CO₂-Responsive Wormlike Micelles Based on Pseudo-Tetrameric Surfactant

Wormlike micelles, which are linear aggregates created by the self-assembly of surfactants, may entangle to form dynamic three-dimensional network-like structures, endowing solutions with considerable macroscopic viscoelasticity. Recently, a pressing need has arisen to research a novel stimuli-responsive worm-like micelle that is efficient and environmentally friendly. CO2 is an inexpensive, abundant, non-toxic, biocompatible, and non-combustible gas, and it is anticipated that CO2 may serve as the trigger for stimuli-responsive worm-like micelles. In this paper, the formation of CO2-switchable pseudo-tetrameric surfactants, which subsequently self-assemble into CO2-switched wormlike micelles, is accomplished using a simple mixing of two commercial reagents, such as stearic acids and cyclen. The rheological characteristics switched by the use of CO2 are cycled between that of a low-viscosity (1.2 mPa·s) fluid and a viscoelastic fluid (worm-like micelles, 3000 mPa·s). This article expands the field of study on stimuli-responsive worm-like micelles