General seminar | 22 October 2021

Nanoporous materials have high surface area and, therefore, they have multiple technological applications involving gas or liquid adsorption. When a fluid is adsorbed in a nanopore, the solid-fluid interaction forces induce significant stresses on the material, so that it deforms. This phenomenon, known as adsorption-induced deformation, takes place in all known nanoporous materials. The magnitude of the strains, however, varies a lot: stiff adsorbents, such as zeolites or activated carbon, deform by only fractions of a percent. Highly porous or soft materials, such as aerogels, porous polymers or MOFs can deform up to tens of percent. My presentation will include an overview of the recent experiments on adsorption-induced deformation, followed by theoretical models, and concluded by possible applications, such as sensors, actuators and membranes with controlled transport.

Additionally, I will show how the stresses that cause the deformation of the solid affect the properties of the fluid itself, in particular the fluid compressibility. I will give an overview of ultrasonic experiments on fluid-saturated nanoporous materials, which provide the information on the fluid compressibility. I will present the results of molecular simulations, which explain the observed deviation of compressibility from its bulk value. These findings provide a basis for employing ultrasound to study adsorption in nanoporous materials.

Main paper/arXiv, related to the seminar, and other references

Dobrzanski, C. D.; Gurevich, B.; Gor, G. Y. "Elastic Properties of Confined Fluids from Molecular Modeling to Ultrasonic Experiments on Porous Solids" Appl. Phys. Rev. 8, 021317, 2021, DOI: 10.1063/5.0024114

Corrente, N. J.; Dobrzanski, C. D.; Gor, G. Y. "Compressibility of Supercritical Methane in Nanopores: a Molecular Simulation Study" Energy & Fuels 2020, 34(2), 1506-1513 DOI: 10.1021/acs.energyfuels.9b03592

Maximov, M. A.; Gor, G. Y. "Molecular Simulations Shed Light on Potential Uses of Ultrasound in Nitrogen Adsorption Experiments" Langmuir 2018, 34(51), 15650-15657, DOI: 10.1021/acs.langmuir.8b02909

Gor, G. Y.; Huber, P.; Weissmüller, J. "Elasto-Capillarity in Nanopores: Sorption Strain from the Actions of Surface Tension and Surface Stress" Phys. Rev. Materials 2018, 2, 086002, DOI: 10.1103/PhysRevMaterials.2.086002

Gor, G. Y.; Huber, P.; Bernstein, N. "Adsorption-Induced Deformation of Nanoporous Materials - a Review" Appl. Phys. Rev. 2017, 4, 011303 DOI: 10.1063/1.4975001