Optimizing Preparation And Application Of Superhydrophobic Surface With Micro/Nano Structures

In recent years, the superhydrophobic surface has aroused great concern for its important application prospect in the fields of self-cleaning materials, anti-ice coating materials, fluid drag-reducing materials, corrosion, microfluidic device. At present, various methods have been used to regulate the micro-nano structure of the surface, such as template method, metal corrosion method, self-assembly technology, general lithography method, etc. Many artificial superhydrophobic surfaces has been prepared, but most methods still need complex processing technology or special processing equipment. This paper, which is based on the zinc plate and the PTFE substrate, has developed two simple and feasible methods which are controllable oxidation reduction method and laser etching method, to prepare the superhydrophobic surface with excellent performance. The preparation conditions are optimized. The components and the structures of the prepared samples were characterized. Furthermore, the properties of the prepared superhydrophobic surfaces, such as the wettability and thermal performance. The preliminary exploration was conducted in its applications such as anti-icing and self-cleaning. The main research contents and the relevant conclusions are as following:1. The petal shaped micro-nano structure combining with micro-nano particles on zinc substrate was prepared by the simple redox reaction and the surface modification treatment. By the scanning electron microscopy, the contact angle measurement instrument and the fourier infrared spectrum, the micro-nano structure, the wettability and the surface composition of the prepared super hydrophobic were characterized and analyzed detailedly. The effects of oxidation time, solution concentrations, modifier type, concentration and time on the wettability of the zinc substrates were analyzed systemically. The preparation conditions are optimized. The results show that under the optimal concentration and time, flower-like micron structure was showed on the zinc sheet surface, and the highest contact angle reaches to 157°.2. The papillary structures were prepared on PTFE substrates by CO2 laser etching. The laser processing parameters were controlled by the computer. First of all, the process of CO2 laser processing PTFE film was characterized by TG and FT-IR. To evaluate the wettability of the prepared surfaces, the contact angle of them was measured by the contact angle meter. The prepared micro-nano structures were observed by the scanning electron microscope. Combined with the above two kinds of characterization methods, we got the optimal laser processing parameters. Finally, under the optimal parameters in laser processing, the influence of the spacing of the papillary structure to the contact angle was explored by changing the mastoid structure spacing.3. The anti-icing and self-cleaning properties of the prepared superhydrophobic surface were studied. The anti-icing contrast tests were conducted between normal tablets and superhydrophobic tablets, respectively. The surface adhesion force of the ice coating on different surfaces were measured and compared. Equivalent anhydrous calcium carbonate powder was sprinkled on ordinary zinc tablets and superhydrophobic tablets, respectively. Equivalent anhydrous copper sulfate powder was sprinkled on ordinary teflon tablets and superhydrophobic teflon tablets, respectively. Then equal amount of water droplets were dropt on their surface, and the eventual residual flour on the table was observed. Finally the droplets motion on different surface was observed by using of the contact angle measurements, and then the self-cleaning principle of the superhydrophobic surface was analyzed.