Dual‐mode sorption kinetics of gases in glassy polymers

Subramanian, S.; Heydweiller, J.C.; Stern, S. A.

doi:10.1002/polb.1989.090270603

Cited by 23 publications

(13 citation statements)

References 10 publications

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“…The apparent diffusion coefficient increased with vapor pressure. In this case, different diffusion coefficients were assigned to the water vapor sorbed by each of the two mechanisms and obtained the following expression for the flux N as the partial immobilization model17–23 developed by Paul and Koros: where D D is the diffusion coefficient of the Henry part and D H is the diffusion coefficient of the Langmuir part. Our results for the PET/water system have been interpreted in terms of a concentration‐dependent diffusion coefficient, which is shown to be mathematically equivalent to the partial immobilization model.…”

Section: Resultsmentioning

confidence: 99%

Sorption and diffusion of water vapor in poly(ethylene terephthalate) film

Shigetomi

Tsuzumi

Toi

et al. 2000

J. Appl. Polym. Sci.

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ABSTRACT:The sorption and diffusion of water vapor in poly(ethylene terephthalate) (PET) film were measured by applying a thermogravimetric analyzer (TG-DTA), which customarily has been used to detect the weight loss of a sample with the increase of temperature under a given atmosphere. In this case, we detected the weight gain of PET film by sorption of water vapor under a given humidity at a constant temperature. Sorption-rate curves were successfully obtained in spite of the low solubility of PET film and the presence of Fickian-type curves. The solubility was better described according to the dual-mode sorption model. The diffusion coefficients were determined in their initial slopes by the short-time method. We found that the diffusion coefficient depended on vapor pressure.

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Section: Resultsmentioning

confidence: 99%

Sorption and diffusion of water vapor in poly(ethylene terephthalate) film

Shigetomi

Tsuzumi

Toi

et al. 2000

J. Appl. Polym. Sci.

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“…In addition to silicate glasses, other glassy systems can be used as analogues. Perhaps the most important such systems are glassy polymers (for summaries, see Crank 1975; Frisch and Stern 1983; Subramanian et al . 1989; Odani and Uyeda 1991; Faupel 1992; Thran et al .…”

Section: Discussionmentioning

confidence: 99%

Isothermal Time‐Series Determination of the Rate of Diffusion of Water in Pachuca Obsidian*

et al. 2004

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s (1960) article introducing an exciting, potentially precise and inexpensive method of dating obsidian artefacts has thus far failed to reach its potential. Numerous efforts to refine, improve and even redevelop the method since that time have similarly failed to achieve the original promise. Only within the last eight years have significant improvements been made, due to both improved analytical techniques and a better understanding of the hydration process. However, most of our mechanistic understanding of the interaction of water with rhyolitic glass is based on experiments performed on melts and glasses at temperatures above their glass transitions, conditions inappropriate for investigation of near-surface environmental conditions. Unfortunately, studies detailing the temporal evolution of the diffusion profile at low temperatures are rare, and few useful data are available on the low-temperature diffusive hydration of silicate glasses. This paper presents data on the experimental hydration of obsidian from the Pachuca source (a.k.a. Sierra de las Navajas, Basin of Mexico) at 75 ° C for times ranging from 3 to 562 days, and compares these results with data for samples obtained from a stratigraphic excavation of the Chalco site in the Basin of Mexico. Samples have been analysed using secondary ion mass spectrometry (SIMS) to provide concentration/depth data. While 75 ° C is still significantly above the temperatures at which archaeological obsidians hydrate, it is well below the glass transition temperature (approx. 400 ° C) and thus processes are likely to be similar to those that occur in nature, but fast enough to be observed over a laboratory timescale. The results demonstrate that a simple square-root-of-time model of the evolution of the diffusion profile is not adequate to describe the diffusion process, as measured diffusion profiles exhibit the effects of concentration-and time-dependent, non-Fickian diffusion. With progressive hydration, characteristic diffusion coefficients first decrease, then increase with time. Surface concentration increases with time, but an intermediate plateau is observed in its time evolution that is consistent with results obtained from the suite of Chalco samples. Both of these effects have been observed during diffusion in glassy polymer systems and are associated with the build-up and relaxation of self-stress caused by the influx of diffusing material.

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Section: Diffusion Coefficientsmentioning

confidence: 99%

Sorption and diffusion of water vapor in poly(ethylene terephthalate) film

Shigetomi

Tsuzumi

Toi

et al. 2000

J. Appl. Polym. Sci.

View full text Add to dashboard Cite

The sorption and diffusion of water vapor in poly(ethylene terephthalate) (PET) film were measured by applying a thermogravimetric analyzer (TG-DTA), which customarily has been used to detect the weight loss of a sample with the increase of temperature under a given atmosphere. In this case, we detected the weight gain of PET film by sorption of water vapor under a given humidity at a constant temperature. Sorption-rate curves were successfully obtained in spite of the low solubility of PET film and the presence of Fickian-type curves. The solubility was better described according to the dual-mode sorption model. The diffusion coefficients were determined in their initial slopes by the short-time method. We found that the diffusion coefficient depended on vapor pressure.

show abstract

Dual‐mode sorption kinetics of gases in glassy polymers

Cited by 23 publications

References 10 publications

Sorption and diffusion of water vapor in poly(ethylene terephthalate) film

Sorption and diffusion of water vapor in poly(ethylene terephthalate) film

Isothermal Time‐Series Determination of the Rate of Diffusion of Water in Pachuca Obsidian*

Sorption and diffusion of water vapor in poly(ethylene terephthalate) film

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