Development of Hydrophilic Self-Cleaning and Ultraviolet-Shielding Coatings Incorporating Micro-Titanium Dioxide/Nano-Calcium Carbonate (µ-TiO<sub>2</sub>)/(Nano-CaCO<sub>3</sub>)

Abstract

The dust accumulation and dirt particles always degrade the transparency of glass, later hampers its various applications such as photovoltaic panels, building glass, and car-windshield. In this study, the hydrophilic self-cleaning coatings have been developed by using the nanocalcium Carbonate particles (nanoCaCO3) and hydrophilic micro-titanium dioxide particles (µ-TiO2). The presence of oxide groups, CO-3 and TiO2- forms a strong attraction of glass to polar water molecules. At the weight ratio of 1: 1 in the CaCO3 to TiO2 mixture, it forms a great hydrophilic property in which the water contact angle (WCA) of coated glass has been recorded as low as 11.46 ±0.85°. The coated glass also showed high transparency in UV and Visible regions. The optical transmission of coated glass was above 89% at the wavelength of 300-400nm and above 97% at the wavelength of 400-800nm. Due to its hydrophilic property, the coated glass is capable of removing the dust particles away via the water stream. The hydrophilic coating spontaneously forms the water-thin film after contact with coated glass without the presence of UV light.