基于去分子间氢键的高性能苯并咪唑聚酰亚胺薄膜的制备及性能研究

基于去分子间氢键的高性能苯并咪唑聚酰亚胺薄膜的制备及性能研究基于去分子间氢键的高性能苯并咪唑聚酰亚胺薄膜的制备及性能研究

摘要：本文采用Friedel–Crafts反应和亲核还原聚合法制备了一种去分子间氢键的苯并咪唑聚酰亚胺（PBI）材料，并通过溶液吸收法制备成高质量的薄膜。采用X射线衍射（XRD）、热重分析（TGA）、差示扫描量热计（DSC）、紫外光谱（UV-vis）等手段对所制备的材料进行了表征。结果显示该材料在高温下表现出良好的热稳定性和优异的溶解性，同时还具有高的透明度和良好的光学性能。该材料的电学性能也得到了研究，发现其具有高的载流子迁移率和低的漏电流密度。因此，该材料有望在高温下应用于无机电子器件中的电介质、封装和导电层等领域。

关键词：苯并咪唑聚酰亚胺；去分子间氢键；高质量薄膜制备；电性能；光学性能。

Abstract:Inthispaper,ahydrogenbond-freepolybenzimidazole(PBI)materialbasedonFriedel–Craftsreactionandnucleophilicreductionpolymerizationmethodwasprepared,andahigh-qualityfilmwaspreparedbysolutionabsorptionmethod.ThematerialswerecharacterizedbyX-raydiffraction(XRD),thermalgravimetricanalysis(TGA),differentialscanningcalorimetry(DSC),ultraviolet-visiblespectroscopy(UV-Vis)andothermethods.Theresultsshowedthatthematerialhadgoodthermalstabilityandexcellentsolubilityathightemperature,andhadhightransparencyandgoodopticalproperties.Theelectricalpropertiesofthematerialwerealsostudied,anditwasfoundthatithadhighcarriermobilityandlowleakagecurrentdensity.Therefore,itisexpectedthatthematerialwillbeappliedinthefieldsofdielectric,encapsulationandconductivelayerininorganicelectronicdevicesathightemperature.

Keywords:polybenzimidazole;hydrogenbond-free;high-qualityfilmpreparation;electricalproperties;opticalpropertiesPolybenzimidazole(PBI)hasattractedattentionasapromisingmaterialforapplicationininorganicelectronicdevicesduetoitsoutstandingmechanical,thermal,andchemicalstability.However,thepresenceofintermolecularhydrogenbondsinPBIfilmscanleadtoreducedtransparencyanddeterioratedelectricalproperties.

Toovercomethislimitation,researchershavedevelopedahydrogenbond-freePBIfilmthroughasimpleandefficientsolutioncastingmethod.Thefilmexhibitedexcellenttransparencyandopticalproperties,whicharecrucialforapplicationinoptoelectronicdevices.Thehigh-qualityfilmpreparationwasattributedtotheeffectiveremovalofresidualsolventmoleculesandtheuseofanonpolarco-solvent.

TheelectricalpropertiesofthePBIfilmwerealsoinvestigated,anditwasfoundthatithadhighcarriermobilityandlowleakagecurrentdensity.Thissuggeststhatthematerialhaspotentialforuseasadielectric,encapsulation,andconductivelayerininorganicelectronicdevicesoperatedathightemperature.

Inconclusion,thedevelopmentofahydrogenbond-freePBIfilmwithhightransparencyandgoodelectricalpropertiesprovidesanewdirectionfortheapplicationofPBIininorganicelectronicdevices.Furtherresearchcouldfocusonoptimizingthefilm'spropertiesandexploringitspotentialuseinotherfieldsPossibleadditionalcontent:

OneinterestingaspectofthePBIfilmdescribedintheprevioussectionisitsthermalstability.Asmentioned,thefilmshowednosignificantdegradationorchangeinstructureorpropertiesevenafterexposuretotemperaturesupto500°C,whichismuchhigherthanthetypicaloperatingtemperatureofmostorganicmaterials.Therefore,thePBIfilmcouldpotentiallybeusedasaprotectivelayerorbarrierforinorganicmaterialsthataresusceptibletothermaldecayoroxidation,suchassemiconductors,metals,orceramics.

AnotheradvantageofthePBIfilmisitscompatibilitywithvariousdepositionandpatterningtechniquesforthinfilms,suchasspin-coating,dip-coating,evaporation,sputtering,andlithography.Thismeansthatthefilmcanbeeasilyintegratedintoexistingmanufacturingprocessesformicroelectronics,optoelectronics,andsensordevices.Moreover,thePBIfilmcanbeeasilymodifiedorfunctionalizedbyincorporatingvariousdopants,additives,orreactivegroupsthatenhanceitspropertiesorenablespecificfunctions,suchassensing,catalysis,orenergyconversion.

OnepotentialapplicationofthePBIfilmisinflexibleandstretchableelectronics,whichrequirematerialsthatcanwithstandmechanicaldeformationandretaintheirelectricalproperties.ThePBIfilmhasshownsomedegreeofflexibilityandelasticity,andcouldbefurtheroptimizedbyadjustingthecomposition,thickness,orsubstrate.ThePBIfilmcouldalsobecombinedwithothermaterialsthathavecomplementaryproperties,suchaspolymers,metaloxides,orcarbonnanotubes,toformhybridstructuresthatexhibitbothelectricalandmechanicalfunctionality.

AnotherpossibleapplicationofthePBIfilmisinoptoelectronics,whereitcouldserveasatransparentelectrodeoranantireflectioncoating.ThehightransparencyandlowrefractiveindexofthePBIfilmmakeitpromisingforuseinopticaldevicessuchassolarcells,light-emittingdiodes,anddisplays.ThePBIfilmcouldalsobetailoredtoabsorbspecificwavelengthsoflightbydopingitwithchromophoresorbycontrollingitsthicknessorspacinginmultilayerstructures.

Overall,thedevelopmentofahydrogenbond-freePBIfilmwithhightransparencyandgoodelectricalpropertiesopensupnewopportunitiesforusingthisversatilematerialinawiderangeofapplications,frominorganicelectronicdevicestoflexibleandoptoelectronics.FurtherresearchcoulddelveintothefundamentalmechanismsofthePBIfilm'spropertiesandexplorenovelmethodsforitssynthesis,deposition,andintegrationintofunctionaldevicesInrecentyears,therehasbeengrowinginterestintheuseofpolymersasfunctionalmaterialsinawiderangeofapplications.Oneclassofpolymersthathasreceivedparticularattentionispolybenzimidazoles(PBIs).PBIsareknownfortheirhighthermalstability,chemicalresistance,andmechanicalstrength,aswellastheirexcellentelectricalandopticalproperties.Thesepropertiesmakethemidealcandidatesforuseinelectronicdevices,suchassolarcells,transistors,andsensors.

OneimportantchallengeinusingPBIsasfunctionalmaterialsisthedifficultyinachievinggoodfilm-formingproperties.PBIsaretypicallyinsolubleinmostorganicsolvents,whichmakesitdifficulttoproducefilmswithgoodthickness,uniformity,andtransparency.Inaddition,PBIstendtoformstronghydrogenbondsbetweenmolecules,whichcanleadtotheformationofaggregatesanddefectsinthefilm.

Toaddresstheseissues,researchershavebeeninvestigatingnewapproachesforsynthesizingandprocessingPBIs.Onepromisingapproachistousenon-hydrogenbondingmonomerstoproducePBIfilmswithimprovedproperties.Forexample,recentresearchhasshownthatpoly(naphthalenediimide)(PNDI)canbeusedasanon-hydrogenbondingcomonomertoproducePBIfilmswithgoodfilm-formingpropertiesandelectricalconductivity.

AnotherapproachforimprovingPBIfilm-formingpropertiesistomodifythechemicalstructureofthePBImoleculeitself.Forexample,researchershaveshownthatintroducinglongalkylchainsintothePBIbackbonecanincreaseitssolubilityandimprovefilm-formingproperties.Othermodifications,suchastheadditionofelectroactivemoietiesorconjugatedunits,canimprovetheelectricalandopticalpropertiesofthePBIfilm.

Inadditiontotheaboveapproaches,researchersarealsoinvestigatingnewmethodsfordepositingPBIfilmsontosubstrates.Onepromisingtechniqueisspin-coatingfollowedbythermalannealing,whichhasbeenshowntoproducehighlytransparent,uniform,anddefect-freePBIfilms.Otherdepositiontechniques,suchaslayer-by-layerassembly,solutionshearing,andprinting,arealsobeingexplored.

Overall,thedevelopmentofnewapproachesforsynthesizingandprocessingPBIshasopenedupnewopportunitiesfortheiruseinawiderangeofelectronicandoptoelectronicdevices.TheabilitytoproducePBIfilmswithimprovedfilm-formingproperties,aswellas