Solvent isotope effects on alkyltrimethylammonium bromide micelles as a function of alkyl chain length

Journal Article · Thu Aug 27 04:00:00 EDT 1987 · J. Phys. Chem.; (United States)

DOI:https://doi.org/10.1021/j100302a024· OSTI ID:5918873

Berr, S S

The effect on micellar structure of changing the solvent from H/sub 2/O to D/sub 2/O for alkyltrimethylammonium bromide (C/sub n/TAB; C/sub n/TAB triple bond C/sub n/H/sub 2n+1/N(CH/sub 3/)/sub 3/Br, with n = 12, 14, and 16) has been examined. The energetics of micellization have been determined by measuring critical micelle concentrations by using surface tensiometry. The micellar structure has been elucidated through the use of small-angle neutron scattering (SANS). It was found that there is a solvent isotope effect that is small for C/sub 12/TAB but increases with n. This effect is manifested mainly by an increase in aggregation number and is attributed to solvent-hydrocarbon interactions of the dissolved monomers. The fractional charge of the micelle is not altered by the isotopic composition of the solvent. C/sub n/TAB micelles are found to be drier than are micelles formed by the corresponding sodium alkyl sulfates, and this results in a larger solvent effect for the quaternary ammonium bromides.

• Research Organization: Univ. of Virginia, Charlottesville
• DOE Contract Number: AC05-84OR21400
• OSTI ID: 5918873
• Journal Information: J. Phys. Chem.; (United States), Journal Name: J. Phys. Chem.; (United States) Vol. 91:18; ISSN JPCHA
• Country of Publication: United States
• Language: English

Related Subjects

37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CHEMISTRY
400201* -- Chemical & Physicochemical Properties
400202 -- Isotope Effects
Isotope Exchange
& Isotope Separation
COHERENT SCATTERING
DATA
DEUTERIUM
DIFFRACTION
ENERGY
EXPERIMENTAL DATA
FREE ENTHALPY
HEAVY WATER
HYDROGEN COMPOUNDS
HYDROGEN ISOTOPES
INFORMATION
ISOTOPE EFFECTS
ISOTOPES
LIGHT NUCLEI
MICELLAR SYSTEMS
NEUTRON DIFFRACTION
NUCLEI
NUMERICAL DATA
ODD-ODD NUCLEI
OXYGEN COMPOUNDS
PHYSICAL PROPERTIES
SCATTERING
SMALL ANGLE SCATTERING
SOLVENT PROPERTIES
STABLE ISOTOPES
STRUCTURAL CHEMICAL ANALYSIS
THERMODYNAMIC PROPERTIES
WATER