Curriculum Vitaes

Takeoka Yuko

  (竹岡 裕子)

Profile Information

Affiliation
Professor, Faculty of Science and Technology, Department of Materials and Life Sciences, Sophia University
Degree
博士(工学)(東京大学)

J-GLOBAL ID
200901054354018811
researchmap Member ID
5000041377

Papers

 217
  • TAKEOKA YUKO, K. Asai, M. Rikukawa, K. Sanui, K. Ishigure
    Nonlinear Optics, 257-258 449-454, 2000  
  • TAKEOKA YUKO, K. Asai, M. Rikukawa, K. Sanui, K. Ishigure
    Nonlinear Optics, 24(1-2) 57-62, 2000  
  • TAKEOKA Yuko, ASAI Keisuke, RIKUKAWA Masahiro, SANUI Kohei, IISHIGURE Kenkichi
    Journal of the School of Engineering, The University of Tokyo, 46 15-27, Nov, 1999  
  • Y Tabuchi, M Rikukawa, K Sanui, N Ogata
    SYNTHETIC METALS, 102(1-3) 1441-1442, Jun, 1999  
    Langmuir-Blodgett films were fabricated from mixed monolayers containing stearic acid (SA) and various Head-to-tail poly(3-alkylthiophene)s (HT-PATs:alkyl = hexyl (HT-PHT), decyl (HT-PDT), octadecyl (HT-PODT)). The HT-PATs could form stable monolayers on the air-water interface with stearic acid, and could be deposited onto solid substrates as Y-type films by vertical dipping method. The structure of HT-PATs/SA LB films were investigated by transmission and reflection-absorption FT-IR measurements. By comparison of transmission and reflection FT-IR spectra, the tilt angles of alkyl side-chains of HT-PATs could be estimated. These results shows that self-organized properties and molecular orientation of HT-PATs were affected by the length of alkyl-side chains. HT-PDT was found to form more planar conformation because of the optimized length of alkyl-side chains.
  • Y Tabuchi, K Asai, K Ishigure, M Rikukawa, K Sanui
    MOLECULAR CRYSTALS AND LIQUID CRYSTALS SCIENCE AND TECHNOLOGY SECTION A-MOLECULAR CRYSTALS AND LIQUID CRYSTALS, 327(1) 131-134, 1999  
    We examined the self-organized properties of regioregular poly(3-alklylthiophene)s(HT-PATs) in Langmuir-Blodgett(LB) films by X-ray diffraction and FT-IR measurements. The HT-PATs showed self-organized properties due to their stereoregularity. The pendent decyl groups of HT-PDT formed more planar conformation and interdigitated structure. Electrical conductivities of doped HT-PATs/SA LB films were dramatically improved compared with random PATs, and HT-PDT films showed the highest in-plane conductivities among HT-PATs LB films.
  • K Ochiai, Y Tabuchi, M Rikukawa, K Sanui, N Ogata
    THIN SOLID FILMS, 327 454-457, Aug, 1998  
    We synthesized an optically active regioregular poly(3-substituted thiophene), head-to-tail poly(3-[2-((S)-2-methylbutoxy)ethyl] thiophene) (HT-P(S)MBET), according to a modified Rieke method. The HT-P(S)MBET was an optically active polymer with the HT linkage of larger than 93%, as estimated by NMR. The mixed monolayers of the polymer and stearic acid (SA) were found to be stable at the air-water interface and could be deposited onto solid substrates as Y-type films by the vertical dipping method. These Langmuir-Blodgett (LB) films exhibited well-defined layer structures and unique optical properties. The electrical conductivities of the LB films with and without doping of SbCl5 were about 10(-1) and 10(-5) S/cm, respectively. (C) 1998 Elsevier Science S.A. All rights reserved.
  • M Rikukawa, Y Tabuchi, K Ochiai, K Sanui, N Ogata
    THIN SOLID FILMS, 327 469-472, Aug, 1998  
    Novel Langmuir-Blodgett (LB) films were fabricated from mixed monolayers containing stearic acid and various poly(3-alkylthiophene)s, which contained almost 100% head-to-tail couplings. The LB films exhibited well-defined layered structures and self-organized properties of the regioregular polymers. The molecular organization, the layered structures and the electrical properties depended on the regioregularity and the length of the alkyl side chains of the regioregular polymers. The regioregular polymers have considerably improved the electrical conductivity and the third-order optical non-linearity. (C) 1998 Elsevier Science S.A. All rights reserved.
  • Y Ueno, S Kishino, H Kunugita, K Ema, M Rikukawa, Y Tabuchi, N Ogata
    JOURNAL OF NONLINEAR OPTICAL PHYSICS & MATERIALS, 7(1) 161-166, Mar, 1998  Peer-reviewed
    Third-order optical nonlinearity of regioregular head-to-tail coupled poly(3-hexylthiophene)(HT-PHT) was measured using degenerate four wave mixing (DFWM), and the dispersion spectrum of \X-(3)\ around the exciton absorption peak was obtained. In addition, the relaxation process of the excitons was measured using the transient grating method. The resultant decay time was less than 2 ps and consisted of two components.
  • S. Kishino, Y. Ueno, H. Kunugita, K. Ema, M. Rikukawa, K. Ochiai, Y. Tabuchi, H. Sato, K. Sanui, N. Ogata
    IEEE Nonlinear Optics: Materials, Fundamentals and Applications - Conference Proceedings, 233-235, 1998  
    The enhancement of third-order optical nonlinearity in poly(3-hexylthiophene)(P3HT) by the control of regularity in the polymetric structure. The enhancement is due to increasing the conjunction length. The thin films of poly(3-[2-((S)-2-methylbutoxy)ethyl]thiophene)(P(S)MBET) is used which possesses large conjunction length. The |χ(3)| at excitonic resonance is measured using degenerate four-wave mixing (DFWM) and the conjunction length of samples are estimated.
  • Yoshihiro Ueno, Shiho Kishino, Hideyuki Kunugita, Kazuhiro Ema, Masahiro Rikukawa, Yuko Tabuchi, Naoya Ogata
    Journal of Nonlinear Optical Physics and Materials, 7(1) 161-166, 1998  
    Third-order optical nonlinearity of regioregular head-to-tail coupled poly(3-hexylthiophene)(HT-PHT) was measured using degenerate four wave mixing (DFWM), and the dispersion spectrum of |χ(3)| around the exciton absorption peak was obtained. In addition, the relaxation process of the excitons was measured using the transient grating method. The resultant decay time was less than 2 ps and consisted of two components.
  • Y Takeoka, T Aoki, K Sanui, N Ogata, R Watanabe
    JOURNAL OF ELECTROANALYTICAL CHEMISTRY, 438(1-2) 153-158, Nov, 1997  Peer-reviewed
    The effect of NaCl concentration on the redox potential of alpha-ferrocenylundecyl-omega-hydroxy-polyoxyethylene (FPEG) micelles has been studied in aqueous solutions. With increasing NaCl concentration, the anodic half-wave potentials E-1/2 of cyclic voltammograms of the aqueous solutions shift to higher potential, and the peak currents of the cyclic voltammograms decrease. The results are discussed in terms of thermodynamics of the micelle formation. An equation which interprets the correlation between the E-1/2, the salt concentration, diffusion coefficient of the micelle D-M, and the aggregation number m, has been derived. The changes in D-M and m with NaCl concentration do not explain the change in the value of E-1/2. The decrease in the equilibrium constant for the micelle-disruption K-d with increasing NaCl concentration affects the redox-potential of the FPEG micellar solutions. (C) 1997 Elsevier Science S.A.
  • 陸川政弘, 竹岡裕子, 落合慶子
    高分子加工, 46(6) 260-265, Jun, 1997  
  • Hideyuki Kawahara, Yoshihiro Ueno, Nanae Abe, Shiho Kishino, Kazuhiro Ema, Masahiro Rikukawa, Yuko Takeoka, Naoya Ogata
    Optical Review, 4(1) 188-190, Mar, 1997  
    We measured the third-order optical nonlinearity of regioregular head-to-tail coupled poly (3-hexylthiophene) (HT-PHT) and regiorandom poly (3-hexylthiophene) (R-PHT) around exciton resonance using degenerate four wave mixing. The observed value of |χ(3)| at the exciton resonance peak of HT-PHT is in the order of 10-9 esu which is approximately three-fold larger than that of R-PHT. We observed for the first time the enhancement in optical nonlinearity that occurs through the control of regularity of the polymeric structure. Response time of the nonlinearity was also measured using the transient grating method. The decay time of the transient grating in R-PHT and HT-PHT was less than 2 ps.
  • Y Takeoka, T Aoki, K Sanui, N Ogata, M Watanabe
    POLYMER GELS AND NETWORKS, 5(4) 369-383, 1997  Peer-reviewed
    The dissolved states of redox-active non-ionic surfactant (FPEG) in the swollen state of N-isopropyl acrylamide (NIPA) hydrogel have been studied by using a gel-modified electrode. The pronounced decrease in the peak current and the negative shift in the formal potential of CV at the gel-modified electrode, as compared with the normal GC electrode, was observed in the micelle-solution; this indicates that the diffusive FPEG molecules which form the micelle hardly penetrate into the NIPA gel. This result suggests that there exists all interaction between FPEG molecules and the NIFA gel in the vicinity of the surface of the NIPA gel in the micelle-solution. However, this also indicates that a small amount of FPEG molecules which can form micelles exist in the NIPA gel. (C) 1997 Elsevier Science Ltd.
  • M Rikukawa, M Nakagawa, Y Tabuchi, K Sanui, N Ogata
    SYNTHETIC METALS, 84(1-3) 233-234, Jan, 1997  
    The conductive ultra thin films were fabricated from mixed monolayers containing stearic acid and Head-to-Tail poly(3-alkylthiophene). These films exhibited well-defined layered structures as determined by optical absorption and X-ray diffraction measurements. The UV-Vis absorption spectra of these films showed lower energy absorption shifts of 48 nm from that of the random poly(3-alkylthiophene)/stearic acid LB films. The blue shift of absorption maximum of the LB film is attributed to the increase of pi-conjugation length caused by no steric hindrance of alkyl side chains. The conductivity of the Head-to-Tail poly(3-hexylthiophene)/stearic acid LB films was greatly improved in the range of 67-100 S/cm.
  • M. Rikukawa, Y. Tabuchi, M. Nakagawa, K. Sanui, N. Ogata
    American Chemical Society, Polymer Preprints, Division of Polymer Chemistry, 37(2) 260-261, Aug, 1996  
  • Y TAKEOKA, T AOKI, K SANUI, N OGATA, M WATANABE
    KOBUNSHI RONBUNSHU, 52(10) 657-661, 1995  Peer-reviewed
    A non-ionic redox active surfactant, alpha-ferrocenylundecyl-omega-hydroxy-oligo(ethylene oxide), exhibits high ability to form polymer complexes with poly(acrylic acid) at a micelle forming concentration, in spite of the low molecular weight of the oligo(ethylene oxide) site. The fraction of carboxyls associated with ether oxygens (theta) between them has a high value (ca. 0.8) which is independent of the concentration of poly(acrylic acid). The complex formation seemed to be caused by hydrogen bonding and hydrophobic interactions. The complex formation influenced on electrochemical reactions of the redox active surfactant.

Misc.

 13

Books and Other Publications

 13

Major Presentations

 299

Research Projects

 5

Social Activities

 8

Media Coverage

 4