Year: 2002
Type: article
Abstract: In situ neutron reflectivity and dynamic secondary ion mass spectrometry measurements were used to investigate the dynamics of polystyrene thin films in supercritical carbon dioxide (scCO 2 ). The results show that the large degree of anomalous swelling observed is associated with a decrease in glass transition temperature that occurs only within a narrow region of the phase diagram associated with the density fluctuation ridge in scCO 2 region. Furthermore, the plasticization effect induced by the density fluctuations was found to enhance the polymer interdiffusion by 2 orders of magnitude as the ridge was approached. Within the ridge the diffusion coefficients scale as M 2 and can be approximated by an effective William-Landel-Ferry (WLF) equation.
Source: Europhysics Letters (EPL)
Language: English
Subfield: Materials Chemistry
Field: Materials Science
Domain: Physical Sciences
Open Access status: bronze
OpenAlex ID: W2051945333