resumo
The 70SiO(2)-30CaO (wt.%) sol-gel glasses doped with 1, 3 and 5 NbF5 (wt.%) were prepared via polystep sol-gel route. The synthesized glasses were characterized by XRD, FTIR and SEM. Changes in 1.5 SBF solutions were measured by ICP-AES. XRD of the glasses stabilized at 700A degrees C for 6 hours proved the presence of niocalite. FTIR was consistent with XRD data. The in vitro bioactivity study of all glasses prepared were carried out by soaking in 1.5 simulated body fluid (1.5 SBF) at 37A degrees C for 6 and 12 days in static conditions. The FTIR reveals the formation of A-type and B-type carbonate containing hydroxyapatite (CO(3)HA) layer. Changes in 1.5 SBF solutions, after 6 days of soaking, show that the Ca concentration increased significantly, compared to the initial Ca content in the 1.5 SBF solution before in vitro test. After 12 days of immersion, the Ca concentration decreased, i.e., the formation of HA phase consumed Ca from 1.5 SBF solution. For all soaking times, the concentration of P is much lower than that the used 1.5 SBF. Based on these results we suggest that Ca and P play an active role in the future of the glasses. SEM depicts that the different morphology of hydroxyapatite can be formed as a function of soaking time.
palavras-chave
SIMULATED BODY-FLUID; TRANSFORM INFRARED-SPECTROSCOPY; CARBONATED HYDROXYAPATITE; CALCIUM HYDROXYAPATITE; TEXTURAL PROPERTIES; FTIR SPECTROSCOPY; APATITE FORMATION; SILICATE-GLASSES; CERAMICS; SYSTEM
categoria
Chemistry
autores
Radev, L; Hristova, K; Jordanov, V; Fernandes, MHV; Salvado, IMM
nossos autores
Isabel Margarida Miranda Salvado
Professor associado
Maria Helena Figueira Vaz Fernandes
Professor(a) Jubilado(a)agradecimentos
The authors kindly acknowledge the Chemistry Department at the University of Aveiro and the AQUACHIM JSC - Bulgaria for their support.