Wetted-Wall Dielectrophoretic Separator for Collection of TiO₂ from SiO₂–TiO₂ Particle Mixture Dispersed in Ethanol

Abstract

To date, particle separation using dielectrophoresis (DEP) has been intensively investigated for small-scale operations mainly for bioapplications and nanoapplications. However, methods for expanding a DEP separator to large scale have not yet been established. In this study, an easily expandable wetted-wall DEP separator is proposed, and experiments to capture TiO₂ particles in ethanol and separate TiO₂ from a mixture with SiO₂ are conducted. During the separation of TiO₂ from the mixture with SiO₂, the selectivity for capturing TiO₂ reached about 90%; however, admixing of SiO₂ negatively influenced this selectivity. Based on the experimental results, several equations are proposed to correlate the operating conditions with the saturated amount of TiO₂ captured by this separator. Since scaling up of the present separator can be conducted based on numbering up, the proposed equations for predicting the amount of particles captured per electrode pair will be useful for estimating the required separator size.