英语五分钟演讲PPT-- lotus effect.ppt

,X-EffectOBAMA,“Liveinthesiltbutnotimbrued”.,Inchinese,wesay:出淤泥而不染,LotusisasymbolofpurityinseveralAsianreligions,becauseitispure.,PureLikethese?,Pity!Theyarejustpureindifferentway,Actually,Inmodernsociety,STAYING“PURE”isbecomingmoreofaCHALLENGEforhumanbeingsundertheinfluenceofsomanytemptations.BUT,forthelotus,KEEPINGPUREisjust,apieceofcake.,But,how?,Themajorreasonforthismightbethe:Self-cleansingpropertyandsuperhydrophobicityofitsleaves.(叶子的自洁性和超疏水性),Tobetterunderstandit,weshouldknowthis:,Then,whatisthesituationofawaterdroponalotussurface?,Specifically,itslikethis:,在表面张力作用下，水与超疏水表面會有一接触角(contactangle),Awaterdroponalotussurfaceshowingcontactanglesofapproximately147.,Whyislotus90?,Specialstructureofitsleavescanexplainmore,Theepidermisofthelotusplantpossessespapillaewith10to20minheightand10to15minwidthonwhichtheso-calledepicuticularwaxesareimposed.Thesesuperimposedwaxesarehydrophobic（疏水的）.（莲类植物的表皮具有10-20微米高，10-15微米宽的乳头结构，上面附着着所谓的表皮下蜡质颗粒.这些附带的蜡质是疏水的）,具有微米级角质层（micron-gradecuticula）与纳米级蜡质洁晶(nano-gradeepiticularwaxes)莲叶表面,Computergraphicofalotusleafsurface.,Thisstructureenablesthecontactareaandtheadhesionforcebetweensurfaceanddroplettobesignificantlyreduced.(这种结构使得液滴和荷叶表面之间的接触面积及粘附力显著降低，从而导致荷叶的自洁过程。),Thehydrophobicity(疏水性)ofasurfaceisrelatedtoitscontactangle（）.Thehigherthecontactanglethehigherthehydrophobicityofasurface.,Plantswithadoublestructuredsurfacelikethelotuscanreachacontactangleof170whereasadropletsactualcontactareaisonly0.6%.,Alltheseleadstoaself-cleaningeffect.,Acomparison,细微结构与自洁作用即使同样具有疏水性的表面，在细微结构上的水珠会吸附着灰尘颗粒滚动，而在光滑表面上，水珠能使颗粒移动的程度有限,AndIhopeyouunderstandthelotus“livinginthesiltbutnotimbrued”better.,Because,ThemoreYouunderstandit,themoreyouunderstand,X-Effect,Thatsallformytopic.,Thanksforyourpatience.,Extra,莲花叶子表面上的化学组成：由腊质组成的角质层和100200奈米的微毛结构构成了莲叶表面。也就是说微毛的构造使液体接触莲叶的表面是一种混合的介面-部分为固态的叶面；部分为孔隙中的空气，若是透过高倍率的电子显微镜来观察：会发现一旦水滴落到莲叶上，水珠都是由凹凸不平的表面中凸起的腊所顶住，这很像是一个人躺在针床上，想要舒舒服服躺平是不可能的，只有卷起身子有如球形的处在针床上。如此一来水珠无法稳定的停留在莲叶上，一旦稍微有气流，即能将水珠吹走，所以说莲叶具有拨水的特性。另一方面，由于奈米级的微毛间距，也使得污垢在莲叶上的接触面只在这小小的顶尖上而已，当水滴滚动过去时，不但水滴会被移走也会顺便将附着在上面的灰尘、污垢跟着带走，这便是莲叶自我清洁的特性。难怪古代文人称赞花中的君子莲花出淤泥而不染！,莲花具有很多小凸起状的角质层和腊质形体。图片中棒形的尺度大小(当比例尺用)为20微米。,空气被封于液体与叶面的凹处中，减少了液体与叶面的接触面积，产生了具强烈疏水性质的表面。棒形的尺度大小(当比例尺用)为20微米。,叶面上的液滴，当其滚动时，便会吸附起叶面上的污染粒，带离叶面。此图说明了莲花效应。棒形的尺度大小(当比例尺用)为50微米。,Thiseffectcaneasilybedemonstratedinmanyotherplants,forexampleTropaeolum(nasturtium),Opuntia(pricklypear),Alchemilla,cane,andonthewingsofcertaininsects.,Tropaeolum旱金莲,Opuntia,羽衣草属(Alchemilla),Applicationoflotus-effect,Clothingindustry防水，防尘，不用洗啦！,汽车的前挡玻璃（不用雨刷了）摄像机的镜头（防水，防尘）,Coatingindustry(涂料产业),Thisself-cleaningsurfacecharacteristicsnotonlyexistonthelotusleafsurface,alsohavebeenvalidatedinanimalskinorotherplantleaves,andself-cleaningfunctionofthehydrophobiccoating,coatingtechnologyprocessdevelopmentcounterfeitlotus,isunmistakabletrend.,Relatedresearchdirectionsinclude:(1)usedinLCDproductsofhighgas,hightransparentcoatingsandanti-reflectivehighhardnesscoatings(2)appliedtoelectronicproductsofelectromagneticshieldingcoatings(3)usedintheconstructionofenergy-savinginsulationcoatingsandself-cleaningcoatings(4)metalcorrosion-resistantanti-rustcoating(5)theenvironmentalcompatibilityofthecoating(6)withagermicidaleffectnanophotocat