Title : Particle Synthesis Mechanisms --- Plenty of Room at the Bottom
Speaker: Prof. Sanjeev Kumar, Department of Chemical Engineering, IISc Bangalore.
Abstract: Of the many building blocks of nanotechnology, nanoparticles are the oldest and the most versatile. Thousands of types of nanoparticles have been synthesized using a vast collection of recipes, based on green, benign, and not-so-benign chemicals, and then characterized for their attributes. The effort made to understand these recipes, even the ones in widespread use, is miniscule. Particle synthesis from their molecular precursors occurs when concentration of the precipitating species increases beyond their solubility limit, leading to formation of nuclei through homogeneous nucleation and their subsequent growth to form stable particles. This classical mechanism explains formation of monosized particles through a burst of nucleation. In this talk, Prof. Sanjeev Kumar will cover recently proposed new mechanisms of particles synthesis, some of which are developed in our group. These mechanisms are interesting in that they lead to synthesis of relatively monosized particles without a burst of nuclei formation or new ways of realizing a burst of nucleation. He will also discuss observations in the literature which suggest that there is plenty more that needs to be understood at the lowest level of particle synthesis---the birth of first seeds for particle growth. The mechanistic understanding obtained has helped in synthesis of more monosized particles.
About the Speaker: Prof. Sanjeev Kumar is currently a professor in the Department of Chemical Engineering at IISc Bangalore. He obtained his BE degree from University of Roorkee (IIT-Roorkee), and ME and PhD from IISc Bangalore, all in Chemical Engineering. After spending a couple of years at Purdue University, USA as a post-doctoral fellow, he joined IISc Bangalore as a faculty in the Department of Chemical Engineering in 1996, and has been there since. Sanjeev’s research interests lie in applying continuum modeling techniques to unravel complex phenomena in the general area of colloids and interfaces, specifically nanoparticles, agitated dispersions, foams, emulsions and more recently flow batteries and super-capacitors. He has, over the years, made substantial contribution to the use population balances as a powerful modeling and simulation tool. Prof. Sanjeev greatly enjoys teaching fresh batches of young chemical engineers the art of model making and the basics of colloids and interfaces.