9731769 Lee The objective of this GOALI project is to achieve a better understanding of the behavior of submicron ferroelectric ceramic powders in aqueous liquid media. Although these powders are processed in nonaqueous media satisfactorily, the need for environmentally safer media for manufacturing ferroelectric components is increasing. Two of most widely used ferroelectric ceramic powders, barium titanate (BT) and lead zirconate titanate (PZT), will be used as "model" systems. Fine powders of BT and PZT will be characterized and dispersed in aqueous media, and the particles will be stabilized by adsorbed organic molecules. The stabilizer molecules will be selected for their solubility in water, strong anchoring groups, and sterically stabilizing chains for dispersion and binding of the ceramic particles. Strong and uniform adsorption of the organic stabilizer acting also as passivating agents to prevent the dissolution of metal ions from the powders will be investigated. The interaction between liquid-particle, particle-dispersant, and liquid-dispersant will be studied based on the physicochemical properties of the participants. The effect of the dispersant on stabilization of the submicron ferroelectric ceramic particles will be assessed by analyzing the rheology, zeta potential/isoelectric points, sedimentation behavior, particle characteristics, conformation of the adsorbates, green body properties, and metal ion dissolution of BT and PZT. %%% The ultimate goal of this study is to obtain high density green bodies with uniform microstructure of high reproducibility and reliability. Formed under these conditions, the green ceramics will lead to lower organic content with high green density which will shorten processing times and lower sintering temperatures. The results will provide the needed assistance to the manufacturing problem the industry is facing now by better controlling the reproducibility of ferroelectric powder slips. This control wil l bring lower manufacturing cost with higher product quality and more environmentally "friendly" systems. This project will be carried out under interdisciplinary cooperation among the Ceramic & Materials Engineering Department at Clemson University, Kemet Electronics Corporation, and the National Institute of Standards and Technology. Kemet Electronics Corporation, the industrial partner, will provide their research, analytical, and production capabilities available to Professor Lee, as well and providing a summer internship for a graduate student. In addition, a graduate student will spend a summer working at the National Institute of Standards and Technology, using facilities that are not available at Clemson or at Kemet. The scientific results obtained from this study will be transferred to the industrial partner. Because of the strong linkage with industry, the educational aspects of the project are enhanced. The summer internship at Kemet will expose the graduate student to industrial-type research. This GOALI project is co-funded by the Ceramics Program of Division of Materials Research, the Particulate and Multiphase Processes Program of Division of Chemical and Transport Systems, the Office of Multidisciplinary Activities of the Mathematical and Physical Sciences Directorate, and the GOALI Office of the Engineering Directorate. ***
