Effect of nanoparticles and silicone surfactants on the foam properties and wettability of dust removal foam

Foam has been widely used in coal mine dust control. However, its instability is still an issue in its application, and some surfactants components in foaming agents, such as fluorocarbons, are harmful to the environment. In this study, the environmentally friendly alkyl glycoside(APG0814) and cetyltrimethylammonium bromide (CTAB) were used as the foaming agents, and modified hydrophilic SiO2 nanoparticles were added to improve foam stability. Also, the surface tension, foam properties, contact angle and intermolecular interaction of APG0814/CTAB/SiO2 dispersion were studied. The experimental results showed that the appropriate concentration of CTAB combined with nanoparticles played a key role in stabilizing the foam. The surface tension of the foaming liquid increased with the increase in nanoparticles and CTAB, leading to the deterioration of foaming properties. The silicone surfactant GT-248 was added to the APG0814/CTAB/SiO2 dispersion to further improve the surface activity of the foaming agent, and the effects of the silicone surfactant on the surface tension, foam properties, and wettability were studied systematically. The experimental results showed that the surface tension of the foaming agent decreased, and the foaming and wettability increased with the increase in silicone surfactant concentration. By the synergistic action of nanoparticles and surfactants, long-lasting and stable foam, fast coal dust deposition rate and low contact angle can be obtained. Among them, 0.8 wt%GT-248 was added to achieve the best surface activity, foaming ability and wettability. These fundamental results might guide the application of silicone surfactants combined with nanoparticle-hydrocarbon surfactants in mine dust control.