Abstract
Interfacial structures of deuterated poly( methyl methacrylate) (dPMMA) and polystyrene (dPS) films with gas such as carbon dioxide (CO2) and nitrogen (N2) under the pressure of 0.1 MPa were discussed on the basis of neutron reflectivity (NR) measurements. The interface was analyzed using a model that the density of the outermost region of a polymer film was lower than that in the interior region due to the penetration of gas molecules and the profile was expressed by a single exponential equation with a decay length (zeta). The zeta value for the dPMMA films under CO2 and N2 atmospheres was larger than that under vacuum at a given temperature, and the extent was more remarkable under CO2 than under N2. On the other hand, such a ‘swollen interfacial layer’ was not clearly discerned for the dPS films.
