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Title: Small-angle neutron scattering study of the structural effects of substitution of tetramethylammonium for sodium as the counterion in dodecyl sulfate micelles

Abstract

Small-angle neutron scattering (SANS) data have been obtained at 303 K for aqueous micellar solutions of CH/sub 3/(CH/sub 2/)/sub 11/SO/sub 4/Na (sodium dodecyl sulfate (SDS)) and CH/sub 3/(CH/sub 2/)/sub 11/SO/sub 4/N(CH/sub 3/)/sub 4/ (tetramethylammonium dodecyl sulfate (TMADS)) and their deuterated analogues CH/sub 3/(CH/sub 2/)/sub 10/CD/sub 2/SO/sub 4/Na (D/sub 2/-SDS) and CH/sub 3/(CH/sub 2/)/sub 11/SO/sub 4/N(CD/sub 3/)/sub 4/ (D/sub 12/-TMADS). Results have been obtained for 0.4 mol dm/sup -3/ surfactant in various H/sub 2/O/D/sub 2/O mixtures and for TMADS as a function of surfactant concentration in D/sub 2/O. The SANS data are well described by charged, monodisperse hard spheres interacting through a screened Coulomb potential. The asphericity and the polydispersity of the systems were estimated to be small. The deuterium for the deuterated surfactants lies mainly in the Stern region of the micelle and increases contrast between the hydrocarbon core and the water-saturated Stern layer. Therefore, these deuterated micellar systems were used to determine the radius of the dry core, which was then used in the determination of the structural parameters for the micellar systems. The degree of hydration was determined without resorting to the assignment of values for the water of hydration for the individual ions present. It was foundmore » that TMADS micelles are smaller and have a higher charge, smaller degree of aggregation, and less but more deeply penetrating water than do SDS micelles. Both SDS and TMADS micelles had substantial amounts of hydrocarbon residing in the aqueous Stern layer.« less

Authors:
; ; ;
Publication Date:
Research Org.:
Wake Forest Univ., Winston-Salem, NC
OSTI Identifier:
7203792
DOE Contract Number:  
AC05-84OR21400
Resource Type:
Journal Article
Journal Name:
J. Phys. Chem.; (United States)
Additional Journal Information:
Journal Volume: 90:24
Country of Publication:
United States
Language:
English
Subject:
37 INORGANIC, ORGANIC, PHYSICAL AND ANALYTICAL CHEMISTRY; 73 NUCLEAR PHYSICS AND RADIATION PHYSICS; ALKANES; SMALL ANGLE SCATTERING; AMMONIUM COMPOUNDS; DEUTERIUM COMPOUNDS; MICELLAR SYSTEMS; STRUCTURAL CHEMICAL ANALYSIS; ORGANIC SULFUR COMPOUNDS; SODIUM COMPOUNDS; SULFATES; DIMENSIONS; EXPERIMENTAL DATA; HYDRATION; MEDIUM TEMPERATURE; NEUTRON REACTIONS; ALKALI METAL COMPOUNDS; BARYON REACTIONS; DATA; HADRON REACTIONS; HYDROCARBONS; HYDROGEN COMPOUNDS; INFORMATION; NUCLEAR REACTIONS; NUCLEON REACTIONS; NUMERICAL DATA; ORGANIC COMPOUNDS; OXYGEN COMPOUNDS; SCATTERING; SOLVATION; SULFUR COMPOUNDS; 400201* - Chemical & Physicochemical Properties; 654003 - Radiation & Shielding Physics- Neutron Interactions with Matter

Citation Formats

Berr, S S, Coleman, M J, Jones, R R.M., and Johnson, Jr, J S. Small-angle neutron scattering study of the structural effects of substitution of tetramethylammonium for sodium as the counterion in dodecyl sulfate micelles. United States: N. p., 1986. Web. doi:10.1021/j100282a017.
Berr, S S, Coleman, M J, Jones, R R.M., & Johnson, Jr, J S. Small-angle neutron scattering study of the structural effects of substitution of tetramethylammonium for sodium as the counterion in dodecyl sulfate micelles. United States. https://doi.org/10.1021/j100282a017
Berr, S S, Coleman, M J, Jones, R R.M., and Johnson, Jr, J S. Thu . "Small-angle neutron scattering study of the structural effects of substitution of tetramethylammonium for sodium as the counterion in dodecyl sulfate micelles". United States. https://doi.org/10.1021/j100282a017.
@article{osti_7203792,
title = {Small-angle neutron scattering study of the structural effects of substitution of tetramethylammonium for sodium as the counterion in dodecyl sulfate micelles},
author = {Berr, S S and Coleman, M J and Jones, R R.M. and Johnson, Jr, J S},
abstractNote = {Small-angle neutron scattering (SANS) data have been obtained at 303 K for aqueous micellar solutions of CH/sub 3/(CH/sub 2/)/sub 11/SO/sub 4/Na (sodium dodecyl sulfate (SDS)) and CH/sub 3/(CH/sub 2/)/sub 11/SO/sub 4/N(CH/sub 3/)/sub 4/ (tetramethylammonium dodecyl sulfate (TMADS)) and their deuterated analogues CH/sub 3/(CH/sub 2/)/sub 10/CD/sub 2/SO/sub 4/Na (D/sub 2/-SDS) and CH/sub 3/(CH/sub 2/)/sub 11/SO/sub 4/N(CD/sub 3/)/sub 4/ (D/sub 12/-TMADS). Results have been obtained for 0.4 mol dm/sup -3/ surfactant in various H/sub 2/O/D/sub 2/O mixtures and for TMADS as a function of surfactant concentration in D/sub 2/O. The SANS data are well described by charged, monodisperse hard spheres interacting through a screened Coulomb potential. The asphericity and the polydispersity of the systems were estimated to be small. The deuterium for the deuterated surfactants lies mainly in the Stern region of the micelle and increases contrast between the hydrocarbon core and the water-saturated Stern layer. Therefore, these deuterated micellar systems were used to determine the radius of the dry core, which was then used in the determination of the structural parameters for the micellar systems. The degree of hydration was determined without resorting to the assignment of values for the water of hydration for the individual ions present. It was found that TMADS micelles are smaller and have a higher charge, smaller degree of aggregation, and less but more deeply penetrating water than do SDS micelles. Both SDS and TMADS micelles had substantial amounts of hydrocarbon residing in the aqueous Stern layer.},
doi = {10.1021/j100282a017},
url = {https://www.osti.gov/biblio/7203792}, journal = {J. Phys. Chem.; (United States)},
number = ,
volume = 90:24,
place = {United States},
year = {1986},
month = {11}
}