Dispersion and Rheological Characterization of TiO_2 Tape Casting Slurry

摘要

Dispersion behavior of TiO_2 in different solvent systems in combination with two different dispersants was studied and optimized for the dispersion of TiO_2. Based on sedimentation, viscosity, and rheological characteristics, zeotropic ethanol: xylene with a ratio of 50:50 along with 1 wt% menhaden fish oil is found to be the best solvent-dispersant combination for TiO_2. Tape casting slurry was optimized using polyethylene glycol 400 and benzyl butyl phthalate as plasticizers and polyvinyl buyral as the binder. Cyclohexanone was used as homogenizer. TiO_2 tapes were obtained by double doctor blade tape casting process. As cast tapes were dried in air at room temperature. The results show that it is possible to obtain homogenous defect-free green tapes of 58.7% solid loading and green density of 55% having thickness of ～90 μm.