Aggregation of sodium alkylbenzenesulfonates in aqueous solution
- Oak Ridge National Lab., TN
The origins of the ultralow tensions (less than 10/sup -2/ dyn/cm) between phases in multi-component systems containing surfactants are currently being actively investigated. Generation and maintenance of these ultralow tensions are essential for successful mobilization of residual oil to immiscible surfactant-water or microemulsion flooding processes. The object of the study is to see whether surfactant aggregation in the aqueous phase has anything to do with the producion of ultralow interfacial tensions (IFTs). Since commercially available petroleum sulfonates contain complex mixtures of surfactants (plus other components) which are unsuitable for fundamental physicochemical work, two pure sodium alkylbenzenesulfonates were used as models for the commercial material. The surfactants studied were sodium p(1-heptylnonyl)benzenesulfonate, 8-phenyl-C/sub 16/SNa, also known as Texas No. 1, and sodium p(1-pentylheptyl)benzenesulfonate, 6-phenyl-C/sub 12/SNa. The surfactant 6-phenyl-C/sub 12/SNa forms a small spherical micelles in aqueous solution, having an aggregation number of 20 to 30 and a fractional charge of 0.45. These micelles are hydrated to the extent of approximately 18 moles H/sub 2/O per moles of surfactant. A second larger aggregate is also present in 6-phenyl-C/sub 12/SNa solution; its importance increases with solution age. Addition of NaCl causes both aggregates to apparently increase modestly in size. The surfactant 8-phenyl-C/sub 16/SNa also contains both aggregates in its solutions; the larger one is relatively more important here. The larger aggregate does not correspond to dispersed bits of a liquid crystalline mesophase.
- OSTI ID:
- 6446992
- Report Number(s):
- CONF-810308-(Vol.1)
- Journal Information:
- Am. Chem. Soc., Div. Pet. Chem., Prepr.; (United States), Journal Name: Am. Chem. Soc., Div. Pet. Chem., Prepr.; (United States) Vol. 26:1; ISSN ACPCA
- Country of Publication:
- United States
- Language:
- English
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Related Subjects
020300* -- Petroleum-- Drilling & Production
AGGLOMERATION
ALKALI METAL COMPOUNDS
AQUEOUS SOLUTIONS
CHLORIDES
CHLORINE COMPOUNDS
DENSITY
DISPERSIONS
ENERGY SOURCES
ENHANCED RECOVERY
ESTERS
FLUID INJECTION
FOSSIL FUELS
FUELS
HALIDES
HALOGEN COMPOUNDS
INTERFACES
MICELLAR SYSTEMS
MICROEMULSION FLOODING
MISCIBLE-PHASE DISPLACEMENT
MIXTURES
ORGANIC COMPOUNDS
ORGANIC SULFUR COMPOUNDS
PETROLEUM
PETROLEUM SULFONATES
PHASE STUDIES
PHYSICAL PROPERTIES
RECOVERY
SODIUM CHLORIDES
SODIUM COMPOUNDS
SOLUTIONS
SULFONATES
SULFONIC ACID ESTERS
SURFACE PROPERTIES
SURFACE TENSION
SURFACTANTS
VISCOSITY