基于粘附功计算的不同微形貌表面抗冰差异

Analysis of difference in micro-morphology for Anti-icing based on adhesion work

超疏水表面的防水性与表面的微观结构直接相关,不同微观形貌将呈现不同的疏水性能,从而亦产生不同的防覆冰性。代表性的选择动植物叶片、翼片、金属与非金属等工程材料固体表面做结冰和覆冰粘附强度测试,结果表明表面材料、微观结构不同,疏水、覆冰粘附性能不一样。设计了几种不同表面微形貌模型仿真自然和人工疏水表面微结构,用高粗糙度维持复合润湿状态,以具有矩形微形貌的表面为例建立覆冰粘附功与表面固体份数的解析关系,并推及其它模型。据粘附功、固体份数和粗糙度计算,发现不同微形貌表面覆冰粘附功的差异,固体份数对粘附功的决定作用以及粗糙度对复合润湿态的维持。理论上提出了选择适合的微观形貌用于防冰的定性标准:高粗糙度,低固体份数,低粘附功。按粘附功从小到大顺序确定适合于防冰、除冰微形貌;从固体份数和粗糙度的大小关系予以证实。

Superhydrophobicity is directly associated with surface micro/nanostructure.Different micromorphology behaves different hy-drophobicity,even possibly showing the opposite state while contacting with the water droplet,thus leading to different anti-icing effect.The leaf of lotus and swing of cicada and the metal/nonmetal solid surface were representatively selected to be used for icing and adhesion strength test,showing that the hydrophobicity and icing adhesion property change with composition and microstructure.Based on the hydrophobic and anti-icing experiment of the natural and artificial surface,several typical surface models were designed to simu-late the surface microstructure and morphology.On the prerequisite of the composite wetting state being maintained by high roughness,and taking the pillar-shaped microstructure for example,the relationship between the adhesion work and the microstructure was estab-lished,followed by it,being applied to the other models.By calculating the adhesion work,the solid fraction and roughness,the difference in the adhesion work of icing for different micro-morphology was found;accompanied by it,the determined effect of the solid fraction on the adhesion work was also discussed as well as the roughness on the wetting state.Finally the standard of selecting adapta-ble morphology for anti-icing was theoretically proposed:high roughness,low solid fraction and low adhesion work.Summarizing the whole study process,property of anti-icing for surfaces with different micro-morphology was analyzed from different aspects of adhesion work,solid fraction and roughness,being all so much theory,of which validity may get to be further confirmed by a series of experi-ment.