The Preparation And Study Of Superhydrophobic-oleophobic Coating

Compared to pure super hydrophobic coatings, super hydrophobic-oleophobic coating due to the alienation effect on water and oil simultaneously rather more applicable to everyday life and industrial production were. However, currently available superhydrophobic-oleophobic coating preparation method has the following disadvantages:the need for special equipment (plasma, laser etching), is not conducive to large-scale construction; special requirements on the substrate, apply only to the specific surface (electrochemical deposition); and generally molding process complex and costly, thus severely limiting the widespread use of such materials.This topic research through the following three steps to the preparation of super hydrophobic-oleophobic coating, make up for the deficiency of the existing process:First, the conventional grinding methods were prepared micron aluminum oxide (Al2O3) particles, the Sol-gel technique was used to prepare the nano-silica (SiO2), the fluorine-containing silane coupling agent are grafted on the surface. Using FT-1R and transmission electron microscopy (sem) had been used to characterize the structure and size of particles, the result shows that:when the reaction temperature of35℃, reaction time is4h, the catalyst concentration is0.8mol/L, is ethyl silicate concentration and water content were0.2mol/L,17mol/L preparation of SiO2such uniform particle size distribution; Modified by the fluorine-containing silane coupling agent, FT-IR peaks show nanoparticles and micron particle surface hydroxyl groups were significantly reduced and the1100cm-1-1300cm-1, there is a clear absorption various fluorocarbon peaks, indicating that the coupling agent has been grafted to the particle surface.Secondly, the use of various types of acrylic monomers of a fluorine-containing hydroxy acrylic resin as a main binder resin, prepared using a perfluoroalkyl alcohol and hexamethylene diisocyanate trimer fluorine-containing isocyanate curing agent, the results of FT-IR show:the successful introduction of fluorine into the two resins were. With paint prepared by mixing the acrylic polyurethane varnishes, showed good film properties, adhesion1level, flexibility lmm, the impact of50cm and the hardness of2H, the static contact angle of water may be up to104°.Finally, the obtained nano-micron particles are dispersed in a fluorine-containing acrylic resin, hydroxyl group, and adjust the ratio of pigment to binder ratio of nano/micro particles, and with a dispersing agent, anti-settling additives and curing agents to obtain a variety of superhydrophobic oleophobic coating, spray coating method using air prepared oleophobic-superhydrophobic coating. Test results show that when the pigment to binder ratio of0.8:1, the ratio of sodium/microparticles is1.2:1, the coating has good adhesion, flexibility and film strength of the coating to water at this time, and rapeseed oil static contact angle aviation hydraulic fluids were154°,100°and94°, indicating that the coating of water and oil have shown a good alienation effect.