Eager: Nano-Particle Coagulation Dynamics In Rapidly Dilating Solvents

<p>PROJECT SUMMARY: During the last few months, we have discovered that all recent experimental and modeling work on the production of valuable pharmaceutical powders (insulin, antibiotics, anti-virals, cortisones,..) was not exploiting or even taking into account a rather basic phenomenon that could lead to very significant future product/process improvements. Our preliminary calculations revealed that if sufficiently small solvent droplets could be sprayed into supercritical CO2 'anti-solvent' the ensuing dilation rate would actually be large enough to dramatically reduce the coagulation rate constant and narrow the PSD of precipitating particles in this unusual particle processing environment.
<br>Program Objectives: The purpose of this 1-year Early Concept/Exploratory Research(EAGER) Grant application to NSF-CBET is to enable our immediate exploration/evaluation of this exciting new research direction. Not one of the many other groups worldwide (often affiliated with Chemistry departments) has even considered this interesting type of coupling [between homogeneous kinetics and fluid deformation rate], not to mention the possible practical implications for pharma particle production using more advanced injectors---ie, producing smaller solvent droplet diameters (ca. sub 10-micron) to exploit these predicted benefits.
<br>Intellectual Merit: Our brief initial quantitative account of this potentially transformative discovery, along with our preliminary calculations already demonstrating its remarkable PSD-consequences. This present EAGER Program will allow us to immediately develop this initial discovery into a more general process modeling approach, even enabling inclusion of the effects of other potentially important types of solvent non-uniformities (eg., spatial gradients) on coagulation rate constants, including the effects of net particle charge and fluid temperature non-uniformity.
<Br>Uniqueness of Approach: Because of our unusual interdisciplinary backgrounds (embracing ChE, Fluid Physics, Mech E, and AeroE) we are in a unique position to investigate this exciting new class of possibilities, and then move on (via a 3-year follow-on NSF/CBET Grant) to improve the modeling of several other key aspects of the attractive supercritical fluid particle processing environment. Broader Impacts: The intellectual and economic impact of this work via its effect on future modeling efforts in the many SCF-based industries (pharma-, catalyst synthesis, energetic materials, food technologies,) already exploiting supercritical fluids is likely to be very significant----especially as a result of our university lectures, talks at international conferences (2010 IAC, and AIChE) and universities, provisional patent disclosure, and, of course, our archival publications.</p>