کد مقاله | کد نشریه | سال انتشار | مقاله انگلیسی | نسخه تمام متن |
---|---|---|---|---|
9770119 | 1501939 | 2005 | 6 صفحه PDF | دانلود رایگان |
عنوان انگلیسی مقاله ISI
Spectroscopic studies of glassy phospho-silicate materials
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موضوعات مرتبط
مهندسی و علوم پایه
شیمی
شیمی آلی
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چکیده انگلیسی
The aim of the work is to determine the internal structure of bioactive glasses based on structural studies. Due to the absence of the long-range order, the X-ray methods usually applied in the studies of crystalline materials are of low applicability in the investigations of glasses. Therefore, spectroscopic methods, such as IR and NMR, which make it possible to 'see' the short- and the middle-range order are extremely suitable in their studies. IR investigations have shown that the glasses studied exhibit non-uniform domain composition, which should facilitate their transformation into glass-crystalline state. Additionally, detailed NMR measurements have been carried out in order to determine the influence of glass structure on the course of its crystallization. These studies make it possible to verify the common opinions on the middle-range order (domains) in the glasses studied. The results obtained for 27Al and 31P are particularly promising. Changes in the environment of [SiO4]4âtetrahedra, which can be spatially connected with various numbers of [PO4]3â and [AlO4]5â tetrahedra cause the presence of various types of bridging bonds, such as Si-O-Si, Si-O-Al and Si-O-P. This in turn has significant impact on the number and the shape of the bands occurring in the spectra.
ناشر
Database: Elsevier - ScienceDirect (ساینس دایرکت)
Journal: Journal of Molecular Structure - Volumes 744â747, 3 June 2005, Pages 621-626
Journal: Journal of Molecular Structure - Volumes 744â747, 3 June 2005, Pages 621-626
نویسندگان
Maciej Sitarz, MirosÅaw Handke, Zbigniew Fojud, Stefan Jurga,