Nature of large aggregates in supercooled aqueous solutions of sodium dodecyl sulfate

Journal Article · Thu Sep 18 04:00:00 EDT 1980 · J. Phys. Chem.; (United States)

DOI:https://doi.org/10.1021/j100456a016· OSTI ID:7083115

Franses, E I ^[1]; Davis, H T; Miller, W G; Scriven, L E

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1. Purdue Univ., West Lafayette, IN

Preparations of 2.0 and 5.5 wt % sodium dodecyl sulfate (SDS) in 3.5 wt % (0.6 M) aqueous NaCl are equilibrium micellar solutions above 28/sup 0/C, the Krafft point of the surfactant at this salinity. These systems can be supercooled and remain transparent for hours and days. At 25/sup 0/C at equilibrium they are biphasic, a hydrated crystal phase and an aqueous salt solution phase containing only 0.01/sub 2/ wt % SDS. Conductimetry and /sup 13/C NMR show that these transparent supercooled systems are indeed supersaturated solutions and not microdispersions of the hydrated crystal. The time lag for the onset of nucleation of the crystals depends strongly on stirring details and probably on presence of gas-liquid interface. The big nonequilibrium aggregates present in the supersaturated systems resemble micelles in conductivity and molecular motion, and are likely to be metastable micelles as is presumed by Mazer, Benedek, and Carey. 21 references, 6 figures, 1 table.

• OSTI ID: 7083115
• Journal Information: J. Phys. Chem.; (United States), Journal Name: J. Phys. Chem.; (United States) Vol. 84:19; 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)
AGGLOMERATION
ALKALI METAL COMPOUNDS
ALKYL RADICALS
AQUEOUS SOLUTIONS
CHLORIDES
CHLORINE COMPOUNDS
DATA
DIAGRAMS
DISPERSIONS
DODECYL RADICALS
EXPERIMENTAL DATA
HALIDES
HALOGEN COMPOUNDS
HYDRATES
INFORMATION
INTERFACES
MAGNETIC RESONANCE
MEDIUM TEMPERATURE
MICELLAR SYSTEMS
MIXTURES
NUCLEAR MAGNETIC RESONANCE
NUMERICAL DATA
OXYGEN COMPOUNDS
PHASE DIAGRAMS
RADICALS
RESONANCE
SATURATION
SODIUM CHLORIDES
SODIUM COMPOUNDS
SOLUBILITY
SOLUTIONS
SULFATES
SULFUR COMPOUNDS
SUPERSATURATION
TEMPERATURE DEPENDENCE
TIME DEPENDENCE