Construction Of Nicke Nano-array Structures And Study Of Their Special Wettability

Wettability is one of the important characteristics of the solid surface, mainly affected by microscopic geometric structure and chemical composition of the solid surface. The surfaces with special wettability (such as wetting at high temperature, anti-condensation at low temperature, superhydrophobic, superoleophobic, superhydrophilic) have very important applications in industrial production and the daily life. Inspired by the superhydrophobic effect of lotus leaf with micro-and nano-structures, people have got special functional surfaces by preparing various of micro-and nano-structures, the research of the surface wettability of micro-and nano-interface materials mainly focuses on the conditions of room temperatures, while it is rarely studied at extreme temperatures (high temperature, low temperature). It has a great significance for the special wettability (wetting at high temperature, anti-condensation at low temperature) of interface materials in the field of high-effective heat transfer and maintain the instruments operating normal at extreme temperature. Nickel is a common metal materials, it has the advantages of low cost, easy and controllable to synthesize in the processing of surface nanostructures, so it is a kind ideal materials to study the special wettability of nano interface materials at extreme temperatures.Based on these ideas, the paper constructed nickel nano-array structures by the template method (anodic aluminum oxide template) and the non-template method to study the phenomenon of surface wettability at high temperature. The specific contents are as follows:1. Anodic aluminum oxide was prepared by a two-step anodization in oxalic acid-sulfuric acid system. The template cycle, hole depth and aperture ware regulated by changing the experimental parameters.2. Nickel nanorod array structures have been controllabely prepared by using of the electrochemical deposition technique with anodic aluminum oxide template. The spacing, height and diameter of the nickel nanorods were controllabely obtained by changing the parameters of anodic aluminum oxide template. The effect of the variation of the surface wettability on the Leidenfrost phenomenon of critical temperature Tb of water droplets completely bounce and partly bounce、critical temperature Ta of water droplets partly bounce and do not bounce were investigated. The results showed that:For the rod spacing of300nm of nickel nanorod array structure, the higher the nickel nanorod is, the smaller the Ta and Tb are; and the greater the diameter of the nickel nanorod is, the smaller the Ta and Tb are also.3. Based on the non-template method, nickel nanocone array structures were fabricated with electrochemical crystallization echnology on the surface of copper. The electrodeposition times, the concentrations of ethylenediamine acetate and the current densities were used to discussed the influences of the array structure. The wettability of nickel nanocone structures under different conditions was also explored to prepare the well wettability nickel nanocone array. The optimized structure was used to study condensation heat transfer, the result showed that it enhanced condensation heat transfer.