A5029331871- Subcritical and Supercritical Water Processes
- Catalytic Processes in Materials Science
- Ferroelectric and Piezoelectric Materials
- Luminescence Properties of Advanced Materials
- Electronic and Structural Properties of Oxides
- Phase Equilibria and Thermodynamics
- Advanced Photocatalysis Techniques
- Graphene research and applications
- Nuclear materials and radiation effects
- Thermal properties of materials
- Innovative Microfluidic and Catalytic Techniques Innovation
- Glass properties and applications
- Advanced Sensor and Energy Harvesting Materials
- Chemical Synthesis and Characterization
- TiO2 Photocatalysis and Solar Cells
- Radioactive element chemistry and processing
- Mesoporous Materials and Catalysis
- Catalysis and Oxidation Reactions
- Copper-based nanomaterials and applications
- Nanomaterials for catalytic reactions
- Laser-induced spectroscopy and plasma
- Semiconductor materials and devices
- Tribology and Wear Analysis
- Diamond and Carbon-based Materials Research
- Electrocatalysts for Energy Conversion
National Institute of Advanced Industrial Science and Technology
2016-2025
Kashiwa Municipal Hospital
2021
The Open University of Japan
2020
The University of Tokyo
2018
University of Tsukuba
2017
Nanomaterials Research (United States)
2016
College of Industrial Technology
2005-2008
Jawaharlal Nehru Centre for Advanced Scientific Research
2008
Tohoku University
1996-2008
Northeastern University
2008
Supercritical water can provide an excellent reaction environment for hydrothermal crystallization of metal oxide particles. Because the drastic change properties around critical point, density, dielectric constant, and ionic product, phase behavior supercritical water−light gas (O2, H2, etc.) system equilibrium/rate be varied to synthesize new materials or define particle morphologies. In this work, experiments were performed with several types flow apparatuses that allow convenient...
Prussian blue is a historical pigment synthesized for the first time at beginning of 18th century. Here we demonstrate that exhibits surprising adsorption properties gaseous ammonia. shows 12.5 mmol/g ammonia capacity 0.1 MPa, whereas standard adsorbents show only 5.08-11.3 mmol/g. Dense was also observed trace contamination in atmosphere. Results higher by analogues with optimization chemical composition. The respective capacities cobalt hexacyanocobaltate (CoHCC) and copper...
There is a growing demand for materials with high thermal conductivity, electrical insulation, flexibility, and toughness application in flexible electronic devices. To develop the aforementioned properties, composites comprising tough polyrotaxane (PR) highly thermally conductive hexagonal boron nitride particles (hBN) were fabricated this study. An electric field was applied during polymerization of to improve their conductivity out-of-plane direction without reducing flexibility....
Rapid and continuous production of phosphor (YAG∶Tb) fine particles by hydrothermal synthesis in supercritical water was studied. At temperatures higher than the critical temperature water, rapid (<60 s) YAG∶Tb achieved. Emission spectra obtained UV excitation were agreement with typical spectral pattern YAG∶Tb. Single phase produced using stoichiometric mixtures metal salts [Al(NO 3 ) , Y(NO TbCl ] as aqueous solutions an alkali molar ratio {[OH – ]/([NO + [Cl ])} 1 a heating method. No...
Hydrothermal synthesis of metal oxide (AlOOH/Al2O3, CuO, Fe2O3, NiO, ZrO2) nanoparticles from nitrate aqueous solution was carried out at 673 K and pressures ranging 25 MPa to 37.5 with a flow-through supercritical water method. Size, phase crystallinity the obtained particles were characterized by TEM, XRD TG, respectively. Effect difference metals in starting materials, concentrations on particle size analyzed basis supersaturation, which evaluated estimated solubility. The result suggests...
Environmental radioactivity, mainly in the Tohoku and Kanto areas, due to long living radioisotopes of cesium is an obstacle speedy recovery from impacts Fukushima Daiichi Nuclear Power Plant accident. Although incineration contaminated wastes encouraged, safe disposal Cs enriched ash big challenge. To address this issue, while restricting release volatile atmosphere was studied. Detailed study on effective removal samples generated wood bark, household garbage, municipal sewage sludge...
The dynamics of solvated electrons were visualized using absorption imaging with sub-picosecond time resolution based on a pump–probe measurement during the early stages femtosecond laser-induced plasma generation in water. generated by propagation laser pump pulse. In area intensity over 2 × 1013 W/cm2, where high density free was produced, exhibited an additional rapid increase optical (OD) at 800 nm, 7–9 ps after pulse excitation. contrast, no two-step OD observed when probed 400...
The solubilities of lead oxide (PbO) and copper (CuO) in subcritical supercritical water were measured at temperatures from 250 °C to 500 pressures 26 MPa 34 MPa, a flow-type apparatus. solubility varied 351 μmol/kg H2O 424.9 25.9 4406 350.3 30.2 MPa. 1.3 449.8 28.0 8.0 324.9 28.1 A hydration reaction model was applied correlate the data.
We propose a flow method to produce barium hexaferrite (BaO6Fe 2 O 3 ) particles with hydrothermal crystallization in supercritical water. Aqueous iron(III) and nitrate solution at room temperature was pressurized 30 MPa then mixed potassium hydroxide (OH:NO = 4) the same conditions generate metal hydroxides. This mixture rapidly heated 400°C by mixing water fed into tubular reactor. Residence time ~1 min. The reaction terminated cooling exit of Ba:Fe mole ratio varied over range 0.1‐2. When...
Hydrothermal synthesis of potassium niobate powders was carried out under various subcritical and supercritical water conditions using crystalline Nb2O5 powder as a starting material. A single phase K4Nb6O17 formed conditions, while mixed phases KNbO3 were obtained where predominant over the heating duration increased. Characterization these hydrothermally synthesized niobates by XRD, SEM, TG-DTA analyses revealed that fine hydrated can be conditions. The used for photocatalytic hydrogen...
Continuous production of BaTiO3 fine particles was performed by hydrothermal synthesis using a flow reaction system. The effect temperature on particle size and its distribution investigated. Aqueous 0.1 M TiO2 sols 0.12 Ba(OH)2 solutions were used as starting materials. in the range 300−420 °C, pressure constant at 30 MPa. time varied from to 40 s with rate 15 or 75 g/min. Characterizations products X-ray diffractometry, scanning electron microscopy equipped energy dispersion spectrometry,...
The solubility of terephthalic acid (TPA) in subcritical water was measured as a function the temperature from (349 to 547) K at pressure 10.0 MPa. A semibatch flow apparatus developed for measurement. N-Methylpyrrolidone used good solvent collection TPA saturated without deposition upon cooling. showed an exponential increase with increasing 1.25·10–5 349 2.99·10–2 547 K. aqueous found be lower than those m- and o-phthalic acids by one three orders magnitude, respectively. Gibbs free energy...