Investigation of The Filler-Shape Effect on The Hydrophobicity and Transparency of Multilayer Nanocomposite Coating

Solar panels are very interesting devices for energy harvesting. Self-cleaning coatings are necessary for the solar panels since rains and sand particles in dusty weather can damage the outer surfaces of the solar panels; in addition to lowering the energy harvested. Therefore, developing a special transparent and self-cleaning coating is of interest. In this work, transparent composite hydrophobic coatings of three layers was prepared using different coating techniques and investigated for hydrophobicity and optical transmittance. The first layer, which was of PMMA with a thickness of 200 μm, was coated by doctor blade technique. A second layer of different particles i.e. PTFE, TiO2 and CaSiO3 was spread out by dipping technique. Finally, a third layer, which was of pure PMMA with a thickness of around 10 nm, was coated by spin technique. A composite coating of PMMA / CaSiO3 / PMMA shows a contact angle of around 129° which was the best performance among the prepared coatings. The results have also revealed that this coating can transmit up to 84% of the visible light at a surface roughness of 16 µm.