Optimization of Cyclopropylamine Plasma Polymerization toward Enhanced Layer Stability in Contact with Water

The present investigation of cyclopropylamine (CPA) plasma polymerization in pulsed and continuous wave radio frequency (RF) discharges leads to the proposition of conditions at which amine-rich films exhibit a good stability in contact with water. The analyses reveal complex structure of CPA plasma polymers containing hydrocarbon chains, primary and secondary amines, nitriles and possibly imines. The decomposition of the monomer in plasma is progressing with the composite parameter W/F (RF power over monomer flow rate) but, in pulsed discharges, it is possible to deposit the films with N/C ratio above 0.24 using higher monomer flow rate. At the optimized monomer flow rate the 280nm thick film exhibits only 20% thickness loss after 48h immersion in water and still contains about 5at% of the NHx environment.