Fabrication And Application Of Superhydrophobic And Micro-patterning Surfaces

For the past few years, research on superhydrophobic surfaces has been developed rapidly and different techniques have been used to construct the rough structure that superhydrophobic surfaces require. However, either special equipment or complex process control is required in most case, these methods have been limited. It remains a great challenge to develop simple and convenient techniques that could be used as largely prepared of superhydrophobic surfaces so as to meet the need of superhydrophobic surfaces both in daily life and industry. On the other hand, because of the unique properties of the superhydrophobic surface, it is an uptrend of research to apply the superhydropobic surfaces in the newly-developed bio-technique and microfluidic devices.In this present thesis, three techniques for fabricating suerphdrophobic surfaces were established, all of which are very simple, costless, and could be used as mass production. Three techniques for fabricating superhydropilic/superhydrophobic micro-patterning surfaces were also established and the uses of the patterning surfaces were preliminary studied. Main work and results are as follows:1. Abrasive papers were proposed as molds for fabricating superhydrophobic. Rough surfaces of polymers were preparend by casting or hot embossing using the metallographic abrasive paper as molds. Superhydrophobic surfaces could be achieved when using types of W7, W5 abrasive papers, and the roughness of these surfaces could be controlled by selecting the abrasive papers used. SEM and contact angle measurement were employed to investigate the effect of roughness on the wetting properties and the contribution of the intrinsic wetting properties of polymer to the apparent CA on rough surfaces.2. Method to prepare superhydrophobic coating by nanoparticles was established. Coating solution was first prepared by mixing commercially available nano-silica particles with some common polymer, which was then cast on different kinds of substrate such as glass, papers, fabric, copper. The effects of the proportion of SiO₂ to polymer, the concentration of the solution and the sorts of polymer on the wetteing properties and surfaces structure were investigated.3. Method to prepare superhydrophobic alumina membrane was established. Alumina membrane with nano-porous was prepared through a single-step anodization procedure. Superhydrophobic surfaces were achieved after the treatment of membrace by fluoroalkyl. The effect of the time of oxidation on the wetteing properties and the roughness of the membrane was investigated.4. Three techniques to fabricate superhydropilic/superhydrophobic micro-patterning surfaces were established. CO2 laser etching, excimer laser etching and oxygen plasma treatment were employed to selectively remove the fluoroalkyl on the superhydrophobic alumina membrane. Superhydrophilic/superhydrophobic patterning surfaces could achieve by optimizing the process parameter. The application of these wetting heterogeneous surfaces in microarray, open microfluidic chip and micromixer were preliminary studied.