Synthesis and characterization of (co)polymeric films obtained under atmospheric plasma conditions

Abstract In our experiments, we propose an atmospheric pressure helium plasma technique as energy source for synthesis of thin (co)polymeric films using a mixture of monomers, especially selected to combine properties of individually polymers into a final (co)polymer film. Three combinations based on thiophene, 3,4-ethylenedioxythiophene and ethylene glycol monomers with specific properties regarding the hydrophobic/hydrophilic character, morphology and electrical behavior have been used. The (co)polymeric films showed a chemistry in a good agreement with the monomers; also oxidative processes are presented in all used combinations. A modified hydrophobic behaviour is detected, except for the polymers that contain ethylene glycol in the mixture of monomers that proved selective water-solubility and a network formation. The surface of films showed an amorphous homogeneous structure and low roughness, also air-stability and reliable attachment on different substrates many months after deposition. The homogeneity is confirmed by dielectric response of samples at large frequency domain. The (co)polymeric films properties recommend the atmospheric pressure helium plasma as an efficient, less expensive and easier method of assisting (co)polymerization reactions. By selection of monomers, these films would be used either as sensors of volatile molecules (chlorine, iodine, chloroform) or as network structures, for studies on interactions with biological compounds.