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1、Supperrepellentmaterial1WettabilityYoung’sequation:cosθ=(γSV–γSL)/γLVHydrophobic:θ?90°;Hydrophilic:θ?90°.WettabilityisafundamentalpropertyofmaterialsurfacesWatercontactangle(WCA)largerthan150°andextremelylowWCAhysteresisorslidinganglelessthan10°.Super
2、hydrophobicitySlidinganglemg(sinα)/ω=γ(cosθa-cosθr)θa–Advancingcontactangle,θr–Recedingcontactangle,m-Thequalityofwaterdrop,g-Accelerationofgravity,ω-Diameterofwaterdrop,γ-SurfaceEnergyofwaterdrop。m,g,ω,γareconstant,then:sinα∝cosθa–cosθr.Awidespectrum
3、ofapplicationssoysauceWatercollector?inthedesertAntifoulingcoatingTheundesirableaccumulationofmicroorganisms,plants,andanimalsonartificialsurfacesimmersedinseawater.Highfrictionalresistanceandfuelconsumption,duetogeneratedroughness,Deteriorationofthec
4、oatingsothatcorrosion,discolouration,andalterationoftheelectricalconductivityofthematerialarefavoured.LowsurfaceenergycoatingformitigatingmarinebiologicalfoulingAntifoulingcoatingDragreductionSelf-cleaningmaterialsAntifrostAntifoggingsurfaces局部放大Oil?
5、waterseparationSupperrepellentmaterialin?nature出淤泥而不染,濯清漣而不妖。--宋.周敦頤《愛(ài)蓮說(shuō)》超疏水的荷葉和表面結(jié)構(gòu)(a)球形的水滴滴在荷葉表面(b)荷葉表面大面積的微結(jié)構(gòu)(c)荷葉表面單個(gè)乳突(d)荷葉表面的納米結(jié)構(gòu)LotuseffectCicada'swings蟬翼表面由規(guī)則排列的納米柱狀結(jié)構(gòu)組成.納米柱的直徑大約在80nm,納米柱的間距大約在180nm.規(guī)則排列納米突起所構(gòu)建的粗糙度使其表面穩(wěn)定吸附了一層空氣膜,誘導(dǎo)了其超疏水的性質(zhì),從而確
6、保了自清潔功能。Butterflywings2、ThetheoreticsofSupperrepellentmaterialWettabilityCassiemodelWenzelmodelYoung’sequationForsmooth,flat,uniformsolidsurface,therelationshipbetweencontactangleandsurfaceenergycanbedescribedbyYong’sequation(ThomasYoung,1805):cosθ=(γ
7、SV–γSL)/γLVInterfacialtension:γSV、γSL、γLVYong’sequationHydrophobicsurfaceThesurfacefreeenergyofmaterialsisrelatedtothespeciesandtheconcentrationofthefunctionalsurfacegroupsFunctionalsurfaceHydrophilicgroups:—OH、—CHO、—COOH、—NH2Hydrophobicgroups:—CnH2n+
8、1、—CH=CH2、—C6H5、—X、—NO2—CF3FluorinatedpolymerCH2(36dyncm-1)>CH3(30dyncm-1)>CF2(23dyncm-1)>CF3(15dyncm-1)ThereasonofchoosingfluorosiliconeLowsurfaceenergyandhighsurface-activeofCF3groupImprovestheadhesionandcompatibilityself-assemblyForsmooth,f