Presentation materials
The exquisite diversity and functionality of biological materials is truly remarkable, especially since they are composed of a small set of abundant chemical elements. While engineering materials primarily require specific, often unsustainable, chemical compositions to realize their functions, nature achieves unparalleled functionality through optimized architectures that span multiple length...
In many applications, such as catalysis, electrochemistry or fuel cell, the performance of nanoporous materials hinges on their ability to retain or repel liquid within their porous structure. A critical challenge in these applications is determining whether this liquid distribution is uniform or whether certain pores remain inaccessible. Macroscale wetting phenomena are well-explained by...
Wood's unique combination of low density, high strength and stiffness, low thermal and electrical conductivity makes it versatile across diverse fields such as construction, furniture making, woodcarving, tooling, sculpture, boat building, along with production of cellulose fibers and paper. However, as a hygroscopic material, the water content and transport within wood strongly affect the...
The micro-occurrence of gas and water in shale nanopores under reservoir conditions, as well as the changes in their distribution following the infiltration of fracturing fluids, are critical for understanding the behavior and flow dynamics of gas and water during shale gas extraction. Small-angle and ultra-small-angle neutron scattering (SANS/USANS) experiments conducted under high-pressure...
CH4 sorption hysteresis is pivotal for predicting coalbed methane (CBM) production, yet its driving factor––the coupling of gas sorption and coal deformation—remains incompletely understood. Here, we use a stepwise hybrid grand canonical Monte Carlo/molecular dynamics (GCMC/MD) simulation technique to track continuous CH4 adsorption and desorption in a deformable coal matrix. Both matrix...
The phenomenon of capillary condensation of water in porous media is common in nature. It can significantly alter the properties of adsorption, wetting and flow in porous media. It is of great importance in the fields of materials, environment and energy. However, at the nanoscale, the internal mechanism of capillary condensation in porous media has not been clearly explained. In this study,...
Nanoporous carbons play an important role in different electrochemical applications and, in particular, are widely used as porous electrodes in super-capacitors. Ions in aqueous electrolytes form the electrical double layer on the charged electrode-solution boundary, which can lead to a complex physical picture in nanosized pores. In this work, using molecular dynamic simulations and the...
The exploitation of shale oil holds significant potential, making it essential to understand the occurrence and transport behavior of multicomponent alkanes through shale nanopores for enhanced oil recovery. However, current molecular simulations primarily focus on single-component alkane flow in shale nanopores, failing to capture the multicomponent nature of shale oil accurately. Moreover,...
Shale rocks are abundant in nanopores that range in size from 1 to 20 nanometers. Within these small pores, the pore surfaces can significantly influence all fluid molecules within the confined space. This strong pore-fluid interaction and its competition with fluid-fluid interactions could lead to a heterogeneous distribution of fluid molecules in the pore spaces, which results in modified...
A new free-energy functional is first proposed for inhomogeneous associating fluids. The general formulation of Wertheim’s thermodynamic perturbation theory is considered as the starting point of the derivation. We apply the hypotheses of the statistical associating fluid theory (SAFT) in the classical density functional theory (DFT) framework to obtain a tractable expression of the...
Kerogen is the most abundant form of organic matter in the subsurface and its properties of adsorption, wettability and geomechanics affect gas (H2, He, CH4 and CO2) geo-storage (GGS) capacity and leakage risk. However, a systematically experimental investigation of these three properties at in-situ GGS conditions is lacking and thus large uncertainties exists in evaluating the impact of...
The microscopic pore structure is critical in determining the CO2 sequestration potential of deep coal seams. This study investigates the alterations and underlying mechanisms of coal’s microscopic pores resulting from interactions with supercritical CO2 (SC- CO2) using low-temperature nitrogen (LTN2) adsorption, low-temperature CO2 (LT- CO2) adsorption, and X-ray diffraction (XRD) techniques....
Shale gas reservoirs are characterized by complex micro- and nano-scale pore structures, where gas exists as free gas, adsorbed gas, and dissolved gas. The adsorption layer, primarily forming on organic matter and clay mineral surfaces, significantly influences gas flow dynamics. When the radius of the gas flow channel approaches the molecular free path, the wall interface layer becomes...
