Results from interactions of non equilibrium oxygen plasmas with both gaseous and liquid substrates are presented. High voltage and radio frequency plasmas are generated by electron impact with 02 molecules which give rise to species such as 0, O2+ O- and consequently, more electrons which are accelerated by the electric field and keep the discharge on. Oxidation products plus polymeric material are obtained if an 100:1 oxygen—hydrocarbon gas mixture is used. As this ratio tends towards 1:1. fragmentation and condensed products, arising from oxygen free organic radicals, are formed instead. Conversely, O3P addition to the hydrocarbon is the unique process that takes place if the oxygen plasma is allowed to impinge on the surface of the liquid substrate. Results are optimum when the temperature of this liquid is so low that its vapor pressure is about 0,01 torr Some theoreutical approaches of the processes are discussed.
