Quantitative assessment to the structural basis of water repellency in natural and technical surfaces

被引:267
作者
Wagner, P [1 ]
Fürstner, R [1 ]
Barthlott, W [1 ]
Neinhuis, C [1 ]
机构
[1] Univ Bonn, Inst Bot, D-53115 Bonn, Germany
关键词
confocal microscopy; epicuticular wax; plant cuticle; water-repellency;
D O I
10.1093/jxb/erg127
中图分类号
Q94 [植物学];
学科分类号
071001 ;
摘要
Many plant surfaces are water-repellent because of a complex 3-dimensional microstructure of the epidermal cells (papillae) and a superimposed layer of hydrophobic wax crystals. Due to its surface tension, water does not spread on such surfaces but forms spherical droplets that lie only on the tips of the microstructures. Studying six species with heavily microstructured surfaces by a new type of confocal light microscopy, the number, height, and average distance of papillae per unit area were measured. These measurements were combined with those of an atomic force microscope which was used to measure the exposed area of the fine-structure on individual papillae. According to calculations based upon these measurements, roughening results in a reduction of the contact area of more than 95% compared with the projected area of a water droplet. By applying water/methanol solutions of decreasing surface tension to a selection of 33 water-repellent species showing different types of surface structures, the critical value at which wetting occurs was determined. The results impressively demonstrated the importance of roughening on different length scales for water-repellency, since extremely papillose surfaces, having an additional wax layer, are able to resist up to 70% methanol. Surfaces that lack papillae or similar structures on the same length scale are much more easily wetted.
引用
收藏
页码:1295 / 1303
页数:9
相关论文
共 45 条
[1]  
Adam N.K., 1963, Water Proofing and Water-Repellency, P1
[2]  
Adam N.K., 1963, WATERPROOFING WATER
[3]  
ADAMSON AW, 1990, PHYSICAL CHEM SURFAC
[4]   STUDIES OF PLANT CUTICLE AND SPRAY DROPLET INTERACTIONS - A FRESH APPROACH [J].
BAKER, EA ;
HUNT, GM ;
STEVENS, PJG .
PESTICIDE SCIENCE, 1983, 14 (06) :645-658
[5]   SCANNING ELECTRON MICROSCOPY OF PLANT CUTICLES [J].
BAKER, EA ;
PARSONS, E .
JOURNAL OF MICROSCOPY, 1971, 94 (NAUG) :39-+
[6]  
Barthlott W., 1981, Nordic Journal of Botany, V1, P345, DOI 10.1111/j.1756-1051.1981.tb00704.x
[7]   Purity of the sacred lotus, or escape from contamination in biological surfaces [J].
Barthlott, W ;
Neinhuis, C .
PLANTA, 1997, 202 (01) :1-8
[8]  
Barthlott W., 1981, TROPISCHE SUBTROPISC, V32, P7
[9]  
Barthlott W., 1990, Scanning Electron Microscopy in Taxonomy anfd Functional Morphology, P69
[10]  
Barthlott W., 1977, TROPISCHE SUBTROPISC, V19, P367