1. Dielectric relaxation of liquid-crystalline polyrotaxane
- Author
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Takao Nakajima, H. Ishibashi, Yasuhiro Sakai, Kohzo Ito, Takeshi Shimomura, Aoi Inomata, and Masatoshi Kidowaki
- Subjects
chemistry.chemical_compound ,Crystallography ,Materials science ,chemistry ,Liquid crystalline ,Relaxation (NMR) ,Supramolecular chemistry ,Solid-state ,General Physics and Astronomy ,Molecule ,Polyethylene glycol ,Dielectric ,Polyrotaxane - Abstract
A new supramolecular system, liquid-crystalline polyrotaxane (LCPR), has been recently prepared by introduction of 4-cyano-4'-n-pentylbiphenyl (5CB) groups to the cyclic molecules of a polyrotaxane (PR) consisting of polyethylene glycol (PEG) and α-cyclodextrin (α-CD). Here we measured and compared the dielectric relaxations of PR and LCPR in solid state to investigate molecular motions of α-CD in PR and LCPR. It was found that PR exhibited a single relaxation mode while LCPR had two modes. These results suggested that the relaxation mode in PR would be due to the sliding fluctuation of α-CD along the axis chain and that the other mode in LCPR should arise from the rotational fluctuation of α-CD modified by 5CB.
- Published
- 2007
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