The interfacial properties of biosurfactant mixtures

Abstract

AbstractThere is growing global demand to transition to more sustainable surfactant technologies. Towards this vision, bio‐based surfactants and biosurfactants are being explored as alternatives to traditional petrochemical surfactants. However, the transition towards these technologies is expected to be gradual, therefore there is a critical need to formulate new biosurfactants in combination with traditional surfactant classes such as alkoxylates, sulfates and amine‐oxides to achieve a balance of performance, cost, and sustainability. To this end, we report a study of the impact of sophorolipid biosurfactants on the cloud point of alcohol ethoxylates, and on the surface tension and foaming of alkyl sulfate/amine‐oxide mixtures. We make the surprising finding that high‐acid sophorolipids can act as highly efficient hydrotropes and increase the cloud point of alcohol ethoxylates. In sulfate/amine‐oxide mixtures, models of experimental data suggest that both high‐acid and high‐lactone sophorolipids can replace 40–50% of the primary surfactants without significant changes to the surface tension or foaming performance. These findings will enable the next‐generation of high performing sustainable cleaning formulations to be realized.