Preparation and characterization of silica sol-impregnated glass fibers

Silica sol-impregnated glass fiber products were prepared via the sol-gel method, with tetraethoxysilane (TEOS) as a precursor and hydrochloric acid (HCl) as a catalyst, and characterized by 1 H NMR, FT-IR, and solid 29 Si NMR analyses. The results indicated that the structure of the impregnating agents was significantly affected by the amount of water added. With a decrease in the molar ratio of added water, the degree of TEOS hydrolysis was reduced, and more ethoxy groups -OCH 2 CH 3 were formed, resulting in the formation of sol products with a linear structure. Furthermore, contact angle and water absorption tests showed that as the molar ratio of water increased, the water contact angle decreased, whereas the water absorption of impregnated glass fiber increased. These results indicate that a higher hydrolysis degree of TEOS with more added water generates more Si-OH groups, facilitating the cross-linking of sol products to form a network structure.