Characterization of lecithin-taurodeoxycholate mixed micelles using small-angle neutron scattering and static and dynamic light scattering

Journal Article · Thu Apr 21 04:00:00 EDT 1994 · Journal of Physical Chemistry; (United States)

DOI:https://doi.org/10.1021/j100067a031· OSTI ID:7069513

Long, M A; Kaler, E W ^[1]; Lee, S P ^[2]; Wignall, G D ^[3]

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1. Univ. of Delaware, Newark, DE (United States)
2. VA Medical Center, Seattle, WA (United States)
3. Oak Ridge National Lab., TN (United States)

We have used small-angle neutron scattering (SANS) to probe the structure and interparticle interactions of lecithin-taurodeoxycholate mixed micelles. The data are fit to a core-shell model that provides the micelle composition and dimensions. The effects on the scattering spectra of electrostatic and excluded-volume interactions are explored in terms of the decoupling approximation and the random phase approximation. We found the TDC-lecithin micelles are cylindrical particles with an average cross-sectional radius of 26.7 [+-] 0.4 A. The core-shell structure is found to be an appropriate model for the highly hydrated micelles. The micelle length increases dramatically with an increase in added electrolyte, but not with decreasing concentration as previously reported. The SANS data analysis shows that particles in 0.05 M NaCl grow by less than 15% with a 3-fold decrease in the total surfactant concentration. This is in contrast to the simple interpretation of dynamic light scattering of the same samples that shows an apparent doubling of the micelle length with the same decrease in surfactant concentration. This discrepancy is attributed to neglect of the thermodynamic and hydrodynamic interactions in the analysis of the dynamic light scattering data. 59 refs., 5 figs., 5 tabs.

• DOE Contract Number: AC05-84OR21400
• OSTI ID: 7069513
• Journal Information: Journal of Physical Chemistry; (United States), Journal Name: Journal of Physical Chemistry; (United States) Vol. 98:16; ISSN JPCHAX; ISSN 0022-3654
• Country of Publication: United States
• Language: English

Related Subjects

37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CHEMISTRY
400201* -- Chemical & Physicochemical Properties
550200 -- Biochemistry
59 BASIC BIOLOGICAL SCIENCES
BARYONS
BILE
BIOLOGICAL MATERIALS
BODY FLUIDS
DISPERSIONS
ELECTROLYTES
ELECTROSTATICS
ELEMENTARY PARTICLES
ESTERS
FERMIONS
FLUID MECHANICS
HADRONS
HYDRATION
HYDRODYNAMICS
LECITHINS
LIGHT SCATTERING
LIPIDS
MATERIALS
MATHEMATICAL MODELS
MECHANICS
MICELLAR SYSTEMS
MIXTURES
NEUTRONS
NUCLEONS
ORGANIC COMPOUNDS
ORGANIC PHOSPHORUS COMPOUNDS
PHOSPHOLIPIDS
POLYMERS
SCATTERING
SMALL ANGLE SCATTERING
SOLUTIONS
SOLVATION
STRUCTURAL MODELS
SURFACTANTS
THERMODYNAMICS