Effect of applying electric field on suspension stability during electrophoretic deposition of ceramic particles in nonaqueous media: a case study

In this paper, the variation of suspension stability under the electric field was studied. Ceramic suspensions such as YSZ/acetyl acetone, YSZ/1propanol, and SnO 2 /ethanol were analyzed by applying different voltages. The novel turbidimetry technique was employed to illustrate the stability changes versus electrophoretic deposition (EPD) time. Macro-photography was employed to study the colloidal stability before and after EPD. Also, the weight of the deposited particles was measured. Particles in the suspension were sediment after applying voltage, making the suspension transparent in our deposition cell, especially at 100 V. The electrical conductivity of suspension increased by applying the electric field, showing a peak at 100 V. The suspension conductivity measurements also revealed a peak at 100 V. The occurred transparency became more in-depth over time. As suspension stability is an essential factor for a successful EPD process, the electric field-assisted agglomeration of particles should be considered in tests to reach repeatable results. Our research showed that despite the use of high voltage in routine EPD research, the instability of suspensions and its effect on the results of the coating should be considered. Graphical abstract