Determination of interparticle structure factors in ionic micellar solutions by small angle neutron scattering

Journal Article · Fri Dec 31 23:00:00 EST 1982 · J. Phys. Chem.; (United States)

DOI:https://doi.org/10.1021/j100237a030· OSTI ID:5132831

Bendedouch, D; Chen, S H; Koehler, W C

A series of small-angle neutron-scattering (SANS) intensity measurements were carried out on aqueous micellar solutions of ionic detergent lithium dodecyl sulfate (LDS). A systematic study of the system was conducted as a function of both detergent concentration, from 0.008 to 1.107 M, and salt (LiCl) concentration, from 0.0 to 1.0 M, at around 37/sup 0/C. The data show that LDS micelles stay small within this range of solution conditions, and therefore analysis can be made regarding the micelles as approximately monodisperse macroions suspended in a solution of given ionic strength I. The SANS spectra exhibit a pronounced interaction peak due to strong intermicellar Coulombic repulsions, especially at low I. Analysis is made by using a mean spherical approximation (MSA) for a model charged hard-sphere system to compute the interparticle structure factor S(Q), and a uniform prolate spheroidal structure for the micellar core to model the intraparticle structure factor P(Q). Excellent agreement is obtained between our data and this model using only two free parameters.

• Research Organization: Massachusetts Institute of Technology, Cambridge
• OSTI ID: 5132831
• Journal Information: J. Phys. Chem.; (United States), Journal Name: J. Phys. Chem.; (United States) Vol. 87; ISSN JPCHA
• Country of Publication: United States
• Language: English

Related Subjects

37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CHEMISTRY
400301* -- Organic Chemistry-- Chemical & Physicochemical Properties-- (-1987)
AQUEOUS SOLUTIONS
BARYON REACTIONS
DISPERSIONS
HADRON REACTIONS
HEAVY WATER
HYDROGEN COMPOUNDS
MICELLAR SYSTEMS
MIXTURES
NEUTRON REACTIONS
NEUTRON SPECTRA
NUCLEAR REACTIONS
NUCLEON REACTIONS
OXYGEN COMPOUNDS
SCATTERING
SOLUTIONS
SPECTRA
STRUCTURAL MODELS
WATER