Rheological properties of ITO slurries prepared from nano-powders for gelcasting process

Indium tin oxide (ITO) powder with a mean particle size of 80 nm was used to prepare ITO slurries for gelcasting. The rheological properties of ITO slurries prepared from nano-powders were investigated. The optimum pH value and dispersant concentration of the ITO slurries are about 10 and 0.75 wt% (based on the weight of ITO powder), respectively. The viscosity of the ITO slurries with a solid loading of 30 vol% (75.4 wt%) decreases obviously by adding acrylamide. The theoretical maximum solid loading of slurry using ITO nano-powders are calculated to be 44.38 vol% (85.1 wt%). The practical highest solid loading of the ITO slurries prepared with the nano-powders could reach 40 vol% (82.7 wt%) and the relative density of the green body and the sintered ceramic are 53% and 92.4%, respectively.