Steady and dynamic rheological behaviors of sodium carboxymethyl cellulose entangled semi-dilute solution with opposite charged surfactant dodecyl-trimethylammonium bromide

The steady and dynamic rheological behaviors of sodium carboxymethyl cellulose (NaCMC) entangled semi-dilute solution filled with different concentrations of dodecyl-trimethylammonium bromide (C₁₂TAB) were investigated. The results reveal that the zero shear rate viscosity (η₀) and dynamic modules (G′and G″) increase with C₁₂TAB concentration (C_s), and there exist three scaling regions divided by two critical C₁₂TAB concentrations (C₁, C₂ and , respectively, from steady and dynamic tests). The increase of viscosity and modules with C_s is ascribed to formation of network due to C₁₂TAB micelles bridging NaCMC chains. The two critical C₁₂TAB concentrations implies that the structure evolution of NaCMC–C₁₂TAB complex is exposed to three states with increasing C_s, i.e., no network formation, network extent progressive formation and perfect network formation, respectively. Moreover, are a little lower than C₁, C₂, indicating that the dynamic test is more sensitive to detect the structure change of the complex as compared with steady test. Furthermore, it is found that as NaCMC concentration increases, , and increase.