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Preparation and properties of microspherical alumina with a magnetic core/shell structure / Jun-Ting Feng in Industrial & engineering chemistry research, Vol. 48 N°2 (Janvier 2009) 

Public ISBD [article]  in Industrial & engineering chemistry research > Vol. 48 N°2 (Janvier 2009) . - p.692–697 Titre : Preparation and properties of microspherical alumina with a magnetic core/shell structure Type de document : texte imprimé Auteurs : Jun-Ting Feng, Auteur ; Lin, Yan-Jun, Auteur ; Feng Li, Auteur ; David G. Evans, Auteur Année de publication : 2009 Article en page(s) : p.692–697 Note générale : chemical engenireeng Langues : Anglais (eng) Mots-clés : Microspherical  --  Alumina Résumé : A series of Ni2+−Co2+−Fe2+−Fe3+−SO42− layered double hydroxide precursors with different Ni/Co ratios have been synthesized by a method involving separate nucleation and aging steps. After calcination at 900 °C, the corresponding Ni1-xCoxFe oxides were obtained. Vibrating sample magnetometry indicated that the Ni1-xCoxFe oxide samples not only had high specific saturation magnetization, but also low coercivity and remanence. Ni1-xCoxFe oxides showed the optimum combination of magnetic properties for x = 0.2. Silica was coated onto the surface of Ni0.8Co0.2Fe oxide particles, and the coated particles were used as magnetic cores to prepare magnetic Ni0.8Co0.2Fe oxide/SiO2/γ-Al2O3 particles by hydrolysis of aluminum isopropoxide. After repeating the hydrolysis twice more, Ni0.8Co0.2Fe oxide/SiO2/γ-Al2O3 particles with about 20 wt % Ni0.8Co0.2Fe oxide were obtained and shown to be suitable for practical applications as a magnetic catalyst or catalyst support by virtue of their efficacious magnetic properties and pore structure. En ligne : http://pubs.acs.org/doi/abs/10.1021/ie801098k [article] Preparation and properties of microspherical alumina with a magnetic core/shell structure [texte imprimé] / Jun-Ting Feng, Auteur ; Lin, Yan-Jun, Auteur ; Feng Li, Auteur ; David G. Evans, Auteur . - 2009 . - p.692–697. chemical engenireeng Langues : Anglais (eng) in Industrial & engineering chemistry research > Vol. 48 N°2 (Janvier 2009) . - p.692–697 Mots-clés : Microspherical  --  Alumina Résumé : A series of Ni2+−Co2+−Fe2+−Fe3+−SO42− layered double hydroxide precursors with different Ni/Co ratios have been synthesized by a method involving separate nucleation and aging steps. After calcination at 900 °C, the corresponding Ni1-xCoxFe oxides were obtained. Vibrating sample magnetometry indicated that the Ni1-xCoxFe oxide samples not only had high specific saturation magnetization, but also low coercivity and remanence. Ni1-xCoxFe oxides showed the optimum combination of magnetic properties for x = 0.2. Silica was coated onto the surface of Ni0.8Co0.2Fe oxide particles, and the coated particles were used as magnetic cores to prepare magnetic Ni0.8Co0.2Fe oxide/SiO2/γ-Al2O3 particles by hydrolysis of aluminum isopropoxide. After repeating the hydrolysis twice more, Ni0.8Co0.2Fe oxide/SiO2/γ-Al2O3 particles with about 20 wt % Ni0.8Co0.2Fe oxide were obtained and shown to be suitable for practical applications as a magnetic catalyst or catalyst support by virtue of their efficacious magnetic properties and pore structure. En ligne : http://pubs.acs.org/doi/abs/10.1021/ie801098k

Preparation of highly dispersed nano-La2O3 particles using modified carbon black as an agglomeration inhibitor / Guirong Wang in Industrial & engineering chemistry research, Vol. 51 N° 45 (Novembre 2012) 

Public ISBD [article]  in Industrial & engineering chemistry research > Vol. 51 N° 45 (Novembre 2012) . - pp. 14692-14699 Titre : Preparation of highly dispersed nano-La2O3 particles using modified carbon black as an agglomeration inhibitor Type de document : texte imprimé Auteurs : Guirong Wang, Auteur ; Yongshan Zhou, Auteur ; David G. Evans, Auteur Année de publication : 2013 Article en page(s) : pp. 14692-14699 Note générale : Industrial chemistry Langues : Anglais (eng) Mots-clés : Agglomeration  Carbon  black  Preparation Résumé : Nanoparticles readily agglomerate, especially during nucleation, growth, and calcination processes. In this work, modified carbon black (MCB) has been used to prevent particle agglomeration during the nucleation step in the preparation of a highly dispersed nano-La(OH), precursor by a coprecipitation reaction. The surface carboxyl groups formed on MCB after modification can adsorb and fix positively charged La3+ ions on the surface. Therefore, nano-La(OH)3 nuclei can be uniformly deposited on the MCB surface. After nucleation, La(OH)3 particles with a size of about 20 nm with a positive surface charge still interact strongly with the negatively charged MCB surface, which effectively prevents their agglomeration during the subsequent aging process. Furthermore, due to the release of CO2 over a wide temperature range from 400 to 700 °C during a subsequent calcination process, La2O3 particles obtained by calcination of the La(OH)3 precursor can be effectively isolated at high temperature and prevented from agglomerating. By using MCB as an agglomeration inhibitor in this way, highly dispersed La2O3 nanoparticles with a size of 50 nm having excellent photoluminescence ability can be prepared. ISSN : 0888-5885 En ligne : http://cat.inist.fr/?aModele=afficheN&cpsidt=26620382 [article] Preparation of highly dispersed nano-La2O3 particles using modified carbon black as an agglomeration inhibitor [texte imprimé] / Guirong Wang, Auteur ; Yongshan Zhou, Auteur ; David G. Evans, Auteur . - 2013 . - pp. 14692-14699. Industrial chemistry Langues : Anglais (eng) in Industrial & engineering chemistry research > Vol. 51 N° 45 (Novembre 2012) . - pp. 14692-14699 Mots-clés : Agglomeration  Carbon  black  Preparation Résumé : Nanoparticles readily agglomerate, especially during nucleation, growth, and calcination processes. In this work, modified carbon black (MCB) has been used to prevent particle agglomeration during the nucleation step in the preparation of a highly dispersed nano-La(OH), precursor by a coprecipitation reaction. The surface carboxyl groups formed on MCB after modification can adsorb and fix positively charged La3+ ions on the surface. Therefore, nano-La(OH)3 nuclei can be uniformly deposited on the MCB surface. After nucleation, La(OH)3 particles with a size of about 20 nm with a positive surface charge still interact strongly with the negatively charged MCB surface, which effectively prevents their agglomeration during the subsequent aging process. Furthermore, due to the release of CO2 over a wide temperature range from 400 to 700 °C during a subsequent calcination process, La2O3 particles obtained by calcination of the La(OH)3 precursor can be effectively isolated at high temperature and prevented from agglomerating. By using MCB as an agglomeration inhibitor in this way, highly dispersed La2O3 nanoparticles with a size of 50 nm having excellent photoluminescence ability can be prepared. ISSN : 0888-5885 En ligne : http://cat.inist.fr/?aModele=afficheN&cpsidt=26620382

Synthesis of an N , N - Bis(phosphonomethyl)glycine anion - intercalated layered double hydroxide and its selective infrared absorption effect in low density polyethylene films for use in agriculture / Lijing Wang in Industrial & engineering chemistry research, Vol. 49 N° 11 (Juin 2010) 

Public ISBD [article]  in Industrial & engineering chemistry research > Vol. 49 N° 11 (Juin 2010) . - pp. 5339–5346 Titre : Synthesis of an N , N - Bis(phosphonomethyl)glycine anion - intercalated layered double hydroxide and its selective infrared absorption effect in low density polyethylene films for use in agriculture Type de document : texte imprimé Auteurs : Lijing Wang, Auteur ; Xiangyu Xu, Auteur ; David G. Evans, Auteur Année de publication : 2010 Article en page(s) : pp. 5339–5346 Note générale : Industrial chemistry Langues : Anglais (eng) Mots-clés : Hydroxide Résumé : Reaction under alkaline conditions of N,N-bis(phosphonomethyl)glycine (glyphosine, GLYP) with an MgAl-NO3-layered double hydroxide (LDH) precursor, prepared by a method involving separate nucleation and aging steps (SNAS) led to the replacement of the interlayer nitrate anions by GLYP3− anions. The resulting MgAl-GLYP-LDH was characterized by X-ray diffraction (XRD), Fourier transfrom infrared (FT-IR), thermogravimetry and differential therm analysis (TG-DTA), elemental analysis, and scanning electron microscopy (SEM). MgAl-GLYP-LDH was mixed with low density polyethylene (LDPE) using a masterbatch method. LDPE films filled with MgAl-GLYP-LDH showed a higher mid- to far-infrared absorption than films filled with MgAl-CO3-LDH in the 7−25 μm range, particularly in the key 9−11 μm range required for application in agricultural plastic films. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie9016978 [article] Synthesis of an N , N - Bis(phosphonomethyl)glycine anion - intercalated layered double hydroxide and its selective infrared absorption effect in low density polyethylene films for use in agriculture [texte imprimé] / Lijing Wang, Auteur ; Xiangyu Xu, Auteur ; David G. Evans, Auteur . - 2010 . - pp. 5339–5346. Industrial chemistry Langues : Anglais (eng) in Industrial & engineering chemistry research > Vol. 49 N° 11 (Juin 2010) . - pp. 5339–5346 Mots-clés : Hydroxide Résumé : Reaction under alkaline conditions of N,N-bis(phosphonomethyl)glycine (glyphosine, GLYP) with an MgAl-NO3-layered double hydroxide (LDH) precursor, prepared by a method involving separate nucleation and aging steps (SNAS) led to the replacement of the interlayer nitrate anions by GLYP3− anions. The resulting MgAl-GLYP-LDH was characterized by X-ray diffraction (XRD), Fourier transfrom infrared (FT-IR), thermogravimetry and differential therm analysis (TG-DTA), elemental analysis, and scanning electron microscopy (SEM). MgAl-GLYP-LDH was mixed with low density polyethylene (LDPE) using a masterbatch method. LDPE films filled with MgAl-GLYP-LDH showed a higher mid- to far-infrared absorption than films filled with MgAl-CO3-LDH in the 7−25 μm range, particularly in the key 9−11 μm range required for application in agricultural plastic films. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie9016978

Thermal evolution and luminescence properties of Zn-Al-layered double hydroxides containing europium(III) complexes of ethylenediaminetetraacetate and nitrilotriacetate / Cang Li in Industrial & engineering chemistry research, Vol. 48 N°4 (Février 2009)

Public ISBD [article]  in Industrial & engineering chemistry research > Vol. 48 N°4 (Février 2009) . - p. 2162–2171 Titre : Thermal evolution and luminescence properties of Zn-Al-layered double hydroxides containing europium(III) complexes of ethylenediaminetetraacetate and nitrilotriacetate Type de document : texte imprimé Auteurs : Cang Li, Auteur ; Lianying Wang, Auteur ; David G. Evans, Auteur Année de publication : 2009 Article en page(s) : p. 2162–2171 Note générale : Chemical engineering Langues : Anglais (eng) Mots-clés : Ethylenediaminetetraacetate  Nitrilotriacetate  Layered  double  hydroxides Résumé : Europium complexes of ethylenediaminetetraacetate (EDTA) and nitrilotriacetate (NTA), [Eu(EDTA)(H2O)3]−, and [Eu(NTA)2(H2O)]3−, which have similar geometries but different charge densities, have been incorporated in Zn−Al layered double hydroxides (LDHs). The orientation and loading of the guest anions as well as their thermal stability and reorientation behavior are significantly influenced by their charge density. The maximal dimension of the [Eu(EDTA)(H2O)3]− anion is nearly perpendicular to the LDH layers and a reversible reorientation occurs on mild heating. The structural changes that occurred on heating were followed by variable temperature photoluminescence (PL) measurements. The kinetics of the structural transformation of ZnAl-Eu(EDTA) LDH in the temperature range 30−150 °C have also been studied. In the case of [Eu(NTA)2(H2O)]3−, the anion adopts a flat orientation in the interlayer galleries with its maximum dimension nearly parallel to the metal hydroxyl layers and no reorientation is observed on heating. [article] Thermal evolution and luminescence properties of Zn-Al-layered double hydroxides containing europium(III) complexes of ethylenediaminetetraacetate and nitrilotriacetate [texte imprimé] / Cang Li, Auteur ; Lianying Wang, Auteur ; David G. Evans, Auteur . - 2009 . - p. 2162–2171. Chemical engineering Langues : Anglais (eng) in Industrial & engineering chemistry research > Vol. 48 N°4 (Février 2009) . - p. 2162–2171 Mots-clés : Ethylenediaminetetraacetate  Nitrilotriacetate  Layered  double  hydroxides Résumé : Europium complexes of ethylenediaminetetraacetate (EDTA) and nitrilotriacetate (NTA), [Eu(EDTA)(H2O)3]−, and [Eu(NTA)2(H2O)]3−, which have similar geometries but different charge densities, have been incorporated in Zn−Al layered double hydroxides (LDHs). The orientation and loading of the guest anions as well as their thermal stability and reorientation behavior are significantly influenced by their charge density. The maximal dimension of the [Eu(EDTA)(H2O)3]− anion is nearly perpendicular to the LDH layers and a reversible reorientation occurs on mild heating. The structural changes that occurred on heating were followed by variable temperature photoluminescence (PL) measurements. The kinetics of the structural transformation of ZnAl-Eu(EDTA) LDH in the temperature range 30−150 °C have also been studied. In the case of [Eu(NTA)2(H2O)]3−, the anion adopts a flat orientation in the interlayer galleries with its maximum dimension nearly parallel to the metal hydroxyl layers and no reorientation is observed on heating.