Detection Mechanism of Water Content in Oil–Water Emulsions by Coaxial Double Cylinder Electrodes

This article proposes a new method for detecting water content in oil–water emulsions by a coaxial double cylinder electrodes system. An equivalent circuit model of the system is developed that consists of the electrical double layers, sample solutions, and electrodes. The impedance response is analyzed for different frequency ranges, and the effect of the electrode surface–sample solution interface is also investigated. A coaxial double cylinder electrodes system is designed and fabricated to conduct measurement experiments. The results verify the validity of the model and uncover a linear relationship between the water content and the electrical properties. Combined with the back propagation artificial neural network, the impedance spectral data also show a strong correlation with water content. We also demonstrate how the method can contribute to determining the water content of an oil–water emulsion system.