Rheology Behaviors of C22-Tailed Carboxylbetaine in High-Salinity Solution

Viscoelastic wormlike micelles have attracted special interests over the past decade due to their unique rheological response. Few efforts were however devoted to the rheological properties of worms in high-salinity solution. Here, worm-containing viscoelastic fluid is designed from single N-erucamidopropyl-N,N-dimethyl carboxybetaine (EMAB), using brine water (total dissolved solids: 32,868 mg L^?1; [Ca²⁺] + [Mg²⁺]: 873 mg L^?1) as solvent. Upon increasing concentration, EMAB brine solution shows remarkable macroscopic viscoelasticity above a low overlapping concentration (0.04 wt%) without adding special hydrotropes, implying a giant 3D network-like entanglement formation. Such a viscoelastic network aggregates exhibit thermo-induced thickening behavior in a comparable temperature range due to the hydrogen bond interaction, and excellent thermal stability. The apparent viscosity at 170 s^?1 can keep above 50 mPa · s at 130°C for 2 hours. These preliminary results will give EMAB a rich prospective for use as rheological modifier, especially for using in some extremely environment such high temperature, high salinity, and high shear.