Effect of electrical potential of microbubbles on ozone dissolution

Microbubbles make ozone water generation effective due to the high dissolution rate of gas in contrast to a conventional generating method. Therefore, it is presumable that ozone water generation using microbubbles can be achieved by the low concentration ozone gas. In our previous study, a compact and low power microbubble generator was developed. The microbubbles are generated by the local shear stress in the flow through a pipe with slits. In the present study, in order to investigate the relationship between the electrical potential of the gas-water interface and the cleaning of cloth using ozone microbubbles, two models with different slit angles (θ=30 and 60 deg) were installed. High concentration ozone water is produced for θ = 60 deg in contrast to the θ=30 deg case. When a cloth is washed in the θ=60 deg case, the soiled cloth can be cleaned easily in comparison with the θ=30 deg case, because the zeta potential of microbubbles for θ=60 deg is larger than that for θ=30 deg.