静电纺丝的原理和应用ppt课件.ppt

《静电纺丝的原理和应用ppt课件.ppt》由会员上传分享，免费在线阅读，更多相关内容在教育资源-天天文库。

1、ElectrospinningGroupNo.62008-12-27CatalogOurintroductionrelateto:HistoryMechanismApplicationTechniqueHistoryFormhalsetc.thefirstpatentBecauseofthefilterindustry:conventionalextrusion-and-drawingprocessesNanotechnologypromotion&Publicationexplode1934Mid-1990snowGapHistoryThepublicationincr

2、easeMechanismpolymersolutionsormeltsMainProcess1.Taylorcone2.repulsiveforcesovercomesurfacetension:jet3.radialchargerepulsion:Splitting4.CollectJetstudyPIG.Jetimagesofa2wt%solutionofPEO(a)Stablejet(E=0.5kV/cm,Q=4ml/min)(b)Unstablejet(E=0.67kV/cm,Q=0.1ml/min,1msexposure)(c)close-upoftheons

3、etofinstability(E=0.67kV/cm,Q=0.1ml/min,18nsexposure)envelopeconeY.M.Shinetal.Appl.Phys.Lett.78(2001):1149-1151JetStabilityTherearemanyfactorsinfluencejetstabilityTherearetwomainkindsofinstabilities:Rayleighinstabilityaxisymmetric,suppressedwhenEandσexceedathresholdWhippinginstabilitynona

4、xisymmetric,including:electricallydrivenbendinginstabilityaerodynamicallydriveninstabilityJetStabilityFIG.Operatingdiagramshowingstabilitytransitionsfora2wt%solutionofPEOinwater.Whiteregion:theoreticalsteadyjet;lightgrayregion:theoreticalRayleighunstable;darkgrayregion:theoreticalwhipping

5、unstable;cross-hatchedregion:theoreticalcomparableinstabilitytoRayleighandwhippingmodes.Circles:experimentaldata.Y.M.Shinetal.Appl.Phys.Lett.78(2001):1149-1151BendinginstabilityFIG.Shapeoftheenvelopecone:experimentvstheory.Pointsshowcalculatedradiiofsuccessiveloops.Experimentalpointswerem

6、easuredfromaphotograph.A.L.Yarinetal.J.Appl.Phys.89(2001):3018-3026FocusingApparatusLeonM.BellanaandH.G.CraigheadJ.Vac.Sci.Technol.B24(2006):3179-3183Variables&ParameterelectricalfieldStrength;fluidflowrate;workingdistancebetweentheelectrodesprocessvariablesViscosity;Electricalconductivit

7、y;surfacetension;solventvolatility;SolutionvariablesTemperaturePressureHumidityEnvironmentalvariablesProcessVariablesJ.M.Deitzeletal.Polymer42(2001):261-272ProcessVariablesJ.M.Deitzeletal.Polymer42(2001):261-272ProcessVariablesJ.M.Deitzeletal.Polymer42(2001):261-272