Ecofriendly Viscoelastic Solutions Formed from a Recyclable Rosin-Based Amine Oxide Surfactant

Innovations in molecular structuresformed using bioresources areefficient means to prepare surfactant aggregates with unique properties.Here, a rosin-based amine oxide surfactant (R-11-3-AO) containing large hydrophobic groups was synthesized from rosinderivatives, namely, dehydroabietic acid and long-chain amino acids.Cryo-transmission electron microscopy showed that R-11-3-AO molecules formed extremely long wormlike micelles with a cross-sectionaldiameter of 4-5 nm at a concentration of approximately 7 mmol center dot L-1. A gel-like system was obtained at approximately30 mmol center dot L-1 due to the dense entanglement ofthe wormlike micelles. The solutions also exhibited unique shear thickeningbehavior at a shear rate of approximately 10 s(-1) even at high concentrations. The large hydrophobic group containedin R-11-3-AO is the origin of the strong van der Waalsinteractions between the surfactant molecules, resulting in the rapidgrowth of wormlike micelles. This rosin-based surfactant is the firstrecoverable amine oxide surfactant from solutions through the salting-outeffect with high recovery rates. This work demonstrates the uniquecapabilities of rosin-based surfactants for forming wormlike micellesand provides opportunities for the development of surfactant recoverytechnologies.