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Coalescence of bubbles and stability of foams in brij surfactant systems / Sayantan Samanta in Industrial & engineering chemistry research, Vol. 50 N° 8 (Avril 2011) 

Public ISBD [article]  in Industrial & engineering chemistry research > Vol. 50 N° 8 (Avril 2011) . - pp. 4484–4493 Titre : Coalescence of bubbles and stability of foams in brij surfactant systems Type de document : texte imprimé Auteurs : Sayantan Samanta, Auteur ; Pallab Ghosh, Auteur Année de publication : 2011 Article en page(s) : pp. 4484–4493 Note générale : Chimie industrielle Langues : Anglais (eng) Mots-clés : Coalescence  air  bubbles  Aqueous  solutions  polyoxyethylene Résumé : This work presents coalescence of air bubbles and stability of foams in aqueous solutions of polyoxyethylene (4) lauryl ether (Brij 30), polyoxyethylene (23) lauryl ether (Brij 35), and polyoxyethylene (20) oleyl ether (Brij 98). Adsorption of these surfactants at the air−water interface was also studied. The surface tension profiles were fitted by the Szyskowski equation. It was found that the surface tensions at the critical micelle concentrations of these surfactants followed the sequence Brij 35 > Brij 98 > Brij 30. The air bubbles were most stable to coalescence in Brij 35 solution and least stable in Brij 30 solution. Coalescence in Brij 35 solution was hindered beyond a certain concentration of the surfactant. Stochastic distributions of coalescence time were observed in all surfactant systems. These distributions were fitted well by the stochastic model. Seven film-drainage models were used to predict the coalescence time. However, their predictions did not agree well with the mean values of the coalescence time distributions. Stability of foams was analyzed by the Ross−Miles test. The initial and residual foam heights were measured at each surfactant concentration. The foam heights followed the trends that are expected from the coalescence times of the bubbles. DEWEY : 660 ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie102396v [article] Coalescence of bubbles and stability of foams in brij surfactant systems [texte imprimé] / Sayantan Samanta, Auteur ; Pallab Ghosh, Auteur . - 2011 . - pp. 4484–4493. Chimie industrielle Langues : Anglais (eng) in Industrial & engineering chemistry research > Vol. 50 N° 8 (Avril 2011) . - pp. 4484–4493 Mots-clés : Coalescence  air  bubbles  Aqueous  solutions  polyoxyethylene Résumé : This work presents coalescence of air bubbles and stability of foams in aqueous solutions of polyoxyethylene (4) lauryl ether (Brij 30), polyoxyethylene (23) lauryl ether (Brij 35), and polyoxyethylene (20) oleyl ether (Brij 98). Adsorption of these surfactants at the air−water interface was also studied. The surface tension profiles were fitted by the Szyskowski equation. It was found that the surface tensions at the critical micelle concentrations of these surfactants followed the sequence Brij 35 > Brij 98 > Brij 30. The air bubbles were most stable to coalescence in Brij 35 solution and least stable in Brij 30 solution. Coalescence in Brij 35 solution was hindered beyond a certain concentration of the surfactant. Stochastic distributions of coalescence time were observed in all surfactant systems. These distributions were fitted well by the stochastic model. Seven film-drainage models were used to predict the coalescence time. However, their predictions did not agree well with the mean values of the coalescence time distributions. Stability of foams was analyzed by the Ross−Miles test. The initial and residual foam heights were measured at each surfactant concentration. The foam heights followed the trends that are expected from the coalescence times of the bubbles. DEWEY : 660 ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie102396v

Coalescence of bubbles in aqueous alcohol solutions / Ayanavilli Srinivas in Industrial & engineering chemistry research, Vol. 51 N° 2 (Janvier 2012) 

Public ISBD [article]  in Industrial & engineering chemistry research > Vol. 51 N° 2 (Janvier 2012) . - pp. 4824-4837 Titre : Coalescence of bubbles in aqueous alcohol solutions Type de document : texte imprimé Auteurs : Ayanavilli Srinivas, Auteur ; Pallab Ghosh, Auteur Année de publication : 2012 Article en page(s) : pp. 4824-4837 Note générale : Chimie industrielle Langues : Anglais (eng) Mots-clés : Foam  Modeling  Prediction  Stochastic  model  Stability  Hydration  Micellar  critical  concentration  Surface  tension  Gas  liquid  interface  Air  water  interface  Adsorption  Alcoholic  solution  Surfactant  Aliphatic  compound  Non  ionic  surfactant  Aqueous  solution  Bubble  Coalescence Résumé : Coalescence of air bubbles in aqueous solutions of two aliphatic alcohols (viz. butanol and hexanol) and four nonionic surfactants (viz. Tween 20, Tween 40, Tween 60 and Tween 80) is reported in this work. Single-component alcohol and surfactant solutions as well as mixed binary surfactant-alcohol solutions were studied. Adsorption of the surface active compounds at air-water interface was studied by measuring the surface tension of the aqueous solutions. The critical micelle concentration and surface tension at this concentration were determined for the single and mixed surfactant-alcohol systems. The effect of concentration of surface active compounds on coalescence of air bubbles at flat air-water interface was studied. The role of electrostatic double layer, hydration and steric forces on coalescence was investigated. It was found that the stability of the thin aqueous films in mixed surfactant-alcohol systems depends on the subtle interplay of the intermolecular and surface forces in the film, which vary with the composition of the monolayer at the air-water interface. Stochastic distributions of coalescence time were observed in all systems. The coalescence time distributions were fitted by the stochastic model. The mean values of the distributions were compared with the predictions of seven film-drainage models. DEWEY : 660 ISSN : 0888-5885 En ligne : http://cat.inist.fr/?aModele=afficheN&cpsidt=24493381 [article] Coalescence of bubbles in aqueous alcohol solutions [texte imprimé] / Ayanavilli Srinivas, Auteur ; Pallab Ghosh, Auteur . - 2012 . - pp. 4824-4837. Chimie industrielle Langues : Anglais (eng) in Industrial & engineering chemistry research > Vol. 51 N° 2 (Janvier 2012) . - pp. 4824-4837 Mots-clés : Foam  Modeling  Prediction  Stochastic  model  Stability  Hydration  Micellar  critical  concentration  Surface  tension  Gas  liquid  interface  Air  water  interface  Adsorption  Alcoholic  solution  Surfactant  Aliphatic  compound  Non  ionic  surfactant  Aqueous  solution  Bubble  Coalescence Résumé : Coalescence of air bubbles in aqueous solutions of two aliphatic alcohols (viz. butanol and hexanol) and four nonionic surfactants (viz. Tween 20, Tween 40, Tween 60 and Tween 80) is reported in this work. Single-component alcohol and surfactant solutions as well as mixed binary surfactant-alcohol solutions were studied. Adsorption of the surface active compounds at air-water interface was studied by measuring the surface tension of the aqueous solutions. The critical micelle concentration and surface tension at this concentration were determined for the single and mixed surfactant-alcohol systems. The effect of concentration of surface active compounds on coalescence of air bubbles at flat air-water interface was studied. The role of electrostatic double layer, hydration and steric forces on coalescence was investigated. It was found that the stability of the thin aqueous films in mixed surfactant-alcohol systems depends on the subtle interplay of the intermolecular and surface forces in the film, which vary with the composition of the monolayer at the air-water interface. Stochastic distributions of coalescence time were observed in all systems. The coalescence time distributions were fitted by the stochastic model. The mean values of the distributions were compared with the predictions of seven film-drainage models. DEWEY : 660 ISSN : 0888-5885 En ligne : http://cat.inist.fr/?aModele=afficheN&cpsidt=24493381