Comparative study on adsorption of iodine vapor by silica-supported Cu nanoparticles and micronized copper / Mohammad Outokesh in Industrial & engineering chemistry research, Vol. 51 N° 47 (Novembre 2012)  

Public ISBD [article]  inIndustrial & engineering chemistry research > Vol. 51 N° 47 (Novembre 2012) . - pp. 15315-15323 Titre : Comparative study on adsorption of iodine vapor by silica-supported Cu nanoparticles and micronized copper Type de document : texte imprimé Auteurs : Mohammad Outokesh, Auteur ; Arezoo Saket, Auteur ; Seyed Javad Ahmadi, Auteur Année de publication : 2013 Article en page(s) : pp. 15315-15323 Note générale : Industrial chemistry Langues : Anglais (eng) Mots-clés : Nanoparticle Adsorption Comparative study Résumé : The current study is aimed at comparison of adsorption behaviors of silica-supported Cu nanopartides (Si―N― Cu) and micrometric copper powder (Mi-Cu) for uptake of iodine vapor. The Si-N-Cu was synthesized by the decomposition of aqueous Cu(NO3)2 solution at supercritical condition, followed by reduction of the sample by H2―N2 mixture. The Si-N-Cu sample with 29.4 nm Cu particles adsorbed 95% of I2 at partial pressure 10―5 bar in 1 h, while the 1 μm Mi-Cu adsorbed 51% of iodine in 6 h, indicating higher yield and faster kinetics of the nanometric sample. Theoretical analysis revealed the existence of a strong thermodynamic size effect in the Cu―I2 reaction system, so that molar |ΔG| for 2 nm Cu particles was 2.5 times larger than |ΔG| for 1 μm particles. For the Mi-Cu, kinetics obeyed a three-dimensional diffusion model, while in the case of Si―N―Cu, diffusion did not play any role in the kinetics. Apparently, no passivation mechanism was operative in the iodination. ISSN : 0888-5885 En ligne : http://cat.inist.fr/?aModele=afficheN&cpsidt=26679652 [article] Comparative study on adsorption of iodine vapor by silica-supported Cu nanoparticles and micronized copper [texte imprimé] / Mohammad Outokesh, Auteur ; Arezoo Saket, Auteur ; Seyed Javad Ahmadi, Auteur . - 2013 . - pp. 15315-15323. Industrial chemistry Langues : Anglais (eng) in Industrial & engineering chemistry research > Vol. 51 N° 47 (Novembre 2012) . - pp. 15315-15323 Mots-clés : Nanoparticle Adsorption Comparative study Résumé : The current study is aimed at comparison of adsorption behaviors of silica-supported Cu nanopartides (Si―N― Cu) and micrometric copper powder (Mi-Cu) for uptake of iodine vapor. The Si-N-Cu was synthesized by the decomposition of aqueous Cu(NO3)2 solution at supercritical condition, followed by reduction of the sample by H2―N2 mixture. The Si-N-Cu sample with 29.4 nm Cu particles adsorbed 95% of I2 at partial pressure 10―5 bar in 1 h, while the 1 μm Mi-Cu adsorbed 51% of iodine in 6 h, indicating higher yield and faster kinetics of the nanometric sample. Theoretical analysis revealed the existence of a strong thermodynamic size effect in the Cu―I2 reaction system, so that molar |ΔG| for 2 nm Cu particles was 2.5 times larger than |ΔG| for 1 μm particles. For the Mi-Cu, kinetics obeyed a three-dimensional diffusion model, while in the case of Si―N―Cu, diffusion did not play any role in the kinetics. Apparently, no passivation mechanism was operative in the iodination. ISSN : 0888-5885 En ligne : http://cat.inist.fr/?aModele=afficheN&cpsidt=26679652

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Comparison of the batch and breakthrough properties of stable and plain alginate microcapsules with a chelating resin and an ion exchanger in Ag+adsorption / Mohammad Outokesh in Industrial & engineering chemistry research, Vol. 47 N°17 (Septembre 2008)  

Public ISBD [article]  inIndustrial & engineering chemistry research > Vol. 47 N°17 (Septembre 2008) . - p. 6742–6752 Titre : Comparison of the batch and breakthrough properties of stable and plain alginate microcapsules with a chelating resin and an ion exchanger in Ag+adsorption Type de document : texte imprimé Auteurs : Mohammad Outokesh, Auteur ; Yuichi Niibori, Auteur ; Hitoshi Mimura, Auteur Année de publication : 2008 Article en page(s) : p. 6742–6752 Note générale : Chemical engineering Langues : Anglais (eng) Mots-clés : Alginate microcapsules Ag+ adsorption Ion exchanger Résumé : A comparative study on the uptake properties of alginate microcapsules containing Cyanex 302 extractant, Lewatite TP 214 chelating resin, and Amberlite 200CT strongly acidic ion exchanger has been conducted using Ag+ as the target ion. The study resulted in an analytical formula, as well as three phenomenological breakthrough formulas that are also applicable in other fixed-bed operations. It also demonstrated a close similarity of the uptake properties of alginate microcapsules (MCs) and the chelating resins. Advantages of MCs over chelating resins include ease of preparation, ability to immobilize different extractants, and, most remarkably, an enormous distribution factor (Kd ≈ 106 cm3/g). As for the stabilization of MCs, two different methods of coating and matrix modification were applied; the latter proved to be superior, because of enhancement of both the uptake capacity and the column performance. Another achievement of the current study was the discovery of a new method for estimating the thickness of the coating layer of MCs. En ligne : http://pubs.acs.org/doi/abs/10.1021/ie071200n [article] Comparison of the batch and breakthrough properties of stable and plain alginate microcapsules with a chelating resin and an ion exchanger in Ag+adsorption [texte imprimé] / Mohammad Outokesh, Auteur ; Yuichi Niibori, Auteur ; Hitoshi Mimura, Auteur . - 2008 . - p. 6742–6752. Chemical engineering Langues : Anglais (eng) in Industrial & engineering chemistry research > Vol. 47 N°17 (Septembre 2008) . - p. 6742–6752 Mots-clés : Alginate microcapsules Ag+ adsorption Ion exchanger Résumé : A comparative study on the uptake properties of alginate microcapsules containing Cyanex 302 extractant, Lewatite TP 214 chelating resin, and Amberlite 200CT strongly acidic ion exchanger has been conducted using Ag+ as the target ion. The study resulted in an analytical formula, as well as three phenomenological breakthrough formulas that are also applicable in other fixed-bed operations. It also demonstrated a close similarity of the uptake properties of alginate microcapsules (MCs) and the chelating resins. Advantages of MCs over chelating resins include ease of preparation, ability to immobilize different extractants, and, most remarkably, an enormous distribution factor (Kd ≈ 106 cm3/g). As for the stabilization of MCs, two different methods of coating and matrix modification were applied; the latter proved to be superior, because of enhancement of both the uptake capacity and the column performance. Another achievement of the current study was the discovery of a new method for estimating the thickness of the coating layer of MCs. En ligne : http://pubs.acs.org/doi/abs/10.1021/ie071200n

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