Effect of interfacial properties on the stability of ultra-dry CO2-in-water (C/W) foams stabilized with zwitterionic surfactants and nonionic/anionic polymers: Experimental and DPD simulation

摘要

Cocamidopropyl betaine (CAPB) and poly(acrylamide) (PAM) were used for the formation of an ultra-dry CO2-in-water (C/W) foam in which the water volume fraction could be as low as 5 %. At water contents between 10 % and 5 % viv, the C/W foam formed with CAPB and nonionic PAM (NPAM) showed four times longer stabilization times than that formed with only CAPB. The synergistic effect of surfactants and polymers on the viscosity, interfacial density and thickness was also analysed using dissipative particle dynamics (DPD) simulations. NPAM could assemble at the C/W interface, act as a surfactant and stretch between surfactants, which enhanced the density of the surfactant at the interface, prevented the aggregation between the surfactants and improved the foam stability. For the CO2/water/CAPB system, the addition of NPAM with a shorter chain length was more conducive to improve the stability of the C/W foam. (C) 2019 Elsevier B.V. All rights reserved.