Plasma Polymerization of Acrylic Acid Revisited

To perform a systematic study over a broad parameter range of acrylic acid discharges, we varied the energy input W/F over a wide range. Five different regimes could be identified (from low to high energy input): regime I, where oligomerization takes place; regime II, the radical-dominated plasma polymerization of acrylic acid; regime III, a transition regime showing etching/oxidation effects; regime IV, where the plasma polymerization resembles the one observed for CO2/C2H4, discharges; and regime V, where etching effects yield a reduction in deposition rate. These results show that the polymerization mechanism can be described as a function of the energy input W/F. Specifically, a parameter range where acrylic acid can be replaced by CO2/C2H4 discharges has been identified.