Soybean-Oil-Based CO(2)-Switchable Surfactants with Multiple Heads

Oligomeric surfactants display the novel properties of low surface activity, low critical micellar concentration and enhanced viscosity, but no CO(2) switchable oligomeric surfactants have been developed so far. The introduction of CO(2) can convert tertiary amine reversibly to quaternary ammonium salt, which causes switchable surface activity. In this study, epoxidized soybean oil was selected as a raw material to synthesize a CO(2)-responsive oligomeric surfactant. After addition and removal of CO(2), the conductivity analyzing proves that the oligomeric surfactant had a good response to CO(2) stimulation. The viscosity of the oligomeric surfactant solution increased obviously after sparging CO(2), but returned to its initial low viscosity in the absence of CO(2). This work is expected to open a new window for the study of bio-based CO(2)-stimulated oligomeric surfactants.