Influences of inorganic binder on photocatalytic oxidation (PCO) and degradation of nano/micro TiO2 containing acrylic composites

Todays, the air impurities caused by different sources, have become one of the most important problems in mega cities. Paints and coatings have been considered as effective materials to overcome this problem. The huge exterior and interior surfaces of the buildings which exposed to air pollutants can be coated by an air purifying paint. In this research preparing a photocatalytic oxidative pseudo paint based on acrylic latex by using Nano and micro TiO2 particles was studied. The water glass (i.e. Na2SiO3), as an inorganic binder, was added to the acrylic latex at 5 and 10 wt.%. The effects of the water glass on dispersion of the particles, the PCO rate, the mechanical properties of the prepared films, the degradation of the films under UV irradiation and the PCO activity were evaluated. Furthermore the effect of water glass on the discoloration of the samples was determined. Results showed that using 5 wt.% of the water glass considerably improved the degradation of the acrylic based samples. It also decreased the discoloration of the samples. It was found that the water glass could improve the PCO activity of the samples. For example, it increased the PCO rate up to 87% for the samples containing 5 wt.% of Nano TiO2 along with 10 and 20 wt.% of TiO2 pigments.