IMPACT OF ALCOHOL CONCENTRATION AND TYPE ON OPTIMAL SALINITY IN SURFACTANT-OIL-WATER MICROEMULSION SYSTEMS

Abstract

In this study, the influence of cosurfactants (n-butanol, sec-butanol, iso-butanol, n-pentanol, iso-pentanol) on the formulation of sodium dodecyl sulfate-oil-water systems was investigated. Salinity sweep, stability and interfacial tension measurements were used to determine the optimum salinity and function alcohol,  f(A). The results showed that systems without alcohol form gelled structures requiring longer equilibration times than systems with alcohols, where an increase in concentration significantly modifies the value of the optimal formulation, especially for primary alcohols in the range of 3 to 5 % v/v alcohol. With n-pentanol, the optimal salinity was shifted from 12 g/dL (1 % v/v n-pentanol) to 5.5 g/dL (3 % v/v n-pentanol), maintaining the same WI-WIII-WII phase behavior contributed by the salinity variation in the formulation sweep. Also, salinity adjustment models were developed as a function of alcohol concentration and function f(A) for each alcohol, which allow numerically estimating the HLD correlation parameter for the studied system and its interpretation out of equilibrium to form or break emulsions; as well as in detergent formulations and microemulsions for cleaning or transport of substances in controlled release of ingredients.