Mixing was conducted in the SpeedMi

Mixing was conducted in the SpeedMixerTM such that the transport phase could be uniformly distributed among the ceramic powder without opening the sealed container and exposing the mixture to the ambient laboratory environment, minimizing water absorption or evaporation to negligible levels. The only point in which the powder formulations were exposed to the ambient laboratory environment was in the final step of loading the pellet die; however, the total exposure time was generally less than 10 s. Experiments quantifying the change in moisture content of powder formulations with respect to time (discussed in the Results and discussion section) revealed that in 10 s there is negligible water absorption or evaporation. Discussion on the benefits and disadvantages of incorporating the hydroxide transport phase as an aqueous solution vs. a powder is included in the Results and discussion section.