Barrier properties of thin films polymerized from CF3H/C2H4 electron cyclotron resonance plasmas

Thin fluoropolymer films are deposited on polyethylene foils in an electron cyclotron resonance plasma. Trifluoromethane (CF 3 H) and ethylene (C 2 H 4 ) are used as monomers. The permeability of toluene through the plasma polymer films is investigated in dependence on the CF 3 H:C 2 H 4 monomer mixture ratio. It is shown that thin fluorinated hydrocarbon layers strongly reduce the permeation, e.g. for toluene the permeability was decreased by a factor of about 1600. The amount of the permeated liquid was measured as a function of time using a flame ionisation detector. Permeability measurements were performed at temperatures of 22 °C, 40 °C and 50 °C.