Gas Transport in Partially Fluorinated Low-Density Polyethylene

摘要

Low-density polyethylene film was subjected to direct fluorination on one surface by exposure to a dilute fluorine gas stream for various periods of time. Various analyses indicate partial fluorination of a thin surface layer. The permeability coefficients for He, CO2, and CH4 were measured at 35 deg C. The permeability of He was not changed by fluorination; whereas, values for CO2 and CH4 were decreased by as much as two orders of magnitude. The selectivity of transport for gas pairs of different molecule size was greatly improved, suggesting applications of this technique for membrane separation processes.