Preparation of High-Density Polymer Brushes with a Multihelical Structure
| Autor: | Noboru Ohta, Kevin L. White, Atsushi Takahara, Kazutoshi Yokomachi, Masanao Sato, Maiko Nishibori, Tomoyasu Hirai, Yuko Konishi, Ryohei Ishige, Kazutaka Kamitani, Kiyu Uno, Nobuyuki Otozawa, Hitoshi Shimamoto, Tomoki Kato |
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| Rok vydání: | 2018 |
| Předmět: |
Materials science
Silicon chemistry.chemical_element High density 02 engineering and technology Crystal structure Substrate (electronics) 010402 general chemistry Polymer brush 01 natural sciences Contact angle Tacticity Electrochemistry General Materials Science Spectroscopy chemistry.chemical_classification technology industry and agriculture Surfaces and Interfaces Polymer equipment and supplies 021001 nanoscience & nanotechnology Condensed Matter Physics 0104 chemical sciences chemistry Chemical engineering 0210 nano-technology |
| Zdroj: | Langmuir : the ACS journal of surfaces and colloids. 34(10) |
| ISSN: | 1520-5827 |
| Popis: | It is well-known that a mixture of isotactic and syndiotactic polymethyl methacrylate (PMMA) forms a stereocomplex consisting of a multihelical structure in which an isotactic chain is surrounded by a syndiotactic chain. Here, we report the basic structure of the stereocomplex formed when the syndiotactic PMMA chains are tethered to a silicon substrate and form a high-density polymer brush. The influence of geometric confinement was investigated by preparing the high-density polymer brushes on a flat and spherical substrate. In both cases, mixing the untethered isotactic PMMA with the grafted syndiotactic PMMA led to the formation of a stereocomplex with a multihelical structure. Static contact angle measurements showed a hindered surface mobility at the outermost surface of the polymer brush, indicating that the stereocomplex forms a crystalline structure. A syndiotactic polymer brush with substituted fluoroalkyl groups was prepared to increase the contrast for grazing incidence wide-angle X-ray diffraction (GIWAXD) measurements. The GIWAXD results verified that the stereocomplex forms a crystalline structure oriented perpendicular to the substrate with a relatively low degree of orientation. |
| Databáze: | OpenAIRE |
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