Synergistic mechanism between laurel alkanolamide and hydrophobically associating polyacrylamide in solutions with high salinity

Synergism of water-soluble hydrophobically associating polyacrylamide (HA-PAM) with nonionic surfactant laurel alkanolamide (LAA) was investigated via the rheology, fluorescence spectroscopy and dissipative particle dynamics (DPD) simulation methods. The viscosity and elasticity of HA-PAM solutions increased in a large LAA concentration range, which was principally ascribed to the crosslinking effect of LAA by aggregating to the hydrophobic chains of HA-PAM molecules as confirmed by the DPD simulation and experimental results. The crosslinking effect was enhanced in the presence of an appropriate amount of electrolyte or with increasing temperature in the studied temperature range of 20-70 degrees C. Thus, the LAA not only significantly enhanced the salt resistance of HA-PAM but also retarded the decrease of the viscosity and elasticity of the HA-PAM solutions at high temperature. The HA-PAM/LAA binary systems exhibit great potential for application in tertiary oil recovery of oil fields with high salinity.