Nanocellulose-Composites-A-New-Class-of-Sustainabl

NanocelluloseComposites:ANewClassofSustainableMaterialsEmilyD.CranstonMcMasterUniversityChemicalEngineering,Hamilton,ONRoyalInstituteofTechnology,Stockholm,SwedenBiomime,SwedishCenterforBiomimeticFibreEngineeringMcGillUniversity,Montreal,QCSustainableChemistrySummitSeptember2011,(2)• Researchfocusedonsustainabilityisappealingnotonlybecauseofitsimpactonhumanhealthandtheenvironmentbutbecauseofthescientificpossibilitiesandtheneedforinnovation.Motivation“Ourplanetwon’tallowustocontinuetodothingsthewaywearedoingthemtoday.”–PaulAnastasDesignandpreparesustainablematerials(inspiredbynature)fromrenewablesourceswhichwillhaveapositiveenvironmentalimpact.SustainableChemistrySummitSeptember2011,(3)Approach• Takealreadyexistingmaterials(mostlyfromnature)andbreakthemdownfurther,functionalizethem,andcombinetheminnewways.• Makematerialsfromwaterbasedsuspensions– Films,coatingsandpackaging– Gelsandfoams– Plastic-likecomposites• Butthenweneedtocharacterizethenewmaterials– chemical,mechanical,optical,thermal,morphological…SustainableChemistrySummitSeptember2011,(4)• Mostabundantnaturalresource(75billiontonnesannually)• Bio-polysaccharidewithhierarchicalchiralstructure• StableandphysiologicallyinertCelluloseβ-1,4-linkedD-glucoseunits=CelluloseFibrilMicrofibrilPlantcellwallSustainableChemistrySummitSeptember2011,(5)1. Mostofwhatweknowaboutpolymerchemistrywelearnedfromcellulose.2. Celluloseiseasilymodifiedthroughthewell-knownfieldofcarbohydratechemistry.WhyStudyCellulose?3. Cellulosehasfavourablemechanicalproperties.– Physicallystrong,stableanddurable– Hightensilestrength– Lightweight– Insolubleinmostsolvents(holdswater&retainsstrength)SustainableChemistrySummitSeptember2011,(6)Nanocellulose• Asustainablenanomaterialderivedfromwoodpulpwithapplicationsincomposites,food,cosmeticsandpigments.So,dowejustgrowreallysmalltrees?What’stheadvantageofnano-sizedcellulose??Webreakdowncelluloseintosmallcrystalsorfibresandmakethesurfaceschargedsothattheyformastablecolloidalsuspensioninwater.xSustainableChemistrySummitSeptember2011,(7)NanocelluloseRevoletal.Int.J.Biol.Macromol.1992,14,170.Turbaketal.JournalofAppliedPolymerScience1983,37,815.Herricketal.JournalofAppliedPolymerScience1983,37,797.Applications:BiocompatiblepigmentsOpticalcoatings/sensorsTemplatesCatalysisBiomedicaldevicesRheologicalmodifierDrugdeliverysystemsPlasticcompositesSustainableChemistrySummitSeptember2011,(8)MoreSurfaceisBetter!• Idealreinforcingcomponentinnanocompositesandfiller/modifierinfood,cosmeticsanddrugexcipients– Strongbutflexible(specificmodulussteel&Kevlar)Eichhorn,S.J.etal.JournalofMaterialsScience2010,45,1.• Nanocellulosehasanextremelyhighsurface-area-to-volumeratio– Alittlegoesalongway!• Retainsthestabilityandnon-toxicityofcellulose• NanocrystallinecellulosehasuniqueopticalpropertiesSustainableChemistrySummitSeptember2011,(9)1%10%5%100%Macro-scale:NCCbyEyePhotoscourtesyofBrianO’Connor,FPInnovationsSustainableChemistrySummitSeptember2011,(10)Nano-scale:NCCbyTEM• ThenanocrystalsarehighlycrystallinecelluloseI• Rod-shapedparticles:100-200nmx5-10nm• Opticallybirefringent(n║=1.595&n┴=1.534)• Anionic(andhydrophilic)600nmTEMbyJ.-F.Revol,circa1990SustainableChemistrySummitSeptember2011,(11)Nano-scale:NCCbyAFM• OrientationofNCCcanbecontrolled:• Radial(byspin-coating)• Linear(byalignmentinamagneticfield)• Liquidcrystalorganization500nmSustainableChemistrySummitSeptember2011,(12)100µmPLiquidCrystals• NCCformsachiralnematicliquidcrystalwhichreflectsonewavelengthoflight(color)dependingonthepitch(P).• Colorcanbeadjustedbysalt,hydrolysisconditions,electric/magneticfield,etc.PolarizedlightmicroscopeimageofadryingNCCsuspensionSustainableChemistrySummitSeptember2011,(13)Layer-by-LayerAssemblyNegativesubstratePlacesubstrateinpolycationbath&rinsePlacesubstrateinpolyanionbath&rinseRepeat=nanocrystallinecellulose(NCC)=poly(allylaminehydrochloride)(PAH)Photosofspin-coatedmultilayerfilmsofalternatingPAHandNCC5layers10layers20layers30layers50layersCranston,E.D.;Gray,D.G.Biomacromolecules2006,7,2522.Cranston,E.D.;Gray,D.G.ColloidsandSurfacesA2008,325,44.Thesefilmshaveuniquepropertiesandmimichowthefibrewallisbuilt-upwithlayersofcelluloseandhemicelluloses/lignin.1cm• Multilayeredthinfilmswerepreparedbysequentialelectrostaticadsorptionofoppositelychargedpolymers.Decher,G.Science1997,277,1232.• Brightlycolored=opticalcoatings,pigmentsandsensors.SustainableChemistrySummitSeptember2011,(14)SurfacePatternedFilmsCranston,E.D.etal.Biomacromolecules,2011,12,961.Modulusforfilms100nmth