The non-equilibrium atmospheric pressure Ar plasma was applied for the polymerization of maleic anhydride (MA). The deposited films were analyzed by using Fourier transform infrared spectroscopy (FT-IR) proving the monomer was successfully polymerized with retaining the functional groups. The intensity of optical emission spectroscopy (OES) of the plasma jet was found to become weaker when the monomer was introduced into the jet. This was interpreted as the result of the energy transfer from the metastable Ar to the monomer. It was proposed that the excited MA changed into π-π* transition state to produce dimer biradicals which initiate the polymerization.
Optical emission spectroscopy of atmospheric-pressure non-equilibrium plasma with mist injection