Characteristics of organic titanate modified titanium dioxide nanoparticles and its dispersibility in acrylic emulsion coating

Abstract

This work presents the characteristics of rutile TiO₂ nanoparticles modified by isopropyl tri[di(octyl) phosphato] titanate (KR‐12) with the content of 3, 5 and 10 wt.% as compared to TiO₂ nanoparticles weight. The infrared (IR) spectroscopy, scanning electron microscopy (SEM), dynamic light scattering (DLS), and thermal gravimetry analysis (TGA) methods were used to evaluate the surface modification efficiency of the TiO₂ nanoparticles with KR‐12. The TGA and IR analysis results indicated that the organic coupling agent (KR‐12) was grafted to the surface of the nanoparticles. The TiO₂ nanoparticles after modification could disperse stably in water easily. The modification caused the shift of surface charge of the TiO₂ nanoparticles to more positive region. The average particle size of TiO₂ nanoparticles modified with 0, 3, 5, and 10 wt.% of KR‐12 was 443.9 nm, 295.3 nm, 334.8 nm, and 392.3 nm, respectively. The hydrophobic ability of TiO₂ nanoparticles was improved significantly after modification. The modified TiO₂ nanoparticles could well disperse in acrylic emulsion coating with dispersed phase size of 200‐400 nm.