Preparation of the Anti-Oxidation SiO2 Coating on Carbon Fibers by Modified Sol-Gel Method

Abstract

Carbon fibers have been widely used in various fields due to excellent physical and chemical properties. However, the presence of oxygen limits the use of carbon fibers in high temperature applications. In this paper, a modified sol-gel method for the preparation of SiO2 coating was proposed. Through the preparation of the emulsion, the SiO2 sol added with the amino-functional silane was uniformly mixed. The results showed that the optimal ratio of SiO2 sol was ethanol: distilled water: tetraethyl orthosilicate = 3:1:5. After the preparation of the emulsion, the coating thickness was greatly increased and the performance was excellent. The initial oxidation temperature of carbon fiber was increased from 400°C to 600°C by preparing SiO2 coating. The coating obtained by emulsifying treatment could reduce the weight loss rate of carbon fiber cloth at 1450°C from 83.72% to 28.67%.