Structural analysis of Si-substituted hydroxyapatite: zeta potential and X-ray photoelectron spectroscopy

• Type: Article in International Scientific Journal
• Date: 2002

Authors

Botelho, CM (Author) Other; Lopes, MA (Author) FEUP; Gibson, IR (Author) Other; Best, SM (Author) Other; Santos, JD (Author) FEUP

Journal

Title: Journal of Materials Science: Materials in Medicine

Vol. 13

Pages: 1123-1127

ISSN: 0957-4530

Publisher: Springer Nature

Indexing

ISI Web of Knowledge - 101 Citations

ISI Web of Science

Scopus - 142 Citations

Scientific classification

FOS: Engineering and technology > Environmental biotechnology

Other information

Authenticus ID: P-000-M8H

DOI: 10.1023/a:1021177601899

Abstract (EN): The aim of this study was to determine the effect of the incorporation of silicon on the surface charge of hydroxyapatite (HA) and to assess surface structural changes of HA and Si-HA induced by dissolution in both static and dynamic systems. X-ray photoelectron spectroscopy (XPS) analysis showed that SiO4- groups were substituted for PO43- groups in the silicon-hydroxyapatite (Si-HA) lattice according to a previously proposed substitution mechanism without the formation of other crystalline phases, such as tricalcium phosphate or calcium oxide. The substituted silicon induced a decrease in the net surface charge and the isoelectric point of HA as determined by zeta potential (ZP) measurements. At physiological pH = 7.4 the surface charge of Si-HA was significantly lowered compared to unmodified HA, i.e. - 50 +/- 5 to - 71 +/- 5 eV, caused by the presence of silicate groups in the HA lattice, which may account for a faster in vitro apatite formation using SBF testing. XPS results indicated that silicon seems to be preferentially leached out from Si-HA surface compared to other ionic species after dissolution studies in tris-buffer using a dynamic system. (C) 2002 Kluwer Academic Publishers.

Language: English

Type (Professor's evaluation): Scientific

No. of pages: 5