymercanbeincreasedseveral-foldbydopingitwithanoxidative/reductivesubstituents(取代基)orbydonor/a
45、cceptor(给体/受体)radicals.ShirakawaandIkedadiscoveredthatdopingofpolyacetylene(PA)withmetallicregimes(态)increasesitsconductivityby9-13ordersofmagnitude.Dopingisaccomplishedbychemicalmethodsofdirectexposureoftheconjugatedpolymertoachargetransferagent(dopant)inthegasorsolutionphase,orbyelectrochemicaloxi
46、dationorreduction.Conductivity improvement techniques-doping你现在浏览的是第四十一页，共85页Thedopingisusuallyquantitativeandthecarrierconcentrationisdirectlyproportionaltothedopantconcentration.Dopingofconductivepolymersinvolvesrandomdispersionoraggregationofdopantsinmolarconcentrationsinthedisorderedstructureofe
47、ntangledchainandfibrils(原纤).Polymerdopingleadstotheformationofconjugationaldefects,viz.solitons,polaronsorbipolaronsinthepolymerchain.Anx-raydiffractionstudyoniodine-dopedpolyacetylenechainincreaseswithdonordopingbutdecreasesonacceptordoping.Conductivity improvement techniques-doping你现在浏览的是第四十二页，共85
48、页Thepresenceoflocalisedelectronicstatesofenergieslessthantheband-gaparisingfromchangesinlocalbondorder,includingtheformationofsolitons,polaronsandbipolaronshaveledtothepossibilityofnewtypesofchargeconductionpresentinthesepolymersystems.Chart1givesthechargeandspincharacteristicsofthesedefects.Conduct
49、ivity improvement techniques-doping你现在浏览的是第四十三页，共85页Conductivity improvement techniques-doping你现在浏览的是第四十四页，共85页Polymersmaybedopedbythefollowingtechniques:1.gaseousdoping2.solutiondoping3.electrochemicaldoping4.selfdoping5.radiation-induceddopingand6.ion-exchangedoping.Conductivity improvement techni
50、ques-doping你现在浏览的是第四十五页，共85页Conductivity improvement techniques-dopingOfthese,thefirstthreetechniquesarewidelyusedbecauseofconvenienceandlowcost.Inthegaseousdopingprocess,polymersareexposedtothevapoursoftheuseofasolventinwhichalltheproductsofdopingaresoluble.你现在浏览的是第四十六页，共85页1,4-Poly(butadiene(丁二烯)p