Facile synthesis of casein-based TiO2 nanocomposite for self-cleaning and high covering coatings: Insights from TiO2 dosage

•Casein-based TiO2 nanocomposite was innovatively prepared via single-in-situ soap-free polymerization.•Casein-based TiO2 nanocomposite latex exhibited evident core-shell structure with TiO2 incorporated inside.•The composite coatings showed superior self-cleaning behaviors.•Nano-TiO2 has positive effects on the covering ability of the composite coatings.

Casein-based TiO2 nanocomposite was innovatively prepared from casein, polyacrylate and TiO2 powders via single-in-situ soap-free polymerization. Effects of TiO2 dosage on the emulsion stability and film properties were investigated. Chemical structure and microstructure of the composite particles were characterized by fourier-transform infrared spectroscopy (FT-IR), transmission electron microscope (TEM) and scanning electron microscope (SEM). The results showed that the as-prepared composite latex exhibited evident core-shell structure with the majority of TiO2 incorporated inside, of which the average size was approximately 100 nm. Significantly, the composite film showed superior covering ability, impressive self-cleaning properties and good tensile strength, which promise its potential use as high-performance coatings on leather, textile or other substrates thus improve their added values.