ε (eV)

like ozone or hydroxyl radical can be produced and play in the same time a major
role in neutralization of bacteria. An increase efficacy also showed the addition
of small halogens volumes such as chlorine, bromine and iodine within the steril-
ization chambers. It was concluded that oxygen mixtures containing gases (e.g.,
CO2, O2, N2, H2O vapors, etc.) are much more effective than others (e.g., inert
gases) [17].
A new step towards a better understanding of sterilization process came when
the ultraviolet emission, inherent in plasmas, was taken into account as an in-
activation agent, especially for its role played in the direct attack against DNA
molecules [15-18, 70]. Until then, in low pressure plasmas, the main mechanism it
was believed to be the incineration and oxidation of the biological structures [55,
58].
The first model of the sterilization process came 1993, based on a thermody-
namic approach revealing some insights on the influence of the substrate tempera-
ture on the oxidation rate of microorganisms [17]. The kinetics of adsorption and
desorption processes which lead to a better destruction rate were analyzed. It was
concluded that the free radicals present in the discharge are reacting with the cell
walls, enzymes and nucleic acids destroying the vital parts of the microorganisms.
However, this simplification of the inactivation mechanisms did not take into ac-
count the UV radiation. A more extensive physical description of the sterilization
process is advanced few years latter, which takes into account the dynamics of
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