Demulsification of O/W emulsion using a novel polyether-polyquaternium copolymer: effect of the demulsifier structure and solution environment conditions

A novel polyether-polyquaternium (PPA) demulsifier was prepared to dispose the alkali–surfactant–polymer flooding-produced water. The PPA replaced the sodium dodecylbenzenesulfonate (SDBS) on the oil/water interface and formed incompact interfacial film that destabilizes the oil droplets, making the oil/water separation easily achieved. Herein, we investigated the effects of the demulsifier structure and solution environment conditions (pH, temperature, and salinity) on the demulsification process. The highest demulsification efficiency reached 82.6% at pH of 6 and temperature of 60°C. These results impact the destabilization of O/W emulsion and provide new insight to enhance the demulsification performance of demulsifiers.