Correlations between data of 29Si NMR and thermogravimetry for silica/monetite nanocomposites

Autor:	J. G. P. Espínola, J. H. P. Barbosa, A. J. D. Fernandes, L. H. N. Arakaki, Oberto G. da Silva, Maria G. Fonseca
Rok vydání:	2011
Předmět:	Materials science Nanocomposite Mineralogy chemistry.chemical_element Calcium Condensed Matter Physics Phosphate Thermogravimetry chemistry.chemical_compound Hydrolysis Crystallinity chemistry Chemical stability Physical and Theoretical Chemistry Nuclear chemistry
Zdroj:	Journal of Thermal Analysis and Calorimetry. 106:463-467
ISSN:	1572-8943 1388-6150
DOI:	10.1007/s10973-011-1503-z
Popis:	Silica/monetite nanocomposites were synthesized through controlled hydrolysis of tetraethoxysilane at concentrations of 5, 10, 15, and 20% mol/mol of calcium phosphate forming the solids named CaPSil1, CaPSil2, CaPSil3, and CaPSil4, respectively. XRD patterns showed formation of nanocomposites with a decrease in crystallinity. The NMR 29Si spectra suggested an increase in the content of incorporated silica with reduction of Q3 (–SiOH) signal, which contributes for mass loss, in agreement with thermogravimetry. The incorporation of silica increased the chemical stability of the precursor phosphate in an acidic medium.
Databáze:	OpenAIRE
Externí odkaz:	https://explore.openaire.eu/search/publication?articleId=doi_________::d58ffacb03695562289668423c71bd14 https://doi.org/10.1007/s10973-011-1503-z