Behavior of wormlike micellar solutions formed without any additives from semi-fluorinated quaternary ammonium salts

Abstract

In the present work a series of fluorinated quaternary ammonium salts were synthesized in two steps. The physical properties of the obtained surfactants were characterized by DLS, zeta potential, viscosity, and Cryo-SEM. The surfactants with a long fluorinated chain form long and highly flexible aggregates that lead to highly viscous solutions and the formation of an entangled network made of flexible worm-like micelles. The viscoelastic properties of the surfactants that form hydrogels without any additives were characterized along with zeta potential and Cryo-SEM observations. They present a maximum viscosity as a function of worm-like micelles formation. The increase of the fluorinated and hydrocarbon chain lengths contributes to the enhancement of this viscoelastic behavior.