Sintese de nanoparticulas de fosfatos de calcio em ambientes confinados no sistema Renex-100 / cicloexano / "brine"

AUTOR(ES)
DATA DE PUBLICAÇÃO

2002

RESUMO

Bone is formed by nanometric calcium phosphate particles, organized through a collagen matrix. Synthetic calcium phosphates with low crystallinity and high surface area (SA) may lead to the understanding of bone formation process and to the improvement of implants, through the mimesis of the natural bone behaviour. Nanometric calcium phosphate particles were synthesized in surfactant/oil/water organized systems composed by Renex-100®, hexanol as a cosurfactant, cyclohexane and calcium and phosphate aqueous solutions as brine. The compositions of the systems prepared were typically of reverse microemulsion, liquid crystal, reverse and normal emulsions. The materiais synthesized showed particles of: i) different morphologies (spherical, film and needle-like form); ii) dimensions ranging from 5 to 200 nm; iii) Ca/P molar ratio from 1.23 to 1.77; and iv) SA (45 to 147 m/g) larger than crystalline calcium phosphate solids. These factors varied with the type of organized system used. The potential developed in the interface of electrodes constructed with these materials and phosphate solutions of different concentrations revealed two tendencies: a dependence of the potential with the materials SA, at pH 6, and with the Ca/P molar ratio, at pH 7. These results may indicate a more effective ionic exchange between materials of large SA and aqueous solutions at low pH, which may lead to an improvement of implants response in vivo, as far as regeneration processes occur after the reduction of the local environment pH.

ASSUNTO(S)

hidrocarbonetos nanoestrutura fosfato de calcio

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