Premium
Biocompatilibity‐related surface characteristics of oxidized NiTi
Author(s) -
Danilov Anatoli,
Tuukkanen Tuomas,
Tuukkanen Juha,
Jämsä Timo
Publication year - 2007
Publication title -
journal of biomedical materials research part a
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.849
H-Index - 150
eISSN - 1552-4965
pISSN - 1549-3296
DOI - 10.1002/jbm.a.31190
Subject(s) - materials science , nickel titanium , oxide , composite material , crystallite , adsorption , adhesive , work function , phase (matter) , shape memory alloy , layer (electronics) , metallurgy , chemistry , organic chemistry
In the present study, we examined the effect of NiTi oxidation on material surface characteristics related to biocompatibility. Correspondence between electron work function (EWF) and adhesive force predicted by electron theory of adsorption as well as the effect of surface mechanical stress on the adhesive force were studied on the nonoxidized and oxidized at 350, 450, and 600°C NiTi alloy for medical application. The adhesive force generated by the material surface towards the drops of α‐minimal essential medium (α‐MEM) was used as a characteristic of NiTi adsorption properties. The study showed that variations in EWF and mechanical stress caused by surface treatment were accompanied by variations in adhesive force. NiTi oxidation at all temperatures used gave rise to decrease in adhesive force and surface stress values in comparison to the nonoxidized state. In contrary, the EWF value revealed increase under the same condition. Variations in surface oxide layer thickness and its phase composition were also followed. The important role of oxide crystallite size in EWF values within the range of crystallite dimensions typical for NiTi surface oxide as an instrument for the fine regulation of NiTi adsorption properties was demonstrated. The comparative oxidation of pure titanium and NiTi showed that the effect of Ni on the EWF value of NiTi surface oxide is negligible. © 2007 Wiley Periodicals, Inc. J Biomed Mater Res, 2007