Role of nanoparticles in the performance of foam stabilized by a mixture of hydrocarbon and fluorocarbon surfactants

Abstract

The molecular interaction, foaming ability, and foam stability of the mixtures of hydrophilic silica nanoparticles, a cationic hydrocarbon surfactant, and a nonionic short-chain fluorocarbon surfactant were studied systematically. The results indicate that nanoparticle concentration has a considerable impact on surface activity, dynamic viscosity, conductivity, foaming ability, and foam stability. The surface activity and dynamic viscosity of the foam dispersions increased rapidly with increasing nanoparticle concentration. The conductivity and foaming ability of the dispersions decreased with the addition of nanoparticles and further decreased with increasing nanoparticle concentration. At a nanoparticle concentration below 0.1%, the addition of nanoparticles accelerated foam drainage and coarsening. At a nanoparticle concentration above 0.1%, the addition of nanoparticles enhanced foam stability by decelerating foam drainage and foam coarsening. The foam stability was further enhanced as the nanoparticle concentration increased. This study provides a basis for the application of foams stabilized by nanoparticles in fire extinguishing agents.