Gas separation membranes plasma‐polymerized from perfluoromethylcyclohexane/methane mixture

Abstract

Abstract Plasma‐polymerizations of perfluoromethylcyclohexane (PFMCH)/methane (CH 4 ) mixture were investigated by elemental analysis, infrared spectroscopy, and ESCA; and gas transport characteristics of the plasma‐films formed were studied. The addition of CH 4 molecules to PFMCH accelerated defluorination to form plasma‐polymers poor in fluorocarbon units. The surface energy of the plasma‐polymers increased with increasing the CH 4 concentration. The oxygen and nitrogen permeation coefficients (P O2 and P N2 ) and the P O2 /P N2 ratio for the polymer films formed from the PFMCH/CH 4 mixture depended on the CH 4 concentration. The small CH 4 addition was effective in improvement of the P O2 value and of the P O2 /P N2 ratio, but the much addition was ineffective. The oxygen transport through the plasma‐polymers was discussed.