Efficient emulsifying properties of glycerol-based surfactant

Two glycerol based non-ionic surfactants 1,3-bis(octylamino)propan-2-ol (BAPO-C8) and 1,3-bis(dodecylamino)propan-2-ol (BAPO-C12) were synthesized, and their surface property, critical micelle concentration (cmc), interfacial property, and emulsifying ability were studied. It was found that the surfactants exhibited low cmc and excellent ability to reduce interfacial tension. They were efficient for emulsifying hexane/water, heptane/water, octane/water and chloroform/water systems. It is worth noting that high-internal-phase emulsions (HIPE, 80% internal phase) (o/w) could be formed in the water/alkane systems. Moreover, a common water in oil emulsion (w/o) was formed in water/chloroform system stabilized by BAPO-C12. Confocal laser scanning microscopy (CLSM) results indicated that the size of droplets in the HIPEs increased with the increase of hydrophobic chain length of oil phase. The hexane/water emulsion had higher apparent viscosity (ƞ) than the emulsions with other alkanes, indicating that the emulsions had much stronger network of oil droplets. All the emulsions showed good stability with and without salts.