Effect of the Firing Method on the Properties of Functional Coating Film Synthesized on the Ceramic Substrate

Introduced herein is a novel hydrophilic coating material designed to increase the self-cleaning of ceramic substrates. This material can be applied to various other materials, such as metal, glass, and polymer films. In this study, a thin coating was applied to each of several ceramic substrates to demonstrate its use as a ceramic insulator in electrical railway systems. Many of these insulators are exposed to polluting environments, such as in tunnels and subterranean sites, leading to electrical power failure. Application of a water-based, self-cleaning coating material would offer an advantage over methods such as photocatalysis, the application of which requires extra energy. Ceramic substrates were coated with the hydrophilic material by means of brushing and spraying, after which the coated layers were cured using different firing methods: natural, microwave, and electrical oven firing. The mechanical and self-cleaning properties of the films were then characterized in terms of their hardness, adhesion, and contact-angle measurements, and the samples were subjected to a water cleaning test. Hardness was measured using the ASTM D3363 test method, and adhesion was tested using the ASTM D3359 method, resulting in 9H hardness and 5B adhesion. To check the wettability of the films, a contact angle analyzer was used. The brush-coated film fired in a microwave environment at 11.2 degrees C had the smallest contact angle. To measure the film's self-cleaning property, a permanent-marker cleaning test was performed.