Synthesis Of Inorganic Superhydrophobic Nanostructures And Application In Oil -Water Separation

Micro- and nano-structure's special wettability (such as superhydrophobic) has attracted much attention for their promising applications in self-cleaning, biomedical, micro-flowing, anti-corrosion and new-type drag reduction material. Surface wettability is governed by the microstructure and surface energy of a solid. In the present dissertation, several surfaces with special wettability have been prepared and constructed by manipulating composition and roughness. By using several methods, super-hydrophobic surfaces modified with four different micro-nanostructures have been successfully prepared. As follows:1. The oriented ZnO nanostructure was synthesized by mild two-step solution(﹤100℃) method. We have modified ZnO nanostructures on the surfaces of different substrates, such as brocade, Wound-paste and metal mesh. The obtained surfaces exhibit contact angles larger than 150°, with a rolling angle of 6°. Meanwhile, ZnO nanoneedles have been synthesized, because the contact area between a water droplet and a nanoneedle was reduced, the roughness of the surface has improved, thus the resulting surface shows great water-repellency, with a contact angle of 163°.2. On the basic of solution method of fabricating Ag leaf-like crystalloids, we provide an Ag~+ solution with low concentration and stable property to prepare superhydrophobic surface. In this way, the resulting surface exhibits superhydrophobicity, with a contact angle of 163°. The obtained surface can resist solution(pH=3~12), the static contact angle can also reach to 157°. Superhydrophobic film has been successfully used as fliter for separating oil-water liquid, the separating rate is high, and the ratio can reach 90%, therefore, has practical application.3. We assembled different super-hydrophobic nanostructures on different substrates by oxidation method. Including: (1) Preparing CuO nanosheets on brass; (2) Fabricating nanoneedles on copper. The obtained surfaces show high roughness, especially for copper mesh with nanoneedles, with a contact angle of 167°, water droplets hardly sticked to the resulting surface. Importantly, nanostructures firmly stick to the substrate, liquid and gas can go through mesh freely, thus, the superhydrophobic film has practical application prospects in oil-water separation.