Bulk and bubble-scale experimental studies of influence of nanoparticles on foam stability

Abstract

Influence of silicon oxide (SiO2) and aluminum oxide (Al2O3) nanoparticles on the stability of nanoparticles and sodium dodecyl sulfate (SDS) mixed solution foams was studied at bulk and bubble-scale. Foam apparent viscosity was also determined in Hele-Shaw cell In order to investigate the foam performance at static and dynamic conditions. Results show that the maximum adsorption of surfactant on the nanoparticles occurs at 3�wt% surfactant concentration. Foam stability increases while the foamability decreases with the increasing nanoparticle concentration. However, optimum nanoparticle concentration corresponding to maximum foam stability was obtained at 1.0�wt% nanoparticle concentration for the hydrophilic SiO2/SDS and Al2O3/SDS foams. Foam performance was enhanced with increasing nanoparticles hydrophobicity. Air-foams were generally more stable than CO2 foams. Foam apparent viscosity increased in the presence of nanoparticles from 20.34�mPa�s to 84.84�mPa�s while the film thickness increased from 27.5�μm to 136�μm. This study suggests that the static and dynamic stability of conventional foams could be improved with addition of appropriate concentration of nanoparticles into the surfactant solution. The nanoparticles improve foam stability by their adsorption and aggregation at the foam lamellae to increase film thickness and dilational viscoelasticity. This prevents liquid drainage and film thinning and improves foam stability both at the bulk and bubble scale.