Order−Disorder Transitions in Block Copolymer Thin Films Studied by Guided Wave Depolarized Light Scattering with Grating Couplers

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• 作者：Jeffrey D. Wilbur ; Zhuangxi Fang ; Bruce A. Garetz ; Maurice C. Newstein ; Nitash P. Balsara
• 刊名：Macromolecules
• 出版年：2008
• 出版时间：June 24, 2008
• 年：2008
• 卷：41
• 期：12
• 页码：4464 - 4470
• 全文大小：1223K
• 年卷期：v.41,no.12(June 24, 2008)
• ISSN：1520-5835

文摘

We demonstrate the use of guided wave depolarized light scattering (GWDLS) with diffraction gratings for studying the properties of soft block copolymer films in the vicinity of order−disorder transitions. The order−disorder transition temperature (T_ODT) of 500 nm thick poly(α-methylstyrene-block-isoprene) films is determined by this technique. Atomic force microscopy on quenched samples is used to verify our conclusion. Disordering and ordering dynamics of these films were examined in real time as the films were heated and cooled across the T_ODT. Our work opens the door for using depolarized light scattering for locating transitions between optically isotropic and optically anisotropic block copolymer phases in thin films.