title: Dip coated silicon-substituted hydroxyapatite films.
abstract: Silicon-substituted hydroxyapatites have been deposited onto Ti6Al4V substrates by sol-gel technology. The Ca(10)(PO(4))(6-x-y)(SiO(4))(x)(CO(3))(y)(OH)(2-x+y) coatings obtained, with silicon contents up to x=1 (2.8 wt.%), show a homogeneous and crack-free surface composed of particles smaller than 20 nm. The silicon enters into the apatite structure in the form of SiO(4)(4-) groups that partially substitute the PO(4)(3-) groups. The Si content and the Ca/P molar ratio of the coatings agree with those originally introduced in the sols. Layers with thicknesses around 600 nm show adhesion strengths superior to 20 MPa as determined by a pull-out test. The formation of an apatite layer onto these coatings after immersion in a simulated body fluid is enhanced by the presence of silicon.
authors.affiliation: Departamento de Química Inorgánica y Bioinorgánica, Facultad de Farmacia, Universidad Complutense, 28040 Madrid, Spain.
authors.forename: Natalia
authors.initials: N
authors.lastname: Hijón
authors.forename: M
authors.initials: M
authors.lastname: Victoria Cabañas
authors.forename: Juan
authors.initials: J
authors.lastname: Peña
authors.forename: María
authors.initials: M
authors.lastname: Vallet-Regí
mesh_terms: D000268:Adhesiveness; D000497:Alloys; D020099:Coated Materials, Biocompatible / Q000737:chemistry*; D005782:Gels; D006882:Hydroxyapatites / Q000737:chemistry*; D066298:In Vitro Techniques; D008422:Materials Testing; D008854:Microscopy, Electron; D012825:Silicon / Q000737:chemistry*; D017550:Spectroscopy, Fourier Transform Infrared; D014025:Titanium / Q000737:chemistry; D014961:X-Ray Diffraction
chemical_list: D000497:Alloys; D020099:Coated Materials, Biocompatible; D005782:Gels; D006882:Hydroxyapatites; C031462:titanium alloy (TiAl6V4); D014025:Titanium; D012825:Silicon