Nanoparticle-stabilized carbon dioxide-in-water foams with fine texture

[Display omitted] ► Hydrophilic/CO2-philic balance was extended to nanoparticles for CO2/water foam. ► Opaque white C/W foams were generated in a beadpack with silica nanoparticles. ► Foam viscosity reached 120x that of a CO2–water mixture without nanoparticles. ► With suitable nanoparticles, the C/W foams were stable for at least 23h. ► 50% SiOH level provided an optimal HCB for foams with high viscosity and stability. The concept of hydrophilic/CO2-philic balance (HCB) was extended to describe stabilization of carbon dioxide-in-water (C/W) foams (also called emulsions) with silica nanoparticles adsorbed at the CO2–water interface. Opaque, white C/W foams (bubble diameter