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1. Active learning of alchemical adsorption simulations; towards a universal adsorption model

   https://doi.org/10.1039/D4SC02156H  

   Osaro, Etinosa; Fajardo-Rojas, Fernando; Cooper, Gregory M; Gómez-Gualdrón, Diego; Colón, Yamil J (October 2024, Chemical Science)

   Active learning facilitated adsorption predictions in porous materials by incorporating “alchemical” molecules, fugacity, and material features (PC1, PC2) using Gaussian process regression. 

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2. Water Adsorption on Goethite: Experimental Infrared Measurements and Theoretical Adsorption Activation

   Paul Ryan Tumminello, Rebecca Meredith (April 2018, Arkansas Aerospace Proceedings)

   The study of water adsorption on mineral surfaces is fundamental to soil and atmospheric science. The physiochemical effects of mineral aerosol influence atmospheric chemistry and climate as well as soil moisture. Iron-containing minerals are abundant on Earth as well as Mars, where the existence and location of surface water is uncertain. Experimental water adsorption measurements have been conducted as a function of relative humidity (RH) on goethite (α-FeO(OH)), a common component of atmospheric mineral dust and Martian crustal material. Water adsorption on goethite was monitored using Horizontal Attenuated Total Reflectance Fourier Transform Infrared (HATR-FTIR) spectroscopy equipped with a flow cell and quantified according to Beer’s Law. Water content as a function of RH was analyzed using type II adsorption isotherms to model multilayer water adsorption. Brunauer Emmet and Teller (BET), Frenkel Halsey and Hill (FHH) and Freundlich adsorption isotherms were applied to model the experimental data. Monolayer water coverage was found to be 4.758x1013 molecules/cm2 based on BET analysis. FHH Adsorption Activation Theory (AT) was used to predict cloud condensation nuclei (CCN) activity of goethite under Earth’s atmospheric conditions. Results aid in the effort of climate prediction on Earth as well as locating liquid water on Mars’ surface. 

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3. Multilayer Random Sequential Adsorption

   https://doi.org/10.1007/s10955-022-02896-5  

   Parida, Priyabrata; Dhillon, Harpreet S. (April 2022, Journal of Statistical Physics)
4. Expanding Cluster, Enhancing Adsorption: Investigating the Role of Electrostatic Configurations on Water Vapor Adsorption

   https://doi.org/10.1021/acs.langmuir.5c01303  

   Mukherjee, Krishnendu; Zastrow, Mckayla; Colón, Yamil J (July 2025, Langmuir)

   Electrostatic configurations─the spatial arrangement of charged sites within an adsorbent─can profoundly influence the adsorbent’s interaction with water and the resulting cluster formation and their orientation. This design feature can serve as a tuning parameter for water vapor adsorption to achieve the desired isotherm behavior. Hence, understanding the role of electrostatic configurations in water vapor adsorption can inform many established and emerging areas concerning the water-energy nexus and water security. In this work, we apply continuous fractional component grand canonical Monte Carlo (CFC-GCMC) to perform water adsorption simulations in idealized cylindrical nanopores across five different charge configurations with varying pore sizes (1, 1.1, and 1.2 nm) and charge magnitudes (∼±0.39–1.17). The alternating along (AA) configuration (positive charges in the inner ring and negative charges in the outer ring while alternating in the z-direction) demonstrates higher water uptake at saturation, and water adsorption starts at a much lower pressure than other configurations. Analysis of the water clustering pattern in AA reveals both radial and axial expansions of water clusters, which facilitates accommodation of extra water molecules. Increasing the charge magnitude shifts the type-V isotherm inflection point to lower pressure, thereby increasing the hydrophilic nature of the cylinder. Probing different energetic interactions and electrostatic potentials of the configuration suggests the unique relaxation of the water clusters in the AA patterned cylinders. Investigating the effect of charge magnitude and pore size provides more insight into their hydrophilic nature. Finally, analyzing the hydrogen bonding and adsorbed phase characteristics at saturation hints at strong ordering induced by pore confinements and electrostatic configurations compared with bulk liquid water. The simulations show that tailored charge arrangements can enhance adsorption by facilitating uptake at a lower pressure and achieving a higher water capacity at saturation. This study presents original insights into the interplay of electrostatic configuration, pore size, and charge strength in controlling water vapor adsorption within nanopores and the resulting confined water vapor structure. 

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5. Tellurite Adsorption onto Bacterial Surfaces

   https://doi.org/10.1021/acs.est.1c01001  

   Goff, Jennifer L.; Wang, Yuwei; Boyanov, Maxim I.; Yu, Qiang; Kemner, Kenneth M.; Fein, Jeremy B.; Yee, Nathan (August 2021, Environmental Science & Technology)