Cold sintering zinc oxide with a crystalline zinc acetate dihydrate mass transport phase

Cold sintering of ZnO using crystalline zinc acetate dihydrate in the absence of added water is examined. Prior studies use an aqueous solvent, usually containing a weak acid, base, or organic salt, as the mass transport phase during cold sintering. This paper shows equivalent densification of ZnO using solid, powdered acetate as compared to previously mentioned aqueous-based transport phases. It also presents the potential to add zinc acetate in higher quantities without increasing the amount of total added transport phase, as solubility limits in aqueous solvents define the maximum amount of zinc acetate that can be added for a given volume of liquid. Experiments were conducted using the previously reported sinterometer, allowing for in situ experimental monitoring to show densification trends of this new transport phase as a function of concentration, time, and temperature. The potentially dramatic impacts of varying humidity during powder preparation on final sample density will also be discussed.