纳米纤维素.ppt

纳米纤维素.ppt

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PreparationofCelluloseNanocrystalsandTheirApplicationsinInorganicNanocomposites,2ChemicalpreparationmethodsofCNCs,3ApplicationsinInorganicNanocomposites,4Outlook,1CelluloseNanocrystals,Content,1CelluloseNanocrystals（cellulosemicrocrystals，cellulosewhiskers，nanocellulosecrystalsornanocrystallinecellulose）,CNCsaregenerallyrefertotherod-shapedcellulosecrystalswithlengthfrom100nmto12umandwidthvaryingfrom5to20nm.Theycanbeextractedfromabroadrangeofnaturalsourcesincludingcotton,tunicate,bacteriaandwood.,Cotton2,Tunicate1,1CelluloseNanocrystals,Nanoscaledimension,Highcrystallineorder,Superiormechanicalstrength,Largesurfacearea,Abundant,Lowcost,availability,renewability,2PreparationofCNCs-chemicalmethods,ChemicalpreparationmethodsofCNCs,Acidhydrolysismethod,Enzymatichydrolysismethod,Oxidationmethod,Acidhydrolysis,2PreparationofCNCs-chemicalmethods,TheacidscanbeH2SO4,HCl,H3PO4,HCOOH,ortheirmixedacids,Acidhydrolysismethod,Crystallineregions,wasteacidandotheruselesscomponentswereformed,Enzymatichydrolysismethod,2PreparationofCNCs-chemicalmethods,Cellulaseisakindofmulti-componentsmixture,containingdifferentenzymes,theseenzymescooperatewitheachtoselectivelyhydrolyzetheamorphousregionsleavingthecrystallineregion.,MildEnvironmental-friendly,Longertimeconsuming,2PreparationofCNCs-chemicalmethods,TEMPO-mediated,Oxidationmethod,Inorganicpersulfatemethod,TEMPO,2,2,6,6-tetramethylpiperidine-1-oxylradical,incombinationwithNaBrandNaClO.,Potassiumpersulfate,ammoniumpersulfateortheirmixture,3ApplicationsinInorganicNanocomposites,CNCssuspensionhastheverygoodporosity,itcanpromotethenucleationofnanoparticles,preventagglomerationtoachieveaverynarrowparticlesizedistribution,andmakethemcanbeusedforthepreparationofpreciousmetaloritsalloynanoparticles.,NanoPd3,NanoSilver5,NanoAu4,3ApplicationsinInorganicNanocomposites,Themostcommonmethodforthedepositionofmetallicnanoparticlesisthetreatmentofmetallicsaltswithreducingagents，forexampleNaBH4,3ApplicationsinInorganicNanocomposites,Antimicrobialandmedicalapplication,Microbialcellulosehasattractedattentionasanovelbiomedicalmaterialduetoitsbiocompatibility,goodstrengthandhighwaterholdingcapacity.,Hydrogels,spheres,films,andtubes，artificialbloodvessels,CNCscanalsobeusedtopreparesilvercolloidalsuspensionswithantimicrobialproperties,disruptbacterialmetabolism,3ApplicationsinInorganicNanocomposites,Catalystsupport,Highlyefficientrecyclableheterogeneouscatalyst,NanoPd,Auortheiralloysupportedoncellulose,Excellentstability（bothchemicalandthermal）,highsurfacearea,goodaccessibility,andorganicgroupscanberobustlyanchoredtothesurfacetoprovidecatalyticcentres.,Enzymeimmobilization,3ApplicationsinInorganicNanocomposites,CNCshavebeenproposedasanagentforprotein/enzymeimmobilizationduetoitslargesurfaceareaandnonporousstructure.,4Outlook,CNCasanewkindofbiomassnanomaterials,sinceithasmanyexcellentphysicalandchemicalpropertiesandisrichinnature,havingwideapplicationsinareassuchasbiology,medicine,material,catalyst.Therearestillalotofcomposites，combinaedrodCNCs，organicpolymermaterialsorinorganicmaterialstogether，arenotexplored.WecanbelievethatmoreCNCsrelatedcompositematerialswillbeexploited.,1LuP,HsiehYL.Preparationandpropertiesofcellulosenanocrystals:

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