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1、Supperrepellent material,1 Wettability,Youngs equation:cos=(SV SL)/LV Hydrophobic:90;Hydrophilic：90.,Wettability is a fundamental property of material surfaces,Water contact angle(WCA)larger than 150 and extremely low WCA hysteresis or sliding angle less than 10.,Superhydrophobicity,Sliding angle,mg
2、(sin)/=(cosa-cosr)a Advancing contact angle,r Receding contact angle,m-The quality of water drop，g-Acceleration of gravity，-Diameter of water drop，-Surface Energy of water drop。m，g，are constant，then：sincosa cosr.,A wide spectrum of applications,soysauce,Water collector in the desert,Antifouling coat
3、ing,The undesirable accumulation of microorganisms,plants,and animals on artificial surfaces immersed in sea water.High frictional resistance and fuel consumption,due to generated roughness,Deterioration of the coating so that corrosion,discolouration,and alteration of the electrical conductivity of
4、 the material are favoured.,Low surface energy coating for mitigating marine biological fouling,Antifouling coating,Drag reduction,Self-cleaningmaterials,Antifrost,Antifogging surfaces,局部放大,Oilwater separation,Supperrepellent material innature,出淤泥而不染，濯清涟而不妖。-宋.周敦颐爱莲说,超疏水的荷叶和表面结构（a)球形的水滴滴在荷叶表面（b)荷叶表面
5、大面积的微结构（c)荷叶表面单个乳突（d）荷叶表面的纳米结构,Lotus effect,Cicadas wings,蝉翼表面由规则排列的纳米柱状结构组成纳米柱的直径大约在80 nm，纳米柱的间距大约在180 nm规则排列纳米突起所构建的粗糙度使其表面稳定吸附了一层空气膜，诱导了其超疏水的性质，从而确保了自清洁功能。,Butterfly wings,2、The theoretics of Supperrepellent material,Wettability,Cassie model,Wenzel model,Youngs equation,For smooth,flat,uniform so
6、lid surface,the relationship between contact angle and surface energy can be described by Yongs equation(Thomas Young,1805):cos=(SV SL)/LV,Interfacial tension:SV、SL、LV,Yongs equation,Hydrophobic surface,The surface free energy of materials is related to the species and the concentration of the funct
7、ional surface groups,Functional surface,Hydrophilic groups:OH、CHO、COOH、NH2Hydrophobic groups：CnH2n+1、CH=CH2、C6H5、X、NO2 CF3,Fluorinated polymer,CH2(36 dyn cm-1)CH3(30 dyncm-1)CF2(23 dyn cm-1)CF3(15 dyn cm-1)The reason of choosing fluorosiliconeLow surface energy and high surface-active of CF3 groupIm
8、proves the adhesion and compatibility,self-assembly,For smooth,flat,uniform solid surface,the highest contact angle is only 119。,Real solid surface with concave-convex structure,Wenzel model,Cassie model,Cos*=,=r COS,Wenzel model：,Cos*=,=r COS,Providing=110，if r0.53，*will be larger than 150,Wenzel m
9、odel,Cassie model,Cos=fcos+(1-f)cos180=fcos+f-1,Area fraction f=a/(a+b),lets assume that=110，if f is less than 0.2,will be larger than 150.,Cassie model,Providing CA between liqiud and air is 180,PAN Nano fiber material,Self-cleaning effect,Dirt,3、The fabrication of Supperrepellent surface,Modifying
10、 a rough surfaces chemical components,Turning a Surface Super-Repellent Even to Completely Wetting Liquids,Tingyi“Leo”Liu,et al.,Science,vol.346,pp.1096-1100,2014.,Template method,Etching,McCarthy等在聚四氟乙烯(PTFE)存在下,用射频等离子体刻蚀聚丙烯(PP)制备出粗糙表面。表面与水的前进角/后退角可达 A/R=172/169。,利用射频等离子体刻蚀法在不同刻蚀时间得到的聚丙烯扫描电子形貌图:(a)
11、0 min,(b)30 min,(c)60 min,(d)90 min,(e)120 min,(f)180 min,Chen等利用纳米球刻蚀的方法首先得到了排列整齐的单层聚苯乙烯(PS)纳米珠阵列,再用氧等离子体处理以进一步减小纳米珠的尺寸从而得到粗糙表面。在其表面覆盖 20nm厚的金膜并用十八硫醇(ODT)进行修饰可以增强其疏水性。通过调整 PS纳米珠的直径(440-190 nm)可以控制表面接触角的大小(132-168)。,氧等离子体处理后的超疏水 PS纳米珠阵列表面,Chemical vapordeposition,江雷等利用化学气相沉积法(CVD)在石英基底上制备了各种图案结构的阵列碳
12、纳米管膜,结果表明,水在这些膜表面的接触角都大于 160,滚动角都小于5,纳米结构与微米结构在表面的阶层排列被认为是产生这种高接触角、低滚动角的原因。,4 Research plan,In order to fabricate superhydrophobic or superhydrophilic surfaces based on sub-micron structures,I think my research in UW can be divided into three stages.,Firstly,the fabrication of artificial structured
13、surface.Several artificial structured surfaces have been disgined.If thesenanopillar and mushroom shaped nanopillars array with piece of 10 mm10 mm can be prepared by electroplate copper or nickel nanopillars?,Secondly,modify its components by surface fluorination.,Lastly,the fabrication of hierarch
14、ical structures.If the property of above structured surface after surface fluorination can not meet superhydrophobic or superhydrophilic requirement,I will increase surface roughness by preparing hierarchical structures on above artificial structured surface.,Some questions,Experiment rig and severalapparatus and devices,including electric-heated thermostatic water bath,spin coating,ovenand so on.Forcharacterization,SEM,contact angle meter andXPSare also needed.,Thank You!,
