Multiple glass transition temperatures of polymer thin films as probed by multi-wavelength ellipsometry

作者：El Ouakili Abderrahim; Vignaud Guillaume^*; Balnois Eric; Bardeau Jean Francois; Grohens Yves

来源：Thin Solid Films, 2011, 519(6): 2031-2036.

DOI：10.1016/j.tsf.2010.10.015

• Glass transition
• Thin films
• Layered structure
• Ellipsometry
• Polystyrene
• Isotactic polymethylmethacrylate

Ellipsometry was used as a technique to determine glass temperature transitions of homopolymer thin films of polystyrene and poly(methyl methacrylate) ranging from 5 to 200 nm. The technique operated systematically at various energies reveals the presence of multiple transitions in these films under certain conditions of preparation. It was observed that in the case of strong polymer-substrate interactions, several Tg were measured and ascribed to a layered structure in the film. In the absence of strong interactions, a more uniform film presenting a single Tg was observed no matter the thickness. The results confirm the recent assumption of thin films organised in multilayers and emphasize the importance of using a highly sensitive multi-wavelength technique in probing such properties.

• 出版日期2011-1-3