Documents disponibles écrits par cet auteur

Continuous hydrothermal synthesis of Fe2O3 nanoparticles using a central collision - type micromixer for rapid and homogeneous nucleation at 673 K and 30 MPa / Kiwamu Sue in Industrial & engineering chemistry research, Vol. 49 N° 18 (Septembre 2010) 

Public ISBD [article]  in Industrial & engineering chemistry research > Vol. 49 N° 18 (Septembre 2010) . - pp. 8841–8846 Titre : Continuous hydrothermal synthesis of Fe2O3 nanoparticles using a central collision - type micromixer for rapid and homogeneous nucleation at 673 K and 30 MPa Type de document : texte imprimé Auteurs : Kiwamu Sue, Auteur ; Toshiyuki Sato, Auteur ; Shin-ichiro Kawasaki, Auteur Année de publication : 2010 Article en page(s) : pp. 8841–8846 Note générale : Industrial chemistry Langues : Anglais (eng) Mots-clés : Nanoparticles  Micromixer Résumé : Continuous hydrothermal synthesis of Fe2O3 nanoparticles was carried out at 673 K and 30 MPa. Two types of mixers, a conventional T-type micromixer and a central collision-type micromixer (CCM), were used for the synthesis. CCM was newly fabricated on the basis of the concept for preventing heterogeneous nucleation induced on the inner wall of the mixer. Residence time and Fe(NO3)3 molality of the starting solution varied from 0.1 to 1.0 s and 0.05 to 0.50 mol/kg, respectively. Effects of the mixer structure, the residence time, and the Fe(NO3)3 molality on crystal structure, Fe3+ conversion, average particle size, and size distribution were discussed. CCM effectively worked for producing smaller Fe2O3 nanoparticles with narrow and monomodal distribution. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie1008597 [article] Continuous hydrothermal synthesis of Fe2O3 nanoparticles using a central collision - type micromixer for rapid and homogeneous nucleation at 673 K and 30 MPa [texte imprimé] / Kiwamu Sue, Auteur ; Toshiyuki Sato, Auteur ; Shin-ichiro Kawasaki, Auteur . - 2010 . - pp. 8841–8846. Industrial chemistry Langues : Anglais (eng) in Industrial & engineering chemistry research > Vol. 49 N° 18 (Septembre 2010) . - pp. 8841–8846 Mots-clés : Nanoparticles  Micromixer Résumé : Continuous hydrothermal synthesis of Fe2O3 nanoparticles was carried out at 673 K and 30 MPa. Two types of mixers, a conventional T-type micromixer and a central collision-type micromixer (CCM), were used for the synthesis. CCM was newly fabricated on the basis of the concept for preventing heterogeneous nucleation induced on the inner wall of the mixer. Residence time and Fe(NO3)3 molality of the starting solution varied from 0.1 to 1.0 s and 0.05 to 0.50 mol/kg, respectively. Effects of the mixer structure, the residence time, and the Fe(NO3)3 molality on crystal structure, Fe3+ conversion, average particle size, and size distribution were discussed. CCM effectively worked for producing smaller Fe2O3 nanoparticles with narrow and monomodal distribution. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie1008597

Continuous Hydrothermal Synthesis of Nickel Ferrite Nanoparticles Using a Central Collision-Type Micromixer / Kiwamu Sue in Industrial & engineering chemistry research, Vol. 50 N° 16 (Août 2011) 

Public ISBD [article]  in Industrial & engineering chemistry research > Vol. 50 N° 16 (Août 2011) . - pp. 9625-9631 Titre : Continuous Hydrothermal Synthesis of Nickel Ferrite Nanoparticles Using a Central Collision-Type Micromixer : effects of temperature, residence time, metal salt molality, and NaOH addition on conversion, particle size, and crystal phase Type de document : texte imprimé Auteurs : Kiwamu Sue, Auteur ; Mitsuko Aoki, Auteur ; Takafumi Sato, Auteur Année de publication : 2011 Article en page(s) : pp. 9625-9631 Note générale : Chimie industrielle Langues : Anglais (eng) Mots-clés : Particle  size  Temperature  effect  Micromixing  Collision  Nanoparticle Résumé : Continuous hydrothermal synthesis of nickel ferrite nanopartides from Fe(NO3)3 and Ni(NO3)2 was performed using a central collision-type micromixer developed for rapid heating of a starting solution to the reaction temperature and homogeneous nucleation. Temperature, residence time, and nitrate molality were varied in the ranges 573―673 K, 0.02―2.00 s, and 0.05―0.50 mol/kg, respectively. The effects of temperature, residence time, nitrate molality, and NaOH addition on conversion, Ni/Fe molar ratio, particle size, and crystal phase were examined using ICP spectroscopy, EDX spectroscopy, TEM, and XRD. In the cases without NaOH, the Ni conversion was less than 2% at temperatures up to 623 K and increased dramatically to around 50% at 673 K, whereas the Fe conversion was more than 94% at all temperatures. In terms of conversion, the Ni/Fe molar ratio was less than 0.01 at temperatures up to 623 K, and stable nickel ferrite was not produced. By contrast, at 673 K, the Ni/Fe molar ratio increased sharply to more than 0.2, and stable nickel ferrite could be obtained. With increasing residence time at 673 K, the Ni conversion and Ni/Fe ratio increased, and the lattice parameter decreased from 8.35 to 8.34 Å. These results indicate that the products at an early stage of the reaction are similar in structure to γ-Fe2O3 and can be considered as a Ni-deficient NiFe2O4 whereas the products at a later stage have a structure dose to that of NiFe2O4. In addition, the average particle size increased slightly from 5.2 to 7.4 nm at 0.05 mol/kg and increased markedly from 5.8 to 12.3 nm at 0.50 mol/kg with increasing temperature despite the high Fe conversion of >97% at the shortest residence time of 0.02 s. In the cases with NaOH, smaller nanoparticles of less than 5.0 nm with a stoichiometric Ni/Fe molar ratio of 0.5 were produced at 673 K. On the basis of these results, the mechanisms of nucleation and growth in the nickel ferrite synthesis are discussed. DEWEY : 660 ISSN : 0888-5885 En ligne : http://cat.inist.fr/?aModele=afficheN&cpsidt=24425206 [article] Continuous Hydrothermal Synthesis of Nickel Ferrite Nanoparticles Using a Central Collision-Type Micromixer : effects of temperature, residence time, metal salt molality, and NaOH addition on conversion, particle size, and crystal phase [texte imprimé] / Kiwamu Sue, Auteur ; Mitsuko Aoki, Auteur ; Takafumi Sato, Auteur . - 2011 . - pp. 9625-9631. Chimie industrielle Langues : Anglais (eng) in Industrial & engineering chemistry research > Vol. 50 N° 16 (Août 2011) . - pp. 9625-9631 Mots-clés : Particle  size  Temperature  effect  Micromixing  Collision  Nanoparticle Résumé : Continuous hydrothermal synthesis of nickel ferrite nanopartides from Fe(NO3)3 and Ni(NO3)2 was performed using a central collision-type micromixer developed for rapid heating of a starting solution to the reaction temperature and homogeneous nucleation. Temperature, residence time, and nitrate molality were varied in the ranges 573―673 K, 0.02―2.00 s, and 0.05―0.50 mol/kg, respectively. The effects of temperature, residence time, nitrate molality, and NaOH addition on conversion, Ni/Fe molar ratio, particle size, and crystal phase were examined using ICP spectroscopy, EDX spectroscopy, TEM, and XRD. In the cases without NaOH, the Ni conversion was less than 2% at temperatures up to 623 K and increased dramatically to around 50% at 673 K, whereas the Fe conversion was more than 94% at all temperatures. In terms of conversion, the Ni/Fe molar ratio was less than 0.01 at temperatures up to 623 K, and stable nickel ferrite was not produced. By contrast, at 673 K, the Ni/Fe molar ratio increased sharply to more than 0.2, and stable nickel ferrite could be obtained. With increasing residence time at 673 K, the Ni conversion and Ni/Fe ratio increased, and the lattice parameter decreased from 8.35 to 8.34 Å. These results indicate that the products at an early stage of the reaction are similar in structure to γ-Fe2O3 and can be considered as a Ni-deficient NiFe2O4 whereas the products at a later stage have a structure dose to that of NiFe2O4. In addition, the average particle size increased slightly from 5.2 to 7.4 nm at 0.05 mol/kg and increased markedly from 5.8 to 12.3 nm at 0.50 mol/kg with increasing temperature despite the high Fe conversion of >97% at the shortest residence time of 0.02 s. In the cases with NaOH, smaller nanoparticles of less than 5.0 nm with a stoichiometric Ni/Fe molar ratio of 0.5 were produced at 673 K. On the basis of these results, the mechanisms of nucleation and growth in the nickel ferrite synthesis are discussed. DEWEY : 660 ISSN : 0888-5885 En ligne : http://cat.inist.fr/?aModele=afficheN&cpsidt=24425206

The Kinetics of the incorporation of metals into tetraphenylporphyrin with metal salts in high-temperature water / Takafumi Sato in Industrial & engineering chemistry research, Vol. 51 N° 43 (Octobre 2012)

Public ISBD [article]  in Industrial & engineering chemistry research > Vol. 51 N° 43 (Octobre 2012) . - pp. 13908–13914 Titre : The Kinetics of the incorporation of metals into tetraphenylporphyrin with metal salts in high-temperature water Type de document : texte imprimé Auteurs : Takafumi Sato, Auteur ; Katsutoshi Ebisawa, Auteur ; Kiwamu Sue, Auteur Année de publication : 2013 Article en page(s) : pp. 13908–13914 Note générale : Industrial chemistry Langues : Anglais (eng) Mots-clés : Kinetics  Metal  salts Résumé : The incorporation of cobalt, nickel, copper, and oxovanadium(IV) into nonpolar 5,10,15,20-tetraphenyl-21H,23H-porphyrin (H2TPP) occurred with their sulfates, nitrates, and chlorides in high-temperature water. The yield of metalloporphyrin significantly increased with increasing temperature for cobalt, nickel, and copper sulfates from 473 to 673 K, which means that the high temperature region was preferred for the incorporation of metals into the porphyrin structure. In high-temperature water, most of H2TPP dissolved, whereas almost all of metals probably existed in solid phase. The incorporation of metal into a porphyrin structure was almost first-order with respect to H2TPP and probably proceeded through the pre-equilibrium state between metal ion and H2TPP. ISSN : 0888-5885 [article] The Kinetics of the incorporation of metals into tetraphenylporphyrin with metal salts in high-temperature water [texte imprimé] / Takafumi Sato, Auteur ; Katsutoshi Ebisawa, Auteur ; Kiwamu Sue, Auteur . - 2013 . - pp. 13908–13914. Industrial chemistry Langues : Anglais (eng) in Industrial & engineering chemistry research > Vol. 51 N° 43 (Octobre 2012) . - pp. 13908–13914 Mots-clés : Kinetics  Metal  salts Résumé : The incorporation of cobalt, nickel, copper, and oxovanadium(IV) into nonpolar 5,10,15,20-tetraphenyl-21H,23H-porphyrin (H2TPP) occurred with their sulfates, nitrates, and chlorides in high-temperature water. The yield of metalloporphyrin significantly increased with increasing temperature for cobalt, nickel, and copper sulfates from 473 to 673 K, which means that the high temperature region was preferred for the incorporation of metals into the porphyrin structure. In high-temperature water, most of H2TPP dissolved, whereas almost all of metals probably existed in solid phase. The incorporation of metal into a porphyrin structure was almost first-order with respect to H2TPP and probably proceeded through the pre-equilibrium state between metal ion and H2TPP. ISSN : 0888-5885