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Drastic Change in Orientation of Cylindrical Microdomains Upon Thermal Annealing in Thin Film of Block Copolymer Having Liquid Crystalline Moiety
Author(s) -
Suita Shigeo,
Maruyama Norihiko,
Asaoka Sadayuki,
Sasaki Sono,
Sakurai Shinichi
Publication year - 2018
Publication title -
macromolecular symposia
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.257
H-Index - 76
eISSN - 1521-3900
pISSN - 1022-1360
DOI - 10.1002/masy.201600184
Subject(s) - materials science , perpendicular , copolymer , annealing (glass) , composite material , azobenzene , cylinder , thermal , scattering , penetration (warfare) , optics , polymer , geometry , physics , engineering , mathematics , operations research , meteorology
We found a drastic change in orientation of cylindrical microdomains from perpendicular to parallel with respect to the film surface by thermal annealing for a liquid crystalline diblock copolymer, PEO 122 ‐PMA(Az) 50 , consisting of poly(ethylene oxide) (PEO) and poly(methacrylate) with the side chain of a liquid crystalline azobenzene moiety. Non‐contact mode AFM (atomic force microscopy) is used to observe the orientation of cylinders on the surface of the film specimen. Perpendicular orientation of the PEO cylinders for the as‐spin‐coat specimen is found to change drastically to the parallel orientation as a function of the thermal annealing time at 140 °C. It is interesting to find inclined cylinders in the course of the transition. Grazing‐incidence small‐angle X‐ray scattering is also conducted to analyze the cylinder orientation in the interior of the specimen. As a result, the parallel orientation of the PEO cylinders is found even for the case when the inclined cylinders are detected by AFM on the surface of the film specimen.