Abstract
The surface molecular motion of monodisperse polystyrene (PS) films was examined using scanning viscoelasticity microscopy (SVM) in conjunction with lateral force microscopy (LFM). The dynamic storage modulus,E′, and loss tangent, tanσ, at a PS film surface with number-average molecular weights,M n , smaller than 30 k were found to be smaller and larger than those for the bulk sample, even at room temperature, meaning that the PS surface is in a glass-rubber transition or fully rubbery sate at this temperature when theM n is small. In order to quantitatively elucidate the dynamics of the molecular motion at the PS surface, SVM and LFM measurements were performed at various temperatures. The glass transition temperature,T g , at the surface was found to be markedly lower than the bulkT g , and this discrepancy between the surface and bulk became larger with decreasingM n . Such an intensive activation of the thermal molecular motion at the PS surfaces can be explained in terms of an excess free volume in the vicinity of the film surface induced by the preferential segregation of the chain end groups.
Similar content being viewed by others
References
F. Garbassi, M. Morra, and E. Occhiello,Polymer Surfaces, from Physics to Technology, Wiley, Chichester, 1994.
G. Beaucage, R. Composto, and R. S. Stein,J. Polym. Sci., Polym. Phys. Ed.,31, 319 (1993).
G. Reiter,Europhys. Lett.,23, 579 (1993).
G. Reiter,Macromolecules,27, 3046 (1994).
J. L. Keddie, R. A. L. Jones, and R. A. Cory,Europhys. Lett.,27, 59 (1994).
J. A. Forrest, K. Dalnoki-Veress, J. R. Stevens, and J. R. Dutcher,Phys. Rev. Lett.,77, 2002 (1996).
J. A. Forrest, K. Dalnoki-Veress, and J. R. Dutcher,Phys. Rev. E,58, 6109 (1998).
T. Kajiyama, K. Tanaka, I. Ohki, S.-R. Ge, J.-S. Yoon, and A. Takahara,Macromolecules,27, 7932 (1994).
K. Tanaka, A. Taura, S.-R. Ge, A. Takahara, and T. Kajiyama,Macromolecules,29, 3040 (1996).
T. Kajiyama, K. Tanaka, and A. Takahara,Macromolecules,30, 280 (1997).
N. Satomi, A. Takahara, and T. Kajiyama,Macromolecules,32, 4474 (1999).
K. Tanaka, A. Takahara, and T. Kajiyama,Macromolecules,30, 6626 (1997).
K. Tanaka, X. Jiang, K. Nakamura, A. Takahara, T. Kajiyama, T. Ishizone, A. Hirao, and S. Nakahama,Macromolecules,31, 5148 (1998).
T. Kajiyama, K. Tanaka, N. Satomi, and A. Takahara,Macromolecules,31, 5150 (1998).
J. A. Hammerschmidt, B. Moasser, W. L. Gladfelter, G. Haugstad, and R. R. Jones,Macromolecules,29, 8996 (1996).
R. H. Schmidt, G. Haugstad, and W. L. Gladfelter,Langmuir,15, 317 (1999).
Y. C. Jean, R. W. Zhang, H. Cao, J. P. Yuan, C.M. Huang, B. Nielsen, and P. Asoka-Kumar,Phys. Rev. B,56, R8459 (1997).
G. B. DeMaggio, W. E. Frieze, D. W. Gidley, M. Zhu, H. A. Hristov, and A. F. Yee,Phys. Rev. Lett.,78, 1524 (1997).
Y. M. Boiko and R. E. Prud’homme,J. Polym. Sci., Polym. Phys. Ed.,36, 567 (1998).
Y. Liu, T. P. Russell, M. G. Samant, J. Stöhr, H. R. Brown, A. Cossy-Favre, and J. Diaz,Macromolecules,30, 7768 (1997).
K. Minato and T. Takemura,Jpn. J. Appl. Phys.,6, 719 (1967).
D. G. H. Ballard, G. D. Wignall, and J. Schelten,Eur. Polym. J.,9, 965 (1973).
N. Saito, K. Okano, S. Iwayanagi, and T. Hideshima,Solid State Physics, Academic Press, New York, 1963, Vol. 14.
T. Fox and P. Flory,J. Polym. Sci.,14, 315 (1954).
P. Doruker and W. L. Mattice,J. Phys. Chem. B,103, 178 (1999).
Author information
Authors and Affiliations
Corresponding author
Rights and permissions
About this article
Cite this article
Kajiyama, T. Activated physical properties at air-polymer interface. Macromol. Res. 15, 109–113 (2007). https://doi.org/10.1007/BF03218761
Received:
Accepted:
Published:
Issue Date:
DOI: https://doi.org/10.1007/BF03218761