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The influence of cathodic polarization and simulated inflammation on titanium electrochemistry
Author(s) -
Brooks Emily,
Tobias Menachem,
Krautsak Kevin,
Ehrensberger Mark
Publication year - 2014
Publication title -
journal of biomedical materials research part b: applied biomaterials
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.665
H-Index - 108
eISSN - 1552-4981
pISSN - 1552-4973
DOI - 10.1002/jbm.b.33123
Subject(s) - titanium , electrochemistry , cathodic protection , materials science , electrolyte , corrosion , dielectric spectroscopy , titanium alloy , polarization (electrochemistry) , analytical chemistry (journal) , chemistry , metallurgy , alloy , electrode , chromatography
This study evaluated the influence of simulated inflammation and cathodic polarization on the electrochemical properties of commercially pure titanium (CpTi) and titanium–6%aluminum–4%vanadium (Ti6Al4V). Normal conditions immersed the metals in phosphate buffered saline at open circuit potential (OCP). Inflammatory conditions immersed the metals in a 150 m M hydrogen peroxide titrated to pH = 5.0 at OCP. Cathodic inflammatory conditions immersed the metals in the inflammatory electrolyte at −1 V versus Ag/AgCl. Cathodic polarization scans revealed a more electropositive corrosion potential ( E corr ) and an increased corrosion current density ( I corr ) for both metals after incubation at inflammatory conditions (CpTi: E corr = 171 mV, I corr = 147 nA/cm 2 and Ti6Al4V: E corr = 241 mV and I corr = 413 nA/cm 2 ) as compared to normal conditions (CpTi: E corr = −249 mV, I corr = 19 nA/cm 2 and Ti6Al4V: E corr = −263 mV and I corr = 11 nA/cm 2 ). Electrochemical impedance spectroscopy showed the polarization resistance ( R p ) decreases and constant phase element (CPE) magnitude increases for both metals when comparing normal (CpTi: R p = 3.5 MΩ cm 2 , CPE = 35 µS s α /cm 2 and Ti6Al4V: R p = 6.5 MΩ cm 2 and CPE = 30 µS s α /cm 2 ) to inflammatory (CpTi: R p = 79 kΩ cm 2 , CPE = 55 µS s α /cm 2 and Ti6Al4V: R p = 230 kΩ cm 2 and CPE = 56 µS s α /cm 2 ) to cathodic inflammatory (CpTi: R p =24 kΩ cm 2 , CPE = 290 µS s α /cm 2 and Ti6Al4V: R p = 12 kΩ cm 2 and CPE = 250 µS s α /cm 2 ) conditions. These observed changes are consistent with the formation of a thin and defective oxide film. Inductively coupled plasma mass spectroscopy revealed that inflammatory conditions increased dissolution of both metals and that the addition of cathodic potential significantly increased the dissolution of the beta phase elements of Ti6Al4V. © 2014 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater, 102B: 1445–1453, 2014.