Speaker
Description
The diverse and tuneable intermolecular interactions present in ionic liquids (ILs) make them excellent media for surfactant self-assembly. Previous studies of polyoxyethylene alkyl ether nonionic surfactants, in ethylammonium nitrate and propylammonium nitrate have shown they can support the full range of amphiphilic self-assembly behaviour of nonionic surfactants for various applications. However, the head group of these nonionic surfactant, ethylene oxide (EO), is a petrochemical product, prompting us to seek bio-renewable substitutes, amongst which carbon dioxide stands out. Recent studies of nonionic surfactants incorporating CO2 (partly substituted for EO) have shown they are promising surface-active molecules. Small angle neutron scattering (QUOKKA, ANSTO) showed a single CO2 unit per surfactant can have an enormous impact on phase behaviour of dodecyl surfactants in water. The formation of gel-like liquid crystalline phases was completely suppressed through reduced hydration of the headgroups. This study is directed at understanding self-assembly behaviour of CO2 nonionic surfactants in ILs. We have examined the structure of surfactant-IL solutions using small angle neutron scattering as a function of surfactant concentration, solvent composition and temperature. Results shown that unlike water, solvation of nonionic headgroup is mostly unaffected by incorporation of CO2 units in pure ILs. However, this can be easily regulated through water dilution or mixing ILs. This demonstrates the composition of surfactant headgroup and the solvent can be used as tools to engineer solvent-headgroup interactions in formulating non-aqueous soft matter.
| Which facility did you use for your research | Australian Centre for Neutron Scattering |
|---|---|
| Condition of submission | Yes |
| Students Only - Are you interested in AINSE student funding | Yes |
| Presenter Gender | Man |
| Level of Expertise | Student |
| Do you wish to take part in the Student Poster Slam | No |
