Skip to main content

Research Repository

Advanced Search

Solvent accelerated polymer diffusion in thin films

Thompson, R.L.; McDonald, M.T.; Lenthall, J.T.; Hutchings, L.R.


M.T. McDonald

J.T. Lenthall


We have investigated the absorption of cyclohexane vapor into polystyrene films and the resulting polymer interdiffusion that is enabled by this process. The swelling of films due to solvent absorption was relatively insensitive to the film thickness or polymer molecular weight but increased with increasing temperature. The interdiffusion enabled by absorbed solvent was examined in multilayered films comprising alternating layers of deuteriopolystyrene (dPS) and hydrogenous polystyrene (hPS). Deuterium concentration gradients were measured in dry films following exposure to cyclohexane vapor at controlled temperatures and times to establish the relationship between the coefficient of solvent accelerated interdiffusion, D*, and (i) M-w of hPS, (ii) M-w of both hPS and dPS, (iii) temperature, and (iv) film thickness. Scaling relationships were established for D* as a function of molecular weight. D* &SIM; M-w(-1) for increasing hPS molecular weight for M-w(hPS) < M-w(dPS) and was independent of M-w(hPS) for M-w(hPS) > M-w(dPS). This indicates that the lower molecular weight polymer, in keeping with predictions of "fast-mode" diffusion theory, dominates the rate of interdiffusion. When both dPS and hPS molecular weights were increased simultaneously, the interdiffusion coefficient scaled with M-w(-1.8). A marked increase in D* with increasing solvent temperature was observed, consistent with the temperature dependence of film swelling. A strong and unexpected correlation between D* and total film thickness was found. This effect was attributed to prolonged solvent retention in thicker films following exposure to solvent vapor.


Thompson, R., McDonald, M., Lenthall, J., & Hutchings, L. (2005). Solvent accelerated polymer diffusion in thin films. Macromolecules, 38(10), 4339-4344.

Journal Article Type Article
Publication Date Apr 1, 2005
Deposit Date May 10, 2007
Journal Macromolecules
Print ISSN 0024-9297
Electronic ISSN 1520-5835
Publisher American Chemical Society
Peer Reviewed Peer Reviewed
Volume 38
Issue 10
Pages 4339-4344