Interfacial Behaviors of Bio-based Surfactant Escin

The interfacial behaviors of natural triterpene saponin escin at gas -liquid, liquid -liquid, and solid -liquid interfaces were investigated by Wilhelmy method, pendant drop method, and high-speed ea.mera dynamic shooting method, respectively. The properties of the emulsion prepared with escin as the emulsifier and the regulation of escin on droplet impact behavior on hydrophobic solid surface were investigated, and the mechanism were analyzed from molecular level. The results showed that escin could be adsorbed at the air water interface, and the surface tension of water was reduced to 42.1 mN/m with the critical micelle concentration of 5x10-4 mot/L. In addition, escin molecules can also be adsorbed at the oil -water interface, inserting the hydrophobic skeleton into the oil phase and the hydrophilic: headgroup into the water phase to form a stable interfacial film, finally reducing the interfacial tension. With the increase of the concentration, the emulsion prepared with escin as the emulsifier could achieve smaller particle size, larger Zeta potential, and showed good stability in a short period of time. Moreover, the bounce and retraction of droplet on hydrophobic: solid surface could be obviously inhibited by escin with higher concentration, leading to good spreading, which is conducive to its application in many fields.