-  “Heteroatom-Doped Carbon Electrocatalysts Derived from Nanoporous Two-Dimensional Covalent Organic Frameworks for Oxygen Reduction and Hydrogen Evolution”
Chao Yang, Shanshan Tao, Ning Huang, Xiaobin Zhang, Jingui Duan*, Rie Makiura*, and Shinya Maenosono*
ACS Applied NanoMaterials
Received:24 March 2020, Accepted:15 May 2020, Published online:1 June 2020
-  “界面活性剤系被膜養生剤による水分蒸発抑制効果に関する研究
Water-Retaining Effect of Surfactant-Based Membrane-Forming Curing Compounds”
Published on October 2019
-  “Controlled Release of DNA from Zinc and Magnesium Ion-Doped Hydroxyapatites”
C. Kojima, K. Watanabe, H. Murata, Y. Nishio, R. Makiura, K. Matsunaga, A. Nakahira
Research on Chemical Intermediates, 45, 23-32(2019).
First Online: 11 October 2018Hydroxyapatite (HA) is a biocompatible and porous material that is useful for gene delivery. In this study, various Zn- and Mg-doped HA samples were produced by adding the ions at different dopant concentrations to control the association and dissociation of DNA. Although the HA crystal structure was retained after doping, it became distorted with increasing doped metal concentration. In 20% Zn-doped HA, a secondary Zn(OH)2 phase was observed. Mg-doped HA did not show significant cytotoxicity against breast tumor cells and osteoblasts. But, highly Zn-doped HAs were toxic, suggesting that doped Zn ions affected the cells. DNA could effectively adsorb to HA, regardless of metal ion doping, but the dissociation behavior of DNA differed. DNA was gradually released from Mg-doped HA for over a week, independent of Mg dope concentration, but not from Zn-doped HA, except for 20% doping. Therefore, the release properties of HA can be controlled by doping with suitable metal ion species at an appropriate dosage.
-  “Influence of Solution pH and Reaction Atmosphere on the Morphology of SrTiO3 Nanocubes Synthesized by Thermohydrolysis”
Research on Chemical Intermediates, 44, 4775-4782(2018).
First Online: 24 January 2018
The influence of synthetic conditions on the shape and size of SrTiO3 (STO) nanocubes was studied. These were synthesized in aqueous solution using Sr(OH)2 as the Sr2+ source and titanium(IV) bis(ammonium lactate)dihydroxide (TALH) as the TiIV source in the presence of oleic acid and hydrazine. A large excess of OH− at a pH of the precursor solution higher than 12 is necessary for the formation of STO nanocubes without the need for any calcination. Performing the synthesis in a N2 atmosphere additionally prevents the formation of SrCO3 impurity, leading to the creation of uniformly sized STO nanocubes in a reproducible manner. Such size-regulated STO nanocubes are found to align over a large area.
-  “Structural Analysis of Molecular Naonsheets for Separation Membrane Assembled with a Bottom‒Up Approach at Liquid Interfaces”
T. Ohata, I. Hirosawa, T. Watanabe, R. Makiura
SPring-8 / SACLA Research Report, 6, 2016B1862 / BL19B2(2017).
Received: June 29, 2017; Early edition: November 24, 2017配位高分子は、有機分子を主成分とした多孔性物質であり、有機分子の設計性を生かし、細孔サイズや形状を多様且つ容易に変化させることができる。そのため、ナノシート化により、透過性と選択性を兼ね備えた分離膜としての応用が期待される。これまでに、気液界面を用いて配位高分子ナノシートの作製に成功しているが、ナノシートの形成状態（厚さ、面積、結晶化度）に影響を及ぼす条件因子、ガス選択性や透過性は未解明である。本課題においては、固体基板に転写した配位高分子ナノシートの構造評価及び気液界面におけるナノシート形成過程解明のためのその場測定に向けた条件確認を行った。波長 0.124 nm における微小角入射X線回折（GIXRD）測定を行い、in‒plane および out‒of‒plane 測定の両方に関してピークが得られていることから、配位高分子ナノシートは高い結晶性を有し、さらに基板に対して配向していることがわかった。また、ビーム打ち下ろし設定における水表面からの全反射の確認を行った。
-  “Air/Liquid Interfacial Nanoassembly of Molecular Building Blocks into Preferentially-Oriented Porous Organic Nanosheet Crystals via Hydrogen Bonding”
R. Makiura, K. Tsuchiyama, E. Pohl, K. Prassides, O. Sakata, H. Tajiri, O. Konovalov
ACS Nano, 11, 10875–10882(2017). Open Access
Publication Date (Web): October 24, 2017
Nanosheets with highly regulated nanopores are ultimately thin functional materials for diverse applications including molecular separation and detection, catalysis, and energy conversion and storage. However, their availability has hitherto been restricted to layered parent materials, covalently bonded sheets, which are layered via relatively weak electrostatic interactions. Here, we report a rational bottom-up methodology that enables nanosheet creation beyond the layered systems. We employ the air/liquid interface to assemble a triphenylbenzene derivative into perfectly oriented highly crystalline noncovalent-bonded organic nanosheets under ambient conditions. Each molecular building unit connects laterally by hydrogen bonding, endowing the nanosheets with size- and position-regulated permanent nanoporosity, as established by in situ synchrotron X-ray surface crystallography and gas sorption measurements. Notably, the nanosheets are constructed specifically by interfacial synthesis, which suppresses the intrinsic complex interpenetrated structure of the bulk crystal. Moreover, they possess exceptional long-term and thermal stability and are easily transferrable to numerous substrates without loss of structural integrity. Our work shows the power of interfacial synthesis using a suitably chosen molecular component to create two-dimensional (2D) nanoassemblies not accessible by conventional bulk crystal exfoliation techniques.
-  “Solution-Based Sequential Modification of LiCoO2 Particle Surfaces with Iron(II) Oxalate Nanolayers”
Y. Kishimoto, S. Yubuchi, A. Hayashi, M. Tatsumisago, R. Makiura
CrysEngComm, 19, 4175-4181(2017).
First published on 19 May 2017
Hybridization of metal–organic frameworks (MOFs) with other inorganic materials offers the opportunity to enhance their properties or open new windows for potential applications. Formation of core/shell structures, in which the core is the inorganic particle and the shell is the surface-deposited MOF, is one of the rational methodologies to create such hybrid materials. Here, we present the facile creation of metal oxide-core/MOF-shell structures by applying a solution-based step-by-step modification of the core surface using a framework compound. The modification procedure includes alternate immersion of LiCoO2 (LCO) – a catalyst for the oxygen evolution reaction – into oxalic acid and ferrous solutions, resulting in the formation of iron(II) oxalate (Fe(ox), ox = oxalate anion) – one of the simplest MOFs with short unit frameworks – nanolayers on the LCO surface (Fe(ox)NL@LCO). The amount of deposited Fe(ox) does not increase monotonically with the number of the modification cycles, but tends to saturate rapidly, implying that the Fe(ox) framework grows laterally on the LCO surface. An increase of the electrical resistivity of the LCO particles that influences adversely catalytic activity is suppressed when a high coverage of the LCO surface by the Fe(ox) framework is achieved at subsequent modification cycles.
-  “Optimization of Dendrimer Structure for Sentinel Lymph Node Imaging: Effects of Generation and Terminal Group”
Y. Niki, M. Ogawa, R. Makiura, Y. Magata, C. Kojima
Nanomedicine: NBM, 11, 2119-2127(2015).
Available online 5 September 2015
The detection of the sentinel lymph node (SLN), the first lymph node draining tumor cells, is important in cancer diagnosis and therapy. Dendrimers are synthetic macromolecules with highly controllable structures, and are potent multifunctional imaging agents. In this study, 12 types of dendrimer of different generations (G2, G4, G6, and G8) and different terminal groups (amino, carboxyl, and acetyl) were prepared to determine the optimal dendrimer structure for SLN imaging. Radiolabeled dendrimers were intradermally administrated to the right footpads of rats. All G2 dendrimers were predominantly accumulated in the kidney. Amino-terminal, acetyl-terminal, and carboxyl-terminal dendrimers of greater than G4 were mostly located at the injection site, in the blood, and in the SLN, respectively. The carboxyl-terminal dendrimers were largely unrecognized by macrophages and T-cells in the SLN. Finally, SLN detection was successfully performed by single photon emission computed tomography imaging using carboxyl-terminal dendrimers of greater than G4.
-  “Liquid-Phase Step-by-Step Growth of an Iron Cyanide Coordination Framework on LiCoO2 Particle Surfaces”
R. Makiura, S. Teragawa, K. Tsuchiyama, A. Hayashi, K. Tadanaga, M. Tatsumisago
Dalton Transactions, 44, 15279-15287(2015).
First published online 13 May 2015
Surface modification of inorganic objects with metal-organic frameworks (MOFs) –organic-inorganic hybrid framework materials with infinite networks– opens wide windows for potential applications. In order to derive a target property, the key is the ability to fine tune the degree of modification. Solution-based step-by-step growth techniques provide excellent control of layer thickness which can be varied with the number of deposition cycles. Such techniques with MOFs have been mainly applied to flat substrates, but not to particle surfaces before. Here, we present the facile surface modification of inorganic particles with a framework compound under operationally simple ambient conditions. A solution-based sequential technique involving the alternate immersion of LiCoO2 (LCO) –a positive electrode material for a lithium ion battery– into FeCl2•4H2O and K3[Fe(CN)6] solutions results in the formation of Prussian blue (PB) nanolayers on the surface of the LCO particles (PBNL@LCO). The PB growth is finely controlled by the number of immersion cycles. An electrochemical cell with PBNL@LCO as a positive electrode material exhibits a discharge capacity close to the specific capacity of LCO. The results open a new direction for creating suitable interfacial conditions between electrode materials and electrolytes in secondary battery materials.
-  “External Stimulation-Controllable Heat-Storage Ceramics”
H. Tokoro, M. Yoshikiyo, K. Imoto, A. Namai, T. Nasu, K. Nakagawa, N. Ozaki, F. Hakoe, K. Tanaka, K. Chiba, R. Makiura, K. Prassides, S. Ohkoshi
Nature Communications, 6, 7037(2015). Open Access
Published 12 May 2015
Commonly available heat-storage materials cannot usually store the energy for a prolonged period. If a solid material could conserve the accumulated thermal energy, then its heat-storage application potential is considerably widened. Here we report a phase transition material that can conserve the latent heat energy in a wide temperature range, T<530 K and release the heat energy on the application of pressure. This material is stripe-type lambda-trititanium pentoxide, λ-Ti3O5, which exhibits a solid–solid phase transition to beta-trititanium pentoxide, β-Ti3O5. The pressure for conversion is extremely small, only 600 bar (60 MPa) at ambient temperature, and the accumulated heat energy is surprisingly large (230 kJ L−1). Conversely, the pressure-produced beta-trititanium pentoxide transforms to lambda-trititanium pentoxide by heat, light or electric current. That is, the present system exhibits pressure-and-heat, pressure-and-light and pressure-and-current reversible phase transitions. The material may be useful for heat storage, as well as in sensor and switching memory device applications.
-  “Towards Rational Modulation of In-Plane Molecular Arrangements in Metal-Organic Framework Nanosheets”
R. Makiura, R. Usui, Y. Sakai, A. Nomoto, A. Ogawa, O. Sakata, A. Fujiwara
ChemPlusChem, 79, 1352-1360 (2014). Open Access
Early View Online 18 Jul 2014
Highlighted in Wiley-Japan Science Cafe
Most accessed for Dec 2014
(Wiley-Japan Science Cafe / ChemistryViews)
A strategy to modulate the in-plane structural arrangement in preferentially oriented crystalline metal–organic framework (MOF) nanosheets assembled by a two-dimensional interfacial reaction between porphyrin units and metal ion linkers is reported. Starting with a tetratopic porphyrin MOF nanofilm, NAFS-2, the framework size and shape are modified by employing specially designed building units, a trans-ditopic and an expanded tetratopic porphyrin, and Cu2+ linkers. Reducing the number of binding parts affords a MOF nanosheet, NAFS-31, with a distorted in-plane structure. Extension of the peripheral substituents, while maintaining the tetratopic porphyrin geometry, results in marked unit cell size enlargement in an undistorted square grid in the MOF nanofilm, NAFS-41. The exquisite geometric control that these structural modifications entail is valuable to allow switching of chemical/physical properties of the nanosheets and lead to realization of their use in nanotechnological applications.
-  “Porphyrin-Based Coordination Polymer Composed of Layered Pillarless Two-Dimensional Networks”
R. Makiura, R. Usui, E. Pohl, K. Prassides
Chemistry Letters, 43, 1161-1163 (2014). Open Access
Advance online publication 14 April 2014
Released on J-STAGE 5 July 2014
Single crystals of a layer-structured coordination polymer, BNAS-11 [ZnTCPP(H2O)Zn2(H2O)2] (ZnTCPP:5,10,15,20-tetrakis(4-carboxyphenyl) porphyrinatozinc(II)), were obtained. Tetratopic ZnTCPP molecules are connected through dimer zinc paddle-wheel secondary building units and form a two-dimensional (2D) network with square grids. The layers are stacked electrostatically without the need of binding pillar ligands.
-  “EQCM Analysis of Redox Behavior of Prussian Blue in a Lithium Battery Electrolyte”
S. Yagi, M. Fukuda, R. Makiura, T. Ichitsubo, E. Matsubara
Journal of Materials Chemistry A, 2, 8041-8047 (2014).
Published online 14 Mar 2014
Prussian blue (PB) and its analogues (PBAs) have been intensively studied and are now increasingly attractive for battery applications in particular because of their ability to accommodate a wide variety of ions including polyvalent cations. The redox reactions of PB and PBAs are believed to be very fast and reversible. However, it is not always true. In this paper, we clarify the detailed redox behavior of PB in an electrolyte for Li (ion) batteries using an electrochemical quartz crystal microbalance under an Ar atmosphere. We quantitatively report for the first time that the electrochemical adsorption/desorption of PF6− ions occurs in addition to the insertion/extraction of Li+ ions upon the redox reactions of PB. The adsorption of PF6− ions is followed by the extraction of Li+ ions during the oxidation of PB, and the adsorbed PF6− ions hinder the extraction of the Li+ ions. In contrast, the adsorbed PF6− ions do not affect Li+ ion insertion because the PF6− ions are desorbed before the insertion of Li+ ions during the reduction of PB. These results show that for practical applications the size of the framework structure should be selected by comparing the anion size in addition to the cation size.
-  “Micropattern Formation by Molecular Migration via UV-Induced Dehydration of Block Copolymers”
K. Okada, Y. Tokudome, R. Makiura, K. Konstas, L. Malfatti, P. Innocenzi, H. Ogawa, T. Kanaya, P. Falcaro, M. Takahashi
Advanced Functional Materials, 24, 2801-2809 (2014).
Published online 23 January 2014
A novel UV lithographic technique for the patterning of the block copolymer (Pluronic) thin films is developed. The present method is based on UV-induced water affinity changes in block copolymer films. By water vapor post-treatment of the film, a difference in water content is established between UV illuminated and unilluminated sections, which can induce an osmotic pressure at the interface. This osmotic pressure drives the migration of Pluronic molecules, resulting in formation of patterns on the block copolymer films. Remarkably, this patterning method requires neither initiators nor polymerizable moieties which are essential for a conventional photolithographic approach. Additionally, the etching process is bypassed, eliminating the use of destructive acids or organic solvents and making this an environmentally friendly patterning protocol. It is reported that Pluronic is photo-responsive to UV exposure, which causes the dehydration of the PEO-PPO-PEO backbone.
-  “Toward Step-by-Step Nuclear Growth of Surface Two-Dimensional Porphyrin Nanonetworks”
R. Makiura, H. Kitagawa, Y. Akita, M. Yoshimoto
Journal of Colloid and Interface Science, 413, 71-77 (2014). Editor’s Choice
Published on 25 September 2013
Top cover image
We report the development of a solution-based step-by-step technique, which utilizes the coordination bond between metalloporphyrin molecular units and metal linkages and results in the nuclear growth of nano-networks on solid substrates. The growth of the surface structures is strongly influenced by the choice of substrate materials and solvents: the molecule-substrate interaction and the solubility of the molecular units are important parameters in tuning the size and growth of the domains.
-  “Bottom-Up Assembly of Ultrathin Sub-Micron Size Metal-Organic Framework Sheets”
R. Makiura, O. Konovalov
Dalton Transactions, 42, 15931-15936 (2013). Open Access
Published on 3 September 2013
Solution-based two-dimensional interfacial reaction between 5,10,15,20-tetra(4-pyridyl)-porphinato zinc(II) (ZnTPyP) and Cu(NO3)2•3H2O results in the assembly of uniform preferentially oriented highly crystalline metal-organic framework nanosheets, NAFS-21 with sub-micron planar size and mono-molecular thickness.
-  “Preparation of Hydroxyapatite-Decorated Poly(Lactide-co-Glycolide) Microspheres for Paclitaxel Delivery”
C. Kojima, K. Watanabe, T. Nagayasu, Y. Nishio, R. Makiura, A. Nakahira
Journal of Nanoparticle Research, 15, 2098/1-2098/11 (2013).
Published on 7 November 2013
Paclitaxel (Tax) is an anticancer drug with extremely low water solubility, and development of the formulation without organic solvents is highly desirable. Hydroxyapatite (HA) is a biocompatible and porous inorganic material that can be used effectively in drug delivery systems, but poor dispersibility in water limits its application. In this study, HA-decorated poly(lactide-co-glycolide) (PLG) spheres with several micrometers were prepared and characterized. PLG microspheres adsorbed Tax, independent in the HA decorating, and their water dispersibility was retained after the HA decorating. Tax-loaded HA-decorated PLG microspheres (Tax/HA/PLG) could thus be highly dispersed in water, increasing their cellular uptake. Most Tax molecules were stably adsorbed to the HA and HA-decorated PLG (HA/PLG) particles. Although the cytotoxicity of Tax-loaded HA was much lower than that of free Tax, the drug activity of Tax/HA/PLG was markedly improved. Since the morphology of microtubules was changed after the Tax/HA/PLG treatment, the HA/PLG could work as a carrier for Tax.
-  “Interfacial Growth of Large-Area Single-Layer Metal-Organic Framework Nanosheets”
R. Makiura, O. Konovalov
Scientific Reports, 3, 2506 (2013). Open Access
Published on 26 August 2013
The air/liquid interface is an excellent platform to assemble two-dimensional (2D) sheets of materials by enhancing spontaneous organizational features of the building components and encouraging large length scale in-plane growth. We have grown 2D molecularly-thin crystalline metal-organic-framework (MOF) nanosheets composed of porphyrin building units and metal-ion joints (NAFS-13) under operationally simple ambient conditions at the air/liquid interface. In-situ synchrotron X-ray diffraction studies of the formation process performed directly at the interface were employed to optimize the NAFS-13 growth protocol leading to the development of a post-injection method –post-injection of the metal connectors into the water subphase on whose surface the molecular building blocks are pre-oriented– which allowed us to achieve the formation of large-surface area morphologically-uniform preferentially-oriented single-layer nanosheets. The growth of such large-size high-quality sheets is of interest for the understanding of the fundamental physical/chemical properties associated with ultra-thin sheet-shaped materials and the realization of their use in applications.
-  “Designer Coordination Polymers: Dimensional Crossover Architectures and Proton Conduction”
T. Yamada, K. Otsubo, R. Makiura, H. Kitagawa
Chemical Society Reviews, 42, 6655–6669 (2013).
Published on 1 July 2013
Inside front cover
Coordination polymers (CPs) have large degrees of freedom in framework compositions and in the structures and environment of the inner pores. This review focuses on the recent significant progress achieved by controlling these degrees of freedom. Two breakthroughs are reviewed for constructing sophisticated structures of CP frameworks, especially in dimensional crossover regions. The first is the synthesis of quasi one-dimensional halogen-bridged coordinative tubes by applying state-of-the-art techniques of coordination chemistry. The electronic state of the coordinative tube was studied by structural, spectroscopic and theoretical methods and found to be distinct from conventional one-dimensional systems. The second breakthrough is the achievement of a quasi-two-dimensional architecture by combining Langmuir–Blodgett and layer-by-layer methods. Two-dimensional LB CP films were prepared on liquid; the films were stacked layer by layer, and a crystalline quasi-two-dimensional structure was constructed.
-  “Paclitaxel-Loaded Hydroxyapatite/Collagen Hybrid Gels as Drug Delivery Systems for Metastatic Cancer Cells”
K. Watanabe, Y. Nishio, R. Makiura, A. Nakahira, C. Kojima
International Journal of Pharmaceutics, 446, 81–86 (2013).
Published on 10 February 2013
Inside front cover
Hydroxyapatite (HA) is a biocompatible and porous inorganic material that can behave as an effective drug carrier. In this study, HA nanoparticles were prepared according to the hydrothermal method and used as a drug carrier for a water-insoluble anticancer drug, paclitaxel (Tax). The absorption of Tax onto the HA was dependent on the solvent composition. The Tax-loaded HA (Tax/HA) exhibited a lower level of activity than the free Tax because the HA material was not stably dispersed in aqueous media. The Tax/HA was therefore embedded in a collagen gel to give the Tax/HA-embedded collagen gel (Tax/HA/Col), which exhibited a higher level of activity than the Tax-containing collagen gel (Tax/Col). Interestingly, the highly metastatic MDA-MB-231 cells were more sensitive to the Tax/HA/Col than the poorly metastatic MCF-7 cells. Tax/HA/Col is therefore useful for the drug delivery into metastatic cancer cells.
-  “Single-Molecule Imaging of Gold-Binding Peptide Adsorbed on Au(111)”
S. Kanata, T. Nishino, R. Makiura, S. Saiki, N. Hayashi
Analytical Science, 29, 405-409 (2013). Hot article
Published on 10 April 2013
We report on the single-molecule analysis of such polypeptides by scanning tunneling microscopy (STM). The adsorbed structure of a gold-binding peptide (GBP) on Au(111) was observed at the single-molecule level. FTIR spectroscopy revealed the helical structure of the GBP, and ab initio calculations confirmed the correlation between the observed STM image and a sample helical structure. It has been demonstrated that the conformational structure of the polypeptide is highly pre-organized, allowing favorable binding onto the gold surface.
-  “Self-Assembly of Highly Crystalline Two-Dimensional MOF Sheets on Liquid Surfaces”
R. Makiura, K. Tsuchiyama, O. Sakata
CrystEngComm, 13, 5538-5541(2011).
Published on 20 July 2011
The formation process of the highly crystalline MOF nanosheet, NAFS-1 at the liquid surface was studied by UV-visible spectroscopy and synchrotron grazing incidence X-ray diffraction – self-assembly of the molecular building metalloporphyrin units and the metal ion joints occurs through a coordination reaction at the air/liquid interface without the necessity of pressing the surface.
-  “Nanoscale Effects on the Stability of the Lambda-Ti3O5 Polymorph”
R. Makiura, Y. Takabayashi, A. N. Fitch, H. Tokoro, S. Ohkoshi, K. Prassides
Chemistry – an. Asian Journal, 6, 1886–1890 (2011).
Published on 28 April 2011
The nanocrystalline valency-delocalized λ-phase of the binary oxide Ti3O5 has recently emerged as a promising phase-change material that exhibits rapid photo-reversible optical and resistance changes at ambient temperature. Nanoscaling caused the monoclinic-λ to monoclinic charge-ordered β-phase structural instability to shift to considerably lower temperatures compared to the bulk material, and led to a broad thermal hysteresis. The structural transformation was accompanied by a large change in volume and large lattice relaxations, which imply the presence of strong electron–phonon coupling. We attribute the suppression of the phase transition to the enhanced surface energy on the nanoscale.
-  “Highly Crystalline Nanofilm by Layering of Porphyrin Metal-Organic Framework Sheets”
S. Motoyama, R. Makiura, O. Sakata, H. Kitagawa
Journal of the American Chemical Society, 133, 5640–5643 (2011).
Published on 30 March 2011
Layer-structured metal−organic framework (MOF) nanofilms (NAFS-2) consisting of 5,10,15,20-tetrakis(4-carboxyphenyl)porphyrin (H2TCPP) molecules and copper ion metal linkers were assembled on a gold or a silicon surface by applying a solution-based layer-by-layer growth technique coupled with the Langmuir−Blodgett method. Synchrotron X-ray diffraction measurements showed that NAFS-2 exhibits highly crystalline order in both the in-plane and out-of-plane orientations. Each MOF sheet (monolayer) adheres without pillaring units, and the nanofilm maintains its highly crystalline order above 200 °C.
-  “Highly-Ordered Porous Coordination Polymer Nanofilms Grown by Layer-by-Layer Deposition Technique”
R. Makiura, H. Kitagawa
MRS Proceedings 2010 Fall meeting, 1312, pp mrsf10-1312-jj06-01 (2011).
Published on 14 Jan 2011
The facile bottom-up fabrication of a perfect preferentially-oriented MOF nanofilm, NAFS-1 on a solid surface, which is endowed with highly crystalline order both in the out-of-plane and in-plane orientations to the substrate, as determined by synchrotron X-ray surface crystallography, was achieved by the unique combination of a layer-by-layer growth technique coupled with the Langmuir-Blodgett (LB) method.
-  “Porous Porphyrin Nanoarchitectures on Surfaces”
R. Makiura, H. Kitagawa
European Journal of Inorganic Chemistry, 24, 3715-3724 (2010).
Published on 26 July 2010
Controlling the size and the growth direction of porous hybrid objects – metal–organic frameworks (MOFs) or porous coordination polymers (PCPs) – at the nanoscale is a critical issue for enabling their use in a number of potential applications that have arisen from the current remarkable activity in studying such porous materials. This microreview describes the recent progress in the design, growth, and characterization of multidimensional nanoarchitectures by employing porphyrin-based components. The versatility of the sequential bottom-up fabrication process, which uses multitopic molecular building units assembled by appropriately chosen linkers, is suitable to be extended to the formation of a rich variety of nanostructures endowed with pores on surfaces.
-  “Surface Nano-Architecture of a Metal–Organic Framework”
R. Makiura, S. Motoyama, Y. Umemura, H. Yamanaka, O. Sakata, H. Kitagawa
Nature Materials, 9, 565-571 (2010).
Published on 30 May 2010
Highlighted in News & Views of Nature Materials
Highlighted in NPG Asia Materials
We report the facile bottom-up fabrication at ambient temperature of such a perfect preferentially oriented MOF nanofilm on a solid surface (NAFS-1), consisting of metalloporphyrin building units. The construction of NAFS-1 was achieved by the unconventional integration in a modular fashion of a layer-by-layer growth technique coupled with the Langmuir–Blodgett method. NAFS-1 is endowed with highly crystalline order both in the out-of-plane and in-plane orientations to the substrate, as demonstrated by synchrotron X-ray surface crystallography. The proposed structural model incorporates metal-coordinated pyridine molecules projected from the two-dimensional sheets that allow each further layer to dock in a highly ordered interdigitated manner in the growth of NAFS-1.
-  “Size-Controlled Stabilisation of the Superionic Phase to Room Temperature in Polymer-Coated AgI Nanoparticles”
R. Makiura, T. Yonemura, T. Yamada, M. Yamauchi, R. Ikeda, H. Kitagawa, K. Kato, M. Takata
Nature Materials, 8, 476-480 (2009).
Published on 17 May 2009
Press release – jst
Press release – Kyushu University
Press release – SPring8
We report the facile synthesis of variable-size AgI nanoparticles coated with poly-N-vinyl-2-pyrrolidone (PVP) and the controllable tuning of the α- to β-/γ-phase transition temperature (Tc¯). Tc¯ shifts considerably to lower temperatures with decreasing nanoparticle size, leading to a progressively enlarged thermal hysteresis. Specifically when the size approaches 10-11 nm, the a-phase survives down to 30°C – the lowest temperature for any AgI family materials. We attribute the suppression of the phase transition not only to the increase of the surface energy, but also to the presence of defects and the accompanying charge unbalance induced by PVP. Moreover, the conductivity of 11 nm b-/g-AgI nanoparticles at 24°C is ~1.5 10-2 W-1 cm-1 – the highest ionic conductivity for a binary solid at room temperature. The stabilised superionic phase we report here suggests promising applications in silver ion based electrochemical devices.
-  “Structural Evaluation of an Iron Oxalate Complex Layer Grown on an Ultra-Smooth Sapphire (0001) Surface by a Wet Method”
R. Haruki, O. Sakata, T. Yamada, K. Kanaizuka, R. Makiura, Y. Akita, M. Yoshimoto, H. Kitagawa
Transactions of the Materials Research Society of Japan, 33, 629-631 (2008).
Published on 1 September 2008
A crystallographic structure of an iron oxalate ultra-thin film growth on an ultra-smooth sapphire (0001) substrate was analyzed using synchrotron X-ray reflectivity and grazing incidence X-ray diffraction. In-plane XRD measurements show that the structure of the layer is random. Out-of-plane XRD measurements show that the iron oxalate structure of the layer is affected by the step structure of sapphire surface, assumed to bond to the step edge.
-  “Electronic State of a Halogen-Bridged Mixed-Valence Binuclear Complex, Ni2(dta)4I”
R. Makiura, H. Kitagawa, R. Ikeda
Molecular Crystals and Liquid Crystals, 379, 309-314 (2002).
Published on 1 January 2002
The electronic state of a halogen-bridged mixed-valence binuclear nickel complex, Ni2 ( dta )4 I ( dta = CH3CS2- ), has been investigated by optical and magnetic measurements.
-  “An Unusual Six-co-Ordinate Platinum(II) Complex Containing a Neutral I2 Ligand”
R. Makiura, I. Nagasawa, N. Kimura, S. Ishimaru, H. Kitagawa, R. Ikeda
Chemical Communications, 642-1643 (2001).
Published on 7 August 2001
The present paper deals with a rare platinum(II) complex containing the κ-I2 ligand, which is an unusual example of a six-co-ordinated octahedral platinum(II) complex.
-  “第II編 合成と成膜プロセシング技術
ポストグラフェン材料の創製と用途開発最前線-二次元ナノシートの物性評価、構造解析、合成、成膜プロセス技術、応用展開, エヌ・ティー・エス (2020)
-  “第2章 PCP/MOFの応用利用,その可能性
PCP/MOFおよび各種多孔質材料の作り方，使い方，評価解析, p.219-224, 技術情報協会 (2019)
-  “2. Liquid-Phase Interfacial Synthesis of Highly Oriented Crystalline Molecular Nanosheets”
Molecular Technology: Life Innovation, p.25-51, Edited by Hisashi Yamamoto, Takashi Kato, Wiley-VCH (2018)
-  “第18章多孔性金属錯体の表面ナノアーキテクチャ” (査読無し)
牧浦 理恵、大坪 主弥、北川 宏
CSJカレントレビューシリーズNo.25 “2次元物質の化学”, p.172-179, (日本化学会編), 化学同人 (2017)
-  “Section 4 : Room temperature superionic conduction of silver iodide nanoparticles and nanosize effect on the phase transition behaviour“
R. Makiura, H. Kitagawa
Materials engineering and experimental methods of ionic conductors, p.178-193, Science & technology Co.,Ltd.
ISBN978-4-86428-033-4, 22 December 2011
-  “ Forefront area : Porous coordination polymers and their catalytic properties”
T. Yamada, H. Kitagawa, R. Makiura
Catalysis Yearbook : Trend and perspective of catalyst technology 2011, p.81-89 (2011).
-  “ブリュースター角顕微鏡による界面活性剤系被膜養生剤の観察”
伊藤 遥子、酒井 雄也、牧浦 理恵
生産研究, 71, 1, p.51-54(2019).
-  “分子の界面積み木細工による高配向性ナノシート結晶の創製” (査読無し)
化学工業, vol.67, pp.237-243, (日本化学会編), 化学工業社 (2016)
-  “Surface molecular architecture : Highly-crystalline metal-organic framework nanofilms assembled by Langmuir-Blodgett and Layer-by-Layer method”
R. Makiura, H. Kitagawa
SPring-8 Research Frontier 2010, 94-95 (2011).
-  “Assembly of a highly-ordered nanofilm comprised of molecular frameworks and surface/interface structural study”
R. Makiura, H. Kitagawa
Journal of the Crystallographic Society of Japan, 52, 295-300 (2010).
-  “AgI nanoplarticles : Size-controlled stabilisation of the superionic phase to room temperature”
R. Makiura, H. Kitagawa, K. Kato
SPring-8 Research Frontier 2009, 100-101 (2010).
-  “Ionics and Hydrogen in Nanoparticles”
R. Makiura, H. Kobayashi, H. Kitagawa
Kyushu University Global-COE program, Science for Future Molecular Systems, Journal 2009, 3, 21-29.
-  HEADLINE REVIEW : “Nanotechnology opens up the door towards realization of new safe and high performance battery”
R. Makiura, H. Kitagawa
OHM, 96 (2009).
-  TOPICS : “Room temperature superionic conduction realized by fine size control at the nanoscale”
R. Makiura, H. Kitagawa
CERAMICS JAPAN, 44, 646 (2009).