Effect of partially hydrolyzed polyacrylamide on the solution and foam properties of sodium alcohol ether sulfate

The solution and foam properties of systems composed of sodium alcohol ether sulfate (AES) and partially hydrolyzed polyacrylamide (HPAM) at different concentrations were investigated. The addition of HPAM could increase the surface tension of AES solutions caused by the decrease of surfactant adsorption density at the air-water surface. The viscosity of the AES/HPAM systems were determined by the HPAM concentration. With the increase in AES concentration, the foam generation time and bubble size first decreased and then reached a plateau, while the initial liquid volume of the foam increased first and then reached a plateau. The inflection occurred at an AES concentration of 0.1 wt%, which is higher than the critical micelle concentration (CMC). This is because the air-water surface area increased dramatically during foam generation, which makes surfactant surface density unsaturated at the CMC. Only a higher surfactant concentration could maintain the saturation of surface adsorption density. The addition of HPAM could improve the foamability and enlarge the bubble size at low AES concentrations, because the increased bulk viscosity and the hydrogen bonds between AES molecules and HPAM chains stabilized bubble films and reduced the breakdown of large bubbles. The increase of HPAM concentration would always improve the liquid-carrying capacity and decrease the drainage rate of the foam. These findings indicate that it is possible to use low concentrations of foaming agents and improve foam properties by adding water-soluble polymer in field applications.