The effect of sintering regime on superhydrophobicity of silicon nitride modified ceramic surfaces

Abstract

The most common method of obtaining a superhydrophobic surface is to create a specific surface morphology and then coat it with a hydrophobic polymer. Numerous such morphological surfaces have been developed but are often fragile. Ceramic-based coatings show longer life with high wear resistance. In this study, surface micro-nano surface morphology was developed with β-Si3N4 powder and the influence of sintering regime on contact angle of ceramic surfaces was investigated. The contact angle, surface energy and surface roughness were determined from the developed surfaces and surface morphology analyzed by scanning electron microscopy, phase evolution was determined by X-Ray diffraction. Changes in sintering regimes lead to different phase evolutions, roughness, surface topography, surface free energies and contact angles. The superhydrophobicity resulted mainly due to the surface structure/topography in the micro-nano hybrid structures of β-Si3N4 crystals. The highest water contact angle achieved was 166º of the samples sintered at 980°C for 5 min.