Effect of TEOS Concentration on the Surface Characteristics and Hydrophobic Performance of Silica-Based Coatings
نویسندگان
1 Department of Mechanical Engineering, Faculty of Engineering, Universitas Andalas, Limau Manis, Padang, West Sumatra 25163, Indonesia
2 Department of Mechanical Engineering, Faculty of Engineering, Universitas Andalas, Limau Manis, Padang, West Sumatra 25163, Indonesia
3 Department of Mechanical Engineering, Politeknik Negeri Padang, Limau Manis, Padang, West Sumatra 25166, Indonesia
4 Department of Electrical Engineering, Universitas Amir Hamzah, Pancing Pasar V Barat, Medan 20221, Indonesia
5 Department of Mechanical Engineering, Faculty of Engineering, Universitas Andalas, Limau Manis, Padang, West Sumatra 25163, Indonesia
6 Department of Civil Engineering, Universitas Amir Hamzah, Pancing Pasar V Barat, Medan 20221, Indonesia
doi
10.48309/ajca.2026.533800.1878چکیده
This study investigates the effect of tetraethyl orthosilicate (TEOS) concentration on the structural and surface properties of silica-based coatings developed for corrosion protection of mild steel. Silica particles were synthesized via a soft-templated sol–gel method using varying TEOS loadings, and subsequently functionalized with methyltrimethoxysilane (MTMS) to induce hydrophobicity. The resulting materials were characterized by XRD, FTIR, SEM-EDS, and water contact angle (WCA) measurements. XRD confirmed the formation of amorphous or partially crystalline SiO₂ phases, while FTIR analysis indicated the presence of both hydrophobic –CH₃ groups and hydrophilic Si–OH functionalities. SEM-EDS analysis indicated that higher TEOS concentrations resulted in larger, smoother particles with lower surface carbon content, likely due to reduced MTMS coverage. WCA measurements demonstrated that lower TEOS concentrations increased surface area and roughness, facilitating greater methyl group grafting and enhanced hydrophobicity. The A1 and A2 samples exhibited the highest WCA values (87.6° and 84.4°, respectively), indicating improved water repellency. Further studies could explore alternative silane coupling agents or dual-functional silanes to enhance the grafting of hydrophobic groups on high-TEOS surfaces.
