CENTRO DE QUIMICA INORGANICA "DR. PEDRO J. AYMONINO"
Unidad Ejecutora - UE
The influence of nickel on brushite structure stabilization
J.R. GUERRA-LÓPEZ; J. A. GÜIDA; G. PUNTE
JOURNAL OF MOLECULAR STRUCTURE
ELSEVIER SCIENCE BV
Lugar: Amsterdam; Año: 2017 vol. 1137 p. 720 - 720
Brushite samples doped with Ni(II) in different concentrations, from 5% to 20%, were prepared in aqueous solution at pH=7 and at two temperatures: 25 and 37 °C. The solid samples were characterized by chemical analysis, infrared spectroscopy (FTIR) and x-ray powder diffraction (XRPD). Chemical analysis has shown Ni(II) almost complete incorporation to the solid phase up to Ni 15%. X-ray diffraction patterns have allowed to identify brushite phase with almost no modification of the line breadth and only small shifts of lines positions with increasing Ni(II) incorporation up to Ni 15%. For larger Ni(II) concentration, in solution, a mixture of phases has been detected. Infrared spectra have supported diffraction results. For Ni 20% and over the characteristic bands of HPO42- anions tend to vanish, and the typical shaped PO43- bands are observed. These results have allowed to establish that the presence of low levels of Ni in the synthetic process not only helps brushite formation; but, also prevents brushite from apatite conversion and, in addition, preserves brushite crystallinity. According to these findings, it is possible to propose that nickel traces present in the urinary system may help triggering brushite stone formation and/or growth, rather than the expected brushite conversion to hydroxyapatite, explaining the detection of big, recurrent, and difficult to treat brushite stones in the last three decades.