Cherng et al. [114] studied the EPD of YSZ thin films using aqueous suspension. To prevent the colloids from agglomeration and sedimentation during EPD, negatively charged polyelectrolyte, such as ammonium polyacrylate (PAA-NH4), are added as dispersant. PAA-NH4 dissociates in water, forming negatively charged polyanions that would adsorb to YSZ particles to stabilize them electrostatically. An addition of ~0.1wt% PAA-NH4 is sufficient to stabilize the YSZ slurry.