resumo
The aim of the present study is to investigate the apatite formation process from glasses in the fluorapatite-diopside-anorthite-albite system. The effects of partial and total replacement of anorthite fraction by albite in the ternary composition 26 Ca-5(PO4)(3)F-44 CaAl2Si2O8-30. CaMgSi2O6 (wt.%) on the properties of glasses and glass-ceramics were evaluated. The scanning electron microscopy (SEM) examination of glasses revealed the precipitation of a nanosize droplet phase in the glassy matrices suggesting the occurrence of amorphous phase separation in all annealed glasses. An overall trend towards polymerization of the glass network with increasing albite content was demonstrated by employing MAS-NMR and FTIR spectroscopy. X-ray diffraction (XRD) and differential thermal analysis (DTA) were used to assess the effect of albite content on the devitrification process and formation of fluorapatite crystalline phase (Ca-5(PO4)(3)F). (C) 2012 Elsevier B.V. All rights reserved.
palavras-chave
CRYSTAL-GROWTH; CERAMICS; FLUOROAPATITE; GLAZES; LASER; K2O; NMR
categoria
Materials Science
autores
Fernandes, HR; Tulyaganov, DU; Ribeiro, MJ; Ferreira, JMF
nossos autores
Hugo Alexandre Gonçalves da Rocha Fernandes
Investigador Júnior
José Maria da Fonte Ferreira
Professor(a) Jubilado(a)Grupos
G3 - Materiais Eletroquímicos, Interfaces e Revestimentos
G5 - Materiais Biomiméticos, Biológicos e Vivos
agradecimentos
Hugo R. Fernandes is grateful for the financial support of CICECO and for the PhD grant (SFRH/BD141307/2007) from the FCT, Portugal.