CO2-controllable smart nanostructured fluids in a pseudo Gemini surfactant system

A novel CO 2 responsive anionic smart wormlike micelles (SWLMs) was constructed by simply mixing sodium oleate (NaOA) and the small organic counterion 2, 6, 10-trimethyl-2, 6, 10-triazaundecane (TMTAD) in a 3:1 M ratio without complex organic synthesis. After bubbling CO 2 , TMTAD and NaOA molecules in aqueous solution, a pseudo Gemini surfactant is formed in situ due to electrostatic interactions. This system shows two obvious performance transitions when CO 2 is continuously introduced, from a water-like solution to a viscoelastic fluid and then a milky solution. Such transitions reflect the continuous transformation of the self-assembled structure from spherical micelles to wormlike micelles and then vesicle or spherical micelles. Additionally, this system can exhibit two similar sequential transformations when the pH changes in the reverse process.