A new approach in biomimetic synthesis of calcium phosphate coatings using lactic acid-Na lactate buffered body fluid solution

WOS: 000278250100046PubMed ID: 20004750The main objective of this study was to investigate calcium phosphate (CaP) coatings on Ti6Al4V substrates by using the biomimetic technique. To this purpose, a new solution was developed to coat CaP on Ti6Al4V alloy substrates. The newly formulated body fluid (Lac-SBF) contained appropriate amounts of sodium lactate (NaL) and lactic acid (HL), as well as all the other ionic constituents of the human blood plasma. The inorganic ion concentrations of the Lac-SBF solutions were identical with those of human blood plasma. The new Lac-SBF solution of this study eliminated the need for using Tris/HCl or Hepes/NaOH buffers. Prior to coating, Ti6Al4V substrates were chemically treated in NaOH and/or NaOH + H(2)O(2) solutions as an alternative route and then heated at 600 degrees C for 1 h in air. In the previous applications, the Cl(-) ion concentration was found to be higher than blood plasma 103 mM, which exists in human blood plasma as a result of Tris/HCl which are used to prevent precipitation and to keep the pH level at certain values. In this study, instead of using Tris/HCl, HL/NaL which are generated by human body and do not show any toxic behavior, are used and Cl(-) concentration was kept at 103 mM value for the first time. The prepared Lac-SBF was shown to have similar concentration to human blood plasma in terms of all inorganic ions for the first time. Solution properties were evaluated by using turbidimeter, pH meter and rheometer. The coatings were characterized using Fourier-transform infrared spectroscopy (FTIR), X-ray diffraction (XRD), scanning electron microscopy (SEM), and a scratch tester. The obtained results are presented and discussed. (C) 2009 Acta Materialia Inc. Published by Elsevier Ltd. All rights reserved.State and Planning Foundation in Ankara, TurkeyTurkiye Cumhuriyeti Kalkinma Bakanligi [06-DPT-002]; EBIL-TEM in Izmir, TurkeyEge UniversityThis work was funded by the State and Planning Foundation in Ankara, Turkey (Project No. 06-DPT-002). The authors thank EBIL-TEM in Izmir, Turkey, because this foundation partially supported our project

Hydrothermal synthesis of dy-doped BaTiO3 powders

Submicron-sized (similar to 200 nm), monodisperse, and spherical powders of pure and dysprosium (Dy)doped (0.8 at, pet) BaTiO3 have been prepared by "hydrothermal synthesis" at 90 degrees C in an air atmosphere. The powder preparation procedure developed in this work did not necessitate the use of strict and expensive processes, which were commonly required for the removal of free CO2 present in the atmosphere. The prepared powders were found to be crystalline, pure, and contained no BaCO3 as an impurity phase. Pure and Dy-doped BaTiO3 powders synthesized at 90 degrees C had the pseudocubic (space group: Pm-3m) crystal structure. Grain growth characteristics of pure and Dy-doped BaTiO3 pellets were compared during sintering in air over the temperature range from 1200 degrees C to 1500 degrees C. The Dy doping was found to be significantly effective in inhibiting the anomalous grain growth in BaTiO3 samples heated at or above 1200 degrees C