Free volume expansion and nanofoaming of supercritical carbon dioxide treated polystyrene

Authors :: Kenji Ito
Chunqing He
Yoshinori Kobayashi
Toshitaka Oka
Hideaki Yokoyama
Cedric Dutriez
Source :: The journal of physical chemistry. B. 112(39)
Publication Year :: 2008
Abstract: Free volume of polystyrene films treated with supercritical carbon dioxide (SCCO 2) were examined by positron annihilation lifetime spectroscopy. Variation of the free volume sizes after the SCCO 2 treatment due to the release of trapped CO 2 and structural relaxation of the polymer was observed. After 500 h from the depressurization, the free volume of the treated films free from CO 2 was approximately 0.306 nm in radius and much larger than that of the untreated films of approximately 0.295 nm in radius due to the freezing of the swollen structure caused by the large solubility of CO 2.

Subjects :: chemistry.chemical_classification
Supercritical carbon dioxide
Materials science
Relaxation (NMR)
Analytical chemistry
Polymer
Radius
Surfaces, Coatings and Films
chemistry.chemical_compound
Volume (thermodynamics)
chemistry
Polymer chemistry
Materials Chemistry
Polystyrene
Physical and Theoretical Chemistry
Solubility
Spectroscopy

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