An advanced gas/vapor permeation system for barrier materials: Design and applications to poly(ethylene terephthalate)

A new gas/vapor mixture permeation system is described to investigate the effect of organic molecules on oxygen (O 2 ) and carbon dioxide (CO 2 ) transport in barrier materials. Methanol vapor was considered as a flavor simulant mainly because of its conveniently high diffusion coefficient, which makes the experimental time accessible. A highly accurate syringe pump was used to introduce a desired activity level of vapor into gas feed stream. Adsorption of methanol on high energy surfaces is carefully characterized to prevent underestimation of methanol permeability. A special permeation cell was also developed to study the effect of interacting vapors on O 2 and CO 2 transport in barrier materials. Systematic permeation measurements were conducted for binary and ternary gas/vapor permeation measurements (e.g., MeOH/O 2 and O 2 /CO 2 /MeOH) to verify the feasibility of our new vapor/gas permeation system.