Curriculum Vitaes

Akihiko Sugimura

  (杉村 明彦)

Profile Information

Affiliation
Professor, Faculty of Design Technology, Department of Information Systems Engineering, Osaka Sangyo University
(Concurrent)Director
(Concurrent)Dean, Faculty of Design Technology
Degree
Doctor of Enginnering(Osaka Prefecture University)

Researcher number
90145813
J-GLOBAL ID
200901076584950417
researchmap Member ID
1000107924

External link

Committee Memberships

 1

Papers

 103
  • Rauzah Hashim, N. Idayu Zahid, T. S. Velayutham, Nurul Fadhilah Kamalul Aripin, Shigesaburo Ogawa, Akihiko Sugimura
    Journal of Oleo Science, 67(6) 651-668, 2018  Peer-reviewedInvited
    Also recognized as carbohydrate liquid crystals, glycolipids are amphiphiles whose basic unit comprises of a sugar group attached to an alkyl chain. Glycolipids are amphitropic, which means these materials form liquid crystal self-assemblies when dry (thermotropic) as well as when dissolved in solvents (lyotropic/surfactants) such as water. Many glycolipids are also naturally derived since these can be found in cell membranes. Their membrane and surfactant functions are largely understood through their lyotropic properties. While glycolipids are expected to play major roles as eco-friendly surfactants in the global surfactant market, their usefulness as thermotropic liquid crystal material is, to date, unknown, due to relatively lack of research performed and data reported in the literature. Understandably since glycolipids are hygroscopic with many hydroxy groups, removing the last trace water is very challenging. In recent time, with careful lyophilization and more consistent characterization technique, some researchers have attempted serious studies into “dry” or anhydrous glycolipids. Motivated by possible developments of novel thermotropic applications, some results from these studies also provide surprising new understanding to support conventional wisdom of the lyotropic systems. Here we review the dry state of glycosides, a family of glycolipids whose sugar headgroup is linked to the lipid chain via a glycosidic oxygen linker. The structure property relationship of both linear and anhydrous Guerbet glycosides will be examined. In particular, how the variation of sugar stereochemistry (e.g. anomer vs. epimer), the chain length and chain branching affect the formation of thermotropic liquid crystals phases, which not only located under equilibrium but also far from equilibrium conditions (glassy phase) are scrutinized. The dry glycolipid assembly has been subjected to electric and magnetic fields and the results show interesting behaviors including a possible transient current generation.
  • Rauzah Hashim, Akihiko Sugimura, Hock-Seng Nguan, Matiur Rahman, Herbert Zimmermann
    JOURNAL OF CHEMICAL PHYSICS, 146(8) 084702-1-084702-8, Feb, 2017  Peer-reviewed
    A static deuterium nuclear magnetic resonance ((HNMR)-H-2) technique (magnetic field, B = 7.05 T) was employed to monitor the thermotropic lamellar phase of the anhydrous 1:1 mixture sample of octyl-b-D-glucoside (beta OG) and that of partially deuterium labelled at the alpha position on the chain, i.e., beta OG-d(2). In the absence of an electric field, the H-2 NMR spectrum of the mixture gives a typical quadrupolar doublet representing the aligned lamellar phase. Upon heating to beyond the clearing temperature at 112 degrees C, this splitting converts to a single line expected for an isotropic phase. Simultaneous application of magnetic and electric fields (E = 0.4 MV/m) at 85 degrees C in the lamellar phase, whose direction was set to be parallel or perpendicular to the magnetic field, resulted in the change of the doublet into a single line and this recovers to the initial doublet with time for both experimental geometries. This implies E- and B-field-induced phase transitions from the lamellar to an isotropic phase and a recovery to the lamellar phase again with time. Moreover, these phase transformations are accompanied by a transient current. A similar observation was made in a computational study when an electric field was applied to a water cluster system. Increasing the field strength distorts the water cluster and weakens its hydrogen bonds leading to a structural breakdown beyond a threshold field-strength. Therefore, we suggest the observed field-induced transition is likely due to a structure change of the (ss)OG lamellar assembly caused by the field effect and not due to Joule heating.
  • Akihiko Sugimura, Geoffrey R. Luckhurst
    PROGRESS IN NUCLEAR MAGNETIC RESONANCE SPECTROSCOPY, 94-95 37-74, May, 2016  Peer-reviewed
    There have been many investigations of the alignment of nematic liquid crystals by either a magnetic and/or an electric field. The basic features of the important hydrodynamic processes for low molar mass nematics have been characterized for the systems in their equilibrium and non-equilibrium states. These have been created using electric and magnetic fields to align the director and deuterium nuclear magnetic resonance (H-2 NMR) spectroscopy has been used to explore this alignment. Theoretical models based on continuum theory have been developed to complement the experiments and found to describe successfully the static and the dynamic phenomena observed. Such macroscopic behaviour has been investigated with H-2 NMR spectroscopy, in which an electric field in addition to the magnetic field of the spectrometer is used to rotate the director and produce a non-equilibrium state. This powerful technique has proved to be especially valuable for the investigation of nematic liquid crystals. Since the quadrupolar splitting for deuterons observed in the liquid crystal phase is determined by the angle between the director and the magnetic field, time-resolved and time-averaged H-2 NMR spectroscopies can be employed to investigate the dynamic director alignment process in a thin nematic film following the application or removal of an electric field. In this article, we describe some seminal studies to illustrate the field-induced static and dynamic director alignment for low molar mass nematics. (C) 2016 Elsevier B.V. All rights reserved.
  • I. Bayach, V. Manickam Achari, W. F. N. Wan Iskandar, A. Sugimura, R. Hashim
    LIQUID CRYSTALS, 43(10) 1503-1513, 2016  Peer-reviewed
    We applied density functional theory to study octyl-D-xyloside isomers in order to explain the features responsible for the liquid crystal mesophases. Compared to a glucoside, the xylose headgroup has a proton instead of the hydroxymethyl group on C5. Thus, a xyloside has a reduced headgroup volume that renders it less hydrophilic. Our results have shown that the xylose headgroup may adopt stable pyranose and furanose conformations, which may lead to different effective headgroup hydrophilicities. These features are probably responsible for forming two non-equivalent inverse micelles, which are self-assembled into a cubic discontinuous phase with a space group of Fd3m commonly found for xylosides. While different factors are responsible for controlling the relative stability of each isomer, the role of intramolecular hydrogen bonding was highlighted for the investigated single molecule. The polarisable continuum model was used to take into account the solvent effect in order to understand the molecular behaviour in very polar systems. Results from calculations carried out in gas phase were used for comparative purposes. The molecular electrostatic potential calculations for these xylolipids demonstrate sugar amphoterism, which is implicated in the heterogeneity nature of lipid self-assembly. [GRAPHICS]
  • Daichi Hamasuna, Rauzah Hashim, Atsuhiro Kasatani, Geoffrey R. Luckhurst, Akihiko Sugimura, Bakir A. Timimi, Herbert Zimmermann
    PHYSICAL REVIEW E, 91(6) 062502, Jun, 2015  Peer-reviewed
    The dynamic alignment of the nematic director by near-orthogonal electric and magnetic fields has been investigated. The intermediate states during the relaxation process were found, with the aid of time-resolved deuterium NMR spectroscopy, to be markedly nonuniform. The macroscopic order was perturbed, although the initial and final states of the director appear to be essentially uniform. However, the initial state does have a profound influence on the uniformity of the director in the intermediate states. We have developed a fundamental model based on the effect of spontaneous director fluctuations to explain these unusual NMR observations.

Misc.

 5
  • Akihiko Sugimura, A. A. Vakulenko, A. V. Zakharov
    9TH INTERNATIONAL CONFERENCE ON NANO-MOLECULAR ELECTRONICS, 14 102-114, 2011  Peer-reviewed
    The nature of the orientational relaxation process of the director, (n) over cap, to its equilibrium orientation, (n) over cap (eq)(r), in a liquid crystal cell has been investigated both experimentally and theoretically. The experiments employ deuterium NMR spectroscopy to investigate the time-resolved field-induced director orientation, and the theory is based on a numerical study of the system of hydrodynamic equations; these include both director motion and fluid flow and take account of backflow. The relaxation time and the influence of the effect of backflow on the orientational relaxation process for a thin nematic film of 4 - n - pentyl -4' - cyanobiphenyl has been investigated for a number of dynamic regimes. Reasonable agreement is observed between the calculated values and experimental results.
  • N. Z. B. M. Rodzi, T. Heidelberg, R. Hashim, A. Sugimura, H. Minamikawa
    9TH INTERNATIONAL CONFERENCE ON NANO-MOLECULAR ELECTRONICS, 14 91-95, 2011  Peer-reviewed
    Due to the amphiphilicity nature of glycolipids, some are known to exhibits liquid crystals phases both in thermotropic and lyotropic phases. Six different glycolipids have been synthesized using three steps process and their structures have been characterized by H-1-NMR and C-13-NMR in acetylated and deacytelated forms. Their liquid crystals properties were studied using optical polarising microscopy (OPM) and differential scanning calorimetry (DSC). The effect of alpha-methylated tails is compared with those of the straight chain glycolipids. The epimeric effect of the hydroxyl group at the C-4 of the sugar group was also commented. (C) 2010 Published by Elsevier B.V.
  • S. Ishihara, K. Komori, A. Sugimura
    Proceedings of The 21st Int. Disp. Res. Conf./The 8th Int.Disp.Workshops., 173-176, Oct, 2001  Peer-reviewed
    The cell gap dependence of the pretilt angle of a parallel cell has been evaluated for the first time:the smaller the cell gap,the smaller the pretilt angle. Experimental results were accounted for by a mathematical modeling of the dependence of the surface anchoring energy on the cell gap.
  • A. Sugimura, K. Nakamura, T. Miyamoto, P. J. Le Masurier, A. Sugimura, K. Nakamura, T. Miyamoto, P. J. Le Masurier, B. A. Timimi, T. H. Payne, G. R. Luckhurst
    Proceedings of The Fourth International Display Workshops(1997), 65-68, Nov, 1997  Peer-reviewed
    種々の表面アンカリングエネルギ条件下での液晶セル内ダイレクタ分布を、理論的実験的に調べた。実験には、重水素化したネマチック液晶を用いた核磁気共鳴法を用いている。本実験では、液晶セルへの強磁場印加に加えて、可変電界を重複印加することにより、セル内での全トルク制御を行っている。実験により得た共鳴スペクトルを、弾性理論に基づくダイレクタ分布解析により明らかにした。
  • A.Sugimura, H.Sonomura, H. Naito(Osaka, Prefecture Univ, M. Okuda(Osaka Prefecture
    Chemistry of Functional Dyes,edited by Z.Yoshida and T.Kitao, 541-544, Jun, 1989  Peer-reviewed

Books and Other Publications

 24

Presentations

 58