Probing the viability of water-in-CO2 microemulsions with Headgroup-free amphiphiles

Recent SANS studies of an unusual headgroup-free surfactant (Nohead FC6-HC4) produced data that implied the formation of W/CO2 microemulsions (MEs) at a particular pressure (P) and temperature (T). However, at other P and T conditions, or for compounds having different tail lengths, SANS data suggested the formation of either hydrated aggregates (without aqueous cores) or no aggregate formation. With the compound Nohead FC6-HC4 having unusual surfactant architecture, the apparent stabilisation of W/CO2 MEs is a surprising find with a significant potential impact in colloid and interface chemistry. This proposal aims to find an answer to the question Can CO2-philic compounds without a headgroup really stabilize W/CO2 MEs, and if so, how do they work? This study explores W/CO2 ME formation using headgroup-free compounds of various structures over a range of experimental conditions.