Preparation Of Wood-Like Structured Materials With Superhydrophobic Properties

Wettability of the solid surface is one of the most important properties of materials, which depends on both geometrical microstructures and chemical composition. In recent years, inspired by "lotus effect", researchers have been paying increased attention to superhydrophobic surfaces with a water contact angle (CA) higher than 150° and a low contact angle hysteresis(CAH). Up to now, artificial superhydrophobic surfaces have been fabricated by tailoring surface morphology and using techniques such as lithography, laser and plasma etching, physical and chemical vapor deposition, anodic oxidation, electro-deposition, sol-gel, electro-spinning, layer-by-layer deposition, and others. While, most of these existing methods are prepared by simple imitation, we cannot precisely mimic the fantastic surface structures of hydrophobic leaves, even by using the highest levels of technology. This limits further improvement of the superhydrophobic properties of materials. Therefore, in this study, we used natural wood lauan as a template to fabricate superhydrophobic biomorphic Cu & ZnO on a carbon substrate mainly through sintering the wood template and chemical modification. Then, the performance of the obtained surface was investigated. If this product can inherit a porous structure similar to that of original wood, it may also have superhydrophobic properties.In this dissertation, we use two methods to fabricate superhydrophobic surfaces on copper, Zinc oxide and monocrystalline silicon substrates.(1) We used lauan, white pine and manchurian ash wood as a template to prepare superhydrophobic biomorphic Cu/C, ZnO/C by immersing the biomorphic carbon derived from the wood in a Cu(NO3)2 or Zn(NO3)2 solution and then sintering it. After modified by FAS, their surface exhibited excellent superhydrophobic properties. Analyzing the effect of changing the process parameters to contact angle, and the optimum conditions were summarized.(2) The micro-colunm arrays were fabricated by the metal-assisted chemical etching (MaCE) on the silicon substrate; the silicon realize superhydrophobic by self-assembling FAS mono layer and the maximum contact angle is 160°. Wherein, the biological Ag act as catalyst to accelerate the reaction rate.