叶片表面微细观结构对润湿性的影响  

Effect of Leaf Surface Microstructure on Wettability

作　　者：郑江韬 杨翼龙 柴恩豪 刘倩[2] 边宇峰 鞠杨[1,2] ZHENG Jiang-tao;YANG Yi-long;CHAI En-hao;LIU Qian;BIAN Yu-feng;JU Yang(State Key Laboratory for Fine Exploration and Intelligent Development of Coal Resources,China University of Mining and Technology,Beijing 100083,China;School of Mechanics and Civil Engineering,China University of Mining and Technology,Beijing 100083,China)

机构地区：[1]中国矿业大学(北京)煤炭精细勘探与智能开发全国重点实验室,北京100083 [2]中国矿业大学(北京)力学与土木工程学院,北京100083

出　　处：《表面技术》2023年第7期288-298,共11页Surface Technology

基　　金：国家自然科学基金(52274045);大学生创新项目(202106014);中央高校基本科研业务费(2023JCCXMT01)。

摘　　要：目的探究叶片表面微细观结构对其润湿性的影响因素,以及控制机理。方法以银杏(Ginkgo biloba,G.biloba)、二乔玉兰(Magnolia soulangeana,M.soulangeana)和二球悬铃木(Platanus acerifolia,P.acerifolia)3种处于落叶期初段的叶片样本为研究对象,测量3种叶片正背面的接触角,结合环境扫描电子显微镜图像,对比分析不同叶片正面和背面微细观结构及其对接触角的影响。结果实验结果表明,落叶期初段银杏、二乔玉兰和二球悬铃木叶片正面均表现出弱亲水性,接触角分别为54.40°~66.80°、57.93°~74.87°、55.73°~82.23°。在银杏叶片背面,无论是顺纹理还是逆纹理方向,均表现出疏水特征,顺纹理方向的接触角为122.63°~135.10°,逆纹理方向的接触角为103.03°~134.13°。二乔玉兰和二球悬铃木的背面为中性润湿,接触角分别为82.87°~96.37°、90.50°~97.47°。结论不同类型叶片的表面微结构显著不同,同种类型叶片正背面微结构也表现出较大差异。3种叶片背面接触角均大于正面接触角,其中银杏叶片正背面的接触角存在显著差异。叶片表面微细观结构的不同是造成叶片正背面润湿性差异的主要原因之一,尤其是多层级突触结构导致银杏背面表现出较强的疏水性质。叶片表面微细观结构对润湿性的影响机理将为不同润湿性需求的表面设计提供参考。Understanding wettability property of a solid material is crucial in surface processing technology and surface engineering.Previous researches show that the wettability of a material is far from a constant value but influenced by the environmental factors such as temperature and humidity,and the surface roughness such as surface microstructure and hierarchical structures.Recent bionics studies,such as the nearly spherical droplet on lotus leaf and the upward water transport on the peristome surface of Nepenthes alata,have inspired researchers to understand the affecting factors on the surface wettability and thus develop artificial surfaces with practical applications.The microstructure of a material surface,especially the hierarchical microstructure or the multiscale microstructure,is one of the main factors affecting the wettability.However,a leaf at its different growth stages shows varied wettability.Moreover,the wettability of upper surface and backside surface of the same leaf usually shows notable difference.There is still not a consensus of the controlling mechanism of leaf surface microstructure on its wettability.In this study,the contact angle on the upper surface and backside surface of Ginkgo biloba,Magnolia soulangeana and Platanus acerifolia leaves in their early deciduous period was measured.Combined with the multiscale microstructure observation by environmental scanning electron microscopy(ESEM),the effect of leaf surface microstructure on wettability was investigated.The typical microstructures on the upper surface and backside surface of the leaves at different scales were characterized firstly.Then,the effect of leaf surface microstructure on wettability was investigated.The basic assumption was that the material property of the upper surface and backside surface of one leaf was the same.It was found that the upper surfaces of the three plants leaves showed weak hydrophilicity in their early deciduous period,the contact angles ranged from 54.40°-66.80°,57.93°-74.87°and 55.73°-82.23°resp

关 键 词：微细观结构 润湿性 接触角 环境扫描电镜 表观接触面积 

分 类 号：O647.5[理学—物理化学] TB34[理学—化学]