Study For The Spray Coating Process Of Superhydrophobic Surfaces

Superhydrophobic surfaces with extensive applications in many high-technology fields and daily life because of their special properties, have become a hot topic of functional surface materials. With further study on the fabrication and applications of superhydrophobic surfaces, more and more methods are used to prepared sundry superhydrophobic surfaces. One-step spray-coating process is one of fabrication method. Compared with traditional method, this method simplify the steps of preparation for superhydrophobic surfaces. In this work, we use one-step spraycoating process to prepare superhydrophobic surface. The main research contents are as follows:1. At first, hydrophobic oxidation particles(ZnO, TiO2 and SiO2) were obtained after being grafted with low energy materials such as stearic acid and octadecyltrichlorosilane. And then the hydrophobic oxidation particles(ZnO, TiO2 and SiO2) were dispersed in ethanol and the resulting suspension was spraying onto desired substrates to prepare superhydrophobic surfaces. The superhydrophobic surfaces showed a contact angle larger than 160° and a sliding angle smaller than 5°.Furthermore, the damaged superhydrophobic particle surfaces were easily repaired by spraying the hydrophobic particle suspensions directly on the wrecked surfaces again to repair roughness and low surfaces energy.2. CuO surfaces have been fabricated successfully by a simple spray-coating method. After being chemically modified with octadecanethiol, the surface got superhydrophobicity. The superhydrophobicity of CuO surface could be erased and rewrote by the alternation of plasma treatment and octadecanethiol coating. The process has been repeated with full reproducibility more than five times,demonstrating that the CuO surfaces exhibit good erasable and rewritable superhydrophobicity.3. Superhydrophobic carbon nanotube(CNT) surfaces with a water contact angle(CA) of 160° and a sliding angle(SA) of 3° was prepared through spraying CNT suspension without any chemical modification onto desired substrates. After being irradiated by UV light with a photomask, the as-prepared low adhesive superhydrophobic CNT surface changes from low adhesion to high water adhesion.However, further heating the irradiated CNT surface, the surface recovers its original low water adhesion. Reversibly switchable transition between the low water adhesion and high water adhesion can be realized by UV mask illumination and heat treatment alternately.