Synthesis of hydrophilic silica nanoparticle and its application as self-cleaning coating for solar cell panels

In past decades, nanotechnology has attracted much attention among researchers and industries due to its high potential of adding significant values to the original materials. Thin film coating with nanomaterial can provide new properties and enhance performances of pristine surfaces for certain applications. In this research, we investigated the development of superhydrophilic self-cleaning coatings for solar panels using colloidal silica nanoparticles. The coatings consist of colloidal silica nanoparticles with the average size of 30 nm, sodium dihydrogen phosphate and boric acid under various formulations. The coatings can be applied by simple painting or fine spraying. The light transmittance of the coated samples was characterized by UV–visible spectrophotometer. The water contact angle (WCA) was measured by a contact angle instrument. It was observed that the optimum weight ratio of silica nanoparticles : sodium dihydrogen phosphate : boric acid was 22:1:1 with contact angle of 1.83° and transmittance of 65%. (paper)