|AVS 54th International Symposium|
|Applied Surface Science||Tuesday Sessions|
|Session:||Aspects of Applied Surface Science Poster Session|
|Presenter:||N. Hosaka, Kyushu University, Japan|
|Authors:||N. Hosaka, Kyushu University, Japan
K. Miyamoto, Kyushu University, Japan
H. Otsuka, Kyushu University, Japan
N. Yamada, KENS, Japan
N. Torikai, KENS, Japan
A. Takahara, Kyushu University, Japan
|Correspondent:||Click to Email|
Polymer thin films have numerous technological applications which require the homogeneous film. However, producing stable films is problematic since the polymer thin films tend to dewet from the substrates. Various approaches have been adopted to stabilize these films against dewetting, and recently, much interest has focused on the use of additives to improve the thin film stability. In this paper, polyhedral oligomeric silsesquioxanes (POSS) were used as a nanofiller. POSS have gained considerable attention due to their organic-inorganic hybrid structure which consists of a silica cage with organic groups. The salient feature of this nanosized material is the ability to functionalize the silicon corners with a variety of organic substituents. Our previous study showed that the blending of cyclopenty substituted-POSS (CpPOSS) with the polystyrene (PS) thin films led to an inhibition of dewetting in the films.1 Structural analyses of the films revealed that CpPOSS segregated to the film surface and film-substrate interface, and the inhibition of dewetting can be attributed to the segregation of CpPOSS, accompanying modification of the energetics and morphologies of the interfaces. However, the film with CpPOSS had a problem that its surface was roughened by the aggregation of CpPOSS. Present work is focused on the surface modification of POSS with several organic groups and PS chains to improve the dispersibility of POSS in PS films. Furthermore, the dispersion state of the surface-modified POSS in the film, especially at the surface and interface of the films, was investigated, and the relationship between dewetting inhibition and structure of the film was discussed. The dispersibility of POSS in PS films depended on the surface composition, and POSS with PS chains dispersed well in the films and also stabilized the film against dewetting.2 Smooth surface morphology of the PS film with POSS modified by PS chains was observed by atomic force microscopy. Neutron reflectivity measurements revealed that the POSS still had the tendency to segregate to the film surface and interface even after the introduction of a PS chain on its surface, and this structure seems to be preferable for the inhibition of dewetting of the films.
1 N. Hosaka, N. Torikai, H. Otsuka, A. Takahara, Langmuir, 23, 902-907 (2007).
2 K. Miyamoto, N. Hosaka, H. Otsuka, A. Takahara, Chem. Lett., 35, 1098-1099 (2006).