Navegando por Palavras-chave "wollastonite"

Agora exibindo 1 - 2 de 2
  • Imagem de Miniatura
    Item
    Acesso aberto (Open Access)
    Si-tricalcium phosphate cement: preparation, characterization and bioactivity in SBF
    (ABM, ABC, ABPol, 2011-12-01) Motisuke, Mariana [UNIFESP]; Carrodeguas, Raúl García; Zavaglia, Cecília Amélia De Carvalho; Universidade Federal de São Paulo (UNIFESP); Universidade Estadual de Campinas (UNICAMP); Consejo Superior de Investigaciones Científicas Instituto de Cerámica y Vidrio
    There are evidences considering the effectiveness of Si on enhancing biological properties of calcium phosphates; however, there are not many works relating to the Si-alpha-TCP bone cement. The influence of silicon doping on the properties of Α-TCP cement was analyzed. Si-TCP was obtained by a solid state reaction employing CaCO3, CaHPO4 and CaSiO3 and powder was analyzed by XRD, FTIR, XRF and BET specific area. Cement samples were analyzed for their surface of fracture morphology, mechanical resistance and SBF bioactivity. Cement mechanical resistance was not satisfactory for biomedical application; nonetheless, sample's surface was coated by an apatite layer after immersion in SBF. Notwithstanding, to ensure that silicon is the element responsible for increasing the material's bioactivity it is necessary to evaluate the in vivo performance of the bone cement obtained in this work.
  • Imagem de Miniatura
    Item
    Acesso aberto (Open Access)
    Síntese de whiskers de CaSiO3 em fluxo salino para elaboração de biomateriais
    (Associação Brasileira de Cerâmica, 2012-12-01) Motisuke, Mariana [UNIFESP]; Bertran, C. A. [UNIFESP]; Universidade Federal de São Paulo (UNIFESP)
    Materials reinforcement by ceramic whiskers has been employed for a long time in a variety of industrial applications. Nevertheless, the materials by which these whiskers are commonly made of (carbide and silicon nitride) do not allow their use in biomaterials field due to their high toxicity. Then, it is of interest to synthesize ceramic whiskers which could reinforce biocompatible ceramic and polymeric biomaterials without harming the patients' health. In this manner, the aim of this work is to propose and analyze the limiting process variables of a new synthetic route to produce whiskers of CaSiO3 (wollastonite): a biocompatible, bioactive and readsorbable biomaterial. It was employed the molten salt synthesis at 900 ºC to grow wollastonite crystals which were characterized by X-ray diffraction and scanning electron microscopy. The proposed method was efficient in growing whiskers; however, the dwell time was not sufficient to guarantee a 100% reaction yield, leading to the formation of cristobalite.