Title:

Wettability, Polarization, and Interfacial Entropy Effects on the Heat Transfer across Alumina-Water Interfaces

Speaker:

Dr. Bladimir Ramos-Alvarado

Affiliation:

Penn State University

When:

Thursday, June 24, 2021 at 2:00:00 PM   Add to Calendar

Where:

https://gatech.webex.com/gatech/j.php?MTID=m597421638e254a1e4ea72469e8e8dc47 Building, Room Virtual

Host:

Dr. G. P. Bud Peterson
bud.peterson@gatech.edu
(770) 355-9070

Abstract

Recent developments in nanofabrication have demonstrated the potential of alumina (Al2O3) for various applications due to its good chemical stability, wide bandgap, and biological compatibility. Special attention is drawn to alumina in aqueous environments, as the behavioral understanding of this solid-liquid interface is crucial for dielectric nanocomposites, water filtration, drug delivery, biosensing devices, combustion, among others. In particular, the new developments in anodic alumina membranes, could be beneficial for filtration and separation of molecules, cells, or proteins, and evaporation in thermal management applications. It has been suggested that most of the interfacial transport (specifically momentum and thermal) is strongly influenced by a thin layer, which usually encompasses no more than a few nanometers from the interfacial region. In this talk, the results from the investigation of interfacial water and thermal transport using reactive and non-reactive molecular dynamics simulations will be presented. The interfacial water structure was characterized by computing the liquid depletion on different crystalline and amorphous surfaces, in addition to the interfacial entropy change. Likewise, the wetting behavior (solid-liquid affinity) of the interfaces was computed in the thermodynamic limit. No predictable trend was found between interfacial thermal conductance and solid-liquid affinity, while liquid depletion and interfacial entropy were the main parameters in determining the magnitude of the interfacial heat transfer and the composition of the interfacial heat flux, respectively. These results underscore the importance of a comprehensive interface modeling approach and potential mechanisms for modulating interfacial heat transfer through engineering the bias imposed on the liquid atoms by a solid substrate.

Biography

Dr. Bladimir Ramos-Alvarado is the principal investigator of the Interfacial Phenomena Lab (IPHEL) at Penn State University, he is a member of the Materials Computation Center at Penn State, and an Associate of the Institute for Computational and Data Sciences (ICDS) at Penn State. Dr. Ramos earned his PhD from the Georgia Institute of Technology (Georgia Tech) in 2016 and after brief Postdoctoral and Instructor appointments at Georgia Tech, he joined the Department of Mechanical Engineering at Penn State University as an Assistant Professor in May of 2017. The objective of his research is to bridge the gap between atomistic scale interactions and observable macroscopic phenomena, such as thermal transport, fluid slip in confinements, wettability, and dielectric properties. Likewise, he is an avid enthusiast of thermal management of electronic devices.