Interfacial Mechanism Research Articles

CFRP-RC fracture strength prediction: A novel approach using deep learning

Externally bonded carbon fiber-reinforced polymer (CFRP) composites have been widely adopted for strengthening and repairing aging concrete structures. However, premature fracture at the CFRP-concrete interface remains a significant concern, necessitating a better understanding of the interfacial bond behavior and fracture mechanisms. Traditional experimental studies and numerical simulations have limitations in accurately capturing the complex nonlinear factors influencing this fracture behavior. This paper explores the novel application of machine learning (ML), specifically artificial neural networks (ANNs), for predicting the fracture strength of CFRP-reinforced concrete (CFRP-RC) members. ANNs enable mapping the intricate relationships between input parameters (e.g., CFRP/concrete properties, geometric configurations) and fracture responses through iterative training on experimental data. Key aspects include comprehensive data collection, preprocessing techniques, feature selection methods like mean impact value (MIV) analysis, and neural network architecture design. The paper highlights successful ANN applications in predicting CFRP-RC bond strength, shear capacity, and overall fracture behavior. A systematic approach is proposed for developing robust ANN models tailored to CFRP-RC fracture prediction, encompassing data curation, input variable screening, network training/validation, and model interpretability analyses. By leveraging ML’s ability to handle multifaceted nonlinearities, this data-driven framework offers a powerful alternative to traditional methods, potentially enhancing the design, analysis, and performance evaluation of CFRP-strengthened concrete structures.

Computational and Experimental Investigations of the Au and NiOOH Interface in the Oxygen Evolution Reaction

The transition to renewable energy sources is crucial for combating climate change, and hydrogen (H2) is a promising clean fuel. Electrolysis of water, specifically the oxygen evolution reaction (OER), is a key process for producing H2. Prior experimental results have shown that gold (Au) could improve the apparent activities of the OER electrocatalysts such as nickel hydroxide (Ni(OH)2) in alkaline electrolytes.1-3 However, the detailed interfacial atomic structure and mechanisms of the increased catalytic activity remain poorly understood.To understand the interfacial effect between Au and Ni(OH)2 in the OER process, our research uses the model system of Au nanoparticles (NPs) and nickel oxyhydroxide (NiOOH), which is the active phase of Ni(OH)2 layers in the OER, to investigate their interfacial interactions with both experimental and computational approaches. We hypothesize that the Au NPs on NiOOH enhances the OER activity by promoting electron transfer at the interface. Our studies involve computational analysis using Density Functional Theory (DFT) calculations to obtain the local density of states (LDOS), which can help us better visualize and compare the local electronic structure of NiOOH in the presence and in the absence of AuNPs. Two architectures of the Au and NiOOH interface will be investigated: Au NPs on a NiOOH film and NiOOH NPs on a Au film.Additionally, Bader analysis is employed to determine the Bader charge, offering a more detailed understanding of how electrons are distributed across the AuNPs/NiOOH interface. Furthermore, the catalytic efficacy of AuNPs on NiOOH is assessed through electrodepositions followed by cyclic voltammetry(CV) measurements. The experimental and computational results will be directly compared, and this research is expected to contribute to the insights of substrate and catalyst interactions for design of more efficient electrocatalysts.

(Invited) Deciphering the Interfacial Chemistry and Degradation Pathway of Layered Cathode Materials

Cathode materials such as layered oxides play a crucial role in determining batteries' energy density and safety. LiNixMnyCozO2 (NMC), as the dominating cathode, has been successfully commercialized for many years. In addition, there is a consensus that integrating NMC cathodes into all-solid-state batteries (ASSBs) is an effective way to achieve high energy densities. However, NMC cathodes are still facing many challenges, particularly, during the perusing of the high Ni concentration and high cut-off voltages. In the presentation, we will discuss the interface degradation of the NMC cathode at multiple length scales. By comprehensive imaging and spectroscopic techniques, we could bridge the degradation phenomenon from the electrode scale to the atomic scale. We will present the challenges of characterizing the surface properties of the cycled layered cathode and summarize our strategies that can enhance the surface stability of NMCs. Our fundamental understanding will inform the design principles at multiple length scales in batteries. Shifting our focus to solid-state batteries (SSBs), there is a growing body of research on SSBs incorporating NMC cathodes and argyrodite solid electrolytes (SEs). However, these advanced ASSBs face significant challenges in terms of low initial Coulombic efficiency and rapid capacity degradation. Therefore, we also try to understand the interfacial degradation mechanisms in composite SE-NMC cathodes in this talk.

Measuring Charge Selective Contacts on Semiconducting Photocatalyst Particles

Water splitting could replace steam-methane reforming, a carbon intensive process, to generate hydrogen for energy storage, fertilizer production, and many other industrial processes. Photoelectrochemical (PEC) overall water splitting (OWS), for example, produces hydrogen from water, without wires or applied voltages, via a clean and renewable energy source, sunlight. To do so, PEC particles or photocatalysts (PC) must absorb light, and selectively collect the generated carriers, either electrons or holes, at specific sites which drive reduction or oxidation reactions, respectively. While theoretical solar to hydrogen (STH) efficiencies are at least 18%, state-of-the-art PCs are below 3%. Despite the extreme efforts screening and tuning semiconductor photocatalysts, a thorough understanding and control of electronic properties of the semiconductor-electrocatalysts (sem|cat) interface is limited.Here, we use advanced electrochemical methods (dual-working electrode), scanning probe microscopy (conductive-AFM) and ambient-pressure XPS to measure and understand the origins of the electrochemical driving force (gradient in electrochemical potential) developed at complimentary electrocatalysts on photocatalyst particles. We use the dual-working electrode geometry on a high-quantum-yield wide-bandgap perovskite oxide, SrTiO3, to demonstrate the adaptive nature of electrocatalysts, Pt and CoOx, as they accumulate electrons and holes respectively. The cooperativity of half-reaction kinetics and adaptive sem|cat barrier height will be demonstrated along with the influence of crystal termination, which we argue is commonly overemphasized. Finally, a new contactless method of measuring the photovoltage at chemically distinct catalysts sites will be presented. Measured photovoltage induced shifts to element specific core levels in ambient pressure XP spectra in the dark and under illumination directly probe interfacial mechanisms operando. In sum, the introduced techniques and their findings demonstrate the underlying mechanisms and the degree that they play, enabling directed research of photocatalyst systems under one dominant engineering condition, charge selective Figure 1

Ferroelectricity-controlled magnetic ordering and spin photocurrent in NiCl2/GeS multiferroic heterostructures

Controlling magnetism solely through electrical means is indeed a significant challenge, yet holds great potential for advancing information technology. Herein, our investigation presents a promising avenue for electrically manipulating magnetic ordering within 2D van der Waals NiCl2/GeS heterostructures. These heterostructures, characterized by their unique magnetic-ferroelectric (FE) layer stacking, demonstrate spin-constrained photoelectric memory, enabling low-power electrical writing and non-destructive optical reading. The two orientations of the polarization in the GeS FE layer bring about changes in the ground state configuration, transitioning from ferromagnetic (FM) to antiferromagnetic (AFM) orderings within the NiCl2magnetic layer. Correspondingly, the light-induced charge transfer prompts either spin-polarized or unpolarized currents from the FM or AFM states, serving as distinct '1' or '0' states, and facilitating applications in logic processing and memory devices. This transition stems from the interplay of interfacial charge transfer mechanisms and the influence of the effective electric field (Eeff), bringing a non-volatile electric enhancement in the magnetic anisotropy energy within the NiCl2/GeS heterostructure. Overall, our study highlights the NiCl2/GeS heterostructure as an optimal candidate for realizing spin-dependent photoelectric memory, offering unprecedented opportunities for seamlessly integrating memory processing capabilities into a single device through the utilization of layered multiferroic heterostructures.

Process optimization, interfacial characteristics, and mechanical properties of titanium-tantalum multi-material structures fabricated via laser powder bed fusion

To fully exploit the biomechanical properties of titanium (Ti) and biocompatibility of tantalum (Ta), Ti-Ta multi-material structures with different printing sequences were fabricated using laser powder bed fusion (LPBF). The interfacial characteristics, mechanical properties, formation mechanisms, and influence of process parameters on bonding strength at the Ti/Ta (Ta printed on Ti) and Ta/Ti (Ti printed on Ta) interfaces were investigated. At the Ti/Ta interface, a wide diffusion zone led to microstructure evolution along the building direction: coarsened lath α′ grain → refined α′ + β grains → columnar β + cellular β grains. This evolution was attributed to keyhole formation and differences in material density that promoted element diffusion. On the other hand, at the Ta/Ti interface with a narrow diffusion zone, direct microstructure evolution occurred from columnar β + cellular β grains to lath α′ grains due to limited solid-state diffusion and compromised element diffusion caused by gravity and heat dissipation. Optimal bonding strengths of 548.11 MPa and 285.42 MPa were achieved for the Ti/Ta and Ta/Ti interfaces, respectively. During LPBF processing of Ti-Ta multi-materials, reducing scanning speed significantly enhanced bonding strength, indicating its significant impact on interfacial bonding. These findings offer novel insights and references to fabricate Ti-Ta multi-material structures with great potential for biomedical implants through LPBF.

Engineering CALF-20/graphene oxide nanocomposites for enhancing CO2/N2 capture performance

Ever-increasing atmospheric CO2 concentrations has necessitated the development of novel and cost-effective nanostructured composites with favorable physicochemical properties. Recently, the potential of metal-organic framework (MOF)-based nanocomposites towards boosting CO2 capture capability has become apparent indicating the importance of the relationship between their structure and properties. Herein, a novel nanocomposite of zinc-based CALF-20 MOF hybridized with graphene oxide is successfully fabricated using the solvothermal method. The construction of the well-structured nanocomposite is confirmed by performing PXRD, BET, FTIR, FESEM/EDX, TEM, and TGA characterization analyses. CO2 and N2 adsorption capacities and CO2/N2 separation performance of these nanocomposites are evaluated by experiment and mathematical modeling for the first time. The CALF-20/GO interfacial interaction and CO2 adsorption mechanisms are also discussed. As the best-performing adsorbent, the CALF-20 containing 20 wt% GO indicates a 42.6 % increment in CO2 uptake at 1.6 bar and a 32.7 % enhancement in CO2/N2 selectivity at 1 bar and 298 K and 1.28 times more CO2 retention time in a fixed bed column compared to that of the pristine MOF. The results show that the MOF and GO form chemical bonds at the interface resulting in generating new pore structures and increasing the porosity which are mostly responsible for boosting CO2 capture capacity. Interestingly, no meaningful effect is observed by the variation of the zinc atomic concentration at the surface. The simple synthesis procedure and understanding the interfacial structure of the novel CALF-20/GO composite as a promising adsorbent for CO2 capture applications can provide new insights for future work.

Sludge biochar accelerates transformative phenolic compounds removal from wastewater via the coupling mechanism

In this work, we investigated the mechanism of the oxidation of phenolic compounds (PCs) by graphitic sludge biochar (SDBCs) via a catalytic coupling regime in the presence of potassium persulfate (PDS). In-situ synchrotron attenuated total reflection Fourier transform infrared spectroscopy (in-situ ATR-FITR) combined with Raman spectroscopy directly monitored the formation of SDBC-PDS* complexes, which drove the electron-transfer pathway as evidenced by electrochemical tests and galvanic cell experiments. The coupling of pollutants into oligomers effectively reduced total organic carbon in water with a low PDS usage (PDS consumption to phenol degradation ratio of 2.2). Furthermore, our research showed that the biochar-based nonradical system effectively treats various PCs, with oxidation rates related to their half-wave potential and Hammett constant. Overall, this work explored sludge biochar engineering, PCs transformation and interfacial coupling mechanism, providing a novel approach for the efficient and cost-effective treatment of phenolic wastewater with low chemical input.

Shear behavior of Cu/Al/Cu trilayered composites prepared by high-temperature oxygen-free rolling

The interfacial microstructure, interfacial shear properties, and shear fracture morphology of Cu/Al/Cu trilayered composites prepared by high-temperature oxygen-free rolling were studied, and the interfacial shear fracture mechanism was revealed. The results showed that the Cu/Al/Cu trilayered composites have a good metallurgical bonding interface. The interfacial microstructure is composed of Al2Cu, AlCu, and Al4Cu9. The intermetallics (IMCs) parallel to the rolling direction show discontinuous distribution, while the IMCs perpendicular to the rolling direction have mainly continuous distribution and occasional discontinuous distribution. The interfacial shear strength at room temperature can reach 68 MPa, and when the test temperature rises to 350 °C, the interfacial shear strength drops sharply to 16.9 MPa. The interfacial shear fracture mainly occurs in the low-strength Al layer due to the good metallurgical bonding interface. The IMCs near the shear fracture exhibit clear signs of cracking, and there is a phenomenon where the Cu layer embeds into the Al layer in a "sawtooth" shape. Meanwhile, shear fracture also occurs in the IMCs layer, and a small amount of Al will attach to the surface of the IMCs. However, the high bonding strength resulting from the excellent metallurgical bonding of the interface makes this type of shear fracture rare. The shear fracture of Cu/Al/Cu trilayered composites is mainly dominated by the fracture of the low-strength Al layer and the occasional fracture of the IMCs.

Investigation on anisotropic toughness and cracking behavior of woven lay-up Fiber Metal Laminates with two-level customized interfaces

Interlaminar toughening for metal-polymer interfaces in woven lay-up Fiber Metal Laminates (w-FMLs) is a critical concern, demanding isotropic mechanics and higher energy dissipation. Customizing interfaces with interlocking structures like dimples or grooves has proven effective in meeting these requirements, while the resulting two-level features introduce greater complexity in toughening effects, and interfacial mechanics are influenced by factors such as fiber orientation and resin distribution. To understand the anisotropy effect and toughening mechanics induced by different two-level features, three types of two-level customized interfaces of w-FMLs are examined. Edge shear tests are utilized to evaluate interfacial mechanics and toughness, with a focus on tracing crack propagation behaviors. Through numerical simulation and characterization, the toughening effect and its mechanisms are unveiled, revealing that differences in toughness pinning effect and local plastic deformation of the customized interfaces are the primary determinants of interlaminar toughness. Additionally, a coupling effect between the woven core and interfaces is observed, showing that the superposition of the tougher orientation of the woven core on the strong toughness pinning orientation of the interfaces is a crucial factor in determining excellent overall interlaminar toughness.

Research on interfacial fusion characteristics of rejuvenator-aged asphalt system: Wettability, permeability and molecular simulation

The research aims to illuminate the interfacial fusion mechanism of rejuvenator-aged asphalt to guide the development of high-performance rejuvenators and foster the high-value utilization of waste asphalt pavement materials. In the research, the contact angle between rejuvenator and aged asphalt was measured to assess its interface wettability, and the permeability and contributing factors in aged asphalt were profiled based on the permeation test and permeation degree parameter. Concurrently, the molecular dynamics simulations of the fusion behavior between rejuvenator and aged asphalt were conducted to comprehend the fusion mechanism deeply. Results reveal that thermal oxygen and photo-oxygen aging enhanced the asphalt mixture’s hydrophobicity with similar effects, and they also had comparable impacts on the wettability of rejuvenator-aged asphalt interface. A more considerable asphalt aging eventuated a more challenging for the rejuvenator to wet the asphalt surface naturally. Waste vegetable oil rejuvenators tended to have a superior wetting effect on the aged asphalt surface compared to mineral oil rejuvenators. Higher permeation temperatures and permeation durations facilitated the rejuvenator’s fusion with aged asphalt, and the permeability varied across different rejuvenators, hinging on the rejuvenator’s permeation performance and composition. The rejuvenator’s permeation process into light aged asphalt or aged matrix asphalt was prone to occur. The aging effect of asphalt negatively impacted the fusion process of the layered system. Compared to oleic acid, aromatic hydrocarbons exhibited superior permeation ability and better fusion effect with aged asphalt. Rejuvenator composition materials yielding high permeation and fusion effects should display the following characteristics: lower viscosity, weak molecular polarity, small molecular weight, linear molecular structure, or end phenyl ring structure.

Effect of brazing temperature on microstructure and tensile strength of γ-TiAl joint vacuum brazed with micro-nano Ti−Cu−Ni−Nb−Al−Hf filler

A novel micro-nano Ti−10Cu−10Ni−8Al−8Nb−4Zr−1.5Hf filler was used to vacuum braze Ti−47Al− 2Nb−2Cr−0.15B alloy at 1160−1220 °C for 30 min. The interfacial microstructure and formation mechanism of TiAl joints and the relationships among brazing temperature, interfacial microstructure and joint strength were emphatically investigated. Results show that the TiAl joints brazed at 1160 and 1180 °C possess three interfacial layers and mainly consist of α2-Ti3Al, τ3-Al3NiTi2 and Ti2Ni, but the brazing seams are no longer layered and Ti2Ni is completely replaced by the uniformly distributed τ3-Al3NiTi2 at 1200 and 1220 °C due to the destruction of α2-Ti3Al barrier layer. This transformation at 1200 °C obviously improves the tensile strength of the joint and obtains a maximum of 343 MPa. Notably, the outward diffusion of Al atoms from the dissolution of TiAl substrate dominates the microstructure evolution and tensile strength of the TiAl joint at different brazing temperatures.

Corrosion inhibition performance and adsorption mechanism of new synthesized symmetrical diarylidenacetone-based inhibitor on C38 steel in 15 % HCl medium: Theoretical insight and experimental validation

Despite the engineering potential of using organic substances to protect vulnerable metallic materials from corrosive environments, the interaction mechanisms and adsorption processes that lead to the formation of hybrid materials remain poorly understood. Further research is necessary to elucidate how these organic compounds interact with metallic surfaces and the specific pathways through which they adsorb to form protective layers. Understanding these mechanisms is crucial for developing more effective corrosion-resistant hybrid materials, which could significantly enhance the properties of metallic components and provide excellent electrochemical stability in various industrial applications. This work aims to explore the corrosion performance and interfacial mechanism of two symmetrical diarylidenacetone-based compounds, namely, (1E,4E)-1,5-bis(4-methoxyphenyl) penta-1,4-dien-3-one (MPD) and 2,6-di((E)-benzylidene) cyclohexan-1-one (BZC), in a bid to control the corrosion kinetics of C38 steel in aggressive environment. This assessment integrated experimental, surface, and theoretical explorations. The results of our study revealed the remarkable ability of MPD and BZC molecules to generate a dense, resistant protective film on the C38 steel surface. This protective film acted as a barrier, effectively blocking the penetration of corrosive ions and their interaction with the C38 substrate. The inhibition efficiencies of the investigated products exhibited a consistent rise with increased amounts of additives. The inhibition efficiency reached 95 % for MPD and 90 % for BZC at 10−3 M, as calculated from the fitting Nyquist diagrams. The interaction between the inhibitor and Fe(110) was studied utilizing density functional tight binding (DFTB) and Molecular dynamics simulations (MDS). The results demonstrate the formation of covalent bonds, with the molecules aligning in a parallel orientation of MPD and BZC. This alignment with experimental findings provides strong validation for the efficacy of the inhibitors in corrosion inhibition.

Artificial neural network framework for the selection of deep eutectic solvents promoted enhanced oil recovery by interfacial tension reduction mechanism

Estimation of interfacial tension (IFT) and % reduction in IFT of Brazil and China regions’ heavy crude oil is employed by Artificial Intelligence (AI) led frameworks. The uniqueness of proposed approach lies in using AI frameworks that are constructed using Artificial Neural Network (ANN) and meta-heuristic algorithms i.e. Genetic Algorithm (GA) and Grey Wolf Optimization (GWO) forms three AI frameworks namely ANN, ANN-GA, and ANN-GWO is employed for IFT estimation of heavy oil and deep eutectic solvent-brine interface. The hyper-parameters of the frameworks are trained, validated, and tested over 18228 IFT data points obtained from the Omani heavy crude oil. The intermolecular interactions between oil, brine, and DES are obtained by generating surface segments in COnductor like Screening MOdel for Real Solvent (COSMO-RS) framework. The composition of brine, mole ratio of oil, DES, and temperature are other input parameters for AI model. The IFT estimation leads to the selection of 3 hydrophilic DESs capable of greater than 75 % IFT reduction and 14 hydrophilic DESs capable of 50–75 % IFT reduction. ANN-GWO scores best AI framework among 3 whereas ANN-GA fails to estimate IFT reduction greater than 50 %. Analysis of IFT with respect to mole fraction reveals the most suitable range of DES addition for IFT reduction.

First-principles calculation on the interfacial stability, electronic structure and fracture mechanism of NbN/AlN interface

The interfacial stability of NbN(111)/AlN(0001) including interfacial energy, Wad(work of adhesion) and electronic structure were studied by first-principles calculation. The N1-Nb-cen interface(constructed with N1-terminated AlN(0001) and Nb-terminated NbN(111)) is determined to be the most stable interface which has the smallest interfacial distance(1.11 Å) and largest Wad(15.04 J/m2) among the 28 considered interface models. The electronic structure and ideal tensile stress of the N1-Nb-cen, N2-Nb-top, Al2-N-top and Al1-Nb-cen interfaces were also investigated. The AlN surface has stronger ionic bond than that in NbN surface according to the analysis of Mulliken charges. The bonding feature of N1-Nb-cen interface is ionic with strong covalent, while the other three interfaces have mainly ionic bond. The ideal tensile stress of the N2-Nb-top interface is the largest (22.88 GPa) at the strain of 17 %, which is larger than that of N1-Nb-cen interface. The fracture will occur at the interface for the Al2-N-top and Al1-Nb-cen interfaces, while it occurs at the AlN interior for the N1-Nb-cen and N2-Nb-top interfaces, due to the Wad of the N1-Nb-cen and N2-Nb-top interfaces are larger than the other two interfaces and atomic stacking of AlN surface.

Multi-scale investigation of silane coupling agent for enhanced corrosion resistance in reinforced concrete

Reinforcement corrosion is a significant factor leading to the deterioration of building performance. In order to enhance the serviceability of reinforced concrete under corrosive environments, this study employs a silane coupling agent (γ-aminopropyltriethoxysilane) for steel reinforcement treatment. The anti-corrosion mechanism, crack propagation patterns, and modified corrosion resistance of the steel are investigated at multiple scales. Experimental techniques such as scanning electron microscopy (SEM), X-ray energy-dispersive spectroscopy (EDS), and Fourier-transform infrared spectroscopy (FT-IR) are utilized to explore the influence of the self-assembled coating of the silane coupling agent on the microscopic morphology, elements, and functional groups of the steel. Concrete specimens with treated reinforcement are fabricated, and electrochemical accelerated corrosion tests are conducted to compare corrosion differences among different specimens. Using untreated specimens as a control group, digital image correlation (DIC) technology is employed to capture the full-field strain and displacement distribution during the loading process. The crack propagation and slip behavior at the steel-concrete interface in the composite specimens are analyzed. The research findings indicate that, at the optimal concentration of 1.2 %, the self-assembled coating of the silane coupling agent successfully adheres to the steel surface, significantly enhancing the interfacial abrasion resistance and mechanical strength of the steel-concrete interface, thereby validating the improved corrosion resistance of the steel. This study proposes the self-assembly mechanism and interfacial enhancement mechanism of the silane coupling agent on steel at multiple scales, contributing to a comprehensive understanding of its effectiveness.

Tuning Interfacial Interaction Mechanisms of Ameliorated Surface-Active/π-Electron-Rich Designer Bioamphiphile via Environmental-Waste Bio-upcycling for Trace Bisphenol A Removal from Municipal Landfill Leachate

Tuning Interfacial Interaction Mechanisms of Ameliorated Surface-Active/π-Electron-Rich Designer Bioamphiphile via Environmental-Waste Bio-upcycling for Trace Bisphenol A Removal from Municipal Landfill Leachate

Interfacial behavior and damage mechanism of Al-B4C/Al laminated composites under ballistic impact

The present study involved the fabrication of Al-B4C/Al laminated composites with a strong bonding interface using an integrated (or one-step) hot-pressed sintering method followed by hot rolling. A comprehensive analysis of the mechanical properties and interface behavior of Al-B4C/Al laminated composites under various loading conditions, particularly focusing on ballistic impact. Findings indicate that the laminated composite exhibits a high-strength interface bonding (greater than 318 MPa) facilitated by the continuous Al matrix, with no interlayer delamination occurring even after Charpy impact failure and ballistic penetration. The integrated interface promotes coordinate deformation between different component layers, enhancing the comprehensive mechanical performance of the Al-B4C/Al laminated composites. Moreover, the integrate interface of the Al-B4C/Al laminated plate enables a higher absorption of impact energy from projectiles, increasing by 10% and 70% compared to the monolithic and unbonded stacked plates, respectively.

Interatomic potential of the MgAl2O4/Al interface and its application in strengthening mechanisms

MgAl2O4 ceramics possess outstanding mechanical properties, making them promising for use as reinforcing or interfacial modulating phase in Al-based metal composites. The challenge lies in the insufficient interatomic potential parameters to accurately characterize the MgAl2O4/Al interfacial interactions, which hampers a detailed understanding of the interfacial strengthening mechanisms at the atomic level. Since the pair potential satisfies the requirements for computational efficiency and accuracy, it has been widely used for investigating the interfacial properties of composite materials. In this study, the interatomic potential parameters for Al–Mg and Al–Al bonds were derived from Buckingham potential, while those for Al–O bonds were obtained from Morse potential via first principles calculations. The uniaxial tensile mechanical properties and interface-dislocation strengthening mechanisms of MgAl2O4/Al interface configuration were explored through molecular dynamics simulations. The analyses reveal that the strength enhancement of the MgAl2O4/Al interface is due to the generation of a large number of immovable 1/6<110> stair-rod dislocations therein. The thickness of MgAl2O4 layer significantly influences the mechanical properties. Below a thickness of 20 Å, the presence of movable dislocations reduces the strengthening effect. Conversely, increasing the thickness of MgAl2O4 encourages the emergence of immovable dislocations and increases the flow stress, while the corresponding yield strain decreases. These insights open up new prospects in the development of aluminum metal matrix composites with enhanced performance.

Interfacial interaction mechanism between Mn doped highly conjugated biochar and berberine hydrochloride

MnSO4-modified biochar (Mn-BC) was synthesized to remove berberine hydrochloride (BH) from wastewater by utilizing tea waste as raw material and MnSO4 as modifier. Brunel Emmett Taylor (BET) analysis reveals that the specific surface area (SSA) and average pore size (Dave) of Mn-BC are 1.4 and 7 times higher than those of pristine biochar apart, attributing to the dissociation effect can promote the dispersion of MnSO4 in the pores of the biochar. Meanwhile, the doping of Mn not only introduces additional oxygen-containing functional groups (OCFGs), but also modulates the π electron density. Furthermore, Response surface method (RSM) analysis reveals that Mn-BC dosage has the most significant effect on BH removal, followed by BH concentration and pH value. Kinetic and isothermal studies reveal that the BH adsorption process of Mn-BC was mainly dominated by chemical and monolayer adsorption. Meanwhile, density functional theory (DFT) calculations confirm the contribution of Mn doping to the conjugation effect in the adsorption system. Originally proposed Mn-BC is one potentially propitious material to eliminate BH from wastewater, meanwhile this also provides a newfangled conception over the sustainable utilization of tea waste resources.