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Vol. 51 N° 14 - Avril 2012 [texte imprimé] . - 2012 . - p. 5117-5374 : ill. ; 28 cm. Chemical engineering Langues : Anglais (eng)
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Ajouter le résultat dans votre panierEffect of salix viminalis pyrolysis derived antioxidants on oxidative stability of diesters and diester – poly - a - olefin mixtures / Andrzej Olejniczak in Industrial & engineering chemistry research, Vol. 51 N° 14 (Avril 2012)
Titre : Effect of salix viminalis pyrolysis derived antioxidants on oxidative stability of diesters and diester – poly - a - olefin mixtures Type de document : texte imprimé Auteurs : Andrzej Olejniczak, Auteur ; Anna Kucinska, Auteur ; Aleksandra W. Cyganiuk, Auteur Année de publication : 2012 Article en page(s) : pp. 5117-5123 Note générale : Chimie industrielle Langues : Anglais (eng) Mots-clés : Stability Oxidation Antioxidant Pyrolysis Résumé : The fabrication of molecular sieves and carbon-based adsorbents by pyrolysis of lignocellulosic material, such as Salix viminalis wood, generates a considerable amount of pyrolysis oil which has no specific application. In the present paper, we investigate phenolic components of S. viminalis derived pyrolysis oil with regard to their potential application to the oxidative stabilization of synthetic lubricating oils. Two phenolic fractions were isolated through solvent extraction (extract A was ether soluble; extract B was methylene chloride soluble) and characterized by chromatographic analysis. High levels of 2,6-dimethoxyphenol and its para-substituted derivatives were attributed to a rather atypical composition of S. viminalis lignin. The antioxidative effect of pyrolysis-derived polyphenols on diesters and their blends with poly-α-olefins was studied by means of a high temperature oxidation test combined with spectroscopic (NMR and FT-IR) product analysis. The test proved that the antioxidant capacity of each extract is high, at the level of ca. 1000 ppm Extract A had the highest increase in the induction period (170 h), and compared with the commercial BHT antioxidant, it prolonged the lag phase ca. 3.3 times. The effect of the o-methoxy and para substituents, intramolecular hydrogen bonding of the hydroxyl H atom, and synergetic interactions on the antioxidant activity is discussed. ISSN : 0888-5885 En ligne : http://cat.inist.fr/?aModele=afficheN&cpsidt=25783418
in Industrial & engineering chemistry research > Vol. 51 N° 14 (Avril 2012) . - pp. 5117-5123[article] Effect of salix viminalis pyrolysis derived antioxidants on oxidative stability of diesters and diester – poly - a - olefin mixtures [texte imprimé] / Andrzej Olejniczak, Auteur ; Anna Kucinska, Auteur ; Aleksandra W. Cyganiuk, Auteur . - 2012 . - pp. 5117-5123.
Chimie industrielle
Langues : Anglais (eng)
in Industrial & engineering chemistry research > Vol. 51 N° 14 (Avril 2012) . - pp. 5117-5123
Mots-clés : Stability Oxidation Antioxidant Pyrolysis Résumé : The fabrication of molecular sieves and carbon-based adsorbents by pyrolysis of lignocellulosic material, such as Salix viminalis wood, generates a considerable amount of pyrolysis oil which has no specific application. In the present paper, we investigate phenolic components of S. viminalis derived pyrolysis oil with regard to their potential application to the oxidative stabilization of synthetic lubricating oils. Two phenolic fractions were isolated through solvent extraction (extract A was ether soluble; extract B was methylene chloride soluble) and characterized by chromatographic analysis. High levels of 2,6-dimethoxyphenol and its para-substituted derivatives were attributed to a rather atypical composition of S. viminalis lignin. The antioxidative effect of pyrolysis-derived polyphenols on diesters and their blends with poly-α-olefins was studied by means of a high temperature oxidation test combined with spectroscopic (NMR and FT-IR) product analysis. The test proved that the antioxidant capacity of each extract is high, at the level of ca. 1000 ppm Extract A had the highest increase in the induction period (170 h), and compared with the commercial BHT antioxidant, it prolonged the lag phase ca. 3.3 times. The effect of the o-methoxy and para substituents, intramolecular hydrogen bonding of the hydroxyl H atom, and synergetic interactions on the antioxidant activity is discussed. ISSN : 0888-5885 En ligne : http://cat.inist.fr/?aModele=afficheN&cpsidt=25783418 Exemplaires
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Titre : Prediction and measurement of gypsum solubility in the systems CaSO4 + HMSO4 + H2SO4 + H2O (HM = Cu, Zn, Ni, Mn) at 298.15 K Type de document : texte imprimé Auteurs : Wenlei Wang, Auteur ; Dewen Zeng, Auteur ; Xia Yin, Auteur Année de publication : 2012 Article en page(s) : pp. 5124-5134 Note générale : Chimie industrielle Langues : Anglais (eng) Mots-clés : Solubility Prediction Résumé : Solubility of gypsum in the quatemary systems CaSO4―HMSO4―H2SO4-H2O (HM = Cu, Zn, Ni, Mn) are predicted up to saturated concentrations of heavy metal sulfates and to a H2SO4 concentration of 2 m by a Pitzer thermodynamic model. Experimental solubility and water activity in the subbinary and subternary systems from the literature were used for model parametrization. Then the solubility phase diagrams for the quaternary systems were predicted directly with these obtained binary and ternary model parameters. In order to verify the reliability of the predicted results, a series of solubility measurements of gypsum in these quaternary systems have been carried out at 298.15 K and the measured results were compared with the predicted ones. It was shown that the Pitzer thermodynamic model can perfectly predict the solubilities of gypsum in the quaternary systems. Meanwhile, the newly obtained experimental data were compared with limited literature data in some of the quaternary systems; good agreement was found between them. Some application examples were given based on the predicted phase diagrams. ISSN : 0888-5885 En ligne : http://cat.inist.fr/?aModele=afficheN&cpsidt=25783419
in Industrial & engineering chemistry research > Vol. 51 N° 14 (Avril 2012) . - pp. 5124-5134[article] Prediction and measurement of gypsum solubility in the systems CaSO4 + HMSO4 + H2SO4 + H2O (HM = Cu, Zn, Ni, Mn) at 298.15 K [texte imprimé] / Wenlei Wang, Auteur ; Dewen Zeng, Auteur ; Xia Yin, Auteur . - 2012 . - pp. 5124-5134.
Chimie industrielle
Langues : Anglais (eng)
in Industrial & engineering chemistry research > Vol. 51 N° 14 (Avril 2012) . - pp. 5124-5134
Mots-clés : Solubility Prediction Résumé : Solubility of gypsum in the quatemary systems CaSO4―HMSO4―H2SO4-H2O (HM = Cu, Zn, Ni, Mn) are predicted up to saturated concentrations of heavy metal sulfates and to a H2SO4 concentration of 2 m by a Pitzer thermodynamic model. Experimental solubility and water activity in the subbinary and subternary systems from the literature were used for model parametrization. Then the solubility phase diagrams for the quaternary systems were predicted directly with these obtained binary and ternary model parameters. In order to verify the reliability of the predicted results, a series of solubility measurements of gypsum in these quaternary systems have been carried out at 298.15 K and the measured results were compared with the predicted ones. It was shown that the Pitzer thermodynamic model can perfectly predict the solubilities of gypsum in the quaternary systems. Meanwhile, the newly obtained experimental data were compared with limited literature data in some of the quaternary systems; good agreement was found between them. Some application examples were given based on the predicted phase diagrams. ISSN : 0888-5885 En ligne : http://cat.inist.fr/?aModele=afficheN&cpsidt=25783419 Exemplaires
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Titre : Mechanism of oxidation of the antituberculosis drug isoniazid by bromate in aqueous hydrochloric acid medium Type de document : texte imprimé Auteurs : Ramesh S. Yalgudre, Auteur ; Gavisiddappa S. Gokavi, Auteur Année de publication : 2012 Article en page(s) : pp. 5135–5140 Note générale : Chimie industrielle Langues : Anglais (eng) Mots-clés : Oxidation Hydrochloric Résumé : The oxidation of isoniazid by bromate was investigated kinetically under pseudo-first-order conditions in acid medium. The reaction was accelerated by the hydrogen ion due to the various protonation equilibria of both the reactants. The mechanism involves diprotonated isoniazid as the active species which forms two complexes with the diprotonated and unprotonated oxidant. The complex formed between the diprotonated oxidant and the protonated −NH2 group of hydrazide moiety of isoniazid decomposes into isonicotinic acid. Formation of another stable ion pair complex decreases the rate of reaction. The UV–vis examination of the solutions support the formation of both protonated isoniazid and the complexes. A probable mechanism on the basis of kinetic results involving formation of an acyl diimide of the isoniazid was proposed. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie203058s
in Industrial & engineering chemistry research > Vol. 51 N° 14 (Avril 2012) . - pp. 5135–5140[article] Mechanism of oxidation of the antituberculosis drug isoniazid by bromate in aqueous hydrochloric acid medium [texte imprimé] / Ramesh S. Yalgudre, Auteur ; Gavisiddappa S. Gokavi, Auteur . - 2012 . - pp. 5135–5140.
Chimie industrielle
Langues : Anglais (eng)
in Industrial & engineering chemistry research > Vol. 51 N° 14 (Avril 2012) . - pp. 5135–5140
Mots-clés : Oxidation Hydrochloric Résumé : The oxidation of isoniazid by bromate was investigated kinetically under pseudo-first-order conditions in acid medium. The reaction was accelerated by the hydrogen ion due to the various protonation equilibria of both the reactants. The mechanism involves diprotonated isoniazid as the active species which forms two complexes with the diprotonated and unprotonated oxidant. The complex formed between the diprotonated oxidant and the protonated −NH2 group of hydrazide moiety of isoniazid decomposes into isonicotinic acid. Formation of another stable ion pair complex decreases the rate of reaction. The UV–vis examination of the solutions support the formation of both protonated isoniazid and the complexes. A probable mechanism on the basis of kinetic results involving formation of an acyl diimide of the isoniazid was proposed. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie203058s Exemplaires
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Titre : Optimum lipase immobilized on diamine - grafted PVDF membrane and its characterization Type de document : texte imprimé Auteurs : Chia-Hung Kuo, Auteur ; Guan-Jie Chen, Auteur ; Yawo-Kuo Twu, Auteur Année de publication : 2012 Article en page(s) : pp. 5141-5147 Note générale : Chimie industrielle Langues : Anglais (eng) Mots-clés : Optimal lipase Résumé : A facile and economic modification of polyvinylidene fluoride (PVDF) with an orientation of diamine is presented herein. The physical characterizations of native and diamine-grafted PVDF membranes are analyzed by three different techniques: the ninhydrin test, Fourier transform infrared spectroscopy (FTIR) and scanning electron microscopy (SEM). The diamine-grafted PVDF is activated by glutaraldehyde for enzyme immobilization. The response surface methodology (RSM) is used to search the optimal immobilization conditions and to understand the significance of the factors affecting the responses of immobilized lipase. The optimal conditions for lipase immobilization are: a reaction time of 90 min, temperature of 35 °C, pH of 6, and an enzyme concentration of 7 mg/mL. An experiment performed under the optimum conditions obtains lipase activity of 60 U per g of membrane. A good agreement between the calculated and experimental values is thereby achieved. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie300011q
in Industrial & engineering chemistry research > Vol. 51 N° 14 (Avril 2012) . - pp. 5141-5147[article] Optimum lipase immobilized on diamine - grafted PVDF membrane and its characterization [texte imprimé] / Chia-Hung Kuo, Auteur ; Guan-Jie Chen, Auteur ; Yawo-Kuo Twu, Auteur . - 2012 . - pp. 5141-5147.
Chimie industrielle
Langues : Anglais (eng)
in Industrial & engineering chemistry research > Vol. 51 N° 14 (Avril 2012) . - pp. 5141-5147
Mots-clés : Optimal lipase Résumé : A facile and economic modification of polyvinylidene fluoride (PVDF) with an orientation of diamine is presented herein. The physical characterizations of native and diamine-grafted PVDF membranes are analyzed by three different techniques: the ninhydrin test, Fourier transform infrared spectroscopy (FTIR) and scanning electron microscopy (SEM). The diamine-grafted PVDF is activated by glutaraldehyde for enzyme immobilization. The response surface methodology (RSM) is used to search the optimal immobilization conditions and to understand the significance of the factors affecting the responses of immobilized lipase. The optimal conditions for lipase immobilization are: a reaction time of 90 min, temperature of 35 °C, pH of 6, and an enzyme concentration of 7 mg/mL. An experiment performed under the optimum conditions obtains lipase activity of 60 U per g of membrane. A good agreement between the calculated and experimental values is thereby achieved. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie300011q Exemplaires
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Titre : Preparation and characterization of N - halamine - based antimicrobial fillers Type de document : texte imprimé Auteurs : Revathi V. Padmanabhuni, Auteur ; Jie Luo, Auteur ; Zhengbing Cao, Auteur Année de publication : 2012 Article en page(s) : pp. 5148–5156 Note générale : Chimie industrielle Langues : Anglais (eng) Mots-clés : Polymer Composites antimicrobial Résumé : The purpose of this study was to demonstrate that the surface of CaCO3 fillers can be coated with an N-halamine-based fatty acid to make the filler surface organophilic and simultaneously achieve antibacterial activity, rendering the resulting polymer–filler composites antimicrobial. Thus, a new bifunctional compound, 4,4-dimethylhydantoin undecanoic acid (DMH-UA), was synthesized by treating the potassium salt of dimethylhydantoin (DMH) with 11-bromoundecanoic acid (BUA). Upon chlorination treatment with dilute bleach, DMH-UA was transformed into 3-chloro-4,4-dimethylhydantoin undecanoic acid (Cl-DMH-UA). Alternatively, DMH-UA could be coated onto the surface of CaCO3 to obtain the corresponding calcium salt, 4,4-dimethylhydantoin undecanoic acid calcium carbonate (DMH-UA-CaCO3). In the presence of dilute chlorine bleach, the DMH-UA coated on the surface of CaCO3 was transformed into Cl-DMH-UA, leading to the formation of Cl-DMH-UA-CaCO3. The reactions were characterized by FT-IR, NMR, UV, DSC, and SEM analyses. Both Cl-DMH-UA and Cl-DMH-UA-CaCO3 were used as antimicrobial additives for cellulose acetate (CA). The antimicrobial efficacy of the resulting samples was evaluated against both Escherichia coli (Gram-negative bacteria) and Staphylococcus aureus (Gram-positive bacteria). It was found that, for the same additive content, CA samples with Cl-DMH-UA-CaCO3 and Cl-DMH-UA had very similar antimicrobial and biofilm-controlling activities, but the former released less active chlorine into the surrounding environment than the latter. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie300212x
in Industrial & engineering chemistry research > Vol. 51 N° 14 (Avril 2012) . - pp. 5148–5156[article] Preparation and characterization of N - halamine - based antimicrobial fillers [texte imprimé] / Revathi V. Padmanabhuni, Auteur ; Jie Luo, Auteur ; Zhengbing Cao, Auteur . - 2012 . - pp. 5148–5156.
Chimie industrielle
Langues : Anglais (eng)
in Industrial & engineering chemistry research > Vol. 51 N° 14 (Avril 2012) . - pp. 5148–5156
Mots-clés : Polymer Composites antimicrobial Résumé : The purpose of this study was to demonstrate that the surface of CaCO3 fillers can be coated with an N-halamine-based fatty acid to make the filler surface organophilic and simultaneously achieve antibacterial activity, rendering the resulting polymer–filler composites antimicrobial. Thus, a new bifunctional compound, 4,4-dimethylhydantoin undecanoic acid (DMH-UA), was synthesized by treating the potassium salt of dimethylhydantoin (DMH) with 11-bromoundecanoic acid (BUA). Upon chlorination treatment with dilute bleach, DMH-UA was transformed into 3-chloro-4,4-dimethylhydantoin undecanoic acid (Cl-DMH-UA). Alternatively, DMH-UA could be coated onto the surface of CaCO3 to obtain the corresponding calcium salt, 4,4-dimethylhydantoin undecanoic acid calcium carbonate (DMH-UA-CaCO3). In the presence of dilute chlorine bleach, the DMH-UA coated on the surface of CaCO3 was transformed into Cl-DMH-UA, leading to the formation of Cl-DMH-UA-CaCO3. The reactions were characterized by FT-IR, NMR, UV, DSC, and SEM analyses. Both Cl-DMH-UA and Cl-DMH-UA-CaCO3 were used as antimicrobial additives for cellulose acetate (CA). The antimicrobial efficacy of the resulting samples was evaluated against both Escherichia coli (Gram-negative bacteria) and Staphylococcus aureus (Gram-positive bacteria). It was found that, for the same additive content, CA samples with Cl-DMH-UA-CaCO3 and Cl-DMH-UA had very similar antimicrobial and biofilm-controlling activities, but the former released less active chlorine into the surrounding environment than the latter. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie300212x Exemplaires
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Titre : Mass transfer from nanofluid single drops in liquid – liquid extraction process Type de document : texte imprimé Auteurs : Javad Saien, Auteur ; Hamid Bamdadi, Auteur Année de publication : 2012 Article en page(s) : pp. 5157-5166 Note générale : Chimie industrielle Langues : Anglais (eng) Mots-clés : Liquid liquid extraction Drop Mass transfer Résumé : This investigation is focused on the behavior of nanofluid single drops in the liquid―liquid extraction process. The chemical system of toluene―acetic acid―water was used, and the drops were organic nanofluids containing magnetite or alumina nanoparticles. Synthesized nanoparticles were modified with fatty acids for hydrophobicity and ease of dispersion in the organic phase and were then characterized using different methods. Maximum enhancements in the rate of mass transfer of 157% and 121% were achieved using about 0.002 wt % magnetite and alumina nanoparticles, respectively; however, a decreasing variation was observed at higher concentrations. The microconvection and particle aggregation due to the interpenetration layers can provide this kind of variation. For the aim of modeling, the determined enhancement factors were correlated with an empirical expression that can be used, together with the Newman equation, for the prediction of the overall mass-transfer coefficient. ISSN : 0888-5885 En ligne : http://cat.inist.fr/?aModele=afficheN&cpsidt=25783423
in Industrial & engineering chemistry research > Vol. 51 N° 14 (Avril 2012) . - pp. 5157-5166[article] Mass transfer from nanofluid single drops in liquid – liquid extraction process [texte imprimé] / Javad Saien, Auteur ; Hamid Bamdadi, Auteur . - 2012 . - pp. 5157-5166.
Chimie industrielle
Langues : Anglais (eng)
in Industrial & engineering chemistry research > Vol. 51 N° 14 (Avril 2012) . - pp. 5157-5166
Mots-clés : Liquid liquid extraction Drop Mass transfer Résumé : This investigation is focused on the behavior of nanofluid single drops in the liquid―liquid extraction process. The chemical system of toluene―acetic acid―water was used, and the drops were organic nanofluids containing magnetite or alumina nanoparticles. Synthesized nanoparticles were modified with fatty acids for hydrophobicity and ease of dispersion in the organic phase and were then characterized using different methods. Maximum enhancements in the rate of mass transfer of 157% and 121% were achieved using about 0.002 wt % magnetite and alumina nanoparticles, respectively; however, a decreasing variation was observed at higher concentrations. The microconvection and particle aggregation due to the interpenetration layers can provide this kind of variation. For the aim of modeling, the determined enhancement factors were correlated with an empirical expression that can be used, together with the Newman equation, for the prediction of the overall mass-transfer coefficient. ISSN : 0888-5885 En ligne : http://cat.inist.fr/?aModele=afficheN&cpsidt=25783423 Exemplaires
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Titre : Sunlight-Assisted Degradation of Dye Pollutants in Ag3PO4 Suspension Type de document : texte imprimé Auteurs : Ming Ge, Auteur ; Na Zhu, Auteur ; Yaping Zhao, Auteur Année de publication : 2012 Article en page(s) : pp. 5167–5173 Note générale : Chimie industrielle Langues : Anglais (eng) Mots-clés : Photodegradation Rhodamine Résumé : Sunlight-induced photodegradation of rhodamine B over Ag3PO4 has been observed. Nanosized Ag3PO4 was synthesized by a facile ion-exchange route. X-ray powder diffraction, scanning electron microscopy, X-ray photoelectron spectroscopy, the Brunauer–Emmett–Teller surface area, UV–vis diffuse reflectance spectroscopy and photoluminescence spectra were employed to investigate the phase structure, morphology and optical property of the Ag3PO4 product. Nearly 100% of rhodamine B was degraded after a very short irradiation time using simulated sunlight in Ag3PO4 suspension, and the total organic carbon measurement revealed that a high degree of mineralization was achieved in the present photocatalytic system. Ag3PO4 catalyst has an excellent photocatalytic performance due to the high separation efficiency of electron and hole pairs. In the neutral pH solution, Ag3PO4 catalyst exhibited the best photoactivity under simulated sunlight. The photoinduced holes were considered to be the dominant active species in the photodegradation process. ISSN : 088 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie202864n
in Industrial & engineering chemistry research > Vol. 51 N° 14 (Avril 2012) . - pp. 5167–5173[article] Sunlight-Assisted Degradation of Dye Pollutants in Ag3PO4 Suspension [texte imprimé] / Ming Ge, Auteur ; Na Zhu, Auteur ; Yaping Zhao, Auteur . - 2012 . - pp. 5167–5173.
Chimie industrielle
Langues : Anglais (eng)
in Industrial & engineering chemistry research > Vol. 51 N° 14 (Avril 2012) . - pp. 5167–5173
Mots-clés : Photodegradation Rhodamine Résumé : Sunlight-induced photodegradation of rhodamine B over Ag3PO4 has been observed. Nanosized Ag3PO4 was synthesized by a facile ion-exchange route. X-ray powder diffraction, scanning electron microscopy, X-ray photoelectron spectroscopy, the Brunauer–Emmett–Teller surface area, UV–vis diffuse reflectance spectroscopy and photoluminescence spectra were employed to investigate the phase structure, morphology and optical property of the Ag3PO4 product. Nearly 100% of rhodamine B was degraded after a very short irradiation time using simulated sunlight in Ag3PO4 suspension, and the total organic carbon measurement revealed that a high degree of mineralization was achieved in the present photocatalytic system. Ag3PO4 catalyst has an excellent photocatalytic performance due to the high separation efficiency of electron and hole pairs. In the neutral pH solution, Ag3PO4 catalyst exhibited the best photoactivity under simulated sunlight. The photoinduced holes were considered to be the dominant active species in the photodegradation process. ISSN : 088 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie202864n Exemplaires
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Titre : Carboxylation of toluene by CO2 generating p - toluic acid : A kinetic look Type de document : texte imprimé Auteurs : Antaram N. Sarve, Auteur ; Pralhad A. Ganeshpure, Auteur ; Pradip Munshi, Auteur Année de publication : 2012 Article en page(s) : pp. 5174-518 Note générale : Chimie industrielle Langues : Anglais (eng) Mots-clés : Kinetics Carbon dioxide Carboxylation Résumé : A kinetic study involving stoichiometry, order of reaction, rate constants (k), and rate laws has been performed on carboxylation of toluene by CO2 generating p-toluic acid by two routes: (a) Friedel—Crafts reaction, C6H5―CH3 + CO2 + Al2Cl6 → CH3―C6H4―COOAl2Cl5 + HCl and (b) Friedel―Crafts reaction with incubation method involving two steps, CO2+ + Al2Cl6 → CO2:Al2Cl6 and CO2:Al2Cl6 + C6H5―CH3→ CH3―C6H4―COOAl2Cl5 + HCl. The adduct OCO:Al2Cl6 was estimated by monitoring the peak at 1662 cm―1 in the FT1R spectra. The k values for the Friedel-Crafts reaction was found to be 2.28 × 10―9 mol―2 h―1, which is much lower than that for the reactions involved in the incubation method, viz, 5.4 × 10―5 and 1.9 X 10―3 mol―1 h―1, respectively. ΔE, ΔG, ΔS, ΔH, and the Arrhenius constant (A) have been calculated for the above reactions. Comparison shows that the incubation method is faster than the Friedel-Crafts reaction. However, both the reactions follow first order kinetics with respect to each of the reactants. ISSN : 0888-5885 En ligne : http://cat.inist.fr/?aModele=afficheN&cpsidt=25783425
in Industrial & engineering chemistry research > Vol. 51 N° 14 (Avril 2012) . - pp. 5174-518[article] Carboxylation of toluene by CO2 generating p - toluic acid : A kinetic look [texte imprimé] / Antaram N. Sarve, Auteur ; Pralhad A. Ganeshpure, Auteur ; Pradip Munshi, Auteur . - 2012 . - pp. 5174-518.
Chimie industrielle
Langues : Anglais (eng)
in Industrial & engineering chemistry research > Vol. 51 N° 14 (Avril 2012) . - pp. 5174-518
Mots-clés : Kinetics Carbon dioxide Carboxylation Résumé : A kinetic study involving stoichiometry, order of reaction, rate constants (k), and rate laws has been performed on carboxylation of toluene by CO2 generating p-toluic acid by two routes: (a) Friedel—Crafts reaction, C6H5―CH3 + CO2 + Al2Cl6 → CH3―C6H4―COOAl2Cl5 + HCl and (b) Friedel―Crafts reaction with incubation method involving two steps, CO2+ + Al2Cl6 → CO2:Al2Cl6 and CO2:Al2Cl6 + C6H5―CH3→ CH3―C6H4―COOAl2Cl5 + HCl. The adduct OCO:Al2Cl6 was estimated by monitoring the peak at 1662 cm―1 in the FT1R spectra. The k values for the Friedel-Crafts reaction was found to be 2.28 × 10―9 mol―2 h―1, which is much lower than that for the reactions involved in the incubation method, viz, 5.4 × 10―5 and 1.9 X 10―3 mol―1 h―1, respectively. ΔE, ΔG, ΔS, ΔH, and the Arrhenius constant (A) have been calculated for the above reactions. Comparison shows that the incubation method is faster than the Friedel-Crafts reaction. However, both the reactions follow first order kinetics with respect to each of the reactants. ISSN : 0888-5885 En ligne : http://cat.inist.fr/?aModele=afficheN&cpsidt=25783425 Exemplaires
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Titre : Fractionation of surface - modified gold nanorods using gas - expanded liquids Type de document : texte imprimé Auteurs : Gregory White, Auteur ; Matthew Grant Provost, Auteur ; Christopher Lawrence Kitchens, Auteur Année de publication : 2012 Article en page(s) : pp. 5181–5189 Note générale : Chimie industrielle Langues : Anglais (eng) Mots-clés : Gold nanorods Nanocomposites Résumé : Gold nanorods (GNRs) have found widespread applications in nanocomposites and thin films, because of their unique optical, chemical, and photothermal properties, which are dictated by the rod size and aspect ratio. In this study, gold nanorods (GNRs, aspect ratio of 3–4) were synthesized using a high-yield, aqueous, solution-based method, followed by a surface modification reaction to facilitate their dispersion in organic media. A gas-expanded liquid (GXL) precipitation technique was used to effectively size-fractionate the GNRs with CO2 as a green antisolvent for hydrophobic nanorods dispersed in toluene, hexane, and cyclohexane. The advantages of using GXL media lie in the tunable solvent properties that enable size-selective nanoparticle precipitation that is easily controlled by the CO2 antisolvent partial pressure. This work demonstrated effective GNR size fractionation and a 73% reduction in the number of residual 4-nm-diameter spherical seed nanoparticles remaining after synthesis with a single precipitation and redispersion. The GNR dispersibility and precipitation was monitored by ultraviolet-visible (UV–vis) absorbance spectroscopy and found to be dependent on the solvent choice and GNR ligand. CO2-expanded cyclohexane provided the greatest dispersibility of GNRs stabilized by 18-carbon-chain-length ligands, which were dispersible at pressures up to roughly 30 bar (0.44 mol fraction CO2), compared to a lower pressure, on the order of 24 bar for CO2-expanded toluene (0.21 mol fraction CO2) and n-hexane (0.31 mol fraction CO2). Varying the hydrophobic stabilizing ligand chain length also impacted nanorod dispersibility in CO2-expanded toluene, where 12-carbon-chain-length dodecanethiol ligands yielded nanorod dispersion/precipitation at CO2 pressures much greater than those for the 18-carbon octadecanethiol ligands. This work is the first application of a GXL solvent medium for the processing, purification, and size fractionation of nonspherical particles, which has led to a greater understanding of gold nanorod dispersibility and demonstrated the feasibility of GXLs as a green solvent medium for post-synthesis nanorod processing. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie201975p
in Industrial & engineering chemistry research > Vol. 51 N° 14 (Avril 2012) . - pp. 5181–5189[article] Fractionation of surface - modified gold nanorods using gas - expanded liquids [texte imprimé] / Gregory White, Auteur ; Matthew Grant Provost, Auteur ; Christopher Lawrence Kitchens, Auteur . - 2012 . - pp. 5181–5189.
Chimie industrielle
Langues : Anglais (eng)
in Industrial & engineering chemistry research > Vol. 51 N° 14 (Avril 2012) . - pp. 5181–5189
Mots-clés : Gold nanorods Nanocomposites Résumé : Gold nanorods (GNRs) have found widespread applications in nanocomposites and thin films, because of their unique optical, chemical, and photothermal properties, which are dictated by the rod size and aspect ratio. In this study, gold nanorods (GNRs, aspect ratio of 3–4) were synthesized using a high-yield, aqueous, solution-based method, followed by a surface modification reaction to facilitate their dispersion in organic media. A gas-expanded liquid (GXL) precipitation technique was used to effectively size-fractionate the GNRs with CO2 as a green antisolvent for hydrophobic nanorods dispersed in toluene, hexane, and cyclohexane. The advantages of using GXL media lie in the tunable solvent properties that enable size-selective nanoparticle precipitation that is easily controlled by the CO2 antisolvent partial pressure. This work demonstrated effective GNR size fractionation and a 73% reduction in the number of residual 4-nm-diameter spherical seed nanoparticles remaining after synthesis with a single precipitation and redispersion. The GNR dispersibility and precipitation was monitored by ultraviolet-visible (UV–vis) absorbance spectroscopy and found to be dependent on the solvent choice and GNR ligand. CO2-expanded cyclohexane provided the greatest dispersibility of GNRs stabilized by 18-carbon-chain-length ligands, which were dispersible at pressures up to roughly 30 bar (0.44 mol fraction CO2), compared to a lower pressure, on the order of 24 bar for CO2-expanded toluene (0.21 mol fraction CO2) and n-hexane (0.31 mol fraction CO2). Varying the hydrophobic stabilizing ligand chain length also impacted nanorod dispersibility in CO2-expanded toluene, where 12-carbon-chain-length dodecanethiol ligands yielded nanorod dispersion/precipitation at CO2 pressures much greater than those for the 18-carbon octadecanethiol ligands. This work is the first application of a GXL solvent medium for the processing, purification, and size fractionation of nonspherical particles, which has led to a greater understanding of gold nanorod dispersibility and demonstrated the feasibility of GXLs as a green solvent medium for post-synthesis nanorod processing. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie201975p Exemplaires
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Titre : Synthesis of high molecular weight poly (l - lactic acid) via melt / solid state polycondensation. II. : Effect of precrystallization on solid state polycondensation Type de document : texte imprimé Auteurs : Bo Peng, Auteur ; Hongbing Hou, Auteur ; Fangchao Song, Auteur Année de publication : 2012 Article en page(s) : pp. 5190–5196 Note générale : Chimie industrielle Langues : Anglais (eng) Mots-clés : Polycondensation Precrystallization Résumé : To enhance the reaction rate of solid state polycondensation (SSP) of poly(l-lactic acid) (PLLA) and thus to prepare high molecular weight PLLA by SSP in a short time, the effects of precrystallization as well as SSP temperature (Ts) on the SSP of PLLA were investigated. It was found that precrystallization at low Tc (70 °C) and then SSP at step-raised Ts could greatly favor the growth of the molecular weight of PLLA. After precrystallization at 70 °C for 60 min and then SSP at 150–160 °C for 20 h, the product’s weight average molecular weight (Mw) exceeds 200 000 g·mol–1 while its optical purity remained as high as 90%. The prepolymer precrystallized at 70 °C for 60 min had smaller crystal size and looser packing of lamellae structure than that at Tcmax (110 °C) and moderate crystallinity of 45%. Such crystal properties may result in enhanced concentration and mobility of chain-end groups and improved diffusion of byproduct water in an amorphous area, so the SSP reaction is accelerated. PLLA continues to crystallize during SSP. The crystallinity and melting temperature increase rapidly at the early stage and slowly at the late stage, implying that the effect of precrystallization on the SSP rate is significant at the early stage, and weakens gradually at the late stage. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie202192q
in Industrial & engineering chemistry research > Vol. 51 N° 14 (Avril 2012) . - pp. 5190–5196[article] Synthesis of high molecular weight poly (l - lactic acid) via melt / solid state polycondensation. II. : Effect of precrystallization on solid state polycondensation [texte imprimé] / Bo Peng, Auteur ; Hongbing Hou, Auteur ; Fangchao Song, Auteur . - 2012 . - pp. 5190–5196.
Chimie industrielle
Langues : Anglais (eng)
in Industrial & engineering chemistry research > Vol. 51 N° 14 (Avril 2012) . - pp. 5190–5196
Mots-clés : Polycondensation Precrystallization Résumé : To enhance the reaction rate of solid state polycondensation (SSP) of poly(l-lactic acid) (PLLA) and thus to prepare high molecular weight PLLA by SSP in a short time, the effects of precrystallization as well as SSP temperature (Ts) on the SSP of PLLA were investigated. It was found that precrystallization at low Tc (70 °C) and then SSP at step-raised Ts could greatly favor the growth of the molecular weight of PLLA. After precrystallization at 70 °C for 60 min and then SSP at 150–160 °C for 20 h, the product’s weight average molecular weight (Mw) exceeds 200 000 g·mol–1 while its optical purity remained as high as 90%. The prepolymer precrystallized at 70 °C for 60 min had smaller crystal size and looser packing of lamellae structure than that at Tcmax (110 °C) and moderate crystallinity of 45%. Such crystal properties may result in enhanced concentration and mobility of chain-end groups and improved diffusion of byproduct water in an amorphous area, so the SSP reaction is accelerated. PLLA continues to crystallize during SSP. The crystallinity and melting temperature increase rapidly at the early stage and slowly at the late stage, implying that the effect of precrystallization on the SSP rate is significant at the early stage, and weakens gradually at the late stage. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie202192q Exemplaires
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Titre : Epoxy resin / ionic liquid systems : The influence of imidazolium cation size and anion type on reactivity and thermomechanical properties Type de document : texte imprimé Auteurs : Honorata Maka, Auteur ; Tadeusz Spychaj, Auteur ; Ryszard Pilawka, Auteur Année de publication : 2012 Article en page(s) : pp. 5197-5206 Note générale : Chimie industrielle Langues : Anglais (eng) Mots-clés : Thermomechanical properties Chemical reactivity Ionic liquid Résumé : The epoxy compositions with ionic liquids (ILs) differing in the alkyl chain length of imidazolium cation (butyl or decyl), anion type [N(CN)2―, BF4―, Cl―], as well as ILs concentration (1, 3, and 9 phr) have been prepared, and their curing characteristics at ambient and elevated temperatures have been investigated Rheometric, differential scanning calorimetry, and Fourier transform infrared measurements revealed substantial differences in the curing characteristics dependent mainly on the IL anion type and its concentration. TGA results showed that thermal decomposition of IL influenced the onset temperature of epoxy resins cross-linking reactions during heat treatment. Dynamic mechanical thermal analysis measurements showed that the type of IL anion had an effect on T8 and tan δ values as well. For materials cross-linked with ILs containing dicyanamide anion the highest Tg (ca. 170 °C) and the lowest tan δ (0.26) values have been found. On the basis of the obtained results and literature data the mechanism of epoxy resin cross-linking in the presence of imidazolium ionic liquids has been proposed. ISSN : 0888-5885 En ligne : http://cat.inist.fr/?aModele=afficheN&cpsidt=25783428
in Industrial & engineering chemistry research > Vol. 51 N° 14 (Avril 2012) . - pp. 5197-5206[article] Epoxy resin / ionic liquid systems : The influence of imidazolium cation size and anion type on reactivity and thermomechanical properties [texte imprimé] / Honorata Maka, Auteur ; Tadeusz Spychaj, Auteur ; Ryszard Pilawka, Auteur . - 2012 . - pp. 5197-5206.
Chimie industrielle
Langues : Anglais (eng)
in Industrial & engineering chemistry research > Vol. 51 N° 14 (Avril 2012) . - pp. 5197-5206
Mots-clés : Thermomechanical properties Chemical reactivity Ionic liquid Résumé : The epoxy compositions with ionic liquids (ILs) differing in the alkyl chain length of imidazolium cation (butyl or decyl), anion type [N(CN)2―, BF4―, Cl―], as well as ILs concentration (1, 3, and 9 phr) have been prepared, and their curing characteristics at ambient and elevated temperatures have been investigated Rheometric, differential scanning calorimetry, and Fourier transform infrared measurements revealed substantial differences in the curing characteristics dependent mainly on the IL anion type and its concentration. TGA results showed that thermal decomposition of IL influenced the onset temperature of epoxy resins cross-linking reactions during heat treatment. Dynamic mechanical thermal analysis measurements showed that the type of IL anion had an effect on T8 and tan δ values as well. For materials cross-linked with ILs containing dicyanamide anion the highest Tg (ca. 170 °C) and the lowest tan δ (0.26) values have been found. On the basis of the obtained results and literature data the mechanism of epoxy resin cross-linking in the presence of imidazolium ionic liquids has been proposed. ISSN : 0888-5885 En ligne : http://cat.inist.fr/?aModele=afficheN&cpsidt=25783428 Exemplaires
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Titre : Process intensification in the production of photocatalysts for solar hydrogen generation Type de document : texte imprimé Auteurs : Chia-Ying Chiang, Auteur ; Ming-Hui Chang, Auteur ; Hwai-Shen Liu, Auteur Année de publication : 2012 Article en page(s) : pp. 5207-5215 Note générale : Chimie industrielle Langues : Anglais (eng) Mots-clés : Photocatalysis Catalyst Hydrogen production Résumé : CuO nanoparticles with diameter in the 20-30 nm range were prepared by a spinning disk reactor at the rate of 16.9 kg/day based on the process intensification concept The intense environment, that is, vigorous mixing and fast reaction at the same time, created within an initially crystal-free liquid film moving over the disk, generated very high supersaturation, and consequently small and fairly uniform crystals were formed via precipitation. These CuO nanoparticles were spin coated and sintered at 450 °C for 1 h to form a thin film electrode for use in a photoelectrochemical cell. The cell had a 1.20% solar to hydrogen conversion efficiency which is the highest among intrinsic CuO photoelectrochemical (PEC) cells reported to date in the literature. The bandgap of CuO films sintered at 450 °C for 1 h was 1.68 eV. The charge carrier density was 9.0 × 1020 cm―3 and the conduction and valence band edges were located at ―3.54 and -5.22 eV, respectively. Furthermore, a detailed comparison based on the preparation method, particle size, bandgap, porosity, and conductivity of the films in the CuO PEC cell literature is also reported in this study. ISSN : 0888-5885 En ligne : http://cat.inist.fr/?aModele=afficheN&cpsidt=25783429
in Industrial & engineering chemistry research > Vol. 51 N° 14 (Avril 2012) . - pp. 5207-5215[article] Process intensification in the production of photocatalysts for solar hydrogen generation [texte imprimé] / Chia-Ying Chiang, Auteur ; Ming-Hui Chang, Auteur ; Hwai-Shen Liu, Auteur . - 2012 . - pp. 5207-5215.
Chimie industrielle
Langues : Anglais (eng)
in Industrial & engineering chemistry research > Vol. 51 N° 14 (Avril 2012) . - pp. 5207-5215
Mots-clés : Photocatalysis Catalyst Hydrogen production Résumé : CuO nanoparticles with diameter in the 20-30 nm range were prepared by a spinning disk reactor at the rate of 16.9 kg/day based on the process intensification concept The intense environment, that is, vigorous mixing and fast reaction at the same time, created within an initially crystal-free liquid film moving over the disk, generated very high supersaturation, and consequently small and fairly uniform crystals were formed via precipitation. These CuO nanoparticles were spin coated and sintered at 450 °C for 1 h to form a thin film electrode for use in a photoelectrochemical cell. The cell had a 1.20% solar to hydrogen conversion efficiency which is the highest among intrinsic CuO photoelectrochemical (PEC) cells reported to date in the literature. The bandgap of CuO films sintered at 450 °C for 1 h was 1.68 eV. The charge carrier density was 9.0 × 1020 cm―3 and the conduction and valence band edges were located at ―3.54 and -5.22 eV, respectively. Furthermore, a detailed comparison based on the preparation method, particle size, bandgap, porosity, and conductivity of the films in the CuO PEC cell literature is also reported in this study. ISSN : 0888-5885 En ligne : http://cat.inist.fr/?aModele=afficheN&cpsidt=25783429 Exemplaires
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Titre : Selective removal of arsenic (V) from aqueous solution using a surface - ion - imprinted amine - functionalized silica gel sorbent Type de document : texte imprimé Auteurs : Hong-Tao Fan, Auteur ; Xuelei Fan, Auteur ; Jing Li, Auteur Année de publication : 2012 Article en page(s) : pp. 5216-5223 Note générale : industrial Chemistry Langues : Anglais (eng) Mots-clés : Silica gel Aqueous solution Résumé : A new surface-ion-imprinted amino-functionalized silica gel sorbent was prepared by the surface imprinting technique with As(V) as the template, 3-(2-aminoethylamino)propyltrimethoxysilane as the functional monomer, silica gel as the support, and epichlorohydrin as the cross-linking agent and was characterized by FTIR, SEM, nitrogen adsorption, and the static adsorption-desorption experiment method. The results showed that the maximum static adsorption capacity of the imprinted silica gel sorbent was 16.1 mg·g―1, the adsorption equilibrium could be reached in 20 min, there was no influence of pH values on adsorption capacity of the imprinted silica gel sorbent in the range of 3.7-9.2, and the imprinted silica gel sorbent could be used repeatedly and indicated high selectivity even in the presence of the other metal ions. The Langmuir adsorption model was more favorable than the Freundlich adsorption model. Kinetic studies indicated that the adsorption followed a pseudosecond-order model. Various thermodynamic parameters such as ΔG°, ΔH°, and ΔS° were evaluated with results indicating that this system was a spontaneous and endothermic process. ISSN : 0888-5885 En ligne : http://cat.inist.fr/?aModele=afficheN&cpsidt=25783430
in Industrial & engineering chemistry research > Vol. 51 N° 14 (Avril 2012) . - pp. 5216-5223[article] Selective removal of arsenic (V) from aqueous solution using a surface - ion - imprinted amine - functionalized silica gel sorbent [texte imprimé] / Hong-Tao Fan, Auteur ; Xuelei Fan, Auteur ; Jing Li, Auteur . - 2012 . - pp. 5216-5223.
industrial Chemistry
Langues : Anglais (eng)
in Industrial & engineering chemistry research > Vol. 51 N° 14 (Avril 2012) . - pp. 5216-5223
Mots-clés : Silica gel Aqueous solution Résumé : A new surface-ion-imprinted amino-functionalized silica gel sorbent was prepared by the surface imprinting technique with As(V) as the template, 3-(2-aminoethylamino)propyltrimethoxysilane as the functional monomer, silica gel as the support, and epichlorohydrin as the cross-linking agent and was characterized by FTIR, SEM, nitrogen adsorption, and the static adsorption-desorption experiment method. The results showed that the maximum static adsorption capacity of the imprinted silica gel sorbent was 16.1 mg·g―1, the adsorption equilibrium could be reached in 20 min, there was no influence of pH values on adsorption capacity of the imprinted silica gel sorbent in the range of 3.7-9.2, and the imprinted silica gel sorbent could be used repeatedly and indicated high selectivity even in the presence of the other metal ions. The Langmuir adsorption model was more favorable than the Freundlich adsorption model. Kinetic studies indicated that the adsorption followed a pseudosecond-order model. Various thermodynamic parameters such as ΔG°, ΔH°, and ΔS° were evaluated with results indicating that this system was a spontaneous and endothermic process. ISSN : 0888-5885 En ligne : http://cat.inist.fr/?aModele=afficheN&cpsidt=25783430 Exemplaires
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Titre : Crystal growth of clathrate hydrate at the interface between seawater and hydrophobic - guest liquid : Effect of elevated salt concentration Type de document : texte imprimé Auteurs : Masatoshi Kishimoto, Auteur ; Satoshi Iijima, Auteur ; Ryo Ohmura, Auteur Année de publication : 2012 Article en page(s) : pp. 5224-5229 Note générale : Chimie industrielle Langues : Anglais (eng) Mots-clés : Seawater Clathrate Crystal growth Résumé : This paper reports the visual observations of the clathrate hydrate crystal growth and morphology at the interface of aqueous NaCl solutions and a guest-substance liquid. The hydrate crystal growth was visually characterized in the systems of a wide range of NaCl concentrations from 0.035 to 0.264 in mass fraction. The mass fraction 0.035 was corresponding to that of ordinary seawater, and the salt concentration tested was extended up to the saturation level, i.e., 0.264. Cyclopentane was used as the guest substance. Formation and growth of hydrate crystals at the cyclopentane-NaCl solution interface were observed. We visually analyzed the individual hydrate crystals and classified the morphology of the crystals according to ΔTsub at atmospheric pressure. It was found that the size of the individual hydrate crystals decreased with increasing ΔTsub. The results showed that the morphology of the individual hydrate crystals in any NaCl concentration is roughly similar at a given ΔTsub. We also measured the lateral growth rates of the hydrate-film propagation. The hydrate film growth rate decreased with decreasing ΔTsub in any of the systems and decreased with increasing concentration of NaCl at a given ΔTsub. ISSN : 0888-5885 En ligne : http://cat.inist.fr/?aModele=afficheN&cpsidt=25783431
in Industrial & engineering chemistry research > Vol. 51 N° 14 (Avril 2012) . - pp. 5224-5229[article] Crystal growth of clathrate hydrate at the interface between seawater and hydrophobic - guest liquid : Effect of elevated salt concentration [texte imprimé] / Masatoshi Kishimoto, Auteur ; Satoshi Iijima, Auteur ; Ryo Ohmura, Auteur . - 2012 . - pp. 5224-5229.
Chimie industrielle
Langues : Anglais (eng)
in Industrial & engineering chemistry research > Vol. 51 N° 14 (Avril 2012) . - pp. 5224-5229
Mots-clés : Seawater Clathrate Crystal growth Résumé : This paper reports the visual observations of the clathrate hydrate crystal growth and morphology at the interface of aqueous NaCl solutions and a guest-substance liquid. The hydrate crystal growth was visually characterized in the systems of a wide range of NaCl concentrations from 0.035 to 0.264 in mass fraction. The mass fraction 0.035 was corresponding to that of ordinary seawater, and the salt concentration tested was extended up to the saturation level, i.e., 0.264. Cyclopentane was used as the guest substance. Formation and growth of hydrate crystals at the cyclopentane-NaCl solution interface were observed. We visually analyzed the individual hydrate crystals and classified the morphology of the crystals according to ΔTsub at atmospheric pressure. It was found that the size of the individual hydrate crystals decreased with increasing ΔTsub. The results showed that the morphology of the individual hydrate crystals in any NaCl concentration is roughly similar at a given ΔTsub. We also measured the lateral growth rates of the hydrate-film propagation. The hydrate film growth rate decreased with decreasing ΔTsub in any of the systems and decreased with increasing concentration of NaCl at a given ΔTsub. ISSN : 0888-5885 En ligne : http://cat.inist.fr/?aModele=afficheN&cpsidt=25783431 Exemplaires
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Titre : Green synthesis of protein stabilized silver nanoparticles using pseudomonas fluorescens, a marine bacterium, and its biomedical applications when coated on polycaprolactam Type de document : texte imprimé Auteurs : Veluchamy Prabhawathi, Auteur ; Ponnurengam Malliappan Sivakumar, Auteur ; Mukesh Doble, Auteur Année de publication : 2012 Article en page(s) : pp. 5230-5239 Note générale : Chimie industrielle Langues : Anglais (eng) Mots-clés : Bacteria Pseudomonadales Pseudomonadaceae Pseudomonas Résumé : Green synthesis of protein stabilized silver nanoparticles (AgNPs) using the supernatant of a marine isolate, Pseudomonas fluorescens PMMD3 (P.fluorescens), and its biomedical applications and biocompatibility when coated on polycaprolactam is reported here. The AgNPs are spherical and are 1-10 nm in size. AgNP-coated polycaprolactam showed 89.7% and 92.4% reduction in colony forming units (CFUs), when compared to bare polymer, against S.aureus and E.coli, respectively. In the biofilm on AgNP composite, when compared to the bare polymer, there were carbohydrate reductions by factors of 3.5 and 6.0 in S.aureus and E.coli biofilm, respectively, and protein reductions by factors of 6.5 and 3.0 in S.aureus and E.coli biofilm, respectively. Reduction in the adhesion of S.aureus, C.albicans, A.niger, and F.proliferatum were observed using scanning electron miaoscopy (SEM) and fluorescence microscopy. The C.albicans biofilm is 15 and 6 μm thick on polycaprolactam and AgNP composite, respectively. We observed 84% and 80% proliferation of 3T3-L1 adipocyte cells and 85% and 97% of L929 fibroblast on the AgNP composite and bare polymer, indicating that this new material is suitable for biomaterial applications. ISSN : 0888-5885 En ligne : http://cat.inist.fr/?aModele=afficheN&cpsidt=25783432
in Industrial & engineering chemistry research > Vol. 51 N° 14 (Avril 2012) . - pp. 5230-5239[article] Green synthesis of protein stabilized silver nanoparticles using pseudomonas fluorescens, a marine bacterium, and its biomedical applications when coated on polycaprolactam [texte imprimé] / Veluchamy Prabhawathi, Auteur ; Ponnurengam Malliappan Sivakumar, Auteur ; Mukesh Doble, Auteur . - 2012 . - pp. 5230-5239.
Chimie industrielle
Langues : Anglais (eng)
in Industrial & engineering chemistry research > Vol. 51 N° 14 (Avril 2012) . - pp. 5230-5239
Mots-clés : Bacteria Pseudomonadales Pseudomonadaceae Pseudomonas Résumé : Green synthesis of protein stabilized silver nanoparticles (AgNPs) using the supernatant of a marine isolate, Pseudomonas fluorescens PMMD3 (P.fluorescens), and its biomedical applications and biocompatibility when coated on polycaprolactam is reported here. The AgNPs are spherical and are 1-10 nm in size. AgNP-coated polycaprolactam showed 89.7% and 92.4% reduction in colony forming units (CFUs), when compared to bare polymer, against S.aureus and E.coli, respectively. In the biofilm on AgNP composite, when compared to the bare polymer, there were carbohydrate reductions by factors of 3.5 and 6.0 in S.aureus and E.coli biofilm, respectively, and protein reductions by factors of 6.5 and 3.0 in S.aureus and E.coli biofilm, respectively. Reduction in the adhesion of S.aureus, C.albicans, A.niger, and F.proliferatum were observed using scanning electron miaoscopy (SEM) and fluorescence microscopy. The C.albicans biofilm is 15 and 6 μm thick on polycaprolactam and AgNP composite, respectively. We observed 84% and 80% proliferation of 3T3-L1 adipocyte cells and 85% and 97% of L929 fibroblast on the AgNP composite and bare polymer, indicating that this new material is suitable for biomaterial applications. ISSN : 0888-5885 En ligne : http://cat.inist.fr/?aModele=afficheN&cpsidt=25783432 Exemplaires
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Titre : Interfacial properties of LiTFSI and LiPF6 - based electrolytes in binary and ternary mixtures of alkylcarbonates on graphite electrodes and celgard separator Type de document : texte imprimé Auteurs : Mouad Dahbi, Auteur ; David Violleau, Auteur ; Fouad Ghamouss, Auteur Année de publication : 2012 Article en page(s) : pp. 5240–5245 Note générale : Industrial chemistry Langues : Anglais (eng) Mots-clés : Adsorption Electrolytes Résumé : For a better understanding of the adsorption behavior of alkylcarbonate-based electrolytes on graphite electrodes and Celgard separator for Li-ion batteries applications, the interface parameters are determined by contact angle and surface tension measurements. The correlation between these parameters and chemical compositions made of alkyl carbonate with a varying nature of lithium salts (LiPF6 and LiTFSI) and volume fractions of binary and ternary mixtures containing propylene carbonate (PC), ethylene carbonate (EC), and dimethyl carbonate (DMC) is investigated. From the obtained contact angle and surface tension (γL) values for each liquid, the dispersive and polar components of the surface tension (γLd and γLp) of the electrolyte and interfacial free energy between the solid and liquid (γSL) were then calculated using the Young’s equation. The variation of contact angle (θ) and the surface tension, as well as the work of adhesion (WA) of binary PC/DMC mixtures on PP, PE, and PET model surfaces were also measured and commented as function of volume fraction of PC in DMC. Finally, the Zisman’s critical surface tension (γC) for studied surfaces was then obtained showing positives slopes of cos θ versus γL. This behavior is explained by a relative higher adsorption of alkylcarbonates to the hydrogenated supports or graphite. These results are decisive to understand the performance of electrolyte/electrode material/separator interfaces in lithium-ion battery devices. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie203066x
in Industrial & engineering chemistry research > Vol. 51 N° 14 (Avril 2012) . - pp. 5240–5245[article] Interfacial properties of LiTFSI and LiPF6 - based electrolytes in binary and ternary mixtures of alkylcarbonates on graphite electrodes and celgard separator [texte imprimé] / Mouad Dahbi, Auteur ; David Violleau, Auteur ; Fouad Ghamouss, Auteur . - 2012 . - pp. 5240–5245.
Industrial chemistry
Langues : Anglais (eng)
in Industrial & engineering chemistry research > Vol. 51 N° 14 (Avril 2012) . - pp. 5240–5245
Mots-clés : Adsorption Electrolytes Résumé : For a better understanding of the adsorption behavior of alkylcarbonate-based electrolytes on graphite electrodes and Celgard separator for Li-ion batteries applications, the interface parameters are determined by contact angle and surface tension measurements. The correlation between these parameters and chemical compositions made of alkyl carbonate with a varying nature of lithium salts (LiPF6 and LiTFSI) and volume fractions of binary and ternary mixtures containing propylene carbonate (PC), ethylene carbonate (EC), and dimethyl carbonate (DMC) is investigated. From the obtained contact angle and surface tension (γL) values for each liquid, the dispersive and polar components of the surface tension (γLd and γLp) of the electrolyte and interfacial free energy between the solid and liquid (γSL) were then calculated using the Young’s equation. The variation of contact angle (θ) and the surface tension, as well as the work of adhesion (WA) of binary PC/DMC mixtures on PP, PE, and PET model surfaces were also measured and commented as function of volume fraction of PC in DMC. Finally, the Zisman’s critical surface tension (γC) for studied surfaces was then obtained showing positives slopes of cos θ versus γL. This behavior is explained by a relative higher adsorption of alkylcarbonates to the hydrogenated supports or graphite. These results are decisive to understand the performance of electrolyte/electrode material/separator interfaces in lithium-ion battery devices. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie203066x Exemplaires
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Titre : Cyclic Voltammetric Synthesis of poly (N - methyl pyrrole) on copper and effects of polymerization parameters on corrosion performance Type de document : texte imprimé Auteurs : Berrin Duran, Auteur ; Gozen Bereket, Auteur Année de publication : 2012 Article en page(s) : pp. 5246-5255 Note générale : Industrial chemistry Langues : Anglais (eng) Mots-clés : Corrosion Polymerization Résumé : In the present work, we report the cyclic voltammetric synthesis of poly(N-methyl pyrrole) films onto copper surface from aqueous solutions of N-methyl pyrrole and oxalic acid. The effects of electropolymerization parameters (applied potential, scan rate, and cycle number) on the protective properties of poly(N-methyl pyrrole) films have been systematically investigated, and it was shown that protection efficiency strongly depends on the electrodeposition parameters. Nanoscale coatings electrodeposited at optimum electrochemical conditions were characterized by cyclic voltammetry, ex-situ attenuated total reflectance-Fourier transform infrared spectroscopy (ATR-FTIR) and scanning electron microscopy (SEM) studies. The performance of poly(N-methyl pyrrole) as protective coating against corrosion of copper in 0.1 M H2SO4 solution was assessed by electrochemical impedance spectroscopy (EIS) and anodic polarization techniques. Corrosion test results demonstrated that the poly(N-methyl pyrrole) coating has ability to protect the copper in acid rain corrosive media during 12 days and the protective behavior of the polymer film results from self-healing effect of the coating against the attack of the corrosive environment. ISSN : 0888-5885 En ligne : http://cat.inist.fr/?aModele=afficheN&cpsidt=25783434
in Industrial & engineering chemistry research > Vol. 51 N° 14 (Avril 2012) . - pp. 5246-5255[article] Cyclic Voltammetric Synthesis of poly (N - methyl pyrrole) on copper and effects of polymerization parameters on corrosion performance [texte imprimé] / Berrin Duran, Auteur ; Gozen Bereket, Auteur . - 2012 . - pp. 5246-5255.
Industrial chemistry
Langues : Anglais (eng)
in Industrial & engineering chemistry research > Vol. 51 N° 14 (Avril 2012) . - pp. 5246-5255
Mots-clés : Corrosion Polymerization Résumé : In the present work, we report the cyclic voltammetric synthesis of poly(N-methyl pyrrole) films onto copper surface from aqueous solutions of N-methyl pyrrole and oxalic acid. The effects of electropolymerization parameters (applied potential, scan rate, and cycle number) on the protective properties of poly(N-methyl pyrrole) films have been systematically investigated, and it was shown that protection efficiency strongly depends on the electrodeposition parameters. Nanoscale coatings electrodeposited at optimum electrochemical conditions were characterized by cyclic voltammetry, ex-situ attenuated total reflectance-Fourier transform infrared spectroscopy (ATR-FTIR) and scanning electron microscopy (SEM) studies. The performance of poly(N-methyl pyrrole) as protective coating against corrosion of copper in 0.1 M H2SO4 solution was assessed by electrochemical impedance spectroscopy (EIS) and anodic polarization techniques. Corrosion test results demonstrated that the poly(N-methyl pyrrole) coating has ability to protect the copper in acid rain corrosive media during 12 days and the protective behavior of the polymer film results from self-healing effect of the coating against the attack of the corrosive environment. ISSN : 0888-5885 En ligne : http://cat.inist.fr/?aModele=afficheN&cpsidt=25783434 Exemplaires
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Titre : Large - scale refinery crude oil scheduling by integrating graph representation and genetic algorithm Type de document : texte imprimé Auteurs : Manojkumar Ramteke, Auteur ; Rajagopalan Srinivasan, Auteur Année de publication : 2012 Article en page(s) : pp. 5256-5272 Note générale : Industrial chemistry Langues : Anglais (eng) Mots-clés : Genetic algorithm Scheduling Crude oil Refinery Résumé : Scheduling is widely studied in process systems engineering and is typically solved using mathematical programming. Although popular for many other optimization problems, evolutionary algorithms have not found wide applicability in such combinatorial optimization problems with large numbers of variables and constraints. Here we demonstrate that scheduling problems that involve a process network of units and streams have a graph structure which can be exploited to offer a sparse problem representation that enables efficient stochastic optimization. In the proposed structure adapted genetic algorithm, SAGA, only the subgraph of the process network that is active in any period is explicitly represented in the chromosome. This leads to a significant reduction in the representation, but additionally, most constraints can be enforced without the need for a penalty function. The resulting benefits in terms of improved search quality and computational performance are established by studying 24 different crude oil operations scheduling problems from the literature. ISSN : 0888-5885 En ligne : http://cat.inist.fr/?aModele=afficheN&cpsidt=25783435
in Industrial & engineering chemistry research > Vol. 51 N° 14 (Avril 2012) . - pp. 5256-5272[article] Large - scale refinery crude oil scheduling by integrating graph representation and genetic algorithm [texte imprimé] / Manojkumar Ramteke, Auteur ; Rajagopalan Srinivasan, Auteur . - 2012 . - pp. 5256-5272.
Industrial chemistry
Langues : Anglais (eng)
in Industrial & engineering chemistry research > Vol. 51 N° 14 (Avril 2012) . - pp. 5256-5272
Mots-clés : Genetic algorithm Scheduling Crude oil Refinery Résumé : Scheduling is widely studied in process systems engineering and is typically solved using mathematical programming. Although popular for many other optimization problems, evolutionary algorithms have not found wide applicability in such combinatorial optimization problems with large numbers of variables and constraints. Here we demonstrate that scheduling problems that involve a process network of units and streams have a graph structure which can be exploited to offer a sparse problem representation that enables efficient stochastic optimization. In the proposed structure adapted genetic algorithm, SAGA, only the subgraph of the process network that is active in any period is explicitly represented in the chromosome. This leads to a significant reduction in the representation, but additionally, most constraints can be enforced without the need for a penalty function. The resulting benefits in terms of improved search quality and computational performance are established by studying 24 different crude oil operations scheduling problems from the literature. ISSN : 0888-5885 En ligne : http://cat.inist.fr/?aModele=afficheN&cpsidt=25783435 Exemplaires
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Titre : Process for CO2 capture from high - pressure and moderate - temperature gas streams Type de document : texte imprimé Auteurs : James C. Fisher, Auteur ; Ranjani V. Siriwardane, Auteur ; Robert W. Stevens, Auteur Année de publication : 2012 Article en page(s) : pp. 5273-5281 Note générale : Industrial chemistry Langues : Anglais (eng) Mots-clés : Carbon dioxide Résumé : A novel CO2 capture process was developed using a Mg(OH)2-based sorbent suitable for warm gas CO2 removal from high-pressure coal gasification gas streams. The purpose of this study is to perform a preliminary energy study and develop a method to implement this sorbent in a power plant. The proposed CO2 removal process involves sorption of CO2 at 200―300 °C and regeneration at 385 °C. The operational temperature is ideal for CO2 capture downstream to the water―gas shift reactor in an integrated gasification combined cycle (IGCC) power plant but is applicable to other warm gas cleanup processes as well. This technology offers the ability to fully utilize the potential efficiency increases associated with warm gas clean up. Additionally, the sorbent is able to operate in the presence of steam, which distinguishes it from other technologies that require an energy-intensive drying step prior to CO2 separation. Regeneration is carried out at 280 psi and 400 °C, resulting in a high-pressure CO2 product stream, which significantly reduces the auxiliary load normally associated with CO2 compression for sequestration. The chemistry of the sorption process also reduces the amount of steam traditionally required for the water-gas shift reactor by 50%, increasing the overall efficiency of the plant. The incorporation of the sorbent and the described methods resulted in an overall IGCC power plant efficiency greater than that of the competing Selexol technology. ISSN : 0888-5885 En ligne : http://cat.inist.fr/?aModele=afficheN&cpsidt=25783436
in Industrial & engineering chemistry research > Vol. 51 N° 14 (Avril 2012) . - pp. 5273-5281[article] Process for CO2 capture from high - pressure and moderate - temperature gas streams [texte imprimé] / James C. Fisher, Auteur ; Ranjani V. Siriwardane, Auteur ; Robert W. Stevens, Auteur . - 2012 . - pp. 5273-5281.
Industrial chemistry
Langues : Anglais (eng)
in Industrial & engineering chemistry research > Vol. 51 N° 14 (Avril 2012) . - pp. 5273-5281
Mots-clés : Carbon dioxide Résumé : A novel CO2 capture process was developed using a Mg(OH)2-based sorbent suitable for warm gas CO2 removal from high-pressure coal gasification gas streams. The purpose of this study is to perform a preliminary energy study and develop a method to implement this sorbent in a power plant. The proposed CO2 removal process involves sorption of CO2 at 200―300 °C and regeneration at 385 °C. The operational temperature is ideal for CO2 capture downstream to the water―gas shift reactor in an integrated gasification combined cycle (IGCC) power plant but is applicable to other warm gas cleanup processes as well. This technology offers the ability to fully utilize the potential efficiency increases associated with warm gas clean up. Additionally, the sorbent is able to operate in the presence of steam, which distinguishes it from other technologies that require an energy-intensive drying step prior to CO2 separation. Regeneration is carried out at 280 psi and 400 °C, resulting in a high-pressure CO2 product stream, which significantly reduces the auxiliary load normally associated with CO2 compression for sequestration. The chemistry of the sorption process also reduces the amount of steam traditionally required for the water-gas shift reactor by 50%, increasing the overall efficiency of the plant. The incorporation of the sorbent and the described methods resulted in an overall IGCC power plant efficiency greater than that of the competing Selexol technology. ISSN : 0888-5885 En ligne : http://cat.inist.fr/?aModele=afficheN&cpsidt=25783436 Exemplaires
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Titre : Identifying key life cycle assessment metrics in the multiobjective design of bioethanol supply chains using a rigorous mixed - integer linear programming approach Type de document : texte imprimé Auteurs : A. Kostin, Auteur ; Gonzalo Guillen-Gosalbez, Auteur ; F. D. Mele, Auteur Année de publication : 2012 Article en page(s) : pp. 5282-5291 Note générale : Industrial chemistry Langues : Anglais (eng) Mots-clés : Mathematical programming Mixed integer Linear Design Life cycle (environment) Résumé : The design of more sustainable bioethanol supply chains (SCs) has recently emerged as an active area of research Most of the approaches presented so far have somehow a limited scope, as they focus on minimizing the emitted greenhouse gases as unique criterion, neglecting the damage caused in other impact categories. In this work, we address the multiobjective design of bioethanol SCs considering several life cycle assessment impacts. To overcome the numerical difficulties of dealing with several objective functions, we investigate the application of a rigorous mixed-integer linear programming-based dimensionality reduction method that minimizes the error of omitting objectives. The usefulness of this approach is tested through its application to the design of a bioethanol/sugar SC in Argentina, in which five environmental objectives are simultaneously optimized along with the net present value. The proposed method makes it possible to reduce the number of environmental indicators, thereby facilitating the calculation and analysis of the Pareto solutions. ISSN : 0888-5885 En ligne : http://cat.inist.fr/?aModele=afficheN&cpsidt=25783437
in Industrial & engineering chemistry research > Vol. 51 N° 14 (Avril 2012) . - pp. 5282-5291[article] Identifying key life cycle assessment metrics in the multiobjective design of bioethanol supply chains using a rigorous mixed - integer linear programming approach [texte imprimé] / A. Kostin, Auteur ; Gonzalo Guillen-Gosalbez, Auteur ; F. D. Mele, Auteur . - 2012 . - pp. 5282-5291.
Industrial chemistry
Langues : Anglais (eng)
in Industrial & engineering chemistry research > Vol. 51 N° 14 (Avril 2012) . - pp. 5282-5291
Mots-clés : Mathematical programming Mixed integer Linear Design Life cycle (environment) Résumé : The design of more sustainable bioethanol supply chains (SCs) has recently emerged as an active area of research Most of the approaches presented so far have somehow a limited scope, as they focus on minimizing the emitted greenhouse gases as unique criterion, neglecting the damage caused in other impact categories. In this work, we address the multiobjective design of bioethanol SCs considering several life cycle assessment impacts. To overcome the numerical difficulties of dealing with several objective functions, we investigate the application of a rigorous mixed-integer linear programming-based dimensionality reduction method that minimizes the error of omitting objectives. The usefulness of this approach is tested through its application to the design of a bioethanol/sugar SC in Argentina, in which five environmental objectives are simultaneously optimized along with the net present value. The proposed method makes it possible to reduce the number of environmental indicators, thereby facilitating the calculation and analysis of the Pareto solutions. ISSN : 0888-5885 En ligne : http://cat.inist.fr/?aModele=afficheN&cpsidt=25783437 Exemplaires
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Titre : Hg removal characteristics of noncarbon sorbents in a fixed - bed reactor Type de document : texte imprimé Auteurs : Liang Zhang, Auteur ; Yuqun Zhuo, Auteur ; Wen Du, Auteur Année de publication : 2012 Article en page(s) : pp. 5292-5298 Note générale : Chimie industrielle Langues : Anglais (eng) Mots-clés : Fixed bed reactor Résumé : This research targeted the development of a low-cost, high-effidenry sorbent for mercury capture in flue gas. Six non-carbon-based carriers and various impregnating substances including Nal, CuCl2, CuBr, and FeCl3 were investigated in this study. The performances of the prepared sorbents were tested in a bench-scale fixed-bed reactor at 140 °C in N2 atmosphere. Some sorbents demonstrated the mercury capture capabilities similar to that of a commercial active carbon sorbent (Norit Darco LH). ISSN : 0888-5885 En ligne : http://cat.inist.fr/?aModele=afficheN&cpsidt=25783438
in Industrial & engineering chemistry research > Vol. 51 N° 14 (Avril 2012) . - pp. 5292-5298[article] Hg removal characteristics of noncarbon sorbents in a fixed - bed reactor [texte imprimé] / Liang Zhang, Auteur ; Yuqun Zhuo, Auteur ; Wen Du, Auteur . - 2012 . - pp. 5292-5298.
Chimie industrielle
Langues : Anglais (eng)
in Industrial & engineering chemistry research > Vol. 51 N° 14 (Avril 2012) . - pp. 5292-5298
Mots-clés : Fixed bed reactor Résumé : This research targeted the development of a low-cost, high-effidenry sorbent for mercury capture in flue gas. Six non-carbon-based carriers and various impregnating substances including Nal, CuCl2, CuBr, and FeCl3 were investigated in this study. The performances of the prepared sorbents were tested in a bench-scale fixed-bed reactor at 140 °C in N2 atmosphere. Some sorbents demonstrated the mercury capture capabilities similar to that of a commercial active carbon sorbent (Norit Darco LH). ISSN : 0888-5885 En ligne : http://cat.inist.fr/?aModele=afficheN&cpsidt=25783438 Exemplaires
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Titre : Role of hydrogen bonds in ionic - liquid - mediated extraction of natural bioactive homologues Type de document : texte imprimé Auteurs : Kun Dong, Auteur ; Yifeng Cao, Auteur ; Qiwei Yang, Auteur Année de publication : 2012 Article en page(s) : pp. 5299–5308 Note générale : Industrial chemistry Langues : Anglais (eng) Mots-clés : Hydrogen Ionic liquid Résumé : The technologies of ionic-liquid-mediated extraction have shown the good prospects for replacing traditional methods for separating natural bioactive homologues. However, so far, the roles and interactions of the anions and cations in the extraction process are not clear, which seriously hinders the further exploration of this new extraction technology. In this work, we report a detailed computational study, combined with experiment, on the interactions and hydrogen bonds between 1-butyl-3-methylimidazlium hexafluorophosphate ([Bmim][PF6]) ionic liquid (IL) and natural bioactive homologues, namely, three soybean isoflavone aglycones as model compounds. The distribution coefficients, D, of the three aglycones were experimentally determined in the [Bmim][PF6]–water biphasic system, and the order was found to be genistein (182.6) > daidzein (51.4) > glycitein (41.9). In DFT calculations, the lowest-energy complexes were obtained, and it was found that H-bonds are explicit intermolecular interactions in these complexes and that the IL can recognize these similar homologues by forming different H-bonds with the phenolic hydroxyls of aglycones. Furthermore, we found that the anions play a more important role in recognition than the cations. Subsequently, results of molecular dynamics (MD) simulations exhibited a good match with the structures of the isolated complexes calculated by DFT and also discovered that H-bonds were the main interactions between the anions and the phenolic hydroxyls in the first solvation shell. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie203044m
in Industrial & engineering chemistry research > Vol. 51 N° 14 (Avril 2012) . - pp. 5299–5308[article] Role of hydrogen bonds in ionic - liquid - mediated extraction of natural bioactive homologues [texte imprimé] / Kun Dong, Auteur ; Yifeng Cao, Auteur ; Qiwei Yang, Auteur . - 2012 . - pp. 5299–5308.
Industrial chemistry
Langues : Anglais (eng)
in Industrial & engineering chemistry research > Vol. 51 N° 14 (Avril 2012) . - pp. 5299–5308
Mots-clés : Hydrogen Ionic liquid Résumé : The technologies of ionic-liquid-mediated extraction have shown the good prospects for replacing traditional methods for separating natural bioactive homologues. However, so far, the roles and interactions of the anions and cations in the extraction process are not clear, which seriously hinders the further exploration of this new extraction technology. In this work, we report a detailed computational study, combined with experiment, on the interactions and hydrogen bonds between 1-butyl-3-methylimidazlium hexafluorophosphate ([Bmim][PF6]) ionic liquid (IL) and natural bioactive homologues, namely, three soybean isoflavone aglycones as model compounds. The distribution coefficients, D, of the three aglycones were experimentally determined in the [Bmim][PF6]–water biphasic system, and the order was found to be genistein (182.6) > daidzein (51.4) > glycitein (41.9). In DFT calculations, the lowest-energy complexes were obtained, and it was found that H-bonds are explicit intermolecular interactions in these complexes and that the IL can recognize these similar homologues by forming different H-bonds with the phenolic hydroxyls of aglycones. Furthermore, we found that the anions play a more important role in recognition than the cations. Subsequently, results of molecular dynamics (MD) simulations exhibited a good match with the structures of the isolated complexes calculated by DFT and also discovered that H-bonds were the main interactions between the anions and the phenolic hydroxyls in the first solvation shell. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie203044m Exemplaires
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Titre : Experimental studies and rate - based process simulations of CO2 absorption with aqueous ammonia solutions Type de document : texte imprimé Auteurs : Zhenqi Niu, Auteur ; Yincheng Guo, Auteur ; Qing Zeng, Auteur Année de publication : 2012 Article en page(s) : pp. 5309-5319 Note générale : Industrial chemistry Langues : Anglais (eng) Mots-clés : Gas absorption Carbon dioxide Résumé : A pilot plant at laboratory scale for absorption of CO2 has been constructed and operated to test the CO2 removal by aqueous ammonia solutions. The design of the pilot plant is based on a standard absorption and desorption flow sheet and partial or complete separation of gas mixtures. Pilot plant data for CO2 removal efficiencies, effects of CO2 loading, and temperature profiles are obtained. A rate-based model, RateFrac in Aspen Plus simulator, is used to simulate the CO2 absorption of the pilot plant. The simulation results of the CO2 capture predicted by the rate-based model are in good agreement with the experimental data of the pilot plant. Further, the optimization covering operational parameters is carried out using the rate-based model. ISSN : 0888-5885 En ligne : http://cat.inist.fr/?aModele=afficheN&cpsidt=25783440
in Industrial & engineering chemistry research > Vol. 51 N° 14 (Avril 2012) . - pp. 5309-5319[article] Experimental studies and rate - based process simulations of CO2 absorption with aqueous ammonia solutions [texte imprimé] / Zhenqi Niu, Auteur ; Yincheng Guo, Auteur ; Qing Zeng, Auteur . - 2012 . - pp. 5309-5319.
Industrial chemistry
Langues : Anglais (eng)
in Industrial & engineering chemistry research > Vol. 51 N° 14 (Avril 2012) . - pp. 5309-5319
Mots-clés : Gas absorption Carbon dioxide Résumé : A pilot plant at laboratory scale for absorption of CO2 has been constructed and operated to test the CO2 removal by aqueous ammonia solutions. The design of the pilot plant is based on a standard absorption and desorption flow sheet and partial or complete separation of gas mixtures. Pilot plant data for CO2 removal efficiencies, effects of CO2 loading, and temperature profiles are obtained. A rate-based model, RateFrac in Aspen Plus simulator, is used to simulate the CO2 absorption of the pilot plant. The simulation results of the CO2 capture predicted by the rate-based model are in good agreement with the experimental data of the pilot plant. Further, the optimization covering operational parameters is carried out using the rate-based model. ISSN : 0888-5885 En ligne : http://cat.inist.fr/?aModele=afficheN&cpsidt=25783440 Exemplaires
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Titre : Affinity and packing of benzene, toluene, and p - xylene adsorption on a graphitic surface and in pores Type de document : texte imprimé Auteurs : Nikom Klomkliang, Auteur ; D. D. Do, Auteur ; D. Nicholson, Auteur Année de publication : 2012 Article en page(s) : pp. 5320–5329 Note générale : Industrial chemistry Langues : Anglais (eng) Mots-clés : Adsorption benzene Toluene Résumé : A grand canonical Monte Carlo simulation has been carried out at ambient temperature to investigate the adsorption of benzene, toluene, and p-xylene (BTX) on a graphite surface and in a graphitic slit and cylindrical pores. Particular emphasis has been paid to the effects of the confined space on the affinity and packing density. Simulation results for adsorption on a graphite surface were tested against the experimental data to validate the potential models used in the description of adsorption. Our extensive simulation has shown that on an open graphite surface, where there is no restriction in the packing, p-xylene has the highest affinity and adsorbed amount at a given reduced pressure and benzene has the lowest values, due to the additional interaction of the methyl groups with the surface. In a confined space, the order of the affinity remains the same, but the packing (hence the amount adsorbed per unit physical pore volume) is affected by the geometry of the space. It was found that benzene has the highest packing density, whether it is expressed in terms of moles or mass. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie300121p
in Industrial & engineering chemistry research > Vol. 51 N° 14 (Avril 2012) . - pp. 5320–5329[article] Affinity and packing of benzene, toluene, and p - xylene adsorption on a graphitic surface and in pores [texte imprimé] / Nikom Klomkliang, Auteur ; D. D. Do, Auteur ; D. Nicholson, Auteur . - 2012 . - pp. 5320–5329.
Industrial chemistry
Langues : Anglais (eng)
in Industrial & engineering chemistry research > Vol. 51 N° 14 (Avril 2012) . - pp. 5320–5329
Mots-clés : Adsorption benzene Toluene Résumé : A grand canonical Monte Carlo simulation has been carried out at ambient temperature to investigate the adsorption of benzene, toluene, and p-xylene (BTX) on a graphite surface and in a graphitic slit and cylindrical pores. Particular emphasis has been paid to the effects of the confined space on the affinity and packing density. Simulation results for adsorption on a graphite surface were tested against the experimental data to validate the potential models used in the description of adsorption. Our extensive simulation has shown that on an open graphite surface, where there is no restriction in the packing, p-xylene has the highest affinity and adsorbed amount at a given reduced pressure and benzene has the lowest values, due to the additional interaction of the methyl groups with the surface. In a confined space, the order of the affinity remains the same, but the packing (hence the amount adsorbed per unit physical pore volume) is affected by the geometry of the space. It was found that benzene has the highest packing density, whether it is expressed in terms of moles or mass. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie300121p Exemplaires
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Titre : Optimizing the poly ethylene oxide flocculation process for isolating lignin of prehydrolysis liquor of a kraft - based dissolving pulp production process Type de document : texte imprimé Auteurs : Haiqiang Shi, Auteur ; Pedram Fatehi, Auteur ; Huining Xiao, Auteur Année de publication : 2012 Article en page(s) : pp. 5330-5335 Note générale : Industrial chemistry Langues : Anglais (eng) Mots-clés : Manufacturing process Flocculation Optimization Résumé : In this work, poly ethylene oxide (PEO) with various molecular weights (MW)s was employed to separate the lignin ot prehydrolysis liquor (PHL) ot a kraft-based dissolving pulp process. The results revealed that, the higher the MW and concentration of PEO in the PHL at pH 2, the higher are the removals of lignin and chemical oxygen demand (COD) but with a marginal removal of sugars. Alternatively, poly aluminum chloride (PAC) (200 mg/L) and PEO (8 MDa MW) (200 mg/L) were employed in a dual polymer system to extract the lignin, and the PAC/PEO system (MWs of 2 kDa/8 MDa) was more effective than the PEO/PEO system (MWs of 0.1 MDa/8 MDa) in removing lignin and COD of PHL. The maximum lignin, sugar, and COD removals were 46%, 18.8%, and 32%, respectively, under the conditions of 400 mg/g PEO (with a MW of 8 MDa) at pH 2 and room temperature in a singular PEO system. ISSN : 0888-5885 En ligne : http://cat.inist.fr/?aModele=afficheN&cpsidt=25783442
in Industrial & engineering chemistry research > Vol. 51 N° 14 (Avril 2012) . - pp. 5330-5335[article] Optimizing the poly ethylene oxide flocculation process for isolating lignin of prehydrolysis liquor of a kraft - based dissolving pulp production process [texte imprimé] / Haiqiang Shi, Auteur ; Pedram Fatehi, Auteur ; Huining Xiao, Auteur . - 2012 . - pp. 5330-5335.
Industrial chemistry
Langues : Anglais (eng)
in Industrial & engineering chemistry research > Vol. 51 N° 14 (Avril 2012) . - pp. 5330-5335
Mots-clés : Manufacturing process Flocculation Optimization Résumé : In this work, poly ethylene oxide (PEO) with various molecular weights (MW)s was employed to separate the lignin ot prehydrolysis liquor (PHL) ot a kraft-based dissolving pulp process. The results revealed that, the higher the MW and concentration of PEO in the PHL at pH 2, the higher are the removals of lignin and chemical oxygen demand (COD) but with a marginal removal of sugars. Alternatively, poly aluminum chloride (PAC) (200 mg/L) and PEO (8 MDa MW) (200 mg/L) were employed in a dual polymer system to extract the lignin, and the PAC/PEO system (MWs of 2 kDa/8 MDa) was more effective than the PEO/PEO system (MWs of 0.1 MDa/8 MDa) in removing lignin and COD of PHL. The maximum lignin, sugar, and COD removals were 46%, 18.8%, and 32%, respectively, under the conditions of 400 mg/g PEO (with a MW of 8 MDa) at pH 2 and room temperature in a singular PEO system. ISSN : 0888-5885 En ligne : http://cat.inist.fr/?aModele=afficheN&cpsidt=25783442 Exemplaires
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Titre : Effects of electric field on multineedle electrospinning : Experiment and simulation study Type de document : texte imprimé Auteurs : Sheng Xie, Auteur ; Yongchun Zeng, Auteur Année de publication : 2012 Article en page(s) : pp. 5336–5345 Note générale : Industrial chemistry Langues : Anglais (eng) Mots-clés : Electric field Electrospinning Résumé : Electrospinning and melt blowing are the most commonly used processes for producing microfibrous nonwovens. In this paper, we study mass production of electrospinning with a multineedle system. To achieve uniform fibers at a high production rate, an auxiliary plate electrode has been used to be connected to a three-needle system to obtain a more uniform electric field. The spinnerets with two kinds of needle array, linear three-needle and triangular three-needle, are studied. The results of electrospinning experiments and electric field simulation demonstrate that the multineedle spinneret with an auxiliary plate can produce finer and more uniform nanofibers. And the fibers can be collected in a more concentrated area with the auxiliary plate. We also focus on the effect of the needle length protruded outside the plate. This study shows a possibility that by designing the electric field distribution, we can produce thinner fibers and more concentrated collection mats at a high production rate. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie2020763
in Industrial & engineering chemistry research > Vol. 51 N° 14 (Avril 2012) . - pp. 5336–5345[article] Effects of electric field on multineedle electrospinning : Experiment and simulation study [texte imprimé] / Sheng Xie, Auteur ; Yongchun Zeng, Auteur . - 2012 . - pp. 5336–5345.
Industrial chemistry
Langues : Anglais (eng)
in Industrial & engineering chemistry research > Vol. 51 N° 14 (Avril 2012) . - pp. 5336–5345
Mots-clés : Electric field Electrospinning Résumé : Electrospinning and melt blowing are the most commonly used processes for producing microfibrous nonwovens. In this paper, we study mass production of electrospinning with a multineedle system. To achieve uniform fibers at a high production rate, an auxiliary plate electrode has been used to be connected to a three-needle system to obtain a more uniform electric field. The spinnerets with two kinds of needle array, linear three-needle and triangular three-needle, are studied. The results of electrospinning experiments and electric field simulation demonstrate that the multineedle spinneret with an auxiliary plate can produce finer and more uniform nanofibers. And the fibers can be collected in a more concentrated area with the auxiliary plate. We also focus on the effect of the needle length protruded outside the plate. This study shows a possibility that by designing the electric field distribution, we can produce thinner fibers and more concentrated collection mats at a high production rate. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie2020763 Exemplaires
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Titre : Turbulent air flow field and fiber whipping motion in the melt blowing process : Experimental study Type de document : texte imprimé Auteurs : Sheng Xie, Auteur ; Yongchun Zeng, Auteur Année de publication : 2012 Article en page(s) : pp. 5346-5352 Note générale : Industrial chemistry Langues : Anglais (eng) Mots-clés : Flow field Air flow Résumé : Electrospinning and melt blowing are the most commonly used processes for producing microfibrous nonwoven materials. A whipping motion during electrospinning has been observed by several researchers. However, much less work has been done on the fiber whipping dynamics in the melt blowing process. In this study, a hot-wire anemometer was used to measure the turbulent air flow field below a single-orifice melt-blowing slot die. The characteristics of the mean velocity, mean temperature, and fluctuating velocity were obtained. Then, a high-speed camera was used to record the motion of a fiber below the die. The fiber whipping path was observed, and the amplitude and frequency of the whipping were obtained. It was found that the turbulent fluctuations are related to the fiber motion in the melt-blowing process. This work examines the physics of turbulent melt-blowing jets and the fiber whipping occurring during melt blowing using an experimental approach. ISSN : 0888-5885 En ligne : http://cat.inist.fr/?aModele=afficheN&cpsidt=25783444
in Industrial & engineering chemistry research > Vol. 51 N° 14 (Avril 2012) . - pp. 5346-5352[article] Turbulent air flow field and fiber whipping motion in the melt blowing process : Experimental study [texte imprimé] / Sheng Xie, Auteur ; Yongchun Zeng, Auteur . - 2012 . - pp. 5346-5352.
Industrial chemistry
Langues : Anglais (eng)
in Industrial & engineering chemistry research > Vol. 51 N° 14 (Avril 2012) . - pp. 5346-5352
Mots-clés : Flow field Air flow Résumé : Electrospinning and melt blowing are the most commonly used processes for producing microfibrous nonwoven materials. A whipping motion during electrospinning has been observed by several researchers. However, much less work has been done on the fiber whipping dynamics in the melt blowing process. In this study, a hot-wire anemometer was used to measure the turbulent air flow field below a single-orifice melt-blowing slot die. The characteristics of the mean velocity, mean temperature, and fluctuating velocity were obtained. Then, a high-speed camera was used to record the motion of a fiber below the die. The fiber whipping path was observed, and the amplitude and frequency of the whipping were obtained. It was found that the turbulent fluctuations are related to the fiber motion in the melt-blowing process. This work examines the physics of turbulent melt-blowing jets and the fiber whipping occurring during melt blowing using an experimental approach. ISSN : 0888-5885 En ligne : http://cat.inist.fr/?aModele=afficheN&cpsidt=25783444 Exemplaires
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Titre : Comparison of the debye – hückel and the mean spherical approximation theories for electrolyte solutions Type de document : texte imprimé Auteurs : Bjorn Maribo-Mogensen, Auteur ; Georgios M. Kontogeorgis, Auteur ; Kaj Thomsen, Auteur Année de publication : 2012 Article en page(s) : pp. 5353-5363 Note générale : Industrial chemistry Langues : Anglais (eng) Mots-clés : Electrolyte solution Approximation Résumé : The thermodynamics of electrolyte solutions has been investigated by many scientists throughout the last century. While several theories have been presented, the most popular models for the electrostatic interactions are based on the Debye-Hückel and mean spherical approximation (MSA) theories. In this paper we investigate the differences between the Debye-Hückel and the MSA theories, and comparisons of the numerical results for the Helmholtz energy and its derivatives with respect to temperature, volume and composition are presented. The investigation shows that the nonrestricted primitive MSA theory performs similarly to Debye―Hückel, despite the differences in the derivation. We furthermore show that the static permittivity is a key parameter for both models and that in many cases it completely dominates the results obtained from the two models. Consequently, we conclude that the simpler Debye―Hückel theory may be used in connection with electrolyte equations of state without loss of accuracy. ISSN : 0888-5885 En ligne : http://cat.inist.fr/?aModele=afficheN&cpsidt=25783445
in Industrial & engineering chemistry research > Vol. 51 N° 14 (Avril 2012) . - pp. 5353-5363[article] Comparison of the debye – hückel and the mean spherical approximation theories for electrolyte solutions [texte imprimé] / Bjorn Maribo-Mogensen, Auteur ; Georgios M. Kontogeorgis, Auteur ; Kaj Thomsen, Auteur . - 2012 . - pp. 5353-5363.
Industrial chemistry
Langues : Anglais (eng)
in Industrial & engineering chemistry research > Vol. 51 N° 14 (Avril 2012) . - pp. 5353-5363
Mots-clés : Electrolyte solution Approximation Résumé : The thermodynamics of electrolyte solutions has been investigated by many scientists throughout the last century. While several theories have been presented, the most popular models for the electrostatic interactions are based on the Debye-Hückel and mean spherical approximation (MSA) theories. In this paper we investigate the differences between the Debye-Hückel and the MSA theories, and comparisons of the numerical results for the Helmholtz energy and its derivatives with respect to temperature, volume and composition are presented. The investigation shows that the nonrestricted primitive MSA theory performs similarly to Debye―Hückel, despite the differences in the derivation. We furthermore show that the static permittivity is a key parameter for both models and that in many cases it completely dominates the results obtained from the two models. Consequently, we conclude that the simpler Debye―Hückel theory may be used in connection with electrolyte equations of state without loss of accuracy. ISSN : 0888-5885 En ligne : http://cat.inist.fr/?aModele=afficheN&cpsidt=25783445 Exemplaires
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Titre : One - pot synthesis of 5 - (Ethoxymethyl) furfural from glucose using Sn - BEA and amberlyst catalysts Type de document : texte imprimé Auteurs : Christopher M. Lew, Auteur ; Nafiseh Rajabbeigi, Auteur ; Michael Tsapatsis, Auteur Année de publication : 2012 Article en page(s) : pp. 5364–5366 Note générale : Industrial chemistry Langues : Anglais (eng) Mots-clés : Glucose Ethano Catalysts Résumé : 5-(Ethoxymethyl)furfural (EMF) was produced from glucose in ethanol in a single reactor at 90 °C. The reaction proceeds via the isomerization of glucose to fructose with zeolite Sn-Beta, a Lewis acid catalyst. Fructose is converted to 5-(hydroxymethyl)furfural, which is then etherified to EMF using a Brønsted acid catalyst, Amberlyst 131. An EMF yield of 31% was achieved. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie2025536
in Industrial & engineering chemistry research > Vol. 51 N° 14 (Avril 2012) . - pp. 5364–5366[article] One - pot synthesis of 5 - (Ethoxymethyl) furfural from glucose using Sn - BEA and amberlyst catalysts [texte imprimé] / Christopher M. Lew, Auteur ; Nafiseh Rajabbeigi, Auteur ; Michael Tsapatsis, Auteur . - 2012 . - pp. 5364–5366.
Industrial chemistry
Langues : Anglais (eng)
in Industrial & engineering chemistry research > Vol. 51 N° 14 (Avril 2012) . - pp. 5364–5366
Mots-clés : Glucose Ethano Catalysts Résumé : 5-(Ethoxymethyl)furfural (EMF) was produced from glucose in ethanol in a single reactor at 90 °C. The reaction proceeds via the isomerization of glucose to fructose with zeolite Sn-Beta, a Lewis acid catalyst. Fructose is converted to 5-(hydroxymethyl)furfural, which is then etherified to EMF using a Brønsted acid catalyst, Amberlyst 131. An EMF yield of 31% was achieved. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie2025536 Exemplaires
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Titre : Development and evaluation of a pseudoreference Pt / / Ag / AgCl electrode for electrochemical systems Type de document : texte imprimé Auteurs : André A. G. F. Beati, Auteur ; Rafael M. Reis, Auteur ; Robson S. Rocha, Auteur Année de publication : 2012 Article en page(s) : pp. 5367–5371 Note générale : Industrial chemistry Langues : Anglais (eng) Mots-clés : Electrochemical systems Résumé : The use of standard reference electrodes, such as Ag/AgCl or saturated calomel electrodes, in potentiometric and amperometric studies involving miniaturized electrochemical systems, or those operating under positive hydraulic pressure, is often impractical. Placement of the reference electrode in the direct vicinity of the working electrode is often prohibited by the dimensions or layout of the electrochemical cell, while the alternative strategy of locating the reference electrode in a separate compartment often leads to electrolyte leakage and contamination of the system. In the present study, we have investigated the functionality of a pseudoreference electrode comprising a platinum wire, one end of which was maintained in intimate contact with the internal solution of an Ag/AgCl reference electrode while the other was connected, via a BNC connector, to a platinum probe located within the electrochemical cell. Linear and cyclic voltammetric studies, involving both aqueous and nonaqueous electrolytes, were carried out using the pseudoreference electrode and an electrochemical cup-type cell with three electrodes or an electrochemical flow reactor. In all cases, the functionality of the Pt//Ag/AgCl system was similar to that of a conventional Ag/AgCl reference electrode. Variations in the electrolyte did not alter the potential or voltammetric profile recorded when using the pseudoreference system, although peak currents were generally improved and potential values shifted by approximately +350 mV in comparison with the Ag/AgCl electrode, therefore, the system pseudoreference can be applied in any electrochemical system due to the constant potential difference. It is concluded that the pseudoreference electrode can be used with advantage to obtain potentiometric and amperometric measurements in both simple and complex electrochemical systems. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie2026025
in Industrial & engineering chemistry research > Vol. 51 N° 14 (Avril 2012) . - pp. 5367–5371[article] Development and evaluation of a pseudoreference Pt / / Ag / AgCl electrode for electrochemical systems [texte imprimé] / André A. G. F. Beati, Auteur ; Rafael M. Reis, Auteur ; Robson S. Rocha, Auteur . - 2012 . - pp. 5367–5371.
Industrial chemistry
Langues : Anglais (eng)
in Industrial & engineering chemistry research > Vol. 51 N° 14 (Avril 2012) . - pp. 5367–5371
Mots-clés : Electrochemical systems Résumé : The use of standard reference electrodes, such as Ag/AgCl or saturated calomel electrodes, in potentiometric and amperometric studies involving miniaturized electrochemical systems, or those operating under positive hydraulic pressure, is often impractical. Placement of the reference electrode in the direct vicinity of the working electrode is often prohibited by the dimensions or layout of the electrochemical cell, while the alternative strategy of locating the reference electrode in a separate compartment often leads to electrolyte leakage and contamination of the system. In the present study, we have investigated the functionality of a pseudoreference electrode comprising a platinum wire, one end of which was maintained in intimate contact with the internal solution of an Ag/AgCl reference electrode while the other was connected, via a BNC connector, to a platinum probe located within the electrochemical cell. Linear and cyclic voltammetric studies, involving both aqueous and nonaqueous electrolytes, were carried out using the pseudoreference electrode and an electrochemical cup-type cell with three electrodes or an electrochemical flow reactor. In all cases, the functionality of the Pt//Ag/AgCl system was similar to that of a conventional Ag/AgCl reference electrode. Variations in the electrolyte did not alter the potential or voltammetric profile recorded when using the pseudoreference system, although peak currents were generally improved and potential values shifted by approximately +350 mV in comparison with the Ag/AgCl electrode, therefore, the system pseudoreference can be applied in any electrochemical system due to the constant potential difference. It is concluded that the pseudoreference electrode can be used with advantage to obtain potentiometric and amperometric measurements in both simple and complex electrochemical systems. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie2026025 Exemplaires
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Titre : Comments on “heat capacity, enthalpy of formation, and entropy of methyl carbamate” Type de document : texte imprimé Auteurs : Ilya I. Marochkin, Auteur ; Olga V. Dorofeeva, Auteur Année de publication : 2012 Article en page(s) : pp. 5372–5373 Note générale : Industrial chemistry Langues : Anglais (eng) Mots-clés : Heat capacity Enthalpy ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie3002793
in Industrial & engineering chemistry research > Vol. 51 N° 14 (Avril 2012) . - pp. 5372–5373[article] Comments on “heat capacity, enthalpy of formation, and entropy of methyl carbamate” [texte imprimé] / Ilya I. Marochkin, Auteur ; Olga V. Dorofeeva, Auteur . - 2012 . - pp. 5372–5373.
Industrial chemistry
Langues : Anglais (eng)
in Industrial & engineering chemistry research > Vol. 51 N° 14 (Avril 2012) . - pp. 5372–5373
Mots-clés : Heat capacity Enthalpy ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie3002793 Exemplaires
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