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Effect of Niobium Oxide on the Structure and Properties of Melt‐Derived Bioactive Glasses
Author(s) -
Lopes João Henrique,
Magalhães Alviclér,
Mazali Italo Odone,
Bertran Celso Aparecido
Publication year - 2014
Publication title -
journal of the american ceramic society
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.9
H-Index - 196
eISSN - 1551-2916
pISSN - 0002-7820
DOI - 10.1111/jace.13222
Subject(s) - devitrification , raman spectroscopy , dissolution , niobium , niobium oxide , nmr spectra database , oxide , phosphate glass , materials science , crystallography , chemistry , analytical chemistry (journal) , spectral line , ion , mineralogy , nuclear chemistry , crystallization , physics , organic chemistry , optics , chromatography , astronomy , metallurgy
The effects of adding Nb 2 O 5 on the physical properties and glass structure of two glass series derived from the 45S5 Bioglass ® have been studied. The multinuclear 29 Si, 31 P, and 23 Na solid‐state MAS NMR spectra of the glasses, Raman spectroscopy and the determination of some physical properties have generated insight into the structure of the glasses. The 29 Si MAS NMR spectra suggest that Nb 5+ ions create cross‐links between several oxygen sites, breaking Si – O – Si bonds to form a range of polyhedra [Nb(OM) 6− y (OSi) y ], where 1 ≤ y ≤ 5 and M = Na, Ca, or P. The Raman spectra show that the Nb–O–P bonds would occur in the terminal sites. Adding Nb 2 O 5 significantly increases the density and the stability against devitrification, as indicated by Δ T ( T x − T g ). Bioglass particle dispersions prepared by incorporating up to 1.3 mol% Nb 2 O 5 by replacing P 2 O 5 or up to 1.0 mol% Nb 2 O 5 by replacing SiO 2 in 45S5 Bioglass ® using deionized water or solutions buffered with HEPES showed a significant increase in the pH during the early steps of the reaction, compared using the rate and magnitude during the earliest stages of BG45S5 dissolution.