Fabrication of super-hydrophobic micro-needle ZnO surface as corrosion barrier against corrosion in simulated condensation environment

Water and mildew proof SiO2 & ZnO/silica sol superhydrophobic composite coating on a circuit board

In order to improve the waterproof and mildew resistance of electronic equipment, a superhydrophobic coating was prepared on a circuit board. First, hexadecyl trimethoxysilane was used to modify the nano silica and nano zinc oxide particles, and then the modified nanoparticles were mixed with the silica sol. Then the superhydrophobic coating was prepared on the surface of the printed circuit board by a spraying process. The preparation technology and physical and chemical properties of the coating were studied. The contact angle of the final sample can reach 169.47°, the sliding angle can reach 1.2°, it has good acid and alkali corrosion resistance, resistance to NaCl, self-cleaning performance and antimildew performance.

A water and mildew proof SiO₂ and ZnO/silica sol superhydrophobic composite coating was prepared by a one-step method and applied to a circuit board. The preparation method is simple and inexpensive, and convenient for large-scale preparation.

Preparation of a Highly Oleophobic Magnesium Alloy AZ31 Surface with Hierarchical Structure and Fluorination

Wettability is an important surface property owing to its useful characteristics such as self-cleaning, antifrosting, and anticorrosion. In particular, an oleophobic surface, which can overcome the limitation of the antifouling performance of a hydrophobic surface, is a considerably valuable research subject. Magnesium alloys are widely used in various industrial fields owing to their superior mechanical performance; however, a technology that is applicable for surface modification has been limited due to their chemical properties. In this study, a new method to prepare a highly oleophobic magnesium alloy AZ31 surface is introduced; this method involves applying a hierarchical structure and fluorination. The hierarchical structure was formed via two-step anodization and magnesium hydroxide formation, and a self-assembled monolayer (SAM) coating method was applied to fluorinate the surface. This hierarchical structure with low surface energy can reduce the contact area between the surface and droplets, thereby decreasing the adhesive force. Contact angles were measured using various test liquids to evaluate the oleophobic surface, and all test liquids, including rapeseed oil (35.0 mN/m), were repelled by the surface.