Russian Journal of Applied Chemistry, 2013, Vol. 86, No. 9, pp. 1340−1343.
Pleiades Publishing, Ltd., 2013.
Original Russian Text © V.S. Rudnev, K.N. Kilin, M.A. Medkov, I.V. Lukiyanchuk, E.E. Dmitrieva, 2013, published in Zhurnal Prikladnoi Khimii, 2013,
Vol. 86, No. 9, pp. 1369−1372.
AND INDUSTRIAL INORGANIC CHEMISTRY
Та-containing Oxide Coatings on Titanium
for Biomedical Application
V. S. Rudnev
, K. N. Kilin
, M. A. Medkov
, I. V. Lukiyanchuk
, and E. E. Dmitrieva
Institute of Chemistry, Far Eastern Branch of Russian Academy of Sciences, Vladivostok, Russia
Far Eastern Federal University, Vladivostok, Russia
Received April 8, 2013
Abstract—Bioinert, biocompatible, chemical-resistant oxide coatings containing Ta
, which are promising to
be applied to titanium implants, were produced on titanium by plasma electrolytic oxidation in an aqueous elec-
trolyte. An effect of formation conditions on the elemental and phase composition, thickness, and roughness of the
coatings was researched. It was found that an addition of polyethylene glycol to electrolyte without affecting the
elemental composition and the thickness causes a change in the porosity and an increase in the roughness of the
formed oxide layer. Changing the surface arrangement may allow affecting an adhesion of biotissues to titanium
implants with coatings and accumulating drugs by the coatings.
In recent years an interest to the use of Ta
ings considerably growths in various ﬁ elds of science
and technology. This is due to the fact that this oxide has
a number of unique properties such as high dielectric
constant, density, melting point, and chemical inertness.
Previously by plasma electrolytic oxidation (PEO) the
coatings of Ta
composition were formed on
titanium . The coatings with a thickness of from 2
to 18 μm containing up to 20 at % tantalum were pro-
duced within 2 minutes under potentiostatic conditions
(formation voltages U
from 50 to 250 V in an aqueous
]). In the coatings surface there
are pore mouths of size from 0.5 to 2 μm. The contact
angle of the coatings by distilled water was 68–85°. The
approach is suitable for applying Ta-containing coatings
to titanium implants and stents for improving their corro-
sion resistance, biocompatibility, and chemical inertness.
Conditions for controlling the properties of the coat-
ings, e.g., by morphology, content of tantalum, titanium
adhesion to the substrate, etc, are of interest for exami-
It is known that porosity, morphology, composition,
thickness, and other characteristics of PEO coatings
parameters can be influenced by an introduction of
macromolecular organic compounds into electrolyte,
in particular, surfactants [2–4]. Polyethylene glycol
–OH (PEG) is a soluble
polymer, one of widely used in medicine and cosmetol-
ogy. The study task was to investigate the effect of the
additional introduction of PEG into aqueous electrolyte
] on the morphology, composition, and
thickness of the Ta-containing coatings on titanium.
Samples for applying the coatings were made of ti-
tanium alloy VT1-0 of a 2×0.5 cm size and a thickness
of 0.5 mm. Pretreatment of samples included chemical
polishing in a mixture of concentrated acids (HNO
: HF =
3 : 1 by volume) at 70°C. Polished samples were rinsed
with distilled water and dried at 70°C in air.
An aqueous electrolyte containing NH
used for the formation of coatings using PEO. The elec-
trolyte was prepared by dissolving Ta(OH)
in a minimum
amount of hydroﬂ uoric acid. The solution was evapo-
rated to remove an acid excess and then it was diluted
with water to a tantalum concentration of 10 g L
stoichiometric amount of ammonium ﬂ uoride was added.