Investigation of the mechanical properties of a photocatalytic pseudo‐paint

Photocatalytic oxidative paints (e.g., a paint containing nano‐TiO₂) are used to break down volatile organic compounds to CO₂ by photooxidation reactions. In this research, a photocatalytic oxidative pseudo‐paint was made with acrylic–styrene copolymer latex, TiO₂ pigment, calcium carbonate extender, and TiO₂ nanoparticles as a photocatalyst. To investigate the effects of the pigment, extender, and nanoparticles on the mechanical properties of the samples and their relationship to their photocatalytic activity, different contents of the particles were dispersed in the paint formulation. The tensile strengths (TSs) of the samples were measured as the mechanical properties. The samples were characterized by scanning electron microscopy analysis. We found that up to 3% nano‐TiO₂ enhanced the mechanical properties of the pigmented resin, whereas beyond this, TS decreased. In samples containing 3% nanoparticles, the incorporation of 15% TiO₂ pigment caused optimized mechanical properties, and beyond that, TS decreased because of particle agglomeration. In the absence of nanoparticles, the samples showed improvements in the mechanical properties with up to a 40% loading of pigment. The results reveal that the samples containing nano‐TiO₂ and pigment showed the same trend for the mechanical and photocatalytic properties before the critical pigment volume concentration (CPVC). However, when the extender was incorporated or TiO₂ particles were loaded beyond CPVC, the mechanical and photocatalytic properties correlation was compromised, and they were not directly correlated. © 2015 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2016 , 133, 42885.