Search

Your search keyword '"Kolay, Sancheeta"' showing total 14 results
Start Over Author "Kolay, Sancheeta"
14 results on '"Kolay, Sancheeta"'

4. Kinetic Studies of Micelle - Assisted Reaction of p-Nitrophenyl Acetate with Benzo-Hydroxamate Ion in Water-Ethylene Glycol Mixtures

Author

Bal, Sunita; School of Studies in Chemistry, Pt. Ravishankar Shukla University, Raipur (C.G.) 492010, Satnami, Manmohan L.; School of Studies in Chemistry, Pt. Ravishankar Shukla University, Raipur (C.G.) 492010, Kolay, Sancheeta; School of Studies in Chemistry, Pt. Ravishankar Shukla University, Raipur (C.G.) 492010, Palepu, Rama M.; School of Studies in Chemistry, Pt. Ravishankar Shukla University, Raipur (C.G.) 492010, Dafonte, P. R.; School of Studies in Chemistry, Pt. Ravishankar Shukla University, Raipur (C.G.) 492010, Ghosh, Kallol K.; School of Studies in Chemistry, Pt. Ravishankar Shukla University, Raipur (C.G.) 492010, Bal, Sunita; School of Studies in Chemistry, Pt. Ravishankar Shukla University, Raipur (C.G.) 492010, Satnami, Manmohan L.; School of Studies in Chemistry, Pt. Ravishankar Shukla University, Raipur (C.G.) 492010, Kolay, Sancheeta; School of Studies in Chemistry, Pt. Ravishankar Shukla University, Raipur (C.G.) 492010, Palepu, Rama M.; School of Studies in Chemistry, Pt. Ravishankar Shukla University, Raipur (C.G.) 492010, Dafonte, P. R.; School of Studies in Chemistry, Pt. Ravishankar Shukla University, Raipur (C.G.) 492010, and Ghosh, Kallol K.; School of Studies in Chemistry, Pt. Ravishankar Shukla University, Raipur (C.G.) 492010

Abstract

The pseudo-first order rate constant for the reaction of p-nitrophenyl acetate by benzohydroxamate ion was determined in water-ethylene glycol mixtures using cationic micellar solutions of alkyldimethyl and diethyl ethanol ammonium bromides. From the conductivity data of these surfactants in ethylene glycol, the critical micelle concentration (cmc), the micellar ionization degree (α), and Gibbs free energy of the micellization (ΔG0m), have been determined. Addition of ethylene glycol in the micellar solutions results in an increase in the cmc and in an increase in micellar ionization degree. The dependence of observed rate constants were explained considering the structure of interfacial region, micellar aggregation number, water content in the micellar interfacial region and the equilibrium binding constants for the p-nitrophenyl acetate and benzohydroxamate ion to the micellar aggregates. The kinetic micellar effect was quantitatively explained by the pseudophase model.

Published
2015

5. Kinetic Studies of Micelle - Assisted Reaction of p-Nitrophenyl Acetate with Benzo-Hydroxamate Ion in Water-Ethylene Glycol Mixtures

Author

Bal, Sunita, Satnami, Manmohan L., Kolay, Sancheeta, Palepu, Rama M., Dafonte, P. R., Ghosh, Kallol K., Bal, Sunita, Satnami, Manmohan L., Kolay, Sancheeta, Palepu, Rama M., Dafonte, P. R., and Ghosh, Kallol K.

Abstract

The pseudo-first order rate constant for the reaction of p-nitrophenyl acetate by benzohydroxamate ion was determined in water-ethylene glycol mixtures using cationic micellar solutions of alkyldimethyl and diethyl ethanol ammonium bromides. From the conductivity data of these surfactants in ethylene glycol, the critical micelle concentration (cmc), the micellar ionization degree (α), and Gibbs free energy of the micellization (ΔG0m), have been determined. Addition of ethylene glycol in the micellar solutions results in an increase in the cmc and in an increase in micellar ionization degree. The dependence of observed rate constants were explained considering the structure of interfacial region, micellar aggregation number, water content in the micellar interfacial region and the equilibrium binding constants for the p-nitrophenyl acetate and benzohydroxamate ion to the micellar aggregates. The kinetic micellar effect was quantitatively explained by the pseudophase model.

Published
2015

13. Micellization behavior of [C16-12-C16], 2Br− gemini surfactant in binary aqueous-solvent mixtures

Author

Kolay, Sancheeta, Ghosh, Kallol K., and Quagliotto, Pierluigi

Subjects
*SURFACE active agents, *SOLVENTS, *MIXTURES, *BROMIDES, *AMMONIUM compounds, *SURFACE area, *MICELLES
Abstract

Abstract: The micellization behavior of bis cationic gemini surfactant, N,N′-dihexadecyl-N,N,N′,N′-tetramethyl-1,12-dodecanediammonium dibromide [C16H33N+(CH3)2-(CH2)12-N+(CH3)2C16H33, 2Br−] has been studied in binary aqueous mixtures of dimethyl sulfoxide, methanol, 1,4-dioxane, glycerol and ethylene glycol by conductivity and surface tension measurements at 300K. The critical micellar concentration, degree of micelle ionization (α), surface excess concentration (Г max), minimum surface area per molecule of surfactant (A min), Gibbs free energy of micellization , the surface pressure at cmc (π cmc), and the Gibbs energy of adsorption of the gemini surfactant have also been determined. The cmc, α, A min increases where as , Г max, and π cmc decreases with increasing volume percentage of the solvents in the solvent–water binary mixture. The interfacial properties of the gemini surfactant, solute–solute, solvent–solute interactions and the effectiveness of a surface-active molecule in binary solvent systems have been discussed. [Copyright &y& Elsevier]

Published
2009
Full Text
View/download PDF

14. Kinetic study of the reactions of p-nitrophenyl acetate and p-nitrophenyl benzoate with oximate nucleophiles.

Author

Tiwari, Shuchi, Kolay, Sancheeta, Ghosh, Kallol K., Kuca, Kamil, and Marek, Jan

Subjects
*CHEMICAL reactions, *ACETATES, *BENZOATES, *SURFACE active agents, *BUTANE
Abstract

The reactions of p-nitrophenyl acetate (PNPA) and p-nitrophenyl benzoate (PNPB) with α-nucleophile oximates, that is, butane 2,3-dione monoximate, pralidoximate, and other oximates have been studied in the presence of different cationic surfactants. The first-order rate constant increases with increasing surfactant concentration. The extent of acceleration is dependent on the head group structure of surfactants. The PNPA is more reactive than PNPB toward all the nucleophiles at higher concentration of surfactants. © 2008 Wiley Periodicals, Inc. Int J Chem Kinet 41: 57–64, 2009 [ABSTRACT FROM AUTHOR]

Published
2009
Full Text
View/download PDF

Catalog

Books, media, physical & digital resources
See catalog results