The proposal aims to explore water-in-CO2 (w/c) microemulsions with very promising hybridCO2-philic surfactants. The surfactants have been systematically synthesised withmodifications centred on two main strategies including different levels of hydrocarbon chainbranching and surfactant headgroups. This study will provide new insight for designingeconomical and efficient hybrid surfactants with high solubilising power (high w ratio) and lowfluorine content. Therefore, it is very beneficial because it advances surfactant moleculardesign for green CO2-based technologies.