resumo
Smooth and adherent bioactive coatings with similar to 0.5 mu m thickness were deposited onto Si substrates by the radiofrequency-magnetron sputtering method at 150 degrees C under 0.4 Pa of Ar atmosphere using a bioglass powder as target with a composition in the SiO2-CaO-MgO-P2O5-CaF2-B2O3-Na2O system. The bioactivity of the as-prepared bioglass samples was assessed by immersion in simulated body fluid for different periods of time up to 30 days. Grazing incidence X-ray diffraction, Fourier transform infra-red spectrometry and energy dispersive spectroscopy revealed that important structural and compositional changes took place upon immersing the samples in SBF. Whilst the excellent biomineralisation capability of the BG thin films was demonstrated by the in vitro induction of extensive and homogenous crystalline hydroxyapatite in-growths on their surfaces, a series of bioactivity process kinetics peculiarities (derogations from the classical model) were emphasised and thoroughly discussed. (C) 2012 Elsevier B. V. All rights reserved.
palavras-chave
SIMULATED BODY-FLUID; SILICATE-GLASSES; FOAM SCAFFOLDS; IN-VITRO; TITANIUM; HYDROXYAPATITE; DEPOSITION; COATINGS; CERAMICS; PRESSURE
categoria
Chemistry; Materials Science; Physics
autores
Berbecaru, C; Stan, GE; Pina, S; Tulyaganov, DU; Ferreira, JMF
nossos autores
agradecimentos
G.E. Stan acknowledges with thanks the financial support of this work by the Romanian National Authority for Scientific Research through the UEFISCDI TE 49/05.10.2011 (TE-0164).r Thanks are due to CICECO for the support and to the Portuguese Foundation for Science and Technology for the fellowship grant of S. Pina (SFRH/BPD/64119/2009).