TITLE:
Synthesis and Structural Characterization of Hydroxyapatite-Wollastonite Biocomposites, Produced by an Alternative Sol-Gel Route
AUTHORS:
Martín A. Encinas-Romero, Jesús Peralta-Haley, Jesús L. Valenzuela-García, Felipe F. Castillón-Barraza
KEYWORDS:
Hydroxyapatite; Wollastonite; Bioceramics; Biocomposites; Sol-Gel
JOURNAL NAME:
Journal of Biomaterials and Nanobiotechnology,
Vol.4 No.4,
September
11,
2013
ABSTRACT: Hydroxyapatite is a type of calcium
phosphate-based material with great interest for biomedical applications, due
to the chemical similarity between this material and the mineral part of human
bone. However, synthetic hydroxyapatite is essentially brittle; the practice
indicates that the use of hydroxyapatite without additives for implant
production is not efficient, due to its low strength parameters. In the present
work, biocomposites of hydroxyapatite-wollastonite were synthesized by an
alternative sol-gel route, using calcium nitrate and ammonium phosphate as
precursors of hydroxyapatite,
and high purity natural wollastonite was added in ratios of 20, 50 and 80 percent by weight immersed in aqueous
medium. Formation of hydroxyapatite occurs at a relatively low temperature of
about 350?C, while the wollastonite remains unreacted. After that, these biocomposites were sintered at 1200?C
for 5 h to produce dense materials. The characterization techniques demonstrated
the presence of hydroxyapatite and wollastonite as unique phases in all products.