کد مقاله کد نشریه سال انتشار مقاله انگلیسی نسخه تمام متن
77171 49158 2006 9 صفحه PDF دانلود رایگان
عنوان انگلیسی مقاله ISI
Increasing the hydrothermal stability of mesoporous SiO2 with methylchlorosilanes—a ‘structural’ study
موضوعات مرتبط
مهندسی و علوم پایه مهندسی شیمی کاتالیزور
پیش نمایش صفحه اول مقاله
Increasing the hydrothermal stability of mesoporous SiO2 with methylchlorosilanes—a ‘structural’ study
چکیده انگلیسی

Mesoporous silica gels with various pore sizes are hydrophobised by liquid-phase silylation with mono- and difunctional methylchlorosilanes. Changes in the pore structure as a result of the silylation reactions are monitored in order to assess the distribution of the hydrophobic groups. Extensive polymerisation of dimethyldichlorosilane (DMDCS) causes blocking of the micropore fraction. For silica with pore sizes in the supermicroporous range (2 nm pore diameter), this leads to hydrophobisation of almost exclusively the outer surface. While for trimethylchlorosilane (TMCS) a smaller number of molecules react with the surface, modification is more homogeneous and an open structure is optimally preserved. Both silanes lead to lower surface polarity and increased hydrothermal stability, i.e., preservation of the porous structure during exposure to water. As DMDCS reacts more extensively, this agent would be recommended for ceramics with pore diameters larger than about 6 nm. TMCS is the most suitable agent for pore diameters smaller than 4 nm and in case preservation of micropores is required.

ناشر
Database: Elsevier - ScienceDirect (ساینس دایرکت)
Journal: Microporous and Mesoporous Materials - Volume 88, Issues 1–3, 21 January 2006, Pages 63–71
نویسندگان
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