Prakt. Met. Sonderband 38 (2006) 439
are far 2.2 Film Characterization
Ss is very The crystallographic structure of the films was analyzed using a Rigaku X-ray diffractometer
provides and a Jeol 2010F field emission analytic transmission electron microscope (TEM) operated at
nd (2) it 200 kV.
en used
fers. 1011
n donor 2.3 Protein Absorption
> activity
00 high, Protein adsorption on the deposited films was evaluated using HSA and Fib solutions in
phosphate buffered saline (PBS, pH = 7.4). The protein solutions had concentrations of 1
chanical mg/ml. The samples were dipped into the protein solutions for 30 min at room temperature.
ate bias The samples were subsequently rinsed with de-ionized water and dried with Na.
bacterial Spectroscopic ellipsometry (SE) measurements were carried out using a Woollam Co. M-
2000 Variable Angle Spectroscopic Ellipsometer equipped with WVASE32™ and EASE™
software to record the optical spectra of the protein films for photon energies in the range
from 1.2 to 3.3 eV.
2.4 Mechanical and Tribological Testing
“oupons The film hardness and elastic modulus were measured using a MTS Systems Corporation
in detail Nanoindenter XP nanomechanical testing system using loads of 1500 uN. The apparatus
rity) in a and the data collection conditions and procedures were described elsewhere. Wear rates
;t to 0.2 were also measured using a Spire Corp. ball-on-disk tribotester. The wear of ZrN-Me coated
3d at Px Ti-Al-V coupons was compared to the wear of ZrN-coated coupons and uncoated ones. The
dd 7 W. tribotester was operated by sliding a 6 mm diameter 440C SS ball on a stationary coated
n Vp = - sample using a normal load of 5 N. The sliding speed was 0.11 m/s, and the total sliding
Ss grown distance was 10 000 m for all tests unless failure was detected earlier. The humidity and
temperature during the test were kept at 50% and 23 °C, respectively. Wear rates were then
determined from multiple surface profilometry traces across the wear track. Scanning
electron microscopy was also used to investigate the surface of the wear track and of the film.
2.5 Antibacterial Activity
The antibacterial activity of ZrN-Ag films was tested against the activity of ZrN films and blank
substrates. All films were grown on surgical titanium substrates. The antibacterial properties
of the films were tested using three strains of bacteria, namely, Staphylococcus epidermis,
Staphylococcus aureus and Escherichia coli. Bacterial solutions were prepared from pure
cultures. Sterile solutions of tryptic soy (TS) broth were inoculated with bacteria and allowed
to incubate at 37°C for a period of 24 hours. The absorbances of these solutions were
measured at 600 nm. The solutions were then diluted with sterile TS broth to a point where
