Surfactants have ability to self-assemble into morphologically different structures, such as micelles, vesicles, liquid crystals, etc. The functions and physical properties of surfactant systems depend strongly on their microstructures.  Controlling the structures and properties of surfactant systems has been an interesting topic for years.

Recently, the researchers of the Institute of Chemistry, Chinese Academy of Sciences found that compressed CO₂ can switch phase transition between lamellar liquid crystal (L_a) and micellar solution (L₁) for some surfactant systems. This method is simple, and the gas can be easily removed by depressurization, which makes the post-processing much easier in comparison with the traditional additives such as cosurfactants and salts that usually cause contamination or modification of products. Some of the results were published in Angew. Chem. Int. Ed. ( 2008, 47, 10119-10123).

Angew. Chem. Int. Ed.  2008, 47, 10119-10123