Events: Chemical Engineering Department Seminars
Foundations of Supercritical Fluid Aided Materials Synthesis
Speaker: Aydin Sunol, Visiting Fellow, Princeton University
Location: Elgin Room (E-Quad A224)
Date/Time: Wednesday, November 18, 2009, 4:00 p.m. - 5:00 p.m.
In the last two decades, there has been influx of new supercritical fluid aided material processing techniques for encapsulation, nucleation of particles/powders, impregnation of porous matrices, formation of porous materials, coating/spraying of flat surfaces,
extrusion, comminution, and drying. The technical and economic drivers for using supercritical techniques are many. These processes usually employ a single material processing step. The solvating power and selectivity are tunable, enabling ease in separation of a particular component from a multi component mixture and complete
solvent recovery with residue levels well below FDA thresholds. The gas like mobility of supercritical fluids allow very fast processing times, increasing throughput for a given equipment size. The low surface tension in the processing environment allows smooth coating
and drying of surfaces. The popular supercritical solvent carbon dioxide is readily available, inexpensive, non-toxic, allow near room temperature processing. Furthermore, carbon dioxide in-activate a wide variety of bacterial organisms allowing sterilized final product. There are several reasons why processing with supercritical fluids
are attractive throughout the world. It is not only because they are
green processes and are effective on-site processing of natural resources. The interest is primarily due to controllability and tunability of the processing environment to enable robust synthesis of materials with unique characteristics. On the other hand, our
understanding and ability to predict the anomalities in the critical region and the capital charges associated with processing at high pressures hinder wider use of these techniques. Foundations and fundamental challenges in these novel materials synthesis techniques
will be presented along with few select applications.
