Non-stick Thin Films And High-performance Micro / Nanostructures

Wettability is an important properties of solid surface, and is the most common kind of interface phenomenon too. It plays a very important role in industrial and agricultural production and in daily life. Changing the surface chemistry and forming micro/nano- structures surface to realize superhydrophobic properties of solid surface is attracting more and more interest from people. The principle work is as follows:1. Through a lot of anti-sticking test and corresponding micro- structure of surface to be observed, it is found that superhydrophobic surface had optimum micro/nano- structures of characteristic. By changing surface free energy and heterogenousity of surface, it can make contact angles of liquid and solid surface change, and it can use contact angles measuring apparatus atomic force microscopy (AFM) and Scanning Electron Microscope (SEM) etc. to observe and analyse the anti-sticking performance of modified metal surface, and decide which is good or bad. At the same time, it is explained that little roll-off angles is an important standard to superhydrophobic surface.2. By theory analysis and model proposed, the superhydrophobicty mechanism of anti-sticking films, which is further described. In analysing models, it found that superhydrophobic structure should make the value ratio of post wide and post high(a/H) little possibly. On the basis of Gibbs function of state, which can decide one drop is in a steady Wenzel state or Cassie, and using chemistry absorption theory and experiment analysis explain the FAS-SAMS forming mechanism of fluoroalkyl silanes on the micro/nano structures, it indicates that special molecule structure of fluoroalkyl silanes has low surface energy and three-dimension netted structure by vertical growing on the substrate.3. It is explored experiment law of creating micro/nano- structures in metal surface by chemistry corroding and oxidize methods and preparing fluoroalkyl silanes films, it is to be the foundation for further improving its method and applying to the project to solve the problem of anti-sticking. The researched prescription and technology of superhydrophobic thin films can prepare superhydrophobic thin films on metal surface.4. It is analysed and proved that micro/nano- structures and fluoroalkyl silanes with low surface energy have the cooperative effect to anti-sticking performance. Calculating out the critical surface energy of modified aluminium is about 1mN/m, Gas/liquid contact surface and solid/liquid contact surface about compound surface of modified anodization and gas, which is 0.93 and 0.07 respectively by CB state calculating. It is future proved that micro/nano- structures and fluoroalkyl silanes films with low surface energy altogether decided lyophobicitv of modified metal surface;5. Developed some new coatings for engineering application, it is tested that the performance of modified metal surface at room temperature coatings is as the same as of routine Polytotra fluorethylene (PTFE), it is to point out the direction of use in daily practically for anti-sticking films.