SiO2 Particle Charging Behavior with a Nonionic Surfactant in Low-Permittivity Liquids

Phase angle light scattering (PALS) was chosen to study the charging behaviors of metal oxide SiO2 distributed in nonpolar solvents, including nonionic surfactant, often known as “charge control agents”. Zeta potential was examined systematically in relation to the concentration of Span80 (Sorbitan monooleate) and particle size and concentration. The findings showed that Zeta potential was unaffected by the surfactant concentration of Span80 over the critical micelle concentration (CMC) at various particle concentrations (volume percentages ranging from 10^–4 to 10^–2). Over a considerable range, the charging of the particles was not significantly affected by the particle concentration. Additionally, the particles showed a size-independent zeta potential. A straightforward model based on meanfield Poisson-Boltzmann theory and preferential adsorption was offered to predict SiO2 particles’ charging procedure in Span80-dodecane solution. The experimental data and the simulated findings agreed well. It was shown that the preferential adsorption of micelles that carry a charge is the cause of the charging of the SiO2 particle in Span80-dodecane solution.