The Experts below are selected from a list of 23283 Experts worldwide ranked by ideXlab platform
Yusheng Zhao - One of the best experts on this subject based on the ideXlab platform.
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synthesis of stoichiometric and bulk crn through a solid state Ion Exchange reactIon
ChemInform, 2013Co-Authors: Miao Chen, Shanmin Wang, Jianzhong Zhang, Yusheng ZhaoAbstract:Phase-pure, stoichiometric, and well-crystallized bulk CrN is prepared from powders of Na2CrO4 and hexagonal BN in a molar ratio of 1:2 by a solid state Ion-Exchange route under high pressure (5 GPa, 1200 °C).
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synthesis of stoichiometric and bulk crn through a solid state Ion Exchange reactIon
Chemistry: A European Journal, 2012Co-Authors: Miao Chen, Shanmin Wang, Jianzhong Zhang, Yusheng ZhaoAbstract:Chromium mononitride (CrN) exhibits interesting magnetic, structural, and electronic properties for technological applicatIons. Experimental reports on these properties are often inconsistent owing to differences in the degree of nonstoichiometry in CrN(x). To date, the preparatIon of bulk and stoichiometric CrN has been challenging; most products are in the form of a thin film produced by non-equilibrium processes, and are often nonstoichiometric and poorly crystallized. In this work, we formulated a solid-state Ion-Exchange route for the synthesis of CrN under high pressure. The final CrN product is phase-pure, stoichiometric, and well-crystallized in the bulk form. Near-stoichiometric and well-crystallized CrN can be synthesized using the same route at atmospheric pressure, making massive and industrial-scale productIon technologically feasible. The successful synthesis of stoichiometric and bulk CrN is expected to open new opportunities in diverse areas of fundamental research.
Yoji Kawamoto - One of the best experts on this subject based on the ideXlab platform.
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synthesis and electrochemical properties of lithium iron oxides with layer related structures
Journal of Power Sources, 1997Co-Authors: Ryoji Kanno, Takayuki Shirane, Yukishige Inaba, Yoji KawamotoAbstract:Abstract Two modificatIons of layered lithium iron oxides were synthesized and characterized by X-ray diffractometry and electrochemical measurements. LiFeO2 with α-NaFeO2 structure was synthesized by the Ion-Exchange reactIon in molten salts; catIonic distributIon in the host, α-NaFeO2, affects the disordering in the reactIon product. However, lithium de-intercalatIon was not confirmed. The Ion-Exchange reactIon in molten salts gave a whole range of solid solutIon, Li(Fe1 − xNix)O2, using the α-Na(Fe1 − xNix)O 2 hosts, and their electrochemical properties were determined. Lithium iron oxide, LiFeO2, with a corrugated layer structure, was synthesized by an Ion-Exchange reactIon between γ-FeOOH and LiOH · H2O. Lithium cells consisting of LiFeO2 cathodes and lithium anodes showed good charge and discharge reversibility in the voltage 1.5–3.0 V range.
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synthesis structure and electrochemical properties of a new lithium iron oxide lifeo2 with a corrugated layer structure
Journal of The Electrochemical Society, 1996Co-Authors: Ryoji Kanno, Takayuki Shirane, Yoji Kawamoto, Yasuo Takeda, Mikio Takano, Masayoshi Ohashi, Yasuo YamaguchiAbstract:A new lithium iron oxide, , with a corrugated layer structure was synthesized by an Ion Exchange reactIon between γ‐FeOOH and and its structure determined by x‐ray and neutron diffractIon measurements. The Ion Exchange reactIon was carried out hydrothermally at 100 to 250°C. Higher vapor pressures produce the disordered phase, and higher reactIon temperatures lead to a mixture of the disordered spinel phase, , and the new phase. Lithium cells consisting of cathodes and lithium anodes showed good charge and discharge reversibility in the voltage range, 1.5 to 3.0 V. Furthermore, the lithium intercalatIon and deintercalatIon mechanism was characterized using x‐ray diffractIon results and electrochemical measurements.
Ryoji Kanno - One of the best experts on this subject based on the ideXlab platform.
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synthesis and electrochemical properties of lithium iron oxides with layer related structures
Journal of Power Sources, 1997Co-Authors: Ryoji Kanno, Takayuki Shirane, Yukishige Inaba, Yoji KawamotoAbstract:Abstract Two modificatIons of layered lithium iron oxides were synthesized and characterized by X-ray diffractometry and electrochemical measurements. LiFeO2 with α-NaFeO2 structure was synthesized by the Ion-Exchange reactIon in molten salts; catIonic distributIon in the host, α-NaFeO2, affects the disordering in the reactIon product. However, lithium de-intercalatIon was not confirmed. The Ion-Exchange reactIon in molten salts gave a whole range of solid solutIon, Li(Fe1 − xNix)O2, using the α-Na(Fe1 − xNix)O 2 hosts, and their electrochemical properties were determined. Lithium iron oxide, LiFeO2, with a corrugated layer structure, was synthesized by an Ion-Exchange reactIon between γ-FeOOH and LiOH · H2O. Lithium cells consisting of LiFeO2 cathodes and lithium anodes showed good charge and discharge reversibility in the voltage 1.5–3.0 V range.
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synthesis structure and electrochemical properties of a new lithium iron oxide lifeo2 with a corrugated layer structure
Journal of The Electrochemical Society, 1996Co-Authors: Ryoji Kanno, Takayuki Shirane, Yoji Kawamoto, Yasuo Takeda, Mikio Takano, Masayoshi Ohashi, Yasuo YamaguchiAbstract:A new lithium iron oxide, , with a corrugated layer structure was synthesized by an Ion Exchange reactIon between γ‐FeOOH and and its structure determined by x‐ray and neutron diffractIon measurements. The Ion Exchange reactIon was carried out hydrothermally at 100 to 250°C. Higher vapor pressures produce the disordered phase, and higher reactIon temperatures lead to a mixture of the disordered spinel phase, , and the new phase. Lithium cells consisting of cathodes and lithium anodes showed good charge and discharge reversibility in the voltage range, 1.5 to 3.0 V. Furthermore, the lithium intercalatIon and deintercalatIon mechanism was characterized using x‐ray diffractIon results and electrochemical measurements.
Jinho Choy - One of the best experts on this subject based on the ideXlab platform.
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phosphate intercalated ca fe layered double hydroxides crystal structure bonding character and release kinetics of phosphate
Journal of Solid State Chemistry, 2011Co-Authors: Myong A Woo, Jinho Choy, Tae Woo Kim, Mi Jeong Paek, Seongju HwangAbstract:Abstract The nitrate-form of Ca–Fe-layered double hydroxide (Ca–Fe-LDH) was synthesized via co-precipitatIon method, and its phosphate-intercalates were prepared by Ion-Exchange reactIon. According to X-ray diffractIon analysis, the Ca–Fe-LDH–NO3− compound and its H2PO4−-intercalate showed hexagonal layered structures, whereas the Ion-Exchange reactIon with HPO42− caused a frustratIon of the layer ordering of LDH. Fe K-edge X-ray absorptIon spectroscopy clearly demonstrated that the Ca–Fe-LDH lattice with trivalent iron Ions was well-maintained after the Ion-Exchange with HPO42− and H2PO4−. Under acidic conditIons, phosphate Ions were slowly released from the Ca–Fe-LDH lattice and the simultaneous release of hydroxide caused the neutralizatIon of acidic media. Fitting analysis based on kinetic models indicated a heterogeneous diffusIon process of phosphates and a distinct dependence of release rate on the charge of phosphates. This study strongly suggested that Ca–Fe-LDH is applicable as bifunctIonal vector for slow release of phosphate fertilizer and for the neutralizatIon of acid soil.
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layered double hydroxide as novel antibacterial drug delivery system
Journal of Physics and Chemistry of Solids, 2010Co-Authors: Seungjin Ryu, Hyun Jung, Jinkyu Lee, Jinho ChoyAbstract:The cephalosporin class antibacterial agent, cefazolin, was intercalated into layered double hydroxides (LDHs) in order to improve the drug efficiency as well as to achieve the controlled release property. Cefazolin molecules were incorporated into LDH through conventIonal Ion Exchange reactIon. X-ray diffractIon pattern analyses confirmed that cefazolin molecules were intercalated between the interlayer spaces of LDH. Fourier-transform infrared spectra and high performance liquid chromatographs clearly showed that the drug molecules were stabilized in LDH lattice through electrostatic interactIon and released without any changes in their chemical integrity. Antibacterial activity of the cefazolin-LDH nanohybrid was also examined by an in vitro test, such as the minimal inhibitory concentratIon (MIC) by dilutIon method. Consequently, the cefazolin-LDH nanohybrid revealed an enhanced antibacterial activity compared to the cefazolin itself not only due to an improvement of chemical stability of cefazolin molecules but also due to a controlled release property.
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itraconazole laponite kinetics and mechanism of drug release
Applied Clay Science, 2008Co-Authors: Hyun Jung, Seongju Hwang, Hyunmi Kim, Young Bin Choy, Jinho ChoyAbstract:Abstract A clay-drug nanohybrid was prepared by interfacial boundary Ion Exchange reactIon, from which the release mechanism of a poorly water soluble drug, itraconazole, was studied systematically. The effect of catIon types on drug release was investigated on the basis of a UPS 25 guide line and the effect of Laponite dissolutIon was also studied at pH = 1.2. To describe the release patterns, mathematical modeling was preformed using first-order, Elovich, parabolic diffusIon, and power functIon equatIons.
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Layered double hydroxide as an efficient drug reservoir for folate derivatives
Biomaterials, 2004Co-Authors: Jinho Choy, Man Park, Ji-sun Jung, Jinyoung Jeong, Young-koo Kang, Ok-jin HanAbstract:Folic acid derivatives such as folinic acid and methotrexate (MTX) have been successfully hybridized with layered double hydroxide (LDH) by Ion-Exchange reactIon. The X-ray diffractIon patterns and spectroscopic analyses indicate that these molecules intercalated into the hydroxide interlayer space are stabilized in the tilted longitudinal monolayer mode by electrostatic interactIon. No significant changes in their structural and functIonal properties are found in the hybrids. The cellular uptake test of MTX-LDH hybrid is carried out in the fibroblast (human tendon) and SaOS-2 cell line (Osteosarcoma, human) by in vitro MTT (3-(4,5-dimethylthiazol-2-yl) 2,5-diphenyl tetrazolium bromide) assay. The initial proliferatIon of SaOS-2 cell is more strongly suppressed by treatment with MTX-LDH hybrid than with MTX alone. This study clearly shows that LDH not only plays a role as a biocompatible-delivery matrix for drugs but also facilitates a significant increase in the delivery efficiency.
Yasushi Kanzaki - One of the best experts on this subject based on the ideXlab platform.
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The Ion-Exchange Property of Some Layered Inorganic Materials with Potassium Ion, Rubidium Ion and Cesium Ion, and Selective Cesium Ion-Exchange of Synthetic Mica
Bulletin of the Chemical Society of Japan, 2000Co-Authors: Noriko Suzuki, Noriko Anaguchi, Hiroko Tsuchiya, Kumi Aoki, Daisuke Yamamoto, Yasushi KanzakiAbstract:The Ion-Exchange property of sodium difluorotetrasilicate, Na-TSM, with potassium, rubidium and cesium Ions was investigated in additIon to two other typical layered inorganic materials. The selectivity sequence of Na-TSM was Cs+ > Rb+ > K+ and the selectivity difference of Na-TSM was highest among the examined layered materials. It was found from a chemical analysis that cesium Ion-Exchange participated in magnesium Ions, which is a lattice component of Na-TSM, in additIon to an ordinary Ion-Exchange reactIon with the interlayer sodium Ions. The Exchange of cesium Ions with magnesium Ions was found to be stoichiometric, and was expected to be an ideal Ion-Exchange reactIon. It was a peculiar phenomenon only on Na-TSM. Once cesium Ions were Exchanged in a Na-TSM lattice, they were hardly released, due to a reverse Ion-Exchange with sodium Ions. The highest selectivity difference and tight binding of cesium Ions were interpreted by an Ion-Exchange with lattice magnesium Ion as well as decreased dehydratIon...
