Updated on 2024/05/26

写真a

 
KAJIYAMA, Satoshi
 
Affiliation
Research Council (Research Organization), Advanced Collaborative Research Organization for SmartSociety
Job title
Researcher(Associate Professor)
Degree
博士(工学) ( 東京大学 )

Research Experience

  • 2024.01
    -
    Now

    WASEDA University   Institute of Energy Informatics   Associate Professot

Education Background

  • 2006.04
    -
    2008.03

    The University of Tokyo   The Faculty of Engineering   Department of Chemistry and Biotechnology  

  • 2004.04
    -
    2006.03

    The University of Tokyo   College of Arts and Sciences  

Professional Memberships

  •  
     
     

    THE JAPANESE LIQUID CRYSTAL SOCIETY

  •  
     
     

    THE ELECTROCHEMICAL SOCIETY OF JAPAN

  •  
     
     

    THE SOCIETY OF POLYMER SCIENCE, JAPAN

  •  
     
     

    THE CHEMICAL SOCIETY OF JAPAN

Research Areas

  • Functional solid state chemistry   液晶 / Organic functional materials   ナノ材料 薄膜 / Energy chemistry   二次電池

Research Interests

  • バイオミネラリゼーション

  • ナノ材料

  • 二次電池

  • 電気化学

  • 薄膜

  • コロイド

  • 液晶

  • 有機無機複合材料

▼display all

 

Papers

  • Experimental probing of dynamic self-organized columnar assemblies in colloidal liquid crystals

    Taiki Hoshino, Masanari Nakayama, Yoshihiro Hosokawa, Kohei Mochizuki, Satoshi Kajiyama, Yoshiki Kohmura, Takashi Kato

    Nanoscale Advances   5   3646 - 3654  2023.05  [Refereed]

    DOI

  • Reentrant 2D Nanostructured Liquid Crystals by Competition between Molecular Packing and Conformation: Potential Design for Multistep Switching of Ionic Conductivity

    Kazuma Hamaguchi, Huanjun Lu, Shota Okamura, Satoshi Kajiyama, Junya Uchida, Shunsuke Sato, Go Watanabe, Yoshiki Ishii, Hitoshi Washizu, Goran Ungar, Takashi Kato

    ChemPhysChem   24 ( 8 )  2023.01

     View Summary

    Abstract

    Reentrant phenomena in soft matter and biosystems have attracted considerable attention because their properties are closely related to high functionality. Here, we report a combined experimental and computational study on the self‐assembly and reentrant behavior of a single‐component thermotropic smectic liquid crystal toward the realization of dynamically functional materials. We have designed and synthesized a mesogenic molecule consisting of an alicyclic trans,trans‐bicyclohexyl mesogen and a polar cyclic carbonate group connected by a flexible tetra(oxyethylene) spacer. The molecule exhibits an unprecedented sequence of layered smectic phases, in the order: smectic A‐smectic B‐reentrant smectic A. Electron density profiles and large‐scale molecular dynamics simulations indicate that competition between the stacking of bicyclohexyl mesogens and the conformational flexibility of tetra(oxyethylene) chains induces this unusual reentrant behavior. Ion‐conductive reentrant liquid‐crystalline materials have been developed, which undergo the multistep conductivity changes in response to temperature. The reentrant liquid crystals have potential as new mesogenic materials exhibiting switching functions.

    DOI

    Scopus

    2
    Citation
    (Scopus)
  • Investigating the local structure of Ti based MXene materials by temperature dependent X-ray absorption spectroscopy

    Wojciech Olszewski, Carlo Marini, Satoshi Kajiyama, Masashi Okubo, Atsuo Yamada, Takashi Mizokawa, Naurang Lal Saini, Laura Simonelli

    Physical Chemistry Chemical Physics   25 ( 4 ) 3011 - 3019  2022.12

     View Summary

    The local structures of Ti based MXene-type electrode materials have been studied by Ti K-edge X-ray absorption fine structure measurements as a function of temperature to obtain direct information on the local bond lengths and their stiffness. In particular, the parent MAX phases Ti2AlC and Ti3AlC2 and their etched MXene systems are characterized and their properties compared. We find that selective etching has a substantial effect on the local structural properties of the Ti based MXene materials. It leads to an increase in the interatomic distances, i.e. a decrease in the covalency, and corresponding bond stiffness, that is a likely cause of higher achievable performances. The obtained results underline the importance of the local atomic correlations as limiting factors in the diffusion capacity of ion batteries.

    DOI PubMed

    Scopus

    3
    Citation
    (Scopus)
  • One-Dimensional Assemblies of Co3O4 Nanoparticles Formed from Cobalt Hydroxide Carbonate Prepared by Bio-Inspired Precipitation within Confined Space

    Viktoria Gruen, Satoshi Kajiyama, Sabine Rosenfeldt, Sabine Ludwigs, Anna S. Schenk, Takashi Kato

    CRYSTAL GROWTH & DESIGN   22 ( 10 ) 5883 - 5894  2022.10

     View Summary

    Nanostructured spinel-type cobalt(II,III) oxide (Co3O4) finds applications in a wide range of technological fields including clean energy conversion systems and electrochemical devices. Low-dimensional morphologies have been identified as particularly promising for the optimization of transport characteristics and the design of anisometric building blocks for the controlled assembly into higher order superstructures. We here introduce a facile bio-inspired room-temperature approach to direct precipitation of one-dimensional basic cobalt carbonate as a precursor to Co3O4 by combining confined submicrometer reaction environments with a carboxylated structure-directing polyelectrolyte. Variation of the polymer concentration and molecular weight then affords control over the mode of infiltration into cylindrical track-etch membrane pores. While a high concentration of the polyelectrolyte additive induces the formation of high aspect ratio smooth fibers with a length resembling the entire pore volume, shorter porous rods with a needle-like substructure are deposited at low polymer concentrations or higher molecular weights. The generality of the infiltration mechanism is demonstrated by gradual substitution of Co2+ ions by Mn2+. Calcination pseudomorphically transforms the resulting intramembrane basic cobalt and manganese carbonate rods and fibers into hierarchical one-dimensional oxides with a porous nanoparticle-based mesostructure.

    DOI

    Scopus

    1
    Citation
    (Scopus)
  • Gemini Thermotropic Smectic Liquid Crystals for Two-Dimensional Nanostructured Water-Treatment Membranes

    Kazuma Hamaguchi, Rino Ichikawa, Satoshi Kajiyama, Shotaro Torii, Yusuke Hayashi, Jiro Kumaki, Hiroyuki Katayama, Takashi Kato

    ACS Applied Materials & Interfaces   13 ( 17 ) 20598 - 20605  2021.05

    DOI

    Scopus

    23
    Citation
    (Scopus)
  • Shear-induced liquid-crystalline phase transition behaviour of colloidal solutions of hydroxyapatite nanorod composites.

    Satoshi Kajiyama, Hiroki Iwase, Masanari Nakayama, Rino Ichikawa, Daisuke Yamaguchi, Hideki Seto, Takashi Kato

    Nanoscale   12 ( 21 ) 11468 - 11479  2020.06  [Refereed]  [International journal]

     View Summary

    Liquid-crystalline (LC) bio-inspired materials based on colloidal nanoparticles with anisotropic morphologies such as sheets, plates, rods and fibers were used as functional materials. They show stimuli-responsive behaviour under mechanical force and in electric and magnetic fields. Understanding the effects of external stimuli on the structures of anisotropic colloidal particles is important for the development of highly ordered structures. Recently, we have developed stimuli-responsive hydroxyapatite (HAP)-based colloidal LC nanorods that are environmentally-friendly functional materials. In the present study, the ordering behaviour of HAP nanorod dispersions, which show LC states, has been examined using in situ small-angle neutron scattering and rheological measurements (Rheo-SANS) under shearing force. The structural analyses and dynamic viscosity observations provided detailed information about the effects of shear force on the structural changes of HAP nanorods in D2O dispersion. The present Rheo-SANS measurements unraveled three kinds of main effects of the shear force: the enhancement of interactions between the HAP nanorods, the alignment of HAP nanorods to the shear flow direction, and the formation and disruption of HAP nanorod assemblies. Simultaneous analyses of dynamic viscosity and structural changes revealed that the HAP nanorod dispersions exhibited distinctive rheological properties accompanied by their ordered structural changes.

    DOI PubMed

    Scopus

    11
    Citation
    (Scopus)
  • Nanostructured liquid-crystalline Li-ion conductors with high oxidation resistance: molecular design strategy towards safe and high-voltage-operation Li-ion batteries

    Atsushi Kuwabara, Mayu Enomoto, Eiji Hosono, Kazuma Hamaguchi, Taira Onuma, Satoshi Kajiyama, Takashi Kato

    Chemical Science   11 ( 39 ) 10631 - 10637  2020

     View Summary

    <p>Ion-conductive liquid-crystalline molecules with high-oxidation resistance, which were designed with density functional theory calculation, improved charge–discharge reactions in Li-ion batteries.</p>

    DOI

    Scopus

    29
    Citation
    (Scopus)
  • Bioinspired selective synthesis of liquid-crystalline nanocomposites: formation of calcium carbonate-based composite nanodisks and nanorods

    Masanari Nakayama, Satoshi Kajiyama, Akihito Kumamoto, Yuichi Ikuhara, Takashi Kato

    Nanoscale Advances   2 ( 6 ) 2326 - 2332  2020

     View Summary

    <p>Colloidal nanodisk liquid-crystalline composites consisting of an acidic polymer and CaCO3 are developed. Selective synthesis of nanodisk and nanorod is achieved by biomineralization-inspired approaches.</p>

    DOI

    Scopus

    11
    Citation
    (Scopus)
  • Liquid-Crystalline Hydroxyapatite/Polymer Nanohybrids with Dual Bioapplications for Photodynamic Therapy and Cellular Scaffolds

    Masanari Nakayama, Wei Qi Lim, Satoshi Kajiyama, Akihito Kumamoto, Yuichi Ikuhara, Yanli Zhao, Takashi Kato

    ACS Applied Materials & Interfaces   11 ( 19 ) 17759 - 17765  2019.07  [Refereed]

    DOI

  • Tuning the c-Axis Orientation of Calcium Phosphate Hybrid Thin Films Using Polymer Templates

    Ichikawa Rino, Kajiyama Satoshi, Iimura Misato, Kato Takashi

    LANGMUIR   35 ( 11 ) 4077 - 4084  2019.03  [Refereed]

    DOI

    Scopus

    9
    Citation
    (Scopus)
  • Negative dielectric constant of water confined in nanosheets

    Sugahara Akira, Ando Yasunobu, Kajiyama Satoshi, Yazawa Koji, Gotoh Kazuma, Otani Minoru, Okubo Masashi, Yamada Atsuo

    NATURE COMMUNICATIONS   10  2019.02  [Refereed]

     View Summary

    Electric double-layer capacitors are efficient energy storage devices that have the potential to account for uneven power demand in sustainable energy systems. Earlier attempts to improve an unsatisfactory capacitance of electric double-layer capacitors have focused on meso- or nanostructuring to increase the accessible surface area and minimize the distance between the adsorbed ions and the electrode. However, the dielectric constant of the electrolyte solvent embedded between adsorbed ions and the electrode surface, which also governs the capacitance, has not been previously exploited to manipulate the capacitance. Here we show that the capacitance of electric double-layer capacitor electrodes can be enlarged when the water molecules are strongly confined into the two-dimensional slits of titanium carbide MXene nanosheets. Using electrochemical methods and theoretical modeling, we find that dipolar polarization of strongly confined water resonantly overscreens an external electric field and enhances capacitance with a characteristically negative dielectric constant of a water molecule.

    DOI

    Scopus

    115
    Citation
    (Scopus)
  • Stimuli-responsive hydroxyapatite liquid crystal with macroscopically controllable ordering and magneto-optical functions

    Masanari Nakayama, Satoshi Kajiyama, Akihito Kumamoto, Tatsuya Nishimura, Yuichi Ikuhara, Masafumi Yamato, Takashi Kato

    Nature Communications   9 ( 1 )  2018.12  [Refereed]

     View Summary

    Liquid crystals are mostly formed by self-assembly of organic molecules. In contrast, inorganic materials available as liquid crystals are limited. Here we report the development of liquid-crystalline (LC) hydroxyapatite (HAp), which is an environmentally friendly and biocompatible biomineral. Its alignment behavior, magneto-optical properties, and atomic-scale structures are described. We successfully induce LC properties into aqueous colloidal dispersions of rod-shaped HAp by controlling the morphology of the material using acidic macromolecules. These LC HAp nanorod materials are macroscopically oriented in response to external magnetic fields and mechanical forces. We achieve magnetic modulation of the optical transmission by dynamic control of the LC order. Atomic-scale observations using transmission electron microscopy show the self-organized inorganic/organic hybrid structures of mesogenic nanorods. HAp liquid crystals have potential as bio-friendly functional materials because of their facile preparation, the bio-friendliness of HAp, and the stimuli-responsive properties of these colloidal ordered fluids.

    DOI

    Scopus

    80
    Citation
    (Scopus)
  • MXene as a Charge Storage Host

    Masashi Okubo, Akira Sugahara, Satoshi Kajiyama, Atsuo Yamada

    Accounts of Chemical Research   51 ( 3 ) 591 - 599  2018.03  [Refereed]

     View Summary

    Conspectus The development of efficient electrochemical energy storage (EES) devices is an important sustainability issue to realize green electrical grids. Charge storage mechanisms in present EES devices, such as ion (de)intercalation in lithium-ion batteries and electric double layer formation in capacitors, provide insufficient efficiency and performance for grid use. Intercalation pseudocapacitance (or redox capacitance) has emerged as an alternative chemistry for advanced EES devices. Intercalation pseudocapacitance occurs through bulk redox reactions with ultrafast ion diffusion. In particular, the metal carbide/nitride nanosheets termed MXene discovered in 2011 are a promising class of intercalation pseudocapacitor electrode materials because of their compositional versatility for materials exploration (e.g., Ti2CTx, Ti3C2Tx, V2CTx, and Nb2CTx, where T is a surface termination group such as F, Cl, O, or OH), high electrical conductivity for high current charge, and a layered structure of stacked nanosheets for ultrafast ion intercalation. Various MXene electrodes have been reported to exhibit complementary battery performance, such as large specific capacity at high charge/discharge rates. However, general design strategies of MXenes for EES applications have not been established because of the limited understanding of the electrochemical mechanisms of MXenes. This Account describes current knowledge of the fundamental electrochemical properties of MXenes and attempts to clarify where intercalation capacitance ends and intercalation pseudocapacitance begins. MXene electrodes in aqueous electrolytes exhibit intercalation of hydrated cations. The hydrated cations form an electric double layer in the interlayer space to give a conventional capacitance within the narrow potential window of aqueous electrolytes. When nonaqueous electrolytes are used, although solvated cations are intercalated into the interlayer space during the initial stage of charging, the confined solvation shell should gradually collapse because of the large inner potential difference in the interlayer space. Upon further charging, desolvated ions solely intercalate, and the atomic orbitals of the desolvated cations overlap with the orbitals of MXene to form a donor band. The formation of the donor band induces the reduction of MXene, giving rise to an intercalation pseudocapacitance through charge transfer from the ions to MXene sheets. Differences in the electrochemical reaction mechanisms lead to variation of the electrochemical responses of MXenes (e.g., cyclic voltammetry curves, specific capacitance), highlighting the importance of establishing a comprehensive grasp of the electrochemical reactions of MXenes at an atomic level. Because of their better charge storage kinetics compared with those of typical materials used in present EES devices, aqueous/nonaqueous asymmetric capacitors using titanium carbide MXene electrodes are capable of efficient operation at high charge/discharge rates. Therefore, the further development of novel MXene electrodes for advanced EES applications is warranted.

    DOI

    Scopus

    318
    Citation
    (Scopus)
  • Stimuli-Responsive Hydroxyapatite Liquid Crystal: Dynamic Control of Macroscopic Ordering and Magneto-Optical Functions

    Masanari Nakayama, Satoshi Kajiyama, Akihito Kumamoto, Tatsuya Nishimura, Yuichi Ikuhara, Masafumi Yamato, Takashi Kato

    Nat. Commun.   9 ( 568 ) 1 - 9  2018.02  [Refereed]

  • Noncovalent approach to liquid-crystalline ion conductors: High-rate performances and room-temperature operation for li-ion batteries

    Taira Onuma, Eiji Hosono, Motokuni Takenouchi, Junji Sakuda, Satoshi Kajiyama, Masafumi Yoshio, Takashi Kato

    ACS Omega   3 ( 1 ) 159 - 166  2018  [Refereed]

     View Summary

    We report advanced liquid-crystalline (LC) electrolytes for use in lithium-ion batteries (LIBs). We evaluated the potential of LC electrolytes with a half cell composed of Li metal and LiFePO4 which is a conventional positive electrode for LIBs. Low-molecular-weight carbonates of ethylene carbonate or propylene carbonate were incorporated into the two-dimensional (2D) nanostructured electrolyte composed of mesogen-containing carbonate and lithium bis(trifluoromethylsulfonyl)imide. The incorporation of low-molecular-weight carbonates increased the ionic conductivity with maintaining 2D nanostructures in the LC state. High-power performances at relatively high current densities induced by higher ionic conductivities have been achieved by LC electrolytes with low-molecular-weight carbonates. Furthermore, room-temperature operation of LIBs using LC electrolytes is reported for the first time. In the research field of electrolytes for LIBs, we demonstrate the progress of a new category of LC electrolytes.

    DOI

    Scopus

    31
    Citation
    (Scopus)
  • Bioinspired Environmentally Friendly Amorphous CaCO<inf>3</inf>-Based Transparent Composites Comprising Cellulose Nanofibers

    Kuo D, Nishimura T, Kajiyama S, Kato T

    ACS Omega   3 ( 10 ) 12722 - 12729  2018  [Refereed]

    DOI

    Scopus

    27
    Citation
    (Scopus)
  • Macromolecular templates for biomineralization-inspired crystallization of oriented layered zinc hydroxides

    Fumiya Katase, Satoshi Kajiyama, Takashi Kato

    POLYMER JOURNAL   49 ( 10 ) 735 - 739  2017.10  [Refereed]

     View Summary

    Biomineralization-inspired approaches are environmentally friendly processes for developing organic/inorganic hybrids with ordered structures. This study demonstrates a biomineralization-inspired approach that is expanded to form organic/inorganic hybrid thin films based on a zinc-layered compound with an organic molecule. The interactions between the acidic polymers and the zinc ions transiently inhibit crystallization in solution, thereby inducing crystallization on/in the insoluble polymer templates. In addition, poly(vinyl alcohol) provides a template for the specific crystallographic orientation of the zinc-layered compounds. The cooperative effects of the soluble and insoluble macromolecular templates lead to the structural and orientational control of organic/inorganic hybrids based on a zinc-layered compound with an organic molecule.

    DOI

    Scopus

    4
    Citation
    (Scopus)
  • Enhanced Li-Ion Accessibility in MXene Titanium Carbide by Steric Chloride Termination

    Satoshi Kajiyama, Lucie Szabova, Hiroki Iinuma, Akira Sugahara, Kazuma Gotoh, Keitaro Sodeyama, Yoshitaka Tateyama, Masashi Okubo, Atsuo Yamada

    ADVANCED ENERGY MATERIALS   7 ( 9 )  2017.05  [Refereed]

     View Summary

    Pseudocapacitance is a key charge storage mechanism to advanced electrochemical energy storage devices distinguished by the simultaneous achievement of high capacitance and a high charge/discharge rate by using surface redox chemistries. MXene, a family of layered compounds, is a pseudocapacitor-like electrode material which exhibits charge storage through exceptionally fast ion accessibility to redox sites. Here, the authors demonstrate steric chloride termination in MXene Ti2CTx (T-x: surface termination groups) to open the interlayer space between the individual 2D Ti2CTx units. The open interlayer space significantly enhances Li-ion accessibility, leading to high gravimetric and volumetric capacitances (300 F g(-1) and 130 F cm(-3)) with less diffusion limitation. A Li-ion hybrid capacitor consisting of the Ti2CTx negative electrode and the LiNi1/3Co1/3Mn1/3O2 positive electrode displays an unprecedented specific energy density of 160 W h kg(-1) at 220 W kg(-1) based on the total weight of positive and negative active materials.

    DOI

    Scopus

    222
    Citation
    (Scopus)
  • One-dimensional supramolecular hybrids: self-assembled nanofibrous materials based on a sugar gelator and calcite developed along an unusual axis

    Haruka Sukegawa, Tatsuya Nishimura, Masafumi Yoshio, Satoshi Kajiyama, Takashi Kato

    CRYSTENGCOMM   19 ( 12 ) 1580 - 1584  2017.03  [Refereed]

    DOI

    Scopus

    9
    Citation
    (Scopus)
  • Potentiometric Study to Reveal Reaction Entropy Behavior of Biphasic Na1+2xV2(PO4)(3) Electrodes

    Satoshi Kajiyama, Kazuhiko Kai, Masashi Okubo, Atsuo Yamada

    ELECTROCHEMISTRY   84 ( 4 ) 234 - 237  2016.04  [Refereed]

     View Summary

    Sodium-ion batteries potentially provide the opportunities to realize the energy storage system beyond the state-of-the-art lithium-ion batteries, though at present their performance is limited partly due to lack of suitable positive electrode materials. NASICON-type Na3V2(PO4)(3) is a promising candidate for the positive electrode materials because of its high capacity and high operating potential, however, the electrode reaction of Na1+2xV2(PO4)(3) (0 &lt;= x &lt;= 1) including a biphasic region is not yet fully understood. Here, in order to clarify the microscopic mechanism of the biphasic reaction, the reaction entropy of the electrochemical cell including the Na1+2xV2(PO4)(3) positive electrode was measured using the potentiometric method. The temperature-dependent open-circuit voltage reveals that the reaction entropy is almost constant for 0.1 &lt;= x &lt;= 0.9. The constant reaction entropy of the electrochemical cell suggests that the electrode reaction proceeds through the boundary migration between the Na-rich and-poor phases without substantial change in the configurational entropy. (C) The Electrochemical Society of Japan, All rights reserved.

    DOI

    Scopus

    6
    Citation
    (Scopus)
  • Sodium-Ion Intercalation Mechanism in MXene Nanosheets

    Satoshi Kajiyama, Lucie Szabova, Keitaro Sodeyama, Hiroki Iinuma, Ryohei Morita, Kazuma Gotoh, Yoshitaka Tateyama, Masashi Okubo, Atsuo Yamada

    ACS NANO   10 ( 3 ) 3334 - 3341  2016.03  [Refereed]

     View Summary

    MXene, a family of layered compounds consisting of nanosheets, is emerging as an electrode material for various electrochemical energy storage devices including supercapacitors, lithium-ion batteries, and sodium-ion batteries. However, the mechanism of its electrochemical reaction is not yet fully understood. Herein, using solid-state Na-23 magic angle spinning NMR and density functional theory calculation, we reveal that MXene Ti3C2Tx in a nonaqueous Na+ electrolyte exhibits reversible Na+ intercalation/deintercalation into the interlayer space. Detailed analyses demonstrate that Ti3C2Tx undergoes expansion of the interlayer distance during the first sodiation, whereby desolvated Na+ is intercalated/deintercalated reversibly. The interlayer distance is maintained during the whole sodiation/desodiation process due to the pillaring effect of trapped Na+ and the swelling effect of penetrated solvent molecules between the Ti3C2Tx sheets. Since Na+ intercalation/deintercalation during the electrochemical reaction is not accompanied by any substantial structural change, Ti3C2Tx shows good capacity retention over 100 cycles as well as excellent rate capability.

    DOI

    Scopus

    441
    Citation
    (Scopus)
  • Rapid and topotactic transformation from octacalcium phosphate to hydroxyapatite (HAP): a new approach to self-organization of free-standing thin-film HAP-based nanohybrids

    Satoshi Kajiyama, Takeshi Sakamoto, Moe Inoue, Tatsuya Nishimura, Taishi Yokoi, Chikara Ohtsuki, Takashi Kato

    CRYSTENGCOMM   18 ( 43 ) 8388 - 8395  2016  [Refereed]

     View Summary

    Biomineralization-inspired processing is attractive for the preparation of functionalized inorganic/organic polymer hybrid materials because the materials are obtained under mild conditions and by using organic templates. As for the formation processes of ordered nanocrystalline hydroxyapatite (HAP), the preparation of self-standing hybrid films based on HAP has not yet been established. In the present study, self-standing thin-film hybrids composed of HAP and poly(vinyl alcohol) (PVA) are obtained by rapid and topotactic transformation of thin films based on octacalcium phosphate (OCP) as a precursor in the organic polymer matrix. Bioinspired crystallization of calcium phosphate on the PVA matrix in the presence of poly(acrylic acid) leads to the formation of nanocomposite structures with oriented OCP nanorod crystals 2-4 nm in width and 10-30 nm in length. The nanostructures allow the composites to transform rapidly into a HAP/PVA hybrid thin film in water. The transformation proceeds without a change in the original OCP/PVA nanostructures, resulting in the formation of a HAP/PVA hybrid thin film with oriented HAP nanorod crystals 5-6 nm in width and 20-50 nm in length. The HAP/PVA hybrids have been obtained as self-standing films with submicrometer scale thickness. The ratio of organic to inorganic components in the self-standing hybrid thin films is similar to that in bones of vertebrates.

    DOI

    Scopus

    22
    Citation
    (Scopus)
  • Formation of Helically Structured Chitin/CaCO3 Hybrids through an Approach Inspired by the Biomineralization Processes of Crustacean Cuticles

    Shunichi Matsumura, Satoshi Kajiyama, Tatsuya Nishimura, Takashi Kato

    SMALL   11 ( 38 ) 5127 - 5133  2015.10  [Refereed]

     View Summary

    Chitin/CaCO3 hybrids with helical structures are formed through a biomineralization-inspired crystallization process under ambient conditions. Liquid-crystalline chitin whiskers are used as helically ordered templates. The liquid-crystalline structures are stabilized by acidic polymer networks which interact with the chitin templates. The crystallization of CaCO3 is conducted by soaking the templates in the colloidal suspension of amorphous CaCO3 (ACC) at room temperature. At the initial stage of crystallization, ACC particles are introduced inside the templates, and they crystallize to CaCO3 nanocrystals. The acidic polymer networks induce CaCO3 crystallization. The characterization of the resultant hybrids reveals that they possess helical order and homogeneous hybrid structures of chitin and CaCO3, which resemble the structure and composition of the exoskeleton of crustaceans.

    DOI

    Scopus

    69
    Citation
    (Scopus)
  • Pseudocapacitance of MXene nanosheets for high-power sodium-ion hybrid capacitors

    Xianfen Wang, Satoshi Kajiyama, Hiroki Iinuma, Eiji Hosono, Shinji Oro, Isamu Moriguchi, Masashi Okubo, Atsuo Yamada

    NATURE COMMUNICATIONS   6  2015.04  [Refereed]

     View Summary

    High-power Na-ion batteries have tremendous potential in various large-scale applications. However, conventional charge storage through ion intercalation or double-layer formation cannot satisfy the requirements of such applications owing to the slow kinetics of ion intercalation and the small capacitance of the double layer. The present work demonstrates that the pseudocapacitance of the nanosheet compound MXene Ti2C achieves a higher specific capacity relative to double-layer capacitor electrodes and a higher rate capability relative to ion intercalation electrodes. By utilizing the pseudocapacitance as a negative electrode, the prototype Na-ion full cell consisting of an alluaudite Na2Fe2(SO4)(3) positive electrode and an MXene Ti2C negative electrode operates at a relatively high voltage of 2.4V and delivers 90 and 40 mAh g(-1) at 1.0 and 5.0 Ag-1 (based on the weight of the negative electrode), respectively, which are not attainable by conventional electrochemical energy storage systems.

    DOI

    Scopus

    955
    Citation
    (Scopus)
  • Liquid-crystalline calcium carbonate: biomimetic synthesis and alignment of nanorod calcite

    Masanari Nakayama, Satoshi Kajiyama, Tatsuya Nishimura, Takashi Kato

    CHEMICAL SCIENCE   6 ( 11 ) 6230 - 6234  2015  [Refereed]

     View Summary

    Liquid-crystalline CaCO3 has been prepared for the first time. The nanorods of CaCO3 calcite are obtained by bio-inspired crystallization through aqueous colloidal precursors of amorphous CaCO3 stabilized by poly(acrylic acid). The synthesized calcite nanocrystals have well-tuned morphologies that are preferable for formation of liquid-crystalline phases in concentrated aqueous colloidal solution. The one-dimensional alignment of calcite crystals is achieved by mechanical shearing of the aqueous colloidal solution showing liquid-crystalline phases. These CaCO3-based liquid crystals formed by a self-organization process in mild conditions may have great potential for use as environmentally friendly materials.

    DOI

    Scopus

    34
    Citation
    (Scopus)
  • Chitin: Formation of Helically Structured Chitin/CaCO3 Hybrids through an Approach Inspired by the Biomineralization Processes of Crustacean Cuticles (Small 38/2015).

    Matsumura Shunichi, Kajiyama Satoshi, Nishimura Tatsuya, Kato Takashi

    Small (Weinheim an der Bergstrasse, Germany)   11 ( 38 ) 5126 - 5126  2015  [Refereed]

    DOI

    Scopus

    3
    Citation
    (Scopus)
  • Assembly of Na3V2(PO4)(3) Nanoparticles Confined in a One-Dimensional Carbon Sheath for Enhanced Sodium-Ion Cathode Properties

    Satoshi Kajiyama, Jun Kikkawa, Junichi Hoshino, Masashi Okubo, Eiji Hosono

    CHEMISTRY-A EUROPEAN JOURNAL   20 ( 39 ) 12636 - 12640  2014.09  [Refereed]

     View Summary

    Structural and morphological control is an effective approach for improvement of electrochemical properties in rechargeable batteries. One-dimensionally assembled ,structure composed of NASICON-type Na3V2(PO4)(3) nanoparticles were fabricated through an electrospinning method to meet the requirements for the development of efficient electrode materials in Na-ion batteries. High-temperature treatment of electrospun precursor fibers under an argon flow provides a nonwoven fabric of nanowires comprising crystallographically oriented nanoparticles of NASICON-type Na3V2(PO4)(3) within a carbon sheath. The mesostructure comprising NASICON-type Na3V2(PO4)(3) and carbon give a short sodium-ion transport pass and an efficient electron conduction pass. Electrochemical properties of NASICON-type Na3V2(PO4)(3) are improved on the basis of one-dimensional nanostructures designed in the present study.

    DOI

    Scopus

    73
    Citation
    (Scopus)
  • Aragonite Nanorods in Calcium Carbonate/Polymer Hybrids Formed through Self-Organization Processes from Amorphous Calcium Carbonate Solution

    Satoshi Kajiyama, Tatsuya Nishimura, Takeshi Sakamoto, Takashi Kato

    SMALL   10 ( 8 ) 1634 - 1641  2014.04  [Refereed]

     View Summary

    Nanostructured inorganic/polymer hybrid thin films comprising aragonite nanorods derived from aqueous suspensions of amorphous calcium carbonate (ACC) are prepared. For the formation of calcium carbonate (CaCO3)/polymer hybrids, spincoated and annealed films of poly(vinyl alcohol) (PVA) that function as polymer matrices are soaked in aqueous colloidal solutions dispersing ACC stabilized by poly(acrylic acid) (PAA). In the initial stage, calcite thin films form on the surface. Subsequently, aragonite crystals start to form inside the PVA matrix that contains PVA crystallites which induce aragonite nucleation. Nanostructured hybrids composed of calcite thin films consisting of nanoparticles and assembled aragonite nanorods are formed in the matrices of PVA.

    DOI

    Scopus

    44
    Citation
    (Scopus)
  • Phase Separation of a Hexacyanoferrate-Bridged Coordination Framework under Electrochemical Na-ion Insertion

    Satoshi Kajiyama, Yoshifumi Mizuno, Masashi Okubo, Ryosuke Kurono, Shin-ichi Nishimura, Atsuo Yamada

    INORGANIC CHEMISTRY   53 ( 6 ) 3141 - 3147  2014.03  [Refereed]

     View Summary

    Phase separation and transformation induced by electrochemical ion insertion are key processes in achieving efficient energy storage. Exploration of novel insertion electrode materials/reactions is particularly important to unravel the atomic/molecular-level mechanism and improve the electrochemical properties. Here, we report the unconventional phase separation of a cyanide-bridged coordination polymer, Eu[Fe(CN)(6)]center dot 4H(2)O, under electrochemical Na-ion insertion. Detailed structural analyses performed during the electrochemical reaction revealed that, in contrast to conventional electrochemical phase separation induced by the elastic interaction between nearest neighbors, the phase separation of NaxEu[Fe(CN)(6)]center dot 4H(2)O is due to a long-range interaction, namely, cooperative rotation ordering of hexacyanoferrates. Kolmogorov-Johnson-Mehl-Avrami analysis showed that the activation energy for the phase boundary migration in NaxEu[Fe(CN)(6)]center dot 4H(2)O is lower than that in other conventional electrode materials such as Li1-xFePO4.

    DOI

    Scopus

    20
    Citation
    (Scopus)
  • CCDC 992673: Experimental Crystal Structure Determination

    Kajiyama Satoshi, Mizuno Yoshifumi, Okubo Masashi, Kurono Ryosuke, Nishimura Shin-Ichi, Yamada Atsuo

    Cambridge Structural Database    2014  [Refereed]

    DOI

  • CCDC 992672: Experimental Crystal Structure Determination

    Kajiyama Satoshi, Mizuno Yoshifumi, Okubo Masashi, Kurono Ryosuke, Nishimura Shin-Ichi, Yamada Atsuo

    Cambridge Structural Database    2014  [Refereed]

    DOI

  • Formation of Rectangular Plate-like alpha-MnOOH and Sheet-like gamma-MnOOH by Slow Diffusion of Ammonia Vapor

    Satoshi Kajiyama, Hiromu Kumagai, Tatsuya Nishimura, Takashi Kato

    CHEMISTRY LETTERS   42 ( 4 ) 341 - 343  2013.04  [Refereed]

     View Summary

    The formation of rectangular plate-like alpha-MnOOH and sheet-like gamma-MnOOH crystals has been achieved under ambient conditions. A gradual crystallization of manganese compounds with the diffusion of ammonia vapor inhibits random oxidization of divalent manganese ions and the formation of aggregates of Mn3O4 crystals. The simple method using ammonia vapor is applicable to the development of manganese-based compounds with ordered structures.

    DOI

    Scopus

    5
    Citation
    (Scopus)
  • CaCO3/Chitin hybrids: recombinant acidic peptides based on a peptide extracted from the exoskeleton of a crayfish controls the structures of the hybrids

    Hiromu Kumagai, Ryou Matsunaga, Tatsuya Nishimura, Yuya Yamamoto, Satoshi Kajiyama, Yuya Oaki, Kei Akaiwa, Hirotaka Inoue, Hiromichi Nagasawa, Kohei Tsumoto, Takashi Kato

    FARADAY DISCUSSIONS   159   483 - 494  2012  [Refereed]

     View Summary

    Functional peptides play an important role in the formation of biominerals. Here we focus on peptides involved in mineralization of the exoskeleton of a crayfish. New recombinant peptides are designed and synthesized on the basis of an acidic functional peptide, CAP-1, derived from the exoskeleton of a crayfish. We have examined the effect of these peptides on the hybrid formation of calcium carbonate and organic molecules in aqueous solution. In the presence of these recombinant peptides having chitin binding moieties, platelike tripodal calcite crystals are formed on the chitin matrix with unidirectional crystallographic orientation. Two kinds of interactions, (1) interactions between an acidic part of the peptides and calcium ions and (2) specific binding interactions of the peptides to chitin, are essential for the formation of the oriented crystals and the induction of specific morphologies. Moreover, the sizes of crystallites decrease with increasing the number of acidic parts of mutational peptides. The bioinspired design of peptides that control the interface of inorganic and organic domains may pave the way for an opportunity to build new hybrid structures.

    DOI

    Scopus

    24
    Citation
    (Scopus)
  • Nanosegregated Amorphous Composites of Calcium Carbonate and an Organic Polymer

    Yuya Oaki, Satoshi Kajiyama, Tatsuya Nishimura, Hiroaki Imai, Takashi Kato

    ADVANCED MATERIALS   20 ( 19 ) 3633 - +  2008.10  [Refereed]

     View Summary

    Transparent and stable composites of calcium carbonate and an acidic macromolecule are obtained at mild conditions. The nanosegregated structure is formed in the amorphous composite materials in the bulk and thin-film states. The transparent, stable, and crack-free thin films might be beneficial for coating of materials. Transparent and stable composites

    DOI

    Scopus

    111
    Citation
    (Scopus)
  • Selective synthesis and thin-film formation of alpha-cobalt hydroxide through an approach inspired by biomineralization

    Yuya Oaki, Satoshi Kajiyama, Tatsuya Nishimura, Takashi Kato

    JOURNAL OF MATERIALS CHEMISTRY   18 ( 35 ) 4140 - 4142  2008  [Refereed]

     View Summary

    An approach inspired by biomineralization leads to the selective formation of highly crystalline alpha-Co(OH)(2) and its oriented thin films in the presence of organic molecules under mild conditions.

    DOI

    Scopus

    37
    Citation
    (Scopus)

▼display all

Research Projects

  • 可逆的な電気化学イオン脱挿入反応を示す分子集合体の開発と反応機構解析

    日本学術振興会  科学研究費補助金 若手研究

    Project Year :

    2018.04
    -
    2020.03
     

    梶山 智司

  • 層状無機化合物/有機分子複合体電極活物質の作製とその反応機構解析

    公益財団法人 村田学術振興財団  研究助成

    Project Year :

    2017.09
    -
    2018.08
     

    梶山 智司

  • 二次電池電極材料開発を指向した機能性分子集合構造の開発と電気化学反応機構解析

    公益財団法人 岩谷直治記念財団  岩谷科学技術研究助成

    Project Year :

    2018.04
    -
     
     

    梶山 智司

Misc

  • Dependence of cation species and negative-dielectric effect on the electric-double layer capacitance of a MXene electrode

    Ando Yasunobu, Sugahara Akira, Kajiyama Satoshi, Otani Minoru, Okubo Masashi, Yamada Atsuo

    Abstract book of Annual Meeting of the Japan Society of Vacuum and Surface Science   2019 ( 0 ) 3Hp04Y  2019

     View Summary

    <p>We experimentally observed that the electric-double layer capacitance of a MXene electrode depends on the cation species intercalated into the electrode. This phenomenon was not observed with activated carbon electrodes. To understand this phenomenon, we simulated on the electric-double layer formed at the interlayer of the electrode by computer simulation combining the classical liquid theory and first-principles calculation. As a result, we revealed that the density of intercalated water depends on the cation species, and the water hydrating around cations exhibits negative dielectric characteristics accordingly, which enhances the electric-double layer capacitance.</p>

    DOI CiNii

  • Nanoparticles Based on Metal Carbonate Compounds Showing Liquid-Crystalline Behavior in Aqueous Dispersion

    Kajiyama Satoshi, Nakayama Masanari, Kato Takashi

    Proceedings of Japanese Liquid Crystal Society Annual meeting   2018 ( 0 ) 3A07  2018

     View Summary

    <p></p>

    DOI CiNii

  • Construction of Organic/Inorganic Fusion Materials through Approaches Inspired by Biomineralization

    市川理乃, 梶山智司, 中山真成, 加藤隆史

    日本接着学会誌   54 ( 10 ) 389 - 395  2018

    CiNii J-GLOBAL

  • Biomineralization-Inspired Synthesis for Functional Inorganic Materials

    梶山智司, 加藤隆史

    科学と工業   91 ( 8 ) 220 - 226  2017.08

    CiNii J-GLOBAL

  • Development of Stimuli-Responsive Environmentally Friendly Liquid-Crystalline Materials

    Nakayama Masanari, Kajiyama Satoshi, Nishimura Tatsuya, Kumamoto Akihito, Ikuhara Yuichi, Yamato Masafumi, Kato Takashi

    Proceedings of Japanese Liquid Crystal Society Annual meeting   2017 ( 0 ) PA24  2017

     View Summary

    <p></p>

    DOI CiNii

  • 有機高分子/リン酸カルシウム複合体薄膜の開発および機能化

    IIMURA MISATO, HAN YULAI, KAJIYAMA SATOSHI, SAKAMOTO TAKESHI, NISHIMURA TATSUYA, OTSUKI CHIKARA, KATO TAKASHI

    高分子学会予稿集(CD-ROM)   64 ( 2 ) ROMBUNNO.1PF110  2015.08

    J-GLOBAL

  • 有機高分子による炭酸カルシウムナノ結晶の合成とモルホロジー制御

    NAKAYAMA MASANARI, KAJIYAMA SATOSHI, NISHIMURA TATSUYA, KATO TAKASHI

    高分子学会予稿集(CD-ROM)   64 ( 1 ) ROMBUNNO.3H18  2015.05

    J-GLOBAL

  • 生物の甲殻を模倣した階層構造を有する有機/無機複合体の構築

    MATSUMURA SHUN'ICHI, KAJIYAMA SATOSHI, NISHIMURA TATSUYA, KATO TAKASHI

    高分子学会予稿集(CD-ROM)   63 ( 2 ) ROMBUNNO.1E03  2014.09

    J-GLOBAL

  • バイオミネラリゼーションのプロセスを基盤とする新規炭酸カルシウム複合材料の開発

    ITO KOTARO, NAGAHARA DAI, HIRABARU CHIKA, KAJIYAMA SATOSHI, NISHIMURA TATSUYA, SAKAMOTO TAKESHI, KATO TAKASHI

    日本化学会講演予稿集   94th ( 3 ) 1008  2014.03

    J-GLOBAL

  • バイオミネラリゼーションのプロセスを基盤とする新規炭酸カルシウム複合材料の開発

    ITO KOTARO, HIRABARU CHIKA, NAGAHARA DAI, KAJIYAMA SATOSHI, NISHIMURA TATSUYA, SAKAMOTO TAKESHI, KATO TAKASHI

    ポリマー材料フォーラム講演予稿集   22nd   50  2013.11

    J-GLOBAL

  • 非晶相前駆体を利用した無機結晶/有機高分子ナノ構造薄膜の自己組織化

    SAKAMOTO TAKESHI, KAJIYAMA SATOSHI, NISHIMURA TATSUYA, KATO TAKASHI

    高分子学会予稿集(CD-ROM)   62 ( 2 ) ROMBUNNO.1B08  2013.08

    J-GLOBAL

  • 金属水酸化物/機能性有機化合物複合体の開発

    YAMAMOTO TAKUMI, SAKAI HIRONARI, KAJIYAMA SATOSHI, NISHIMURA TATSUYA, KATO TAKASHI

    日本化学会講演予稿集   93rd ( 3 ) 1023  2013.03

    J-GLOBAL

  • 非晶結晶転移の制御による有機高分子/無機結晶複合体薄膜の形成

    KAJIYAMA SATOSHI, NISHIMURA TATSUYA, SAKAMOTO TAKESHI, OTSUKI CHIKARA, KATO TAKASHI

    日本化学会講演予稿集   93rd ( 3 ) 778  2013.03

    J-GLOBAL

  • 高分子テンプレートを用いた高分子/リン酸カルシウム複合体薄膜の開発

    INOUE MOE, KAJIYAMA SATOSHI, SAKAMOTO TAKESHI, NISHIMURA TATSUYA, KATO TAKASHI

    高分子学会予稿集(CD-ROM)   61 ( 1 ) ROMBUNNO.1PB076  2012.05

    J-GLOBAL

  • 高分子テンプレートを用いる三次元構造を有する無機/有機複合体の開発

    MATSUMURA SHUN'ICHI, KAJIYAMA SATOSHI, NISHIMURA TATSUYA, KATO TAKASHI

    日本化学会講演予稿集   92nd ( 3 ) 1111  2012.03

    J-GLOBAL

  • 酸性高分子を用いた炭酸カルシウムおよび炭酸ストロンチウム結晶の形態制御

    KAJIYAMA SATOSHI, NISHIMURA TATSUYA, KATO TAKASHI

    高分子学会予稿集(CD-ROM)   60 ( 2 Disk1 ) ROMBUNNO.2PF078  2011.09

    J-GLOBAL

  • 高分子テンプレートを用いる遷移金属水酸化物の形態制御

    MATSUMURA SHUN'ICHI, KAJIYAMA SATOSHI, NISHIMURA TATSUYA, KATO TAKASHI

    高分子学会予稿集(CD-ROM)   60 ( 1 Disk1 ) ROMBUNNO.1PC099  2011.05

    J-GLOBAL

  • Hybrid materials inspired by biomineralization

    梶山智司, 西村達也, 加藤隆史

    Function & materials   30 ( 12 ) 23 - 28  2010.12

    CiNii J-GLOBAL

  • 有機高分子/水酸化コバルト複合体薄膜の形成

    KAJIYAMA SATOSHI, OAKI YUYA, NISHIMURA TATSUYA, KATO TAKASHI

    高分子学会予稿集(CD-ROM)   59 ( 2 Disk1 ) ROMBUNNO.2PE093  2010.09

    J-GLOBAL

  • 有機高分子を用いる遷移金属/有機複合体の構造制御

    KUMAGAI HIROMU, KAJIYAMA SATOSHI, NISHIMURA TATSUYA, KATO TAKASHI

    高分子学会予稿集(CD-ROM)   59 ( 2 Disk1 ) ROMBUNNO.2PC103  2010.09

    J-GLOBAL

  • 高分子テンプレートを用いる水酸化マンガン薄膜の構築

    KUMAGAI HIROMU, KAJIYAMA SATOSHI, NISHIMURA TATSUYA, KATO TAKASHI

    高分子学会予稿集(CD-ROM)   59 ( 1 Disk1 ) ROMBUNNO.3PD118  2010.05

    J-GLOBAL

  • 有機高分子テンプレートを用いる水酸化コバルトの薄膜化と構造制御

    KAJIYAMA SATOSHI, OAKI YUYA, NISHIMURA TATSUYA, KATO TAKASHI

    高分子学会予稿集(CD-ROM)   59 ( 1 Disk1 ) ROMBUNNO.3PC117  2010.05

    J-GLOBAL

  • 有機高分子を用いた遷移金属水酸化物の結晶化制御

    SAKAI HIRONARI, KAJIYAMA SATOSHI, OAKI YUYA, NISHIMURA TATSUYA, KATO TAKASHI

    高分子学会予稿集(CD-ROM)   58 ( 2 Disk1 ) ROMBUNNO.2PB120  2009.09

    J-GLOBAL

  • 有機分子/水酸化コバルト複合体の作製

    KAJIYAMA SATOSHI, OAKI YUYA, NISHIMURA TATSUYA, KATO TAKASHI

    高分子学会予稿集(CD-ROM)   58 ( 1 Disk1 ) 2PE103  2009.05

    J-GLOBAL

  • 配向キチンをテンプレートに用いる配向有機/無機複合体の構築

    NISHIMURA TATSUYA, OAKI YUYA, KAJIYAMA SATOSHI, KATO TAKASHI

    粉体粉末冶金協会講演概要集   2008   29  2008.11

    J-GLOBAL

  • バイオミネラリゼーションに倣う遷移金属水酸化物の作製

    KAJIYAMA SATOSHI, OAKI YUYA, NISHIMURA TATSUYA, KATO TAKASHI

    高分子学会予稿集(CD-ROM)   57 ( 2 Disk1 ) 3PC093  2008.09

    J-GLOBAL

  • ナノ相分離構造を有する有機高分子/炭酸カルシウムアモルファス複合材料の開発

    OAKI YUYA, KAJIYAMA SATOSHI, NISHIMURA TATSUYA, IMAI HIROAKI, KATO TAKASHI

    高分子学会予稿集(CD-ROM)   57 ( 2 Disk1 ) 1L17  2008.09

    J-GLOBAL

  • 有機/無機複合体における有機高分子の設計と構造制御

    NISHIMURA TATSUYA, ITO TAKAHIRO, OAKI YUYA, KAJIYAMA SATOSHI, KATO TAKASHI

    高分子学会予稿集(CD-ROM)   57 ( 2 Disk1 ) 3E04  2008.09

    J-GLOBAL

  • バイオミネラリゼーションに倣う有機高分子/水酸化コバルト複合体薄膜の作製

    OAKI YUYA, KAJIYAMA SATOSHI, NISHIMURA TATSUYA, KATO TAKASHI

    高分子学会予稿集(CD-ROM)   57 ( 1 Disk1 ) 3PA127  2008.05

    J-GLOBAL

  • 配向キチン誘導体を用いる無機結晶の結晶成長制御

    NISHIMURA TATSUYA, ITO TAKAHIRO, OAKI YUYA, KAJIYAMA SATOSHI, KATO TAKASHI

    高分子学会予稿集(CD-ROM)   57 ( 1 Disk1 ) 3PB140  2008.05

    J-GLOBAL

  • 有機高分子マトリクスを用いた水酸化コバルト複合体薄膜の作製

    KAJIYAMA SATOSHI, OAKI YUYA, NISHIMURA TATSUYA, KATO TAKASHI

    日本化学会講演予稿集   88th ( 1 ) 509  2008.03

    J-GLOBAL

▼display all

Industrial Property Rights