Polymers - Vol. 58, No. 9 (September, 2009)

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Vol. 58, No. 9 September,( 2009)

Conformational Properties of Rod Brushes
Seigou KAWAGUCHI
Graduate School of Science and Engineering, Yamagata University

Conformational properties of cylindrical rod brushes consisting of a flexible polystyrene main chain and poly(n-hexyl isocyanate) (PHIC) rod side chains have been studied by static light and small-angle X-ray scattering (SAXS) in THF at 25Ž. The molecular weight dependence of z-averaged mean-square radius of gyration (<Rg2>z) of the brush is analyzed in terms of the wormlike cylinder model taking into account the end effects. The main chain stiffness of the rod brush ƒÉ-1 remarkably increases by the densely located rod side chains, to follow the scaling law of ƒÉ-1 å Ls1, where Ls is the contour length of the side rod. The backbone stiffness of the rod brush is much higher than that of the flexible brush consisting of flexible polystyrene side chains with the corresponding Ls. Polymer Preprints, Japan 2009, 58, 55.

Nanotemplating Process using Liquid Crystalline Block Copolymer Film
Kaori ITO and Tomokazu IYODA
JST-PRESTO, Division of Integrated Molecular Engineering, Chem. Res. Lab., Tokyo Inst. of Tech
Self-organization ordering into periodic nanostructures has potential use in applications ranging from optics to microelectronics as bottom-up nanotechnologies. Block copolymer is one of the foremost examples due to its micro/nanophase separated structure with high scalability easily tuned by the polymer structure, i.e., polymer compositions. We have designed a series of amphiphilic LC diblock copolymers, PEO-b-PMA(Az), consisting of poly(ethylene oxide) as hydrophilic segment and poly(methacrylate) containing azobenzene moiety as hydrophobic liquid crystalline segment. The PEO-b-PMA(Az) forms a hexagonally arranged PEO nanocylinder array with perpendicular alignment. We demonstrate new microdomain alignment control with electrochemical ion diffusion through the PEO nanocylinders, enhanced under electrochemical E-field, as well as the selective doping with magnetic and electric conducting metal oxides, and electropolymerizable organic monomers. Polymer Preprints, Japan 2009, 58, 96.

Solvent-Dependent Helical Conformation of Amylose Derivatives
Ken TERAO
Graduate School of Science, Osaka University
Helical conformational change of amylose derivatives in solution causes an appreciable difference in their helical pitch per residue h. We determined this value for amylose tris(phenylcarbamate) (ATPC) in five solvents and found that the obtained h value significantly depends on the solvent (Polymer Journal, 2009, 41, 201. Biopolymers, 2009, 91, 729.). The h values in 1,4-dioxane and 2-ethoxyethanol are smaller than those in a ketone and esters, owing to the intramolecular hydrogen bonding in the former solvents. Both h and the Kuhn segment length (chain stiffness parameter) in the latter solvents, which may hydrogen-bond to NH groups of ATPC, increase with increasing the bulkiness around the carbonyl group of each solvent molecule. This is most likely due to the solvent molecules interacting with NH groups of ATPC which is hindering the internal rotation of the amylosic main chain. Polymer Preprints, Japan 2009, 58, 84.

Novel Approach for Solid State Luminescent Materials
Norimitsu TOHNAI
Graduate School of Engineering, Osaka University
The development of tunable organic fluorophores has recently been met with increasing interest because of their many applications in analytical and material sciences. Recently, we proposed a tunable solid-state fluorescence system consisting of organic salts of anthracene disulfonic acid (ADS) with aliphatic amines. Depending on the difference of aliphatic amines, the resulting crystalline materials show various anthracene arrangements. The photophysical properties of the resulting crystals, such as emission spectra, emission quantum efficiencies and lifetime, are effectively and easily modulated by the different arrangement of anthracene moieties. The physical properties of the obtained solid materials depend not only on the molecular structure but also on the molecular arrangement. These approaches, which reveal a novel concept, may open new doors for future material science research. Polymer Preprints, Japan 2009, 58, 102

Dynamic Nanofishing of a Single Polystyrene Chain to Reveal Viscoelastic Properties
Ken NAKAJIMA* and Toshio NISHI
WPI Advanced Institute for Materials Research, Tohoku University
Single molecule force spectroscopy (SMFS), realized by atomic force microscope (AFM) on a single polymer chain (static nanofishing), is schematically shown in Fig. 1, where a polymer chain is picked up and pulled at its chemically modified terminals. This otherwise powerful method unfortunately only gives structural information such as persistence length and contour length. Beyond this technique, dynamic nanofishing, where an AFM cantilever is imposed on the forced oscillation at its resonant frequency (~10 kHz), enables us additionally to investigate more fruitful information. The method gave extension-dependent changes of entropic elasticity and frictional coefficient with solvent molecules for mono- disperse living-polymerized polystyrene (PS) as shown in Fig. 2. The solvent temperature dependence revealed that the frictional coefficient could be correlated with macroscopic "intrinsic viscosity." Polymer Preprints, Japan 2009, 58, 93.

Gel Photonics: Creation of Engineering Gel Materials with Photonics
Hidemitsu FURUKAWA
Department of Mechanical Systems Engineering, Graduate School of Science and Engineering, Yamagata University
For research of gels, we sometimes cannot apply the older methods of material sciences for hard and dry materials, such as metals, ceramics, plastics, etc. The reason is that gels are in the state of very soft and wet materials, always unstable, easily disturbed by external stimuli, and sometimes gels have inhomogeneous, hierarchical complex structures. A new concept is to take advantage of light, in order to study the structure and properties of gels nondestructively in a wide spatio-temporal ranges. I named this new approach "GEL PHOTONICS". This paper reports the latest development of gel-photonics investigations, describing the toughening mechanism of high-strength double network gels and the creation of novel high-extensible anisotropic gels, which were studied with scanning microscopic light scattering, polarized optical microscopy, laser con-focal scanning microscopy, and other methods. Polymer Preprints, Japan 2009, 58, 105.

Relationship between Spatial Size of Single Conjugated Polymer Chains and Their Single-Photon Emission Behavior Revealed by Photon Correlation Measurements
Sadahiro MASUO
Department of Macromolecular Science and Engineering, Kyoto Institute of Technology
Recently, we have demonstrated that the emission from single conjugated polymer chains embedded in host polymer matrices can be made to behave as single-photon sources by controlling their size, that is, molecular weight (Mn) and conformation of the conjugated polymers. In this work, simultaneous measurements of photon correlation and fluorescence correlation spectroscopy (FCS) were applied to the conjugated polymer chains with different Mn dissolved in appropriate solvents in order to reveal the relationship between spatial size and single-photon emission behavior in detail. As a result, we have successfully demonstrated that the polymer chain with a faster diffusion time exhibits high probability of single-photon emission, that is, the single-photon emission behavior strongly depends on the spatial size of the polymer chain. Polymer Reprints, Japan 2009, 58, 99. .

Development of Antistatic Polymer for Polyolefin Resins
Takashi YABUTA
Functional Resins Research Dept. Research & Application Division Sanyo Chemical Industries, LTD.
Antistatic polymer, such as polyether ester amide, is usually finely dispersed in styrene resins (ABS resin etc.), and the domains are highly elongated in the mold. These elongated domains are forming conductive networks in the surface layer (surface resistivity 1011ohms/sq.). But in the case of polyolefin, it doesn't form a fine dispersion (surface resistivity 1015ohms/sq.). As the results of our investigation, we have developed a new Polypropylene (PP)-Polyethylene oxide(PEO) block copolymer type antistatic polymer for polyolefin. In PP resins, it formed fine dispersion (see Figure) and had lower resistivity. These abilities of antistatic polymer are controlled by the compatibility with PP, viscosity ratio of PP / PP-PEO block copolymer and melt tension of PP-PEO block copolymer. Polymer Preprints, Japan 2009, 58, 87.

Formation of Nanostructured Inorganic Oxide Thin Films by Using Polymer Particle Template
Mitsuru WATANABE
Osaka Municipal Technical Research Institute
A novel method of controlling inorganic oxide nanostructures was developed. The sphere-like ZnO nanostructure was obtained from the electrodeposition on the polymer particle template having anionic surface functional groups. This characteristic structure was attributed to the ZnO nucleation site selectivity derived from the specific interaction between the polymer particle template surface and Zn2+ ion. CeO2, TiO2, and SiO2 nanostructures could be fabricated onto the anionic polymer particle templates under similar conditions. The morphology of the nanostructures could also be controlled by tuning electrolysis potential and the concentration of the metal ion. Moreover, inorganic oxide nanostructures showing a hollow sphere-like structure were obtained by removing the polymer particles with heat treatment. Thus, inorganic oxide nanostructures with selective morphology and high surface area were fabricated directly on a conductive substrate. Polymer Preprints, Japan 2009, 58, 90.