PERFORMANCE EVALUATION OF SELF-CLEANING EFFECT FOR PHOTOCATALYST-APPLIED EXTERIOR FINISHING MATERIALS THROUGH OUTDOOR EXPOSURE TEST AND LABORATORY TEST

摘要

Application of Photocatalyst to building materials and components is rather newly developed technology. One of advantageous features by applying this photocatalyst would be capability of self-cleaning or self-desoiling on the surface of materials. This paper introduces the results of the outdoor exposure test and the laboratory tests for the various exterior finishing materials such as coating materials, ceramic tiles and membrane materials treated with photocatalyst (TiO_2) aiming at imparting self-cleaning or self-desoiling performance. The following conclusions could be made in this study; 1) Self-cleaning effect was clearly recognized in the outdoor exposure test. The degree of effect was dependent upon each commercial product at present stage; however, the products treated with photocatalyst showed significantly higher self-cleaning effect compared with the ordinary products which were not treated with photocatalyst. 2) Measurement of contact angles with water for the exposed specimens were also conducted in the laboratory after the outdoor exposure test. The relationships between the outdoor exposure test results and the results of contact angles were discussed. Consequently, the outdoor exposure test results were consistent with the results of contact angles with water for the exposed specimens in outdoor condition.