Wormlike micelles constructed by a highly water-soluble carboxylate surfactant containing a phenoxy and nonionic surfactant

Abstract Limited wormlike micelles were formed from anionic surfactants, especially for carboxylate surfactants due to their poor solubility. As we all know sodium hexadecanoate (C 16 Na) has a higher Krafft point (60 °C). Introducing a phenoxy at α-position of C 16 Na, a new carboxylate surfactant, sodium 2-phenoxyhexadecanoate (C 16 phNa), was synthesized. And the aqueous solution of C 16 phNa could keep water-like even at a concentration of 2 M at 25 °C. Wormlike micelles were successfully constructed by adding tri(oxyethylene) monododecyl ether (C 12 EO 3 ) into the dilute solution of C 16 phNa. Steady state and dynamic rheological measurements were used to investigate the viscoelasticity of C 16 phNa/C 12 EO 3 wormlike micellar solution. The results show zero shear viscosity ( η 0 ) and relaxation time ( τ Rmax ) increase at first and then decrease with the increasing concentration of C 16 phNa or ratio of C 12 EO 3 and C 16 phNa. The value of η 0 in the system could reach 2194.4 Pa·s. In addition, η 0 is extremely dependent upon the concentration of C 16 phNa. And the value of exponents between the η 0 and concentration is 13.1, 20.2 and 18.3 for a 1:1, 1:1.5 and 1:1.8 system of C 16 phNa and C 12 EO 3 , respectively, which is rather large. Cyro-TEM gave a direct image of wormlike micelles of the system. The present systems enrich the contents of anionic wormlike micelles systems.