Nanosize Particles as Building Blocks for Uniform Colloids of Different Morphologies

Clarkson University, Potsdam NY

Investigators

Abstract

This project aims to unravel the fundamental principles of the formation of particles with well defined shapes by aggregation of nanosize precursors by investigating several precipitation processes that are capable of yielding dispersions consisting of uniform polycrystalline particles of different well defined shapes (cubes, plates, rods, ellipsoids). The selected systems are based on simple chemical reactions, to prevent the complexity of the systems to obscure the kinetics of the particle nucleation, and provide the possibility to separate and control different stages of the formation process so that highly sophisticated instrumentation can be used to follow the precipitation process and to evaluate the structure and surface characteristics of the intermediate and final dispersed uniform particles. The aim is to develop theoretical models to explain how a huge number of nanosize subunits can get together to yield perfectly uniform much larger final entities. In addition to its significant impact on the colloid and materials science, it is expected that the incorporation of the results of this research in various courses and the involvement of graduate and undergraduate students in the actual experimental work will result in training scientists capable to deal with the materials and processes required by future advanced technologies. The assembly of nanosize crystals into larger uniform colloids is a fundamental process that plays a critical role in the formation of a very broad range of fine-particles used in numerous applications in technology, medicine, and national security. It is widely accepted that, along with size, in most of these applications the shape of the particles represents a critical factor. The proposed research seeks to investigate the formation mechanisms of uniform particles with well-defined size and shape and develop the scientific basis for designing and manufacturing high performance materials for both existing and emerging technologies. In doing so, we expect to develop the basic knowledge needed to 'apriori' select the experimental conditions that can successfully lead to uniform particles of metals, ceramics, and drugs with well-defined and controllable shapes (platelets, needles, rods, cubes, etc.), which can function as building elements for many novel devices and structures. The incorporation of the scientific findings in existing and newly developed courses and the involvement of graduate and undergraduate students as well as postdoctoral scientists in the actual experimental work are expected to result in the training of scientists capable to deal with the materials and processes required by future advanced technologies.