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Title: Association of nitrophenols to sodium dodecylsulfate micelles

Abstract

The luminescence quenching of tris(2,2{prime}-bipyridine)ruthenium(II) Ru(bpy){sub 3}{sup 2+} by 2-, 3-, and 4-nitrophenol (NO{sub 2}PhOH), in their protonated forms, has been studied by static and time-resolved techniques in water and sodium dodecyl sulfate (SDS) aqueous solution. In water, the biomolecular rate constants were obtained separately from both techniques and they were coincident. The values were close to the diffusional limit. In the presence of SDS micelles at a fixed detergent concentration, the Stern-Volmer plots of {tau}{sup 0}/{tau} vs quencher total concentration ([Q]{sub t}) were linear in the whole range of [Q]{sub t} used. However, the Stern-Volmer plots of the ratio I{sup 0}/I vs [Q]{sub t} in SDS micelles showed an upward deviating curve. From these plots of I{sup 0}/I, the concentrations of the NO{sub 2}PhOHs in the micellar pseudophase were measured. The treatment of the data of both types of measurements let the authors determine the association constants (K) of the NO{sub 2}PhOHs to SDS micelles and the exit (k{sub {minus}}) and entrance (k{sub +}) rate constants of NO{sub 2}PhOHs to the micelles. The K values obtained from either static or time-resolved luminescence techniques were in agreement within experimental error. An electron-transfer mechanism was also proposed for the quenching reactionmore » of the excited state Ru(bpy){sub 3}{sup 2+} by nitrophenols in which the metallic complex is oxidized.« less

Authors:
;  [1]
  1. Univ. Nacional de Rio Cuarto (Argentina)
Publication Date:
OSTI Identifier:
596996
Resource Type:
Journal Article
Resource Relation:
Journal Name: Journal of Colloid and Interface Science; Journal Volume: 195; Journal Issue: 1; Other Information: PBD: 1 Nov 1997
Country of Publication:
United States
Language:
English
Subject:
54 ENVIRONMENTAL SCIENCES; 32 ENERGY CONSERVATION, CONSUMPTION, AND UTILIZATION; WATER TREATMENT; NITROPHENOL; WASTE WATER; SURFACTANTS; MICELLAR SYSTEMS; ELECTRON TRANSFER; RUTHENIUM COMPLEXES; SOLUBILITY

Citation Formats

Senz, A., and Gsponer, H.E. Association of nitrophenols to sodium dodecylsulfate micelles. United States: N. p., 1997. Web. doi:10.1006/jcis.1997.5141.
Senz, A., & Gsponer, H.E. Association of nitrophenols to sodium dodecylsulfate micelles. United States. doi:10.1006/jcis.1997.5141.
Senz, A., and Gsponer, H.E. Sat . "Association of nitrophenols to sodium dodecylsulfate micelles". United States. doi:10.1006/jcis.1997.5141.
@article{osti_596996,
title = {Association of nitrophenols to sodium dodecylsulfate micelles},
author = {Senz, A. and Gsponer, H.E.},
abstractNote = {The luminescence quenching of tris(2,2{prime}-bipyridine)ruthenium(II) Ru(bpy){sub 3}{sup 2+} by 2-, 3-, and 4-nitrophenol (NO{sub 2}PhOH), in their protonated forms, has been studied by static and time-resolved techniques in water and sodium dodecyl sulfate (SDS) aqueous solution. In water, the biomolecular rate constants were obtained separately from both techniques and they were coincident. The values were close to the diffusional limit. In the presence of SDS micelles at a fixed detergent concentration, the Stern-Volmer plots of {tau}{sup 0}/{tau} vs quencher total concentration ([Q]{sub t}) were linear in the whole range of [Q]{sub t} used. However, the Stern-Volmer plots of the ratio I{sup 0}/I vs [Q]{sub t} in SDS micelles showed an upward deviating curve. From these plots of I{sup 0}/I, the concentrations of the NO{sub 2}PhOHs in the micellar pseudophase were measured. The treatment of the data of both types of measurements let the authors determine the association constants (K) of the NO{sub 2}PhOHs to SDS micelles and the exit (k{sub {minus}}) and entrance (k{sub +}) rate constants of NO{sub 2}PhOHs to the micelles. The K values obtained from either static or time-resolved luminescence techniques were in agreement within experimental error. An electron-transfer mechanism was also proposed for the quenching reaction of the excited state Ru(bpy){sub 3}{sup 2+} by nitrophenols in which the metallic complex is oxidized.},
doi = {10.1006/jcis.1997.5141},
journal = {Journal of Colloid and Interface Science},
number = 1,
volume = 195,
place = {United States},
year = {Sat Nov 01 00:00:00 EST 1997},
month = {Sat Nov 01 00:00:00 EST 1997}
}
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  • Dynamic fluorescence spectroscopy of micelle-solubilized pyrene was used to measure the size of the sodium dodecylsulfate (SDS) aggregate bound to polyethylene glycol (PEG). The measurements were carried out with very dilute PEG and SDS concentrations, to ensure that there were no free surfactant aggregates in solution and that all aggregates present were bound to the polymer. Effect of salts of sodium, cesium, lithium, and magnesium of varying concentrations on the size of the bound aggregate was determined. The affinity of the cation toward PEG controlled the size of the SDS aggregate bound to the polymer. The stronger the binding betweenmore » the cation and PEG, the smaller was the bound SDS aggregate. There was no effect of either the anion or the salt concentration for a particular cation on the size of the bound SDS aggregate. As the ionic strength increased, the only parameter affected was the number of bound surfactant aggregates per polymer chain. Results are discussed in terms of simultaneous affinities of the cations toward the polymer and the micelle.« less
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