¡Anti-Bacteria Property of Hydrogen-Free Carbon Films Grown with Microwave Plasma at Low Temperature
Carbon film has many excellent properties, such as high hardness, low friction
coefficient, chemical inertness and biocompatibility. These combined properties
make carbon film a promising material for bio-medical application. Recently
it is also found that carbon film has the property of anti-bacteria. The
characteristics will help to dissolve the problem of bacteria infection
for medical implant.
At present, as to our knowledge, carbon film is mostly prepared by chemical
vapor deposition (CVD) method using hydrocarbon as carbon source. Hydrogen
is unavoidably contained in this kind of carbon film. In this work, we
have investigated the influence of hydrogen on the anti-bacterial performance
of carbon films, amorphous hydrogenated carbon (a-C:H) film and hydrogen
free carbon (H-free C) film, coated on the stainless steel (AINI 316L).
Carbon films were deposited on microwave plasma reactor.
Figure 1 shows the atomic force microscope (AFM) images of carbon film
on the area of 5 x 5 Êm. it can be seen that a-C:H film was much smoother
than H-free carbon film according the value of average roughness.
Fig. 1. AFM images of carbon film.
Figure 2 shows the FT-IR spectra of carbon films. Compared with that of
H-free carbon film, there are several peaks in the FT-IR spectrum of a-C:H
film as the evidence of hydrogen existence.
Figure 3 shows the bacteria quantity adhered on the different surface after
being immersed in the culture media containing 103 /ml for 24 hours. The quantity of E. coli adhered to C:H film was about 33% of that adhered to the original SUS
surface. While it was about 10% in the case of SUS coated with hydrogen-free
carbon film. It shows that the antibacterial performance of H-free carbon
film was better than a-C:H films.
Fig. 2. FT-IR spectra of carbon films
Fig. 3. Anti-bacterial performance of carbon films.