Materials Research (Jun 2003)

Hydrothermal method for preparing calcium phosphate monoliths

  • Raúl García Carrodeguas,
  • Loreley Morejón Alonso,
  • José Angel Delgado García-Menocal,
  • Lizette Morejón Alonso,
  • María Pau Ginebra Molins,
  • Salvador Martínez Manent,
  • Javier Gil Mur,
  • Jorge Toledo Pérez,
  • José Antonio Planell Estany

DOI
https://doi.org/10.1590/S1516-14392003000300014
Journal volume & issue
Vol. 6, no. 3
pp. 395 – 401

Abstract

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A new hydrothermal route for preparing biphasic calcium phosphate monoliths is proposed. Firstly, a slurry of beta-tricalcium phosphate/ortho-phosphoric acid (b-TCP/H3PO4) is cast into the desired final shape and size to obtain a block composed of dicalcium phosphate dihydrate (DCPD) and b-TCP. This block is then treated in 1.0 M Na2HPO4 at 60 °C in order to hydrolyze the DCPD into Ca10-x(HPO4)x(PO4) 6-x(OH)2-x (CDHA) and Ca8H2(PO4)6 .5H2O (OCP). The result is a monolithic piece which preserves the initial shape and size, but which is composed instead of CDHA, OCP, and b-TCP. During the initial stage, when the pH is slightly alkaline, the product of DCPD hydrolysis is CDHA. However, when a neutral or slightly acidic pH is reached OCP is formed. Test samples processed by this method showed complete conversion of DCPD into CDHA and OCP after 112 h of hydrolysis, and with a compressive strength of 16.2 MPa, similar to cancellous bone.

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