Materials studio and catalysis series#

Research on deformation parameters is expected to further improve the properties of Gr/Al composites and would provide a deep understanding of the strengthening effect of graphene.ДЄbstract: Ore particles, especially fine interlayers, commonly segregate in heap stacking, leading to undesirable flow paths and changeable flow velocity fields of packed beds. This review summarizes different deformation treatments involved in the preparation process of Gr/Al composites and the evolution of the microstructure during the process. However, they paid less attention to post-deformation processing.

Materials studio and catalysis series#

Researchers have conducted a series of research and literature reviews of the graphene predispersion and consolidation of composites. In the preparation process, predispersion treatment and deformation treatment can play important roles in graphene dispersion. Decreasing the agglomeration of graphene and dispersing it uniformly in the Al matrix is a key challenge. However, graphene agglomerates easily because of the van der Waals force between graphite sheets, thereby affecting the performance of the composites. Future studies can explore outburst mechanisms at the microscale.ДЄbstract: Graphene/aluminum (Gr/Al) composites have attracted the attention of researchers all over the world due to their excellent properties. Restoring the original outburst scene by constructing a geomechanical model or numerical model and reproducing the entire outburst process based on mining environment conditions, including stratigraphic distribution, gas occurrence, and geological structure, are important. Outburst experiments can compensate for the deficiency of first-hand observation at the scene. Modern physical-chemical methods can help characterize the natural properties of outburst-prone coal. The most appealing research is the microscopic process of the interaction between coal and gas.

Additional topics about outburst mechanisms are proposed by summarizing the phenomena that need precise explanation. The multi-factor mechanism is widely accepted, but all statistical phenomena during a single outburst cannot be explained using present knowledge.

Outburst mechanisms are divided into two categories: single-factor and multi-factor mechanisms. Studies on outburst mechanisms worldwide focused on the physicochemical and mechanical properties of outburst-prone coal, laboratory-scale outburst experiments and numerical modeling, mine-site investigations, and doctrines of outburst mechanisms. After about 150 years of exploration, the mechanisms of outbursts remain unclear to date. The hydration layer between different surfaces shows large qualitative differences.ДЄbstract: Coal and gas outburst is a frequent dynamic disaster during underground coal mining activities. The interfacial water structure largely depends on surface chemistry. Meanwhile, the ion correlations in high-concentration electrolyte systems become long range. Electrolyte concentration exerts a significant effect on the hydration force at high ion concentrations. For ions of the same valence, the effect of surface charge on the hydration force follows the Hofmeister adsorption series. For example, the hydration and adsorption states completely differ between monovalent and divalent ions. The factors affecting the adsorption behavior of ions and water molecules, such as ion concentration, ion hydration radius and valence, and surface properties, are discussed.

The correlation between the surface charge and hydration of minerals is summarized on the basis of innovative experimental, theoretical, and molecular dynamics simulation studies. These properties usually coexist and interact with each other. Abstract: Surface charges and hydration are predominant properties of colloidal particles that govern colloidal stability in aqueous suspensions.