Linker-modified microemulsions for a variety of oils and surfactants

Previously, we reported on the use of hydrophilic and lipophilic linker molecules to enhance the solubilization capacity of chlorinated hydrocarbons using sodium dihexyl sulfosuccinate (SDHS). In this work we extend the use of linker molecules to a wider range of oils and surfactants. The data show that the linker effect works for all the systems studied and that linker-based systems are even more economical than surfactant-only systems for more hydrophobic oils. Using a more hydrophobic surfactant, such as sodium bis(2-ethyl)dihexyl sulfosuccinate (Aerosol-OT), requires a formulation enriched with a hydrophilic linker, whereas the formulation for the more hydrophilic SDHS requires the use of a more lipophilic linker. By considering the properties and appearance of the formulation before contacting with the oil, and by evaluation the coalescence dynamics, we found that hydrophilic linker-rich formulations were preferred. These formulations were tested as fabric pretreatments for removing motor oil and hexadecane from cotton, and as flushing solutions for glass bead columns contaminated with these oils. The cleaning performance of these linker-based systems was superior to common surfactant and pretreatment formulations in the detergency tests, achieving more than 80% removal of motor oil and hexadecane trapped in the packed-column flushing tests.