Studies by the Bristol group, and elsewhere [1, 2], have shown that highly branched hydrocarbon chains is the key factor for generating effective non-fluorous CO2 philic surfactants. This experiment aims to examine synergism between two highly branched hydrocarbon surfactants, TC14 and TMN-6 (Figure 1) both of which have been shown to aggregate in CO2 and stabilize microemulsions [1]. We propose to investigate the effects of mixing these two surfactants to obtain structural information on the micelles and water-in-CO2 (w/CO2) microemulsions. A better understanding of interactions and aggregation in mixed surfactants will have implications for the second generation design of CO2 phillic amphiphiles. This will contribute in the search for more environmentally friendly, economic and efficient compounds needed for emerging CO2 based fluid technologies.