Negative gas adsorption transitions and pressure amplification phenomena in porous frameworks.

Nanoporous solids offer a wide range of functionalities for industrial, environmental, and energy applications. However, only a limited number of porous materials are responsive, the nanopore dynamically alters its size and shape in response to external stimuli such as temperature, pressure, light or the presence of specific molecular stimuli adsorbed inside the voids deforming the framework. Adsorption-induced structural deformation of porous solids can result in unique counterintuitive phenomena.

Unraveling the influence of surface functionalities on gas Physisorption: A comprehensive study on SBA-15 nanoporous material from Monte Carlo simulation for improved Textural-Energetic characterization.

In this study, we conducted experimental and Monte Carlo simulation studies in the grand canonical ensemble (GCMC) to investigate the role of molecular orientation and surface heterogeneity on the adsorption of N at 77 K. Our research focused on a series of ordered nanoporous materials (SBA-15) with varying degrees of oxygen functionalities. Specifically, we examined the effects of surface heterogeneity on the calculation of pore size distribution (PSD) and the Brunauer-Emmett-Teller (BET) area of porous materials.

How Reproducible are Surface Areas Calculated from the BET Equation?

Porosity and surface area analysis play a prominent role in modern materials science. At the heart of this sits the Brunauer-Emmett-Teller (BET) theory, which has been a remarkably successful contribution to the field of materials science. The BET method was developed in the 1930s for open surfaces but is now the most widely used metric for the estimation of surface areas of micro- and mesoporous materials.

Benchtop Measurement of Full Adsorption Isotherms by NMR.

Physisorption using gas or vapor probe molecules is the most common characterization technique for porous materials. The method provides textural information on the adsorbent as well as the affinity for a specific adsorbate, typically through equilibrium pressure measurements. Here, we demonstrate how low-field NMR can be used to measure full adsorption isotherms, and how by selectively measuring H spins of the adsorbed probe molecules, rather than those in the vapor phase, this "NMR-relaxorption" technique provides insights about local dynamics beyond what can be learned from physisorption alone.