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Graphene and graphene oxide (GO), as wonder materials, have penetrated nearly every field of research. One of their most attractive features is the functionality and assembly of graphene or GO, in which they can be considered to be chemically functionalized building blocks for creating unconventional porous graphene materials (PGMs) that not only combine the merits of both porous materials and graphene, but also have major advantages over other porous carbons for specific applications. The chemistry and approaches for functionalizing graphene and GO are first introduced, and typical procedures for pore creation (e.g., in‐plane pores, 2D laminar pores, and 3D interconnected pore assemblies), self‐assembly, and tailoring mechanisms for PGMs to highlight the significance of precise control over the pore morphology and pore size are summarized. Because of their unique pore structures, with different morphologies and intriguing properties, PGMs serve as key components in a variety of applications such as energy storage, electrocatalysis, and molecular separation. Finally, the challenges relating to PGMs from the understanding of chemical self‐assembly to specific applications are discussed, and promising solutions on how to tackle them are presented. This provides an insightful outlook for the future development of the chemistry and applications of PGMs.Recent advances in the chemistry of graphene and porous graphene materials, including surface chemistry, interface chemistry, assembly chemistry, and functionalization chemistry, and their potential applications are reviewed. Additionally, their porous structure‐performance relationships for energy storage and conversion, electrocatalysis, and molecular separation are summarized. [ABSTRACT FROM AUTHOR]

Abstract: A free energy (FE) model, the Shan–Chen (S–C) model, and the Rothman and Keller (R–K) model are studied numerically to evaluate their performance in modeling two-dimensional (2D) immiscible two-phase flow in porous media on the pore scale. The FE model is proved to satisfy the Galilean invariance through a numerical test and the mass conservation of each component in the simulations is exact. Two-phase layered flow in a channel with different viscosity ratios was simulated. Comparing with analytical solutions, we see that the FE model and the R–K model can give very accurate results for flows with large viscosity ratios. In terms of accuracy and stability, the FE model and the R–K model are much better than the S–C model. Co-current and countercurrent two-phase flows in complex homogeneous media were simulated and the relative permeabilities were obtained. Again, it is found that the FE model is as good as the R–K model in terms of accuracy and efficiency. The FE model is shown to be a good tool for the study of two-phase flows with high viscosity ratios in porous media. [Copyright &y& Elsevier]

In article number 1909035, Zhong‐Shuai Wu, Hui‐Ming Cheng, and co‐workers review the state‐of‐the‐art advances of the chemistry of graphene and porous graphene materials, and summarize their promising applications such as supercapacitors, batteries, electrocatalysis, and molecular separation. [ABSTRACT FROM AUTHOR]

This paper presents an electrochemical–thermal–hydraulic–mechanical (ETHM) coupling model by introducing the electrolyte flow field into the model of lithium-ion batteries (LIBs). First, the ETHM coupling model is established on the basis of the electrochemical–thermal–mechanical (ETM) coupling model and poroelasticity model. Then, the ETHM coupling model for the discharge of LIBs is numerically resolved and verified against the ETM coupling model using the commercial 11.5 Ah LiMn2O4 battery as an example. Subsequently, the flow and deformation characteristics (such as the Darcy's velocity, the pore pressure, the Péclet number, and the volumetric strain) are analyzed. The results suggest that the electrolyte does flow during the operation of LIBs. Furthermore, the electrolyte flow is governed by the internal pore pressure gradient induced by the poroelastic effect. The electrolyte flow behavior is also influenced by the boundary conditions. The findings in this study are of benefit to obtain in-depth understanding of the coupling mechanisms among the electrolyte flow field and the stress (strain) field, the temperature field, and the electrochemical field. [ABSTRACT FROM AUTHOR]

• Fully coupled THM model of porous media under LTNE condition is presented. • T s is always higher than T f due to the LTNE effect. • Dependences of multi-physical fields on the pertinent parameters are investigated. This paper presents a fully coupled thermo-hydro-mechanical (THM) model of a fluid-saturated and compressible porous medium under local thermal non-equilibrium (LTNE) condition and carries out the corresponding numerical simulation. First, the coupling among the temperature field, the pore fluid pressure field, and the solid stress/displacement field is fulfilled by means of strong explicit coupling of governing equations in this study. Then, the presented model is applied to the THM coupling problem in an infinite porous medium with a cylindrical borehole subjected to uniform fluid pressure and temperature at the borehole boundary. Subsequently, the partial differential equations (PDEs) module in COMSOL Multiphysics software is employed to numerically solve the studied problem. Consequently, the finite element solutions of the pore fluid pressure field, the strain/stress fields and the two temperature fields of pore fluid and skeleton solid are obtained, and the spatial-temporal distribution characteristics of the above multi-physical fields are investigated. Finally, the corresponding parametric studies are carried out. The numerical results show that the stress decreases with the increase of the bulk volumetric thermal expansion coefficient of porous media. And the pore pressure decreases when the pore fluid mobility increases. Meanwhile, it is found in this work that the solid temperature is always higher than that of pore fluid due to the LTNE effect. Besides, with increasing the specific solid–fluid interfacial heat transfer coefficient, the solid temperature decreases, while the temperature of pore fluid increases. Accordingly, the temperature difference between the solid and the pore fluid diminishes. In addition, the thermal conductivity of solid grains has a greater impact on the solid temperature but has a limited impact on the temperature of pore fluid, and vice versa. The findings in this work are of benefit to obtain in-depth understanding of THM fully coupling mechanism and LTNE effect in a fluid-saturated porous medium. [ABSTRACT FROM AUTHOR]

The friction properties of oil-impregnated porous polyimide (PPI) material are closely related to surface pore size which is subject to changes during processing. Though the pores inside PPI, designed according to requirements of applications, could not be changed conveniently, surface pores are easy to be modified. To study the effects of surface pores, pores on PPI surface was enlarged by laser scanning and shrunk by spreading a thin layer of finer polyimide particles on PPI surface during molding. Oil absorption of PPI materials was tested with a U-tube test rig and a contact angle goniometer. The friction tests were carried out on a ball-on-disc tribometer. The results shows that though larger surface pores may increase oil absorption-extrusion, the friction coefficient gets higher. The friction coefficient can be decreased by shrinking surface pores. Larger surface pores make oil extrude easily but lead to low capacity of oil film, vice versa. Therefore, a balance exists between oil absorption-extrusion and the capacity of oil film by fabricating proper surface pore size. In this paper, the oil-impregnated friction coefficient is reduced by 18.8 % through spreading finer powder filtered by 400 mesh on PPI material surface. • Effect of surface pore size on tribological properties of PPI material was studied. • Though larger surface pores may increase oil absorption speed, COF gets higher. • Smaller surface pores are conducive to the reduction in friction coefficient. • Shrinking surface pores improve friction properties without changing internal pores. [ABSTRACT FROM AUTHOR]