Understanding the "Microwave" in Microwave Chemistry

Microwave chemistry has long been a subject of interest in both the organic and inorganic synthesis communities. Microwave heating has the potential to become a powerful force for green synthesis in industry as it uses much less power to accomplish the same goals, but a lack of understanding in how to translate traditional convective reactions into microwave reactions is hampering this progress. In this manuscript an overview of microwave physics and mathematics is given first. Then the role of microwave source and choice of microwave reaction vessel, along with precursor and solvent choice in the design of a microwave chemical reaction is explored. Next, synthesis of nickel and gold nanoparticles—chosen because of their ubiquitous nature in the literature—in a microwave is explored, and the kinetics examined. Additionally, the role of size dependent properties of the nanoparticles, as well as the role of the oxide layer on the nanoparticle, are explored in relationship to how the reaction heats in a standard laboratory microwave. Lastly, the role of power and frequency of the microwave radiation in the synthesis of nickel nanoparticles is examined, and relationships between the kinetics of the synthesis and the applied power and frequency of the microwave is extracted.