NIRT - Collaborative Research: Experimental and Computational Investigations of Fluid Interactions/Transport in Nanodomains and Around Nanoparticles

This grant is funded in response to Nanoscale Science and Engineering initiative, NSF 01-157, category NIRT. Fluidization and transport of micron-sized powder materials are routine unit operations for large-scale manufacturing and processing of a variety of particulate products in many industries, such as petroleum, chemical, agricultural, food, pharmaceutical and ceramics. While many of these industries can benefit from the unique properties of nanostructured materials, little attention has been paid to the fluidization and transport of nanoparticles. In this proposal, the challenging problem of understanding the physics of fluidization and transport of nanoparticles, in order to be able to process them to manufacture nanocomposites with tailored properties, is addressed. Normally, nanoparticles cannot be fluidized because of the very large interparticle forces that exist between them. Recent research, however, indicates that nanoparticles can be fluidized at gas velocities well above the minimum fluidization velocity of the primary particles without being elutriated, because they form large stable agglomerates. These agglomerates are very porous, allowing for a variety of physical and chemical surface treatments that take advantage of the extremely large surface area of the nanoparticles. The NJIT/IIT research program includes experiments to study the flow behavior of nanoparticles in conventional, rotating and circulating fluidized beds. Theoretical modeling and computer simulations, using kinetic theory at various length scales, are also proposed. These models will be used to predict the size and structure of agglomerates of nanoparticles and the flow behavior of nanoparticles in risers. Experiments will also be performed to manufacture nanocomposites with tailored properties by coating 'fluidized' nanoparticles with polymer or by mixing two different species of nanoparticles. The modeling and computer simulations will provide predictive capabilities that will also help in optimization and scale-up. The investigations at NJIT/IIT will be complemented by research on the flow of fluids in nanoscale channels/cavities, performed by the NIRT group at Worcester Polytechnic Institute (WPI).

Another positive outcome of the research will be the education and training of undergraduate and graduate students in the area of particle technology, a relatively neglected area in engineering education but of extreme technological, economic and environmental importance. This will be accomplished in part by a new course in nanotechnology incorporating the results of the research which will also help in disseminating the results. Moreover, because of the large diversity of NJIT's and IIT's student body, many of the students in the particle technology programs at both institutions, and who will be involved with the proposed research, are women and underrepresented minorities. Research and education collaborations and partnerships will also be initiated with academic institutions, industry and government agencies involved with the flow and processing of nanoparticles. Academic collaborations, in addition to that with (WPI) include the Ecole des Mines in Albi, France and Osaka Prefecture University in Japan.