PDF Publication Title:
Text from PDF Page: 027
US 9,905,856 B1 19 3,2004).Single-layergraphenecanbeasthinas0.34nm, Bothmechanicalexfoliationandliquidphaseexfoliationof whilemulti-layergraphenecanhaveathicknesupto10 graphitefluoridecanbereadilyacomplished. nm,butmoretypicalylesthan10nm(commonlyrefered InteractionofF2withgraphiteathightemperatureleads toasfew-layergraphene).Multiplegrapheneshetsor tocovalentgraphitefluorides(CF)nor(C2F)n,whileatlow plateletsmaybemadeintoashetofNGPpaperusinga 5 temperaturesgraphiteintercalationcompounds(GIC)CF paper-makingproces.ThisshetofNGPpaperisan (2sx524)form.In(CF),carbonatomsaresp3-hybridized exampleoftheporousgraphenestructurelayerutilizedin andthusthefluorocarbonlayersarecorugatedconsistingof thepresentlyinventedproces. trans-linkedcyclohexanechairs.In(C2F),onlyhalfoftheC Route2entailsultrasonicatingthegraphiteoxidesuspen atomsarefluorinatedandeverypairoftheadjacentcarbon sion(e.g.graphiteoxideparticlesdispersedinwater)forthe10shetsarelinkedtogetherbycovalentC—Cbonds.Sys purposeofseparating/isolatingindividualgrapheneoxide tematicstudiesonthefluorinationreactionshowedthatthe shetsfromgraphiteoxideparticles.Thisisbasedonthe resultingF/Cratioislargelydependentonthefluorination notionthattheinter-grapheneplaneseparationhasbeen temperature,thepartialpresureofthefluorineinthe increasedfrom0.354nminnaturalgraphiteto0.6-1.1nm fluorinatinggas,andphysicalcharacteristicsofthegraphite m 15precursor,includingthedegreofgraphitization,particle inhighlyoxidized graphiteoxide,significantlyweakening thevanderWaalsforcesthatholdneighboringplanes otherfluorinatingagentsmaybeused,althoughmostofthe together.Ultrasonicpowercanbesuficienttofurthersepa- availableliteratureinvolvesfluorinationwithF,gas,some rategrapheneplaneshetstoformfulyseparated,isolated, timesinpresenceoffluorides. ordiscretegrapheneoxide(GO)shets.Thesegraphene20 Forexfoliatingalayeredprecursormaterialtothestateof oxideshetscanthenbechemicalyorthermalyreducedto individuallayersorfew-layers,itisnecesarytoovercome obtain“reducedgrapheneoxides”(RGO)typicalyhaving theatractiveforcesbetweenadjacentlayersandtofurther anoxygencontentof0.01%-10%byweight,moretypi stabilizethelayers.Thismaybeachievedbyeithercovalent caly0.01%-5%byweight,mosttypicalyandpreferably modificationofthegraphenesurfacebyfunctionalgroupsor lesthan2%byweightofoxygen. 25 by non-covalentmodification using specificsolvents,sur Forthepurposeofdefiningtheclaimsoftheinstant factants,polymers,ordonor-acceptoraromaticmolecules. aplication,NGPsorgraphenematerialsincludediscrete Theprocessofliquidphaseexfoliationincludesultrasonic shets/plateletsofsingle-layerandmulti-layer(typicaly treatmentofagraphitefluorideinaliquidmedium. lesthan 10layers)pristinegraphene,grapheneoxide, Thenitrogenationofgraphenecanbeconductedby reducedgrapheneoxide(RGO),graphenefluoride,graphene 30exposingagraphenematerial,suchasgrapheneoxide,to chloride,graphenebromide,grapheneiodide,hydrogenated ammonia athigh temperatures (200-400° C.).Nitrogenated graphene,nitrogenatedgraphene,chemicalyfunctionalized graphenecouldalsobeformedatlowertemperaturesbya graphene,dopedgraphene(e.g.dopedbyBorN).Pristine hydrothermalmethod;e.g.bysealingGOandammoniain graphenehasesentialy0%oxygen.RGOtypicalyhasan anautoclaveandthenincreasedthetemperatureto150-250° oxygencontentof0.001%-5%byweight.Grapheneoxide 35 C.Othermethodstosynthesizenitrogendopedgraphene (includingRGO)canhave0.001%-50%byweightofoxy- includenitrogenplasmatreatmentongraphene,arc-dis gen.Otherthanpristinegraphene,althegraphenematerials chargebetweengraphiteelectrodesinthepresenceof have0.001%-50%byweightofnon-carbonelements(e.g. ammonia,ammonolysisofgrapheneoxideunderCVD O,H,N,B,F,Cl,Br,I,etc.).Thesematerialsareherein conditions,andhydrothermaltreatmentofgrapheneoxide referedtoasnon-pristinegraphenematerials. 40 andureaatdifferenttemperatures. Pristinegraphene,insmalerdiscretegrapheneshets Theaforementionedfeaturesarefurtherdescribed and (typicaly0.3umto10um),maybeproducedbydirect explainedindetailasfolows:AsilustratedinFIG.4(B),a ultrasonication(alsoknownasliquidphaseexfoliationor graphiteparticle(e.g.100)istypicallycomposedofmultiple production)orsupercriticalfluidexfoliationofgraphite graphitecrystalitesorgrains.Agraphitecrystaliteismade particles.Theseprocessesarewell-known intheart. 45 upoflayerplanesofhexagonalnetworksofcarbonatoms. Thegrapheneoxide(GO)maybeobtainedbyimmersing Theselayerplanesofhexagonallyarangedcarbonatoms powdersorfilamentsofastartinggraphiticmaterial(e.g. aresubstantialyflatandareorientedororderedsoastobe naturalgraphitepowder)inanoxidizingliquidmedium(e.g. substantialyparalelandequidistanttooneanotherina amixtureofsulfuricacid,nitricacid,andpotassiumper- particularcrystalite.Theselayersofhexagonal-structured manganate)inareactionvesselatadesiredtemperaturefor50 carbonatoms,commonlyreferredtoasgraphenelayersor aperiodoftime(typicalyfrom0.5to96hours,depending basalplanes,areweaklybondedtogetherintheirthicknes uponthenatureofthestartingmaterialandthetypeof direction(crystalographicc-axisdirection)byweakvander oxidizingagentused).Aspreviouslydescribedabove,the Waalsforcesandgroupsofthesegraphenelayersare resultinggraphiteoxideparticlesmaythenbesubjectedto arangedincrystalites.Thegraphitecrystalitestructureis thermalexfoliationorultrasonicwave-inducedexfoliation 55usuallycharacterizedintermsoftwoaxesordirections:the toproduceisolatedGOshets.TheseGOshetscanthenbe c-axisdirectionandthea-axis(orb-axis)direction.The convertedintovariousgraphenematerialsbysubstituting c-axisisthedirectionperpendiculartothebasalplanes.The –OHgroupswithotherchemicalgroups(e.g.—Br,NH2, a-orb-axesarethedirectionsparaleltothebasalplanes etc.). (perpendiculartothec-axisdirection). Fluorinatedgrapheneorgraphenefluorideishereinused60 DuetotheweakvanderWaalsforcesholdingtheparalel asanexampleofthehalogenatedgraphenematerialgroup. graphenelayers,naturalgraphitecanbetreatedsothatthe Therearetwodiferentaproachesthathavebeenfolowed spacingbetweenthegraphenelayerscanbeapreciably toproducefluorinatedgraphene:(1)fluorinationofpre openedupsoastoprovideamarkedexpansioninthec-axis synthesizedgraphene:Thisaproachentailstreatinggra- direction,andthusformanexpandedgraphitestructurein phenepreparedbymechanicalexfoliationorbyCVD 65whichthelaminarcharacterofthecarbonlayersissubstan growth with fluorinatingagent such as Xef ,or F-based tialy retained. The process for manufacturing flexible plasmas;(2)Exfoliationofmultilayeredgraphitefluorides: graphiteiswel-knownintheart.Ingeneral,flakesofnatural 20 size,and specificsurfacearea.Inaditiontofluorine(F2),PDF Image | FLEXIBLE AND SHAPE-CONFORMAL ROPE-SHAPE ALKALI METAL-SULFUR BATTERIES
PDF Search Title:
FLEXIBLE AND SHAPE-CONFORMAL ROPE-SHAPE ALKALI METAL-SULFUR BATTERIESOriginal File Name Searched:
US9905856.pdfDIY PDF Search: Google It | Yahoo | Bing
Sulfur Deposition on Carbon Nanofibers using Supercritical CO2 Sulfur Deposition on Carbon Nanofibers using Supercritical CO2. Gamma sulfur also known as mother of pearl sulfur and nacreous sulfur... More Info
CO2 Organic Rankine Cycle Experimenter Platform The supercritical CO2 phase change system is both a heat pump and organic rankine cycle which can be used for those purposes and as a supercritical extractor for advanced subcritical and supercritical extraction technology. Uses include producing nanoparticles, precious metal CO2 extraction, lithium battery recycling, and other applications... More Info
CONTACT TEL: 608-238-6001 Email: greg@infinityturbine.com (Standard Web Page)