Reverse Micelles as Templates for the Fabrication of Size-Controlled Nanoparticles: A Physical Chemistry Experiment

Abstract

Synthesis and characterization of nanomaterials yields opportunities for instruction of related topics in solution chemistry and materials science, as well as spectroscopy connecting to band theory, the particle in a box quantum mechanical model, and thermodynamics. In collaboration with an undergraduate research assistant, we have developed a synthesis experiment that investigates the use of reverse micelles as reaction templates for the preparation of size-controlled nanomaterials through simple, controlled precipitation reactions. This experiment is designed for an undergraduate physical or inorganic chemistry laboratory course. The proposed method boasts several advantageous features, including simplicity, functionality both at low temperature and in the presence of oxygen, applicability to a wide variety of compounds including semiconductors and colloidal metals, and precise control of particle size. To demonstrate our method, we chose CdSe as a model system due to its readily observable size-dependent optical effects. The particles produced are well-controlled and show high optical quality. Additionally, the use of reverse micelles allows us to further broaden the scope of this assessment, incorporating other key topics including ligand–metal chelation, nucleation/growth kinetics, thermodynamics, surfactant chemistry, and hydrodynamics.