CO2-Responsive microemulsion: reversible switching from an apparent single phase to near-complete phase separation

Abstract

A CO₂-switchable microemulsion was fabricated by introducing low-cost commercial N,N-dimethyl-N-dodecyl amine into a sodium dodecyl sulphate–butanol–heptane solution. Upon alternate bubbling of CO₂ and N₂, the system reversibly switched between a monophasic microemulsion and nearly complete phase separation, reflecting the disruption and re-formation of a thermodynamically stable microemulsion.