8-Phenyl n-hexadecyl p-sulfonate

The surfactant is the sodium salt of 8-phenyl n-hexadecyl p-sulfonate (molecular weight 404.6 dalton). One sample was generously provided by Prof. W. H. Wade of the University of Texas, Austin. Another batch (Research Sample 8727J) was kindly provided by Continental Oil Company, Ponca City, Oklahoma. 

At low enough concentrations that the surfactant is totally dissolved and unassociated, the apparent equivalent conductivities of sodium 8-phenyl-n-hexadecyl-p-sulfonate ought to be about the same as the equivalent conductivities of sodium dodecyl sulfate (SDS), because they have the same cation and this ion contributes the most (around 51/71 =75%) to the conductivity. It followed that the much larger equivalent conductivities measured in samples six or more months old could be attributed neither to the surfactant alone nor to a surfactant impurity, because they did... 

Spectroturbidimetry, conductimetry, ultrafiltration, ultracentrifugation, vapor sorption, polarizing microscopy, and nuclear magnetic resonance spectroscopy were used to study phase behavior of pure sodium 8-phenyl-n-hexadecyl-p-sulfonate in water as a function of temperature and sodium chloride concentration, and in decane. The first four techniques gave information on solubility and states of dispersion ranging from visible, settling suspensions to transparent, stably dispersed submicro-scopic particles. Surfactant solubility in water was only 0.06 wt% at 25°C, increased 11-fold at 90°C, but decreased 300-fold with 3 wt% salt at 25°C. The surfactant-rich phase in... 

Chemicals Sodium 8-phenyl-n-hexadecyl-p-sulfonate (Texas 1) was obtained from Professor Wade of the University of Texas and has been used as received. According to Frances et al. (2), the purity of the sample exceeds 98%. 

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