Oil incorporation can strongly affect the phase behavior of surfactant/water systems. In the first part of our experiments, the effect of perfluorodecalin (PFD) addition on the fluorinated surfactant CF3(CF2)(7)C2H4(OC2H4)(9)OH/water system was investigated. L, micellar phase, direct hexagonal (H-1), and cubic (I-1) liquid crystals were identified. Phase behavior and SAXS measurements proved that the liquid crystals phase can be swelled by PFD, whereas only 1% of oil can be incorporated into the hydrophobic core of micelles (L-1). Reflections lines of the cubic phase have been indexed in the Fm3m space group. Large pore mesoporous materials were then synthesized by incorporating PFD as a swelling agent. The present work shows that PFD is an effective expander to enlarge the pore size of mesoporous materials. Characterization of the recovered materials and evolution of CF3(CF2)(7)C2H4(OC2H4)(9)OH/water system with PFD loading led us to propose a mechanism describing the swelling effect of PFD.