Dynamic Behavior of Lubricant Molecules Under Oscillating Motion: Insight from Molecular Dynamics Simulations.

Understanding the dynamic behavior of lubricant molecules under oscillation lubrication is important for the development of advanced film lubrication technology. Herein, the dynamic behaviors of lubricant molecules under oscillating motion are studied by using molecular dynamics simulations. The effects of oscillation period on the film temperature, film velocity distribution, film stress and strain, and molecular orientation are investigated.

Lattice-Doped Ir Cooperating with Surface-Anchored IrO for Acidic Oxygen Evolution Reaction with Ultralow Ir Loading.

Reducing iridium (Ir) loading while maintaining efficiency and stability is crucial for the acidic oxygen evolution reaction (OER). In this study, we develop a synthetic method of sequential electrochemical deposition and high-temperature thermal shock to produce an IrO/Ir-WO electrocatalyst with ∼1.75 nm IrO nanoparticles anchoring on Ir-doped WO nanosheets.

Modification Strategies of Bismuth-Based Halide Perovskites for Solar to Fuel Conversion by Photocatalytic CO Reduction.

In light of the increasingly pressing energy and environmental challenges, the use of photocatalysis to convert solar energy into chemical energy has emerged as a promising solution. Halide perovskites have recently attracted considerable interest as photocatalysts due to their outstanding properties. Early developments focused on Lead-based perovskites, but their use has been severely restricted due to the toxicity of Lead.

Bubble Nucleation and Heat Transfer on Three-Dimensional Mixed-Wettable Nanostructured Surfaces: A Molecular Dynamics Study.

This study explores the bubble nucleation process and heat transfer characteristics on nanostructured solid surfaces with mixed-wettable pillars using molecular dynamics simulations. Five different surfaces were designed by varying the wettability of the central pillars while keeping the lateral pillars hydrophilic. The nucleation behavior of argon bubbles was observed to differ significantly across these surfaces due to the combined effects of nanostructuring and mixed wettability.

3D Ordered Macroporous Mn, Zr-Doped CaCO Nanomaterials for Stable Thermochemical Energy Storage.

Developing high-performance Ca-based materials that can work for long-term heat transfer and storage in concentrated solar power plants is crucial to achieve the large-scale conversion of solar photon fluxes to dispatchable electricity. This work demonstrates that a series of Mn, Zr co-doped CaCO nanomaterials with the 3D ordered macroporous (3DOM) skeletons are successfully prepared by a novel strategy of templated metal salt co-precipitation. The characterization results indicate that a majority of Zr and Mn are atomically dispersed into the highly-crystallized CaCO framework, whereas a minor amount of Mn is present in the form of CaMnO nanoparticles (NPs).

Rational Design of Liquid-Liquid Microdispersion Droplet Microreactors for the Controllable Synthesis of Highly Uniform and Monodispersed Dextran Microspheres.

Hydrogel microspheres are biocompatible materials widely used in biological and medical fields. Emulsification and stirring are the commonly used methods to prepare hydrogels. However, the size distribution is considerably wide, the monodispersity and the mechanical intensity are poor, and the stable operation conditions are comparatively narrow to meet some sophisticated applications.

Droplet Microfluidic Devices: Working Principles, Fabrication Methods, and Scale-Up Applications.

Compared with the conventional emulsification method, droplets generated within microfluidic devices exhibit distinct advantages such as precise control of fluids, exceptional monodispersity, uniform morphology, flexible manipulation, and narrow size distribution. These inherent benefits, including intrinsic safety, excellent heat and mass transfer capabilities, and large surface-to-volume ratio, have led to the widespread applications of droplet-based microfluidics across diverse fields, encompassing chemical engineering, particle synthesis, biological detection, diagnostics, emulsion preparation, and pharmaceuticals. However, despite its promising potential for versatile applications, the practical utilization of this technology in commercial and industrial is extremely limited to the inherently low production rates achievable within a single microchannel.

Multi-Physics Simulation of Tar-Rich Coal In Situ Pyrolysis with a Multiregion Homogenization Treatment.

The macroscopic multi-physics simulation of tar-rich coal in situ pyrolysis (TCISP) is conducted, in the fractured porous zone, by coupling heat transfer, fluid flow, and chemical reaction. A novel TCISP pattern of gas injection between fractured zones is proposed by treating the fractured porous zone as a homogeneous porosity gradient descending region. In this case, nearly 11,500 kg of oil can be produced within 6 months from a 10*10*1 m area.

Thermally-enhanced sono-photo-catalysis by defect and facet modulation of Pt-TiO catalyst for high-efficient hydrogen evolution.

Sono-photo-catalysis (SPC) has been regarded as a promising route for hydrogen evolution from water splitting due to the sono-photo-synergism, whereas its current performance (∼μmol g h) is yet far from expectation. Herein, we give the first demonstration that the intrinsically coupled thermal effects of light and ultrasound, which is normally underestimated or neglected, can simultaneously reshape the photo- and sono-catalytic activities for hydrogen evolution and establish a higher degree of synergy between light and ultrasound in SPC even on the traditional Pt-TiO catalyst. A high-efficient hydrogen evolution rate of 225.

Effect of the Addition of Graphene Nanoplatelets on the Thermal Conductivity of Rocket Kerosene: A Molecular Dynamics Study.

Rocket kerosene plays an important role in the regenerative cooling process of rocket thrust chambers. Its thermal conductivity determines the cooling efficiency and the tendency to coke in rocket kerosene engines. In this paper, graphene nanoplatelets (GNPs) were introduced into rocket kerosene to improve its thermal conductivity.

Effect of Polymer Drag Reducer on Rheological Properties of Rocket Kerosene Solutions.

Adding drag reduction agent (DRA) to rocket kerosene is an effective way to reduce the pipeline resistance of rocket kerosene transportation systems. However, so far, there have been few research reports on the effect of DRA on the rheological properties of rocket kerosene solution, especially from a microscopic perspective. In this study, coarse-grained molecular dynamics simulations were conducted to investigate the rheological properties of rocket kerosene solutions with DRAs of different chain lengths and concentrations.

Molecular Dynamics Study on the Combined Effects of the Nanostructure and Wettability of Solid Surfaces on Bubble Nucleation.

In this paper, molecular dynamics (MD) simulations are conducted to investigate the bubble nucleation process of liquid argon on surfaces with a nanostructure of different wettabilities. To account for the combined effects of the nanostructure and surface wettability on bubble nucleation, the variation of the bubble volume, the nucleation starting time, as well as the heat flux between the solid surface and fluid are examined. It is found that the position of bubble nucleation depends on the pillar wettability.

Micro-pin-finned Surfaces with Fractal Treelike Hydrophilic Networks for Flow Boiling Enhancement.

Due to its outstanding heat transfer performance, flow boiling has a wide range of applications in many fields, especially for cooling of electronic devices. Previous studies have shown that the liquid replenishment on the downstream of the heating surface is the critical restriction of the increase of the critical heat flux (CHF). In this work, we designed a series of heterogeneous surfaces with fractal treelike hydrophilic networks for flow boiling enhancement.

Convenient and large-scale fabrication of cost-effective superhydrophobic aluminum alloy surface with excellent reparability.

Superhydrophobic surfaces are widely used in industry and daily life, yet their practical application is limited by their complicated preparation process, high cost, and poor repairability. We propose a low-cost, facile process for preparing superhydrophobic surfaces to address this limitation. Through a simple three-step spraying process, the rough structure was first constructed on the aluminum alloy, and upon modification by modifier, the superhydrophobic aluminum alloy surface was successfully prepared.

Dynamics and Structure Formation of Confined Polymer Thin Films Supported on Solid Substrates.

The stability/instability behavior of polystyrene (PS) films with tunable thickness ranging from higher as-cast to lower residual made on Si substrates with and without native oxide layer was studied in this paper. For further extraction of residual PS thin film (h) and to investigate the polymer-substrate interaction, Guiselin's method was used by decomposing the polymer thin films in different solvents. The solvents for removing loosely adsorbed chains and extracting the strongly adsorbed irreversible chains were selected based on their relative desorption energy difference with polymer.

Nanoparticle-Assisted Pool Boiling Heat Transfer on Micro-Pin-Fin Surfaces.

Boiling heat transfer intensification is of significant relevance to energy conversion and various cooling processes. This study aimed to enhance the saturated pool boiling of FC-72 (a dielectric liquid) by surface modifications and explore mechanisms of the enhancement. Specifically, circular and square micro pin fins were fabricated on silicon surfaces by dry etching and then copper nanoparticles were deposited on the micro-pin-fin surfaces by electrostatic deposition.

Visible-Light Activation of Photocatalytic for Reduction of Nitrogen to Ammonia by Introducing Impurity Defect Levels into Nanocrystalline Diamond.

Nitrogen impurity has been introduced in diamond film to produce a nitrogen vacancy center (NV center) toward the solvated electron-initiated reduction of N to NH in liquids, giving rise to extend the wavelength region beyond the diamond's band. Scanning electron microscopy and X-ray diffraction demonstrate the formation of the nanocrystalline nitrogen-doped diamond with an average diameter of ten nanometers. Raman spectroscopy and PhotoLuminescence (PL) spectrum show characteristics of the NV and NV charge states.

Can Steam- and CO-Rich Streams Be Produced Sequentially in the Isothermal Chemical Looping Super-Dry Reforming Scheme?

Super-dry reforming of methane (CH + 3CO → 2HO + 4CO) is a very promising route for CO utilization. To maximize the yield of CO, a water-gas shift reaction (CO + HO → CO + H) should be circumvented. Combination of dry reforming of methane, redox reactions (metal oxide is reduced by CO and H in one step and then oxidized by CO in the next step), and CO sorption in a fixed-bed reactor was proposed as a potential approach to suppress the water-gas shift reaction.

Interfacial Interaction Enhanced Rheological Behavior in PAM/CTAC/Salt Aqueous Solution-A Coarse-Grained Molecular Dynamics Study.

Interfacial interactions within a multi-phase polymer solution play critical roles in processing control and mass transportation in chemical engineering. However, the understandings of these roles remain unexplored due to the complexity of the system. In this study, we used an efficient analytical method-a nonequilibrium molecular dynamics (NEMD) simulation-to unveil the molecular interactions and rheology of a multiphase solution containing cetyltrimethyl ammonium chloride (CTAC), polyacrylamide (PAM), and sodium salicylate (NaSal).

T-NbO nanoparticle enabled pseudocapacitance with fast Li-ion intercalation.

Orthorhombic NbO (T-NbO) nanocrystallites are successfully fabricated through an evaporation induced self-assembly (EISA) method guided by a commercialised triblock copolymer - Pluronic F127. We demonstrate a morphology transition of T-NbO from continuous porous nanofilms to monodisperse nanoparticles by changing the content of Pluronic F127. The electrochemical results show that the optimized monodisperse Nb-2 with a particle size of 20 nm achieves premier Li-ion intercalation kinetics and higher rate capability than mesoporous T-NbO nanofilms.

Anchoring Tailored Low-Index Faceted BiOBr Nanoplates onto TiO Nanorods to Enhance the Stability and Visible-Light-Driven Catalytic Activity.

In this work, a fantastic one-dimensional (1D) BiOBr/TiO nanorod (NR) heterojunction composite was rationally proposed and designed from the perspective of molecular and interface engineering. The fabricated intimately connected interfacial heterojunction between two-dimensional BiOBr nanoplates and 1D TiO NRs acts as an interfacial nanochannel to promote efficient interfacial charge migration and separation of photogenerated electron-hole pairs. As a result, 1D BiOBr/TiO NR heterojunctions exhibited outstanding visible-light photocatalytic activities and sustained cycling performance.