This proposal involves manipulating the curvature of aggregated polar materials in supercritical CO2 (scCO2) by tuning the mixing ratio of fluorocarbon (FC) and hydrocarbon (HC) amphiphiles that act as “headgroup-free” surfactants. This allows for the formation of elongated aggregates able to thicken CO2 and improve viscosity for applications like enhanced oil recovery (EOR). Oil fields typically contain large quantities of metal ions and seawater that can affect the morphology and stability of surfactant aggregates, which in turn reduces the effectiveness of CO2-EOR. This SANS study will provide important information enabling the development of novel, EOR-oriented, CO2-thickeners, which are insensitive to ionic strength, the nature of metal ion contaminants and the quantity of water present.