Smart Nanoporous Materials: Mechanisms of Actuation by Adsorption and Electrosorption

Abstract: For porous or nanostructured materials, where surface to volume ratio is high, chemical processes taking place on a surface can strongly affect the entire bulk of the material. Adsorption of guest species on the solid surface induces stresses, which result in material’s deformation. Experiments show deformation when the species are atoms or molecules adsorbing from the gas phase, as well as when the species are ions, adsorbing from electrolyte solutions (electrosorption). Typically, deformation induced by both adsorption and electrosorption is undesired, but if well understood and controlled, it can be utilized for actuation of "smart" nanoporous materials.

In this presentation, I will focus on mechanisms of adsorption-induced deformation in nanoporous materials, showing that in most cases the driving force is the solvation pressure in the pores acting normal to the pore surface. I will further demonstrate the cases when solvation pressure is not sufficient to describe the effects even qualitatively. These require introducing the stresses along the solid surface, so-called surface stress, and quantifying its change as a result of adsorption. Lastly, I will discuss the systems where coupling between adsorption and deformation processes is essential, and show how it can be achieved in molecular modeling.

Bio: Dr. Gennady Gor is an associate professor at NJIT and a visiting research fellow at Princeton University. He received a PhD in theoretical physics from St. Petersburg University, Russia, in 2009. He continued his research in the United States, first at Rutgers University, and then at Princeton University and Naval Research Laboratory. In 2016, he joined the faculty of NJIT.

The central focus of Dr. Gor's research is in interactions of fluids with porous materials. He is an expert in molecular modeling of fluid adsorption, known for his contributions to modern methods of adsorption porosimetry and the development of the theory of adsorption-induced deformation. His current research interests include confined liquids and electrolytes, atmospheric aerosols, chemical warfare agents, lithium-ion batteries, and ultrasound propagation in porous media. Dr. Gor authored more than 70 peer-reviewed publications and is the recipient of the National Research Council Associateship (2014) and the NSF CAREER Award (2020).

All seminars are held on Wednesdays from 12:00 noon-1:00 p.m. in the Bowen Hall Auditorium Room 222. A light lunch is provided at 11:30 a.m. in the Bowen Hall Atrium immediately prior to the seminar.