Controlled fabrication of porous titania beads by a sol−gel templating method / Kai-Feng Du in Industrial & engineering chemistry research, Vol. 48 N°2 (Janvier 2009)  

Public ISBD [article]  inIndustrial & engineering chemistry research > Vol. 48 N°2 (Janvier 2009) . - p. 755–762 Titre : Controlled fabrication of porous titania beads by a sol−gel templating method Type de document : texte imprimé Auteurs : Kai-Feng Du, Auteur ; Dong Yang, Auteur ; Yan Sun, Auteur Année de publication : 2009 Article en page(s) : p. 755–762 Note générale : chemical engineering Langues : Anglais (eng) Mots-clés : Porous titania beads -- Fabrication Résumé : Porous titania beads were synthesized by a sol−gel templating method using agarose gel as template. The morphology and structure of the materials were characterized by X-ray diffraction, scanning electron microscopy, high-resolution transmission electron microscopy, and N2 adsorption analysis, etc. It was found that the size and pore structure of the resultant titania beads could be readily controlled by using various sized templates and by changing the precipitation conditions. Under optimized conditions (i.e., impregnating agarose gel into titanium precursors for 6 h, three cycles of repeated impregnation and hydrolyzing process, and calcination at 450 °C), porous titania beads of 7−150 μm in mean diameters were fabricated by using different sized agarose beads as templates. The beads displayed perfect spherical shape, with an average pore size of 6 nm and specific surface area of 69.9 m2 g−1. The titania beads of 15 μm in average diameter were further characterized for application as liquid chromatographic packings. Flow hydrodynamic experiment indicated that they possessed high mechanical strength to withstand a pressure drop up to 12 MPa. The column efficiency reached 6165 plates m−1 for acetone and 4650 plates m−1 for N,N-dimethylaniline under nonretained condition. Moreover, baseline separation of three aniline derivatives featuring only small structural differences was realized by using this packed column. En ligne : http://pubs.acs.org/doi/abs/10.1021/ie8011165 [article] Controlled fabrication of porous titania beads by a sol−gel templating method [texte imprimé] / Kai-Feng Du, Auteur ; Dong Yang, Auteur ; Yan Sun, Auteur . - 2009 . - p. 755–762. chemical engineering Langues : Anglais (eng) in Industrial & engineering chemistry research > Vol. 48 N°2 (Janvier 2009) . - p. 755–762 Mots-clés : Porous titania beads -- Fabrication Résumé : Porous titania beads were synthesized by a sol−gel templating method using agarose gel as template. The morphology and structure of the materials were characterized by X-ray diffraction, scanning electron microscopy, high-resolution transmission electron microscopy, and N2 adsorption analysis, etc. It was found that the size and pore structure of the resultant titania beads could be readily controlled by using various sized templates and by changing the precipitation conditions. Under optimized conditions (i.e., impregnating agarose gel into titanium precursors for 6 h, three cycles of repeated impregnation and hydrolyzing process, and calcination at 450 °C), porous titania beads of 7−150 μm in mean diameters were fabricated by using different sized agarose beads as templates. The beads displayed perfect spherical shape, with an average pore size of 6 nm and specific surface area of 69.9 m2 g−1. The titania beads of 15 μm in average diameter were further characterized for application as liquid chromatographic packings. Flow hydrodynamic experiment indicated that they possessed high mechanical strength to withstand a pressure drop up to 12 MPa. The column efficiency reached 6165 plates m−1 for acetone and 4650 plates m−1 for N,N-dimethylaniline under nonretained condition. Moreover, baseline separation of three aniline derivatives featuring only small structural differences was realized by using this packed column. En ligne : http://pubs.acs.org/doi/abs/10.1021/ie8011165

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Fabrication of bimodal porous CaTiO3 microspheres using composite agarose/CaCO3 beads as template / Kai-Feng Du in Industrial & engineering chemistry research, Vol. 49 N° 24 (Décembre 2010)  

Public ISBD [article]  inIndustrial & engineering chemistry research > Vol. 49 N° 24 (Décembre 2010) . - pp. 12560–12566 Titre : Fabrication of bimodal porous CaTiO3 microspheres using composite agarose/CaCO3 beads as template Type de document : texte imprimé Auteurs : Kai-Feng Du, Auteur ; Xiao-Yan Dong, Auteur ; Yan Sun, Auteur Année de publication : 2011 Article en page(s) : pp. 12560–12566 Note générale : Chimie industrielle Langues : Anglais (eng) Mots-clés : Microspheres Bimodal porous Résumé : Agarose gel entrapping CaCO3 granules is used for the synthesis of bimodal porous CaTiO3 beads by a method that combines a sol−gel process and solid phase reaction, in which CaCO3 (1.05 μm) performed as both calcium resource and porogen for creating macropores. The amount of CaCO3 granules embedded in agarose gel is varied from 0 to 16 wt %, and the macropores on the surface and in the inner of final CaTiO3 beads are investigated. It is found that the addition of 12 wt % of CaCO3 produced CaTiO3 beads that present interconnected macropores of about 745 ± 20 nm. The calcination temperature affects the surface area, mesopore size, phase state, and crystalline size of the CaTiO3 beads. By calcination at 450 °C, the CaTiO3 beads prepared by the addition of 12 wt % CaCO3 are amorphous with an average pore size of 9 nm and possess a high surface area of about 225 m2 g−1. With an increase of temperature to 600, 750, and 900 °C, the CaTiO3 is transformed into perovskite in size of about 32, 34, and 37 nm with mesopores of about 20, 23, and 24 nm, respectively, and its specific surface area decreases below 20 m2 g−1. The bimodal porous CaTiO3 beads of about 15 μm are packed into a column for investigating its chromatographic performance. The column shows much higher column efficiency than that packed with CaTiO3 beads without removal of the porogen. The remarkably high separation performance is attributed to the unique surface property and interconnected macropores present in the CaTiO3 beads. DEWEY : 660 ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie901727s [article] Fabrication of bimodal porous CaTiO3 microspheres using composite agarose/CaCO3 beads as template [texte imprimé] / Kai-Feng Du, Auteur ; Xiao-Yan Dong, Auteur ; Yan Sun, Auteur . - 2011 . - pp. 12560–12566. Chimie industrielle Langues : Anglais (eng) in Industrial & engineering chemistry research > Vol. 49 N° 24 (Décembre 2010) . - pp. 12560–12566 Mots-clés : Microspheres Bimodal porous Résumé : Agarose gel entrapping CaCO3 granules is used for the synthesis of bimodal porous CaTiO3 beads by a method that combines a sol−gel process and solid phase reaction, in which CaCO3 (1.05 μm) performed as both calcium resource and porogen for creating macropores. The amount of CaCO3 granules embedded in agarose gel is varied from 0 to 16 wt %, and the macropores on the surface and in the inner of final CaTiO3 beads are investigated. It is found that the addition of 12 wt % of CaCO3 produced CaTiO3 beads that present interconnected macropores of about 745 ± 20 nm. The calcination temperature affects the surface area, mesopore size, phase state, and crystalline size of the CaTiO3 beads. By calcination at 450 °C, the CaTiO3 beads prepared by the addition of 12 wt % CaCO3 are amorphous with an average pore size of 9 nm and possess a high surface area of about 225 m2 g−1. With an increase of temperature to 600, 750, and 900 °C, the CaTiO3 is transformed into perovskite in size of about 32, 34, and 37 nm with mesopores of about 20, 23, and 24 nm, respectively, and its specific surface area decreases below 20 m2 g−1. The bimodal porous CaTiO3 beads of about 15 μm are packed into a column for investigating its chromatographic performance. The column shows much higher column efficiency than that packed with CaTiO3 beads without removal of the porogen. The remarkably high separation performance is attributed to the unique surface property and interconnected macropores present in the CaTiO3 beads. DEWEY : 660 ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie901727s

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Ionic Strength Dependence of Protein Adsorption to Dye-Ligand Adsorbents / Zhang, Songping in Aiche journal, Vol. 48 N°1 (Janvier 2002)  

Public ISBD [article]  inAiche journal > Vol. 48 N°1 (Janvier 2002) . - 178-186 p. Titre : Ionic Strength Dependence of Protein Adsorption to Dye-Ligand Adsorbents Titre original : la Dépendance de Concentration Ionique de l'Adsorption de Protéine pour Teindre des Adsorbants de Ligand Type de document : texte imprimé Auteurs : Zhang, Songping, Auteur ; Yan Sun, Auteur Année de publication : 2007 Article en page(s) : 178-186 p. Note générale : Génie Chimique Langues : Anglais (eng) Mots-clés : Adsorption Cinétique Albumine de sérum boeuf Lysozyme Agarose Cibacron Acier Sépharose Amortisseur Concentration ionique Phase aqueuse Protéines Interactions électrostatiques Molécules Diffusivité Index. décimale : 660.627.3 Résumé : The adsorption equilibria and kinetics of bovine serum albumin (BSA) and lysozyme to two Cibacron Blue 3GA (CB) modified agarose gels, that is, 6% agarose-coated steel (6AS) and Sepharose CL-6B, in 0.01 kmol·m-3 tris-HCl buffer (pH 7.5) were studied. Effects of aqueous-phase ionic strength on both the adsorption equilibrium and uptake rate of the proteins were significant and distinctly different between BSA and lysozyme. The adsorption of lysozyme decreased monotonically with increasing ionic strength. Ionic strengths, however, maximized BSA adsorption capacities of the two CB-modified agarose gels in the tris-HCl buffer (about 0.2 kmol·m-3 for CB-6AS and 0.05 kmol·m-3 for CB-Sepharose), when the pore-size difference of the two matrixes and electrostatic interactions between the BSA and CB molecules of like charge were considered. The effective diffusivity of BSA, derived from a pore-diffusion model, to both the CB-modified agarose gels increased significantly with the increasing ionic strength at the ionic strength range of 0.01 to 0.3 kmol·m-3, due to the electrostatic interactions between the BSA and CB molecules of like charge. In contrast, the effective diffusivities of lysozyme to CB-Sepharose in the buffer containing 0.1 and 0.3 kmol·m-3 NaCl were nearly the same. Les équilibres d'adsorption et la cinétique de l'albumine de sérum de boeuf (BSA) et du lysozyme à deux gels modifiés bleus de l'agarose 3GA (CB) de Cibacron, c'est-à-dire, à acier enduit par agarose de 6% (6AS) et à sépharose CL-6B, dans 0.01 amortisseur de tris-HCl du · m-3 de kmol (pH 7.5) ont été étudiés. Les effets de la concentration ionique de phase aqueuse sur l'équilibre d'adsorption et lèvent le taux de prise des protéines étaient significatifs et distinctement différent entre BSA et lysozyme. L'adsorption du lysozyme a diminué monotoniquement avec l'augmentation de la concentration ionique. Les concentrations ioniques, cependant, ont maximisé des capacités d'adsorption de BSA des deux gels Cb-modifiés d'agarose dans l'amortisseur de tris-HCl (environ 0.2 · m-3 de kmol pour CB-6AS et 0.05 · m-3 de kmol pour la Cb-Sépharose), quand la différence de taille de pore des deux matrices et des interactions électrostatiques entre les molécules de BSA et de CB de comme la charge ont été considérées. La diffusivité efficace de BSA, dérivée d'un modèle de diffusion de pore, les aux deux les gels Cb-modifiés d'agarose accrus sensiblement avec la concentration ionique croissante à la gamme de concentration ionique de 0.01 à 0.3 · de kmol m-3, due aux interactions électrostatiques entre les molécules de BSA et de CB de comme la charge. En revanche, les diffusivités efficaces du lysozyme à la Cb-Sépharose dans l'amortisseur contenant 0.1 et 0.3 NaCl du · m-3 de kmol étaient presque identiques. DEWEY : 660.627.3 ISSN : 0001-1541 RAMEAU : Génie Chimique En ligne : www.aiche.org, aichej@che.udel.edu [article] Ionic Strength Dependence of Protein Adsorption to Dye-Ligand Adsorbents = la Dépendance de Concentration Ionique de l'Adsorption de Protéine pour Teindre des Adsorbants de Ligand [texte imprimé] / Zhang, Songping, Auteur ; Yan Sun, Auteur . - 2007 . - 178-186 p. Génie Chimique Langues : Anglais (eng) in Aiche journal > Vol. 48 N°1 (Janvier 2002) . - 178-186 p. Mots-clés : Adsorption Cinétique Albumine de sérum boeuf Lysozyme Agarose Cibacron Acier Sépharose Amortisseur Concentration ionique Phase aqueuse Protéines Interactions électrostatiques Molécules Diffusivité Index. décimale : 660.627.3 Résumé : The adsorption equilibria and kinetics of bovine serum albumin (BSA) and lysozyme to two Cibacron Blue 3GA (CB) modified agarose gels, that is, 6% agarose-coated steel (6AS) and Sepharose CL-6B, in 0.01 kmol·m-3 tris-HCl buffer (pH 7.5) were studied. Effects of aqueous-phase ionic strength on both the adsorption equilibrium and uptake rate of the proteins were significant and distinctly different between BSA and lysozyme. The adsorption of lysozyme decreased monotonically with increasing ionic strength. Ionic strengths, however, maximized BSA adsorption capacities of the two CB-modified agarose gels in the tris-HCl buffer (about 0.2 kmol·m-3 for CB-6AS and 0.05 kmol·m-3 for CB-Sepharose), when the pore-size difference of the two matrixes and electrostatic interactions between the BSA and CB molecules of like charge were considered. The effective diffusivity of BSA, derived from a pore-diffusion model, to both the CB-modified agarose gels increased significantly with the increasing ionic strength at the ionic strength range of 0.01 to 0.3 kmol·m-3, due to the electrostatic interactions between the BSA and CB molecules of like charge. In contrast, the effective diffusivities of lysozyme to CB-Sepharose in the buffer containing 0.1 and 0.3 kmol·m-3 NaCl were nearly the same. Les équilibres d'adsorption et la cinétique de l'albumine de sérum de boeuf (BSA) et du lysozyme à deux gels modifiés bleus de l'agarose 3GA (CB) de Cibacron, c'est-à-dire, à acier enduit par agarose de 6% (6AS) et à sépharose CL-6B, dans 0.01 amortisseur de tris-HCl du · m-3 de kmol (pH 7.5) ont été étudiés. Les effets de la concentration ionique de phase aqueuse sur l'équilibre d'adsorption et lèvent le taux de prise des protéines étaient significatifs et distinctement différent entre BSA et lysozyme. L'adsorption du lysozyme a diminué monotoniquement avec l'augmentation de la concentration ionique. Les concentrations ioniques, cependant, ont maximisé des capacités d'adsorption de BSA des deux gels Cb-modifiés d'agarose dans l'amortisseur de tris-HCl (environ 0.2 · m-3 de kmol pour CB-6AS et 0.05 · m-3 de kmol pour la Cb-Sépharose), quand la différence de taille de pore des deux matrices et des interactions électrostatiques entre les molécules de BSA et de CB de comme la charge ont été considérées. La diffusivité efficace de BSA, dérivée d'un modèle de diffusion de pore, les aux deux les gels Cb-modifiés d'agarose accrus sensiblement avec la concentration ionique croissante à la gamme de concentration ionique de 0.01 à 0.3 · de kmol m-3, due aux interactions électrostatiques entre les molécules de BSA et de CB de comme la charge. En revanche, les diffusivités efficaces du lysozyme à la Cb-Sépharose dans l'amortisseur contenant 0.1 et 0.3 NaCl du · m-3 de kmol étaient presque identiques. DEWEY : 660.627.3 ISSN : 0001-1541 RAMEAU : Génie Chimique En ligne : www.aiche.org, aichej@che.udel.edu

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