Kobunshi

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2007 Volume 56 Issue 6 Pages 408-410
Published: June 01, 2007
Released on J-STAGE: October 14, 2011

DOIhttps://doi.org/10.1295/kobunshi.56.408

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Inspired by a Single Chain

Kenichi YOSHIKAWA

2007 Volume 56 Issue 6 Pages 411
Published: June 01, 2007
Released on J-STAGE: October 14, 2011

DOIhttps://doi.org/10.1295/kobunshi.56.411

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Entanglement among Polymers

Yuichi MASUBUCHI

2007 Volume 56 Issue 6 Pages 412-415
Published: June 01, 2007
Released on J-STAGE: October 14, 2011

DOIhttps://doi.org/10.1295/kobunshi.56.412

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Entanglement among polymers is an established concept which stands for topological constraint on polymer dynamics in concentrated solutions and melts. Theories for polymer dynamics based on the entanglement idea such as reptation models and sliplink models have achieved remarkable success to reproduce experiments such as viscoelasticity. In the theories entanglement is assumed to be a dispersed structure carrying elasticity with relaxation and to corresponds a certain molecular weight much larger than Kuhn segment and much less than contour length. Though such a characteristic length has been confirmed experimentally, microscopic description of the entanglement among polymers has not been clarified yet. Recently methods to extract topological constraint in polymer melts by molecular simulations have been proposed by several groups independently and the topological network in the polymers has became observable. Comparison on statistics between the networks obtained by the molecular simulations and by the sliplink theories and simulations reveals the fact that structures of the networks originated from the theoretical assumptions of the sliplink and from the microscopic topological constraint among polymers are quite close. The similarity of the entanglement networks in different class of descriptions on polymers is promising link for multi-scale considerations though the nature of the network structures and the similarity are still open problems.

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Conformation of Polymer Chains in Dilte Solution

Takenao YOSIZAKI

2007 Volume 56 Issue 6 Pages 416-419
Published: June 01, 2007
Released on J-STAGE: October 14, 2011

DOIhttps://doi.org/10.1295/kobunshi.56.416

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On the basis of the helical wormlike (HW) chain, a rather sharply defined image of a single polymer chain in dilute solution may be obtained from an analysis of dilute-solution properties such as the mean-square radius of gyration and the intrinsic viscosity. This review article gives an introductory explanation of the HW model and sketches out its characteristic features which bring the contrast between this model and others such as the Gaussian chain, the wormlike chain, and the rotational isomeric state chain. Then it is shown how the local conformation of polymer chains in dilute solution may be imaged.

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Single-Molecular Wires

Hiroshi SAKAGUCHI

2007 Volume 56 Issue 6 Pages 420-423
Published: June 01, 2007
Released on J-STAGE: October 14, 2011

DOIhttps://doi.org/10.1295/kobunshi.56.420

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We have demonstrated a unique single-molecule processing-technique using electrochemistry, called‘electrochemical epitaxial polymerization.’This technique is based on the step-by-step electropolymerization of a monomer along a lattice of iodine on a gold electrode surface to form single conjugated-polymer wires by applying voltage pulses to a monomer-electrolyte solution. By using this technique, we have succeeded in building a uniform high-density array of single conjugated-polymer wires on an electrode as long as 200 nm, controlling the wire's density, length and direction. Also a single-molecular connection of two different kinds of polymers on surface has become possible.

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Isolation and Properties of One Chain of Conducting and Polar Polymers

Isao YAMAGUCHI

2007 Volume 56 Issue 6 Pages 424-427
Published: June 01, 2007
Released on J-STAGE: October 14, 2011

DOIhttps://doi.org/10.1295/kobunshi.56.424

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One chain of conducting and polar polymers was isolated by using inclusion in the cavity of cyclodextrins (CD's) and intercalation between the crystal lattices of tris(2, 3-naphthylenedioxy)cyclotriphosphazene (NapCP). Optical, electrochemical, and thermal properties of the isolated one chain of the polymers were considerably different from those of polymers in bulks. Water-insoluble poly(thiophene-2, 5-diyl) (PTh), poly(3-methylthiophene-2, 5-diyl), and poly(pyridine 2, 5-diyl) (PPy) became water-soluble by inclusion in β-CD. The aqueous solution of PPy included in β-CD showed an absorption peak at a longer wavelength (434 nm) than PPy in formic acid by 50 nm and a higher quantum yield of photoluminescence (Φ=41%) than PPy in formic acid (Φ=4%). Standing an N-methyl-2-pyrrolidone solution containing emeraldine base form of polyaniline (PANI) and NapCP caused intercalation of PANI in the channels generated by self-assembling of NapCP to give an inclusion adduct. Thermal stability of PANI was improved by intercalation in the channel. Polar polymers such as polybenzimidazole and polyurethane form interchain hydrogen bonding, which strongly effects on thermal properties of the polymers. Inclusion of the polymers into CDs disturbed the interchain hydrogen bonding, which resulted in lowering of glass transition temperatures of the polymers.

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Exotic Properties of a Single DNA Chain

Hiroyuki MAYAMA

2007 Volume 56 Issue 6 Pages 428-432
Published: June 01, 2007
Released on J-STAGE: October 14, 2011

DOIhttps://doi.org/10.1295/kobunshi.56.428

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Individual giant DNA chains show a discrete conformational change, the folding phase transition, between an elongated coil state and a folded compact state under existence of multivalent cations, polymer chains, multivalent anions, and alcohols on the level of a single molecular chain. The stiffness of a polymer chain is essential for the transition. The single DNA chain also expresses a rhythmic conformational change between the coil and folded states under a thermodynamically open condition such as a local temperature gradient generated by optical tweezers. The coupling between the folding phase transition and the thermodynamically open condition is essential. These will be common for semiflexible polymer chains.

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[title in Japanese]

2007 Volume 56 Issue 6 Pages 433
Published: June 01, 2007
Released on J-STAGE: October 14, 2011

DOIhttps://doi.org/10.1295/kobunshi.56.433

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[title in Japanese]

2007 Volume 56 Issue 6 Pages 433a
Published: June 01, 2007
Released on J-STAGE: October 14, 2011

DOIhttps://doi.org/10.1295/kobunshi.56.433a

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[title in Japanese]

2007 Volume 56 Issue 6 Pages 433b
Published: June 01, 2007
Released on J-STAGE: October 14, 2011

DOIhttps://doi.org/10.1295/kobunshi.56.433b

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[title in Japanese]

2007 Volume 56 Issue 6 Pages 433c
Published: June 01, 2007
Released on J-STAGE: October 14, 2011

DOIhttps://doi.org/10.1295/kobunshi.56.433c

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[title in Japanese]

2007 Volume 56 Issue 6 Pages 433d
Published: June 01, 2007
Released on J-STAGE: October 14, 2011

DOIhttps://doi.org/10.1295/kobunshi.56.433d

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Nanomechanical Projerties of Single Polymer Chains Investigated by AFM

Ken NAKAJIMA

2007 Volume 56 Issue 6 Pages 434
Published: June 01, 2007
Released on J-STAGE: October 14, 2011

DOIhttps://doi.org/10.1295/kobunshi.56.434

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Diffusion of Block Copolymer Chains

Hideaki YOKOYAMA

2007 Volume 56 Issue 6 Pages 435
Published: June 01, 2007
Released on J-STAGE: October 14, 2011

DOIhttps://doi.org/10.1295/kobunshi.56.435

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Polymer Nanowires Fabricated Using a Tip

Yuji OKAWA, Daisuke TAKAJO, Masakazu AONO

2007 Volume 56 Issue 6 Pages 436
Published: June 01, 2007
Released on J-STAGE: October 14, 2011

DOIhttps://doi.org/10.1295/kobunshi.56.436

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Direct Observation of Single Molecules in a π-Conjugated Polymer

Ken-ichi SHINOHARA

2007 Volume 56 Issue 6 Pages 437
Published: June 01, 2007
Released on J-STAGE: October 14, 2011

DOIhttps://doi.org/10.1295/kobunshi.56.437

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Single Polymer Wiring and Nano-Scale Optoelectronic Properties

Hiroshi NAKASHIMA, Kazuaki FURUKAWA

2007 Volume 56 Issue 6 Pages 438
Published: June 01, 2007
Released on J-STAGE: October 14, 2011

DOIhttps://doi.org/10.1295/kobunshi.56.438

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Synthesis and Behaviors of Single Polymer Chains in Coordination Nanospaces

Susumu KITAGAWA, Takashi UEMURA

2007 Volume 56 Issue 6 Pages 439
Published: June 01, 2007
Released on J-STAGE: October 14, 2011

DOIhttps://doi.org/10.1295/kobunshi.56.439

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DNA-Based Nanosystems

Masami HAGIYA

2007 Volume 56 Issue 6 Pages 440
Published: June 01, 2007
Released on J-STAGE: October 14, 2011

DOIhttps://doi.org/10.1295/kobunshi.56.440

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[title in Japanese]

Taro ICHIMURA, Satoshi KAWATA

2007 Volume 56 Issue 6 Pages 441-445
Published: June 01, 2007
Released on J-STAGE: October 14, 2011

DOIhttps://doi.org/10.1295/kobunshi.56.441

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[title in Japanese]

Masa-aki MORIKAWA

2007 Volume 56 Issue 6 Pages 446
Published: June 01, 2007
Released on J-STAGE: October 14, 2011

DOIhttps://doi.org/10.1295/kobunshi.56.446

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