ACMD Seminar: Fundamentals and Applications of Electrokinetics in Porous Media

 

Abstract: Electrokinetics encompasses utilizing electric fields or salt gradients to generate particle and fluid motion. Electrokinetics in porous media has received much attention in recent years given its relevance in natural settings such as intracellular transport and metamorphic transformation, and in applications, including geological carbon sequestration, enhanced oil recovery, rare-earth extraction, and nanoparticle drug delivery. In this talk, I present recent projects in my group concerning the fundamentals and applications of electrokinetics in porous media. First, recent experiments showed that, in a concentrated electrolyte, a charged particle migrates towards an electrode of the same charge – an apparent violation of the Coulomb's law! We develop a predictive computational model for particle electromigration in concentrated electrolytes. By accounting for ion-ion electrostatic correlations which are prominent in concentrated electrolytes, our model successfully predicts experiments, including the above-mentioned intriguing response, which otherwise cannot be achieved by existing theories. Second, recent experiments showed the use of salt gradients to transport particles, known as diffusiophoresis, in porous media for nanoparticle drug delivery and enhanced oil recovery, but existing theories cannot predict the particle motion. We open a new area of research by developing a foundational computational model that can predict diffusiophoresis in porous media. A comparison between our model predictions and experiments demonstrates excellent agreements. We show examples of optimizing particle transport by tuning the composition of the electrolyte mixture in diffusiophoresis. Overall, our models will motivate future theories and experiments, and enable efficient design of current and emerging applications.

 

Bio: Dr. Henry Chu is a Lecturer in Mechanical Engineering at Santa Clara University. He obtained a M.Phil. from The University of Hong Kong and a Ph.D. from Cornell University. He was a Postdoctoral Fellow at Carnegie Mellon University and an Assistant Professor at University of Florida (UF). His research group develops predictive computational tools to address National Academy of Engineering Grand Challenges in soft matter transport and design, collaborating with experimental groups to translate knowledge into applications. His work has been recognized through several awards, including the Inaugural Rising Stars of Small (journal by Wiley-VCH), Nanoscale Emerging Investigator by The Royal Society of Chemistry, UF Associate Provost’s Recognition of Outstanding Teaching and Academic Excellence, ACS Petroleum Research Fund Doctoral New Investigator Grants, and U.S. Department of Energy Geosciences Research Grants. He welcomes collaboration with academia, government agencies, and industry sponsors.

 

Host: Ryan Evans

 

Note: This talk will be recorded to provide access to NIST staff and associates who could not be present to the time of the seminar. The recording will be made available in the Math channel on NISTube, which is accessible only on the NIST internal network. This recording could be released to the public through a Freedom of Information Act (FOIA) request. Do not discuss or visually present any sensitive (CUI/PII/BII) material. Ensure that no inappropriate material or any minors are contained within the background of any recording. (To facilitate this, we request that cameras of attendees are muted except when asking questions.)