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Vol. 61, No. 1, January (2012)

A Harmonious Relationship Between a Polymer and a Frustrated Liquid Crystal Phase
Hirotsugu KIKUCHI
Institute for Materials Chemistry and Engineering, Kyushu University

In general, flexible polymers and liquid crystals are poorly miscible because the rotational entropy of a polymer chain and the translational entropy of liquid crystal molecules are reduced by mixing each other. We found that after acrylate monomers were polymerized in a liquid crystal blue phase, which is a typical frustrated phase, a stable temperature range of the blue phase was remarkably enlarged from about a few K to more than 60 K, indicating that the polymer stabilized the blue phase. A possible mechanism is proposed to explain this miracle phenomenon that the polymer is concentrated in the disclination lines, which must coexist in a blue phase, then the fixed disclination lines stabilize the blue phase. In this situation, both entropies mentioned above are not reduced and a harmonic relationship between them is formed. The polymer-stabilized blue phase is found to show a large electro-optic Kerr effect and fast response without any surface orientation treatment.
Polymer Preprints, Japan 2011, 60, 34.

The Relationship between Diffusion Behavior and Entanglement of Cyclic Polymers
Daisuke KAWAGUCHI
Department of Applied Chemistry, Nagoya University
Diffusion of cyclic polymers is one of the most attractive subjects of polymer dynamics since chain ends play an important role for diffusion of linear polymers. We have systematically investigated interdiffusion of polystyrene bilayers with various topological diffusion couples such as cyclic/cyclic, linear/linear and linear/cyclic. Mutual diffusion coefficients of cyclic/cyclic polystyrenes are twice as large as those of linear/linear ones at same molecular weights. This is due to less entanglement of cyclic polymers than the linear ones. In the case of linear/cyclic bilayer film, the linear chains diffuse faster than the cyclic ones even though the molecular weight of cyclic molecules is smaller than that of linear ones. This means that cyclic polymers are hard to diffuse into an entangled media.
Polymer Preprints, Japan 2011, 60, 99.

Self-Assembly of Discrete Metal Complexes Integrated by Block Copolypeptide Amphiphiles in Water
Yoshitaka MASAKI, Satoru NAKAHARA, Yuko KOGA, and Keita KUROIWA
Department of Nanoscience, Faculty of Engineering, Sojo University
Block copolypeptide amphiphiles have been attracting much interest as one of the motifs of self-assembly such as nanoparticles, nanosheets, and nanofibers. In this study, we first focus on self-assembly of discrete metal complexes using the block copolypeptides in water. Generally, discrete metal complexes such as [Au(CN)2]ﾐ are molecularly dispersedin water, which cannot interact with each other. On the other hand, block copolypeptide amphiphiles such as Lys183Leu19 lead to one-dimensional integration of discrete metal complexes, resulting in photoluminescence originating from multinuclear complexes with metal-metal interaction. In transmission electron microscopy (TEM), fibrous nanostructure with length of ca. 200 nm and width of ca. 5 nm were observed, which grew to advanced nanoarchitectures. The concept of combination of block copolypeptides and discrete coordination compounds allows us to design flexible and functional supramolecular coordination systems in water.
Polymer Preprints, Japan 2011, 60, 4084.