Soil-resistant surfaces for traditional ceramics

Increasing demands for better cleanability have led to development of functional coatings on traditional glaze surfaces. However, mechanical and chemical durability of these coatings are not yet fully understood. In this work a traditional white sanitaryware glaze was coated with both commercial fluoropolymers and new hybrid sol-gel functional coatings. Also the influence of a transparent double-glaze on the surface properties was tested. Surface energy, hydrophobic and oleophobic properties of the surfaces were determined by contact angle measurements. Mechanical properties were evaluated by applying the accelerated abrasion tests by means of Erichsen apparatus. Chemical durability was determined in acidic, neutral and basic solutions. Cleanability of the surfaces was studied by FTIR technique with oleic acid as soiling agent. Surface topology and surface analysis were determined by scanning electron microscope and confocal optical microscope. The improved anti-soiling property of the coatings was due to the increased hydrophobicity and oleophobicity. The mechanical durability of the sol-gel coatings was shown to be highly dependent on the increased number of ceramic components. The coatings have good chemical durability in acidic and neutral environments but rapidly fail in alkaline solutions.