Stability of CO2/N2 foam generated in CaCO3 nanoparticle/CTAB aqueous dispersion

Abstract

In an attempt to design a thermally stable foam with carbon sink attributes, the foamability and stability of aqueous foams generated from dispersions of CaCO3 nanoparticles (NPs) and hexadecyltrimethylammonium bromide (CTAB) are investigated. Much higher foam stability is reported here relative to literature. When compared to CTAB alone, the addition of CaCO3 NPs increases foam half-life from 5–7 min to 5–6 h in the presence of pure N2 and a gas mixture of CO2 and N2, respectively. Although there is no evidence of CTAB adsorption onto the NPs, the presence of CTAB is crucial to create the initial foam structure that is later stabilized by a network of NPs. Relative to CTAB alone, CaCO3 NPs/CTAB foam displays a higher bubble density and an average bubble size reduction of 67 %. In addition, CaCO3 NPs/CTAB foam is 20-fold more stable at 80 °C.