Handling micron-sized particles in bulk and depositing a large number of them onto a substrate in a controllable manner in the presence of electrostatic effects is a critical, general process step in various industries such as printing and copying, pharmaceutics, food processing, powder metallurgy and electronics and semiconductor manufacturing. Experiments show that there is considerable variation in particle-substrate adhesion force among particles prepared in an identical manner. It has been hypothesized that this variation results from non-uniform charge distribution on the surface of individual particles. To verify this hypothesis, and to understand the underlying mechanisms responsible for non-uniform charge distribution, it is necessary as a first step to determine charge distribution on the surface of individual particles. This project will develop techniques for determining charge distribution on individual toner particles under controlled conditions. Force required to roll a single particle will be determined by two techniques: one based on the Atomic Force Microscopy (AFM) and the other based on acoustics. The measured force will be used to estimate charge distribution under varying conditions.
New knowledge generated in this research program will be useful in the design and production of novel classes of energy-efficient emulsion aggregation toner and associated powder handling/deposition systems. Reduction in cost, energy consumption and environmental impact through the utilization of this technology in toner design and development phases are among the chief benefits of the program to society at large. The emulsion aggregation technology offers 60-70% energy savings per printed page in comparison to the conventional pulverized toner. It is projected that its adoption will result in substantial reductions in toner material usage, toner waste and greenhouse gas emissions. This project also includes a strong education component. The program will enhance undergraduate and graduate curricula at Clarkson by providing industrial internships and will support a state-funded K-12 teacher summer training program for increasing nanotechnology awareness. Students and participating teachers will have opportunities to interact and work with researchers from Clarkson and Xerox in fundamental research problems of practical relevance.
