کد مقاله کد نشریه سال انتشار مقاله انگلیسی نسخه تمام متن
1486628 1510561 2005 7 صفحه PDF دانلود رایگان
عنوان انگلیسی مقاله ISI
29Si CPMAS NMR and near-IR study of sol–gel microporous silica with tunable surface area
کلمات کلیدی
موضوعات مرتبط
مهندسی و علوم پایه مهندسی مواد سرامیک و کامپوزیت
پیش نمایش صفحه اول مقاله
29Si CPMAS NMR and near-IR study of sol–gel microporous silica with tunable surface area
چکیده انگلیسی

High-resolution solid-state NMR and IR techniques were used to investigate the surface structure of microporous silica with tunable surface areas, obtained by a sol gel method acting on a variation of gelation time. 29Si MAS NMR and Med-IR evidenced a similar number of silanol groups in all the silicas. Near-IR results revealed the existence of a different ratio of hydrogen bonded silanols and free silanols as a function of surface area. 29Si CP-MAS experiments, including CP spin dynamics studies, were employed to probe hydrogen bonding and local structural environments of various hydroxyl groups of silica surface. These studies showed that for high surface area silicas both free and hydrogen bonded silanols are present at the surface of the samples and the amount of free silanol groups increases with the increasing of the surface area of the samples.

ناشر
Database: Elsevier - ScienceDirect (ساینس دایرکت)
Journal: Journal of Non-Crystalline Solids - Volume 351, Issues 43–45, 1 November 2005, Pages 3476–3482
نویسندگان
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