Effect of Resin Concentration on Hydrophobicity, Transparency, and Durability of the Antisoiling Coating for Solar Cover Glass

Antisoiling coatings mitigate surface contamination, thereby reducing cleaning frequency and maintaining optical performance. However, their large-scale deployment is constrained by limited durability under long-term environmental conditions. In this work, silica (SiO2) nanoparticles functionalized with perfluorooctyltriethoxysilane (PFOTES) were synthesized and used to prepare mechanically robust hydrophobic coatings on a borosilicate glass substrate using two different weight percentages (1.5% and 3%) of silicone resin, which acts as both a binder and an adhesion promoter. Both coatings demonstrated good optical transmittance and strong hydrophobicity with water contact angles of approximately 150° and 135° for functionalized SiO2 with 1.5 and 3 wt % resin content, respectively. The prepared coatings were evaluated under simulated conditions to assess their self-cleaning performance, abrasion resistance against brushing, Scotch tape peel resistance, and durability under accelerated raindrop impact. The results highlight the critical role of the resin-to-particle ratio in determining coating performance. Coating with higher resin exhibited superior transparency and mechanical durability, whereas coating with lower resin showed higher initial hydrophobicity but lower mechanical stability. Overall, these coatings demonstrate potential for solar glass applications that demand long-term transparency and water repellence.