Modification of the glass surface with hydrophobic silica thin layers using tetraethylorthosilicate (TEOS) and trimethylchlorosilane (TMCS) precursors

The synthesis of the hydrophobic silica layer was conducted using the sol-gel method by reacting silica precursor trimethylchlorosilane (TMCS) and tetraethylorthosilicate (TEOS) with variations in the precursor composition ratio (TMCS:TEOS) of 10:90, 25:75, 50:50, 75:25, and 90:10 and then calcined at various temperatures. The TMCS-TEOS silica thin layer has a significant influence on the surface hydrophobicity of the glass. The higher the number of TMCS precursors, the greater the contact angle produced. The highest contact angle produced was 98 degrees at a TMCS-TEOS ratio of 75:25 and without calcination. The TMCS-TEOS silica thin layer contact angle decreased with increasing calcination temperature. The hydrophobicity of the TMCS-TEOS silica thin layer could withstand temperatures up to 300 degrees C. Quantitative analysis of FTIR spectra's peak area shows that with the increasing TMCS, the ratio of silanol/siloxane decreases. Gas sorption analysis shows that the TMCS-TEOS thin layers' pore sizes are in the mesoporous region, and the pore shapes are cylindrical at all TMCS:TEOS ratios and calcination temperatures.

Automated summary

The hydrophobic silica layer was synthesized using the sol-gel method, with varying TMCS:TEOS ratios influencing the surface hydrophobicity of glass. A higher TMCS precursor content led to a greater contact angle, although this angle decreased with higher calcination temperatures. The pore sizes of the TMCS-TEOS thin layers were found to be in the mesoporous range, with cylindrical pore shapes maintained across different ratios and calcination temperatures.