TEOS/HDTMS inorganic–organic hybrid compound used for stone protection

• Published in: Journal of sol-gel science and technology Vol. 61; no. 2; pp. 429 - 435
• Main Authors: Xu, Feigao, Li, Dan, Zhang, Hean, Peng, Wei
• Format: Journal Article
• Language: English
• Published: Boston Springer US 01.02.2012; Springer; Springer Nature B.V
• Subjects: Acid rain; Catalysis; Ceramics; Chemistry; Chemistry and Materials Science; Colloidal gels. Colloidal sols; Colloidal state and disperse state; Composites; Contact angle; Exact sciences and technology; Gelation; General and physical chemistry; Glass; Hydrophobicity; Inorganic Chemistry; Limestone; Materials Science; Morphology; Nanotechnology; Natural Materials; Networks; Optical and Electronic Materials; Pore size; Porosity; Porous materials; Protective; Protective coatings; Resists; Silica gel; Silicon dioxide; Sol gel process; Solid-liquid interface; Stone; Surface physical chemistry; Theory of reactions, general kinetics. Catalysis. Nomenclature, chemical documentation, computer chemistry; Ultrasonic testing; Xerogels; Xerogel; Crack-free; Inorganic–organic hybrid; Modification; Binary compound; Contact angle; Hydrophobicity; Surfactant; Silica; Inorganic compound; Additive; Pore size; Acids; Inorganic-organic hybrid; Sol gel process; Morphology; pH; Protection; Catalyst; Organic compounds
• ISSN: 0928-0707; 1573-4846
• DOI: 10.1007/s10971-011-2643-0

Inorganic–organic hybrid crack-free xerogels were obtained by using a surfactant n -octylamine as a catalyst containing tetraethoxyorthosilicate (TEOS) and hexadecyltrimethoxysilane as an additive. We studied the effect of gelling time and sol pH on n -octylamine concentration. The organic modification was confirmed by infrared spectroscopic studies, and the hydrophobicity of the coating was tested by the contact angle measurements. The stone surface morphology of sample treated with hybrid sol was characterized. The results show the hybrid gel network exhibits a larger pore size than the gel containing exclusively the silica from TEOS. After the limestone’s surface was modified by hybrid sol, the contact angle of limestone increased from 58° to 123°. The protective performance evaluated by its ability to resist acid rain reveals that the protective effects are satisfied.