SGER: Accumulation of Particulates in Complex Flows: Characterization by NMR Imaging

Columbia University, New York NY

Investigators

Abstract

Abstract CTS-0425187 N. Shapley, Columbia University Accumulation of Particulates in Complex Flows: Characterization by NMR Imaging The mission of this research is to probe the behavior of dispersed particulates (particles or droplets) in complex flows that are relevant to industrial and biological systems. Flows of concentrated dispersions (liquids containing many discrete particles or droplets) are found in many processes in the pharmaceutical, food, oil, and plastics industries, but their behavior is difficult to control, generally due to nonuniform distributions of the continually interacting particles or droplets. The intellectual merit of this research derives from the goal of quantifying the distribution of particulates in complex flow geometries and time-dependent flows. In complex flows (where both shearing and elongation are present), existing continuum models of concentrated suspensions often do not predict observed particle distributions, numerical simulations in complex geometries are too overburdened by intensive computations to be practical, and experimental data are sparse. Our aim then is to acquire incisive sets of measurements of concentrated suspensions and emulsions in simplified model systems that capture key elements of real circulatory, bioreactor, or manufacturing processes. We will apply noninvasive nuclear magnetic resonance imaging (NMRI) along with optical methods to quantify concentration and velocity distributions in these systems and relate observations to particulate properties. The enormous capability of NMRI to be employed in opaque systems and both in vitro and in vivo opens up an entire new dimension of systems that are not accessible to optical techniques. The targeted element of complex flows that this study will address is particulate accumulation in disturbed flows. We aim to identify the most important system parameters determining particulate accumulation and to quantify particulate concentration and velocity profiles as benchmarks for testing continuum model predictions. The study is anticipated to reveal new insights into the behavior of dispersion dynamics. The broader impact of this research program has two main directions. First, there are the applications in which our fundamental research results can be implemented as practical guidelines in the long term, ranging from hydrodynamic targeting of drug delivery microspheres to plastics and pharmaceuticals processing. In addition, there is the educational value of the intensive research training that the graduate and undergraduates dents in our laboratory will experience.