title: Assessing surface area evolution during biomimetic growth of hydroxyapatite coatings.
abstract: The surface area of biomimetically deposited hydroxyapatite (HA) coatings on metallic implants is important for the biological performance of the implant. Thus, a nondestructive method of assessing this quantity directly on the solid substrate would be highly valuable. The objective of this study was to develop such a method and for the first time assess the evolution of surface area of HA during biomimetic growth. The surface area of a TiO2-covered titanium substrate was measured prior to and following the biomimetic coating deposition using Ar gas adsorption at 77 K. The presence of HA on the surface was verified with scanning electron microscopy and X-ray diffraction. The specific surface area of the coating was found to increase linearly during 1 week of deposition at a rate of approximately 100 cm2 day-1 (g substrate)-1. The presented method may be used as a tool for studying the evolution in surface area of coatings on solid substrates during biomimetic deposition or other growth processes.
authors.affiliation: Division for Nanotechnology and Functional Materials, Department of Engineering Sciences, The Angström Laboratory, Uppsala University, Box 534, 75121 Uppsala, Sweden. albert.mihranyan@angstrom.uu.s
authors.forename: Albert
authors.initials: A
authors.lastname: Mihranyan
authors.forename: Johan
authors.initials: J
authors.lastname: Forsgren
authors.forename: Maria
authors.initials: M
authors.lastname: Strømme
authors.forename: Håkan
authors.initials: H
authors.lastname: Engqvist
mesh_terms: D040761:Biomimetic Materials / Q000737:chemistry*; D017886:Durapatite / Q000737:chemistry*; D008855:Microscopy, Electron, Scanning; D013499:Surface Properties; D014025:Titanium / Q000737:chemistry; D014961:X-Ray Diffraction
chemical_list: C009495:titanium dioxide; D017886:Durapatite; D014025:Titanium