A simple and sensitive method for measuring CO2 permeability in polymer films has been developed. The method is based on the use of 14CO2. At time zero 14CO2 is injected on the high pressure side of the cell. Permeation is monitored with a Geiger counter which senses 14CO2 on the low pressure side of the cell. The counts/time on the low pressure side are proportional to the total concentration of CO2 which has diffused through the film. With the known source concentration the volume-time curve is constructed and the permeability and time lag are calculated. The system sensitivity as it is presently configured is on the order of 10-15 em3(STP).cm/cm2.sec.cm Hg. Results are presented for a measurement of a 0.025 cm polycarbonate film.
All Science Journal Classification (ASJC) codes
- Surfaces, Coatings and Films
- Polymers and Plastics
- Materials Chemistry