Interface Interaction Research Articles

A high improvement of tensile properties and interfacial interaction of calcium silicate hydrate/hexagonal boron nitride layered nanostructures via defect field

Previous studies have shown that the increase in Young's modulus of cement-based materials by h-BN (about 20%) is lower than that of graphene and graphene oxide (an increase of 35.8%−78.6%). In order to further improve the interfacial interaction between calcium silicate hydrate (CSH) and hBN nanostructures, a series of defective hBN nanostructures were inserted between CSH layers to form defective hBN-CSH layered nanostructures. The interfacial interaction and tensile properties of hBN-CSH layered nanostructures were investigated, in considering the effect of internal (defect sizes in hBN) and external field (strain rate and temperature). The results show that the failure strain and stress of CSH models are enhanced by 18.18% and 14.74% with the incorporation of pure hBN while an increase of 35.53% and 31.58% in failure strain and stress is achieved by incorporating defective hBN (R3), attributed to high interfacial interaction. In addition, the tensile strain of defective hBN-CSH nanostructures (with a decrease of 33.49%) is more sensitive to temperature than that of free-defect hBN-CSH (with a decrease of 29.71%). Also, the tensile strain of defective hBN-CSH (R3) nanostructure (with an increase of 6.49%) is more sensitive to strain rate than that of free-defect hBN-CSH (with an increase of 4.38%). By constructing different interface interactions, a parameterized scheme is provided for the optimization and regulation of the spatial structure of the cement matrix.

Interfacial mechanism of hydrogel with controllable thickness for stable drag reduction

Surface wettability plays a significant role in reducing solid-liquid frictional resistance, especially the superhydrophilic/hydrophilic interface because of its excellent thermodynamic stability. In this work, poly(acrylic acid)-poly(acrylamide) (PAA–PAM) hydrogel coatings with different thicknesses were prepared in situ by polydopamine (PDA)-UV assisted surface catalytically initiated radical polymerization. Fluid drag reduction performance of hydrogel surface was measured using a rotational rheometer by the plate-plate mode. The experimental results showed that the average drag reduction of hydrogel surface could reach up to about 56% in Couette flow, which was mainly due to the interfacial polymerization phenomenon that enhanced the ability of hydration layer to delay the momentum dissipation between fluid layers and the diffusion behavior of surface. The proposed drag reduction mechanism of hydrogel surface was expected to shed new light on hydrogel-liquid interface interaction and provide a new way for the development of steady-state drag reduction methods.

Observing π-Au Interaction between Aromatic Molecules and Single Au Nanodimers with a Subnanometer Gap by SERS.

Interface interaction between aromatic molecules and noble metals plays a prominent role in fundamental science and technological applications. However, probing π-metal interactions under ambient conditions remains challenging, as it requires characterization techniques to have high sensitivity and molecular specificity without any restrictions on the sample. Herein, the interactions between polycyclic aromatic hydrocarbon (PAH) molecules and Au nanodimers with a subnanometer gap are investigated by surface-enhanced Raman spectroscopy (SERS). A cleaner and stronger plasmonic field of subnanometer gap Au nanodimer structures was constructed through solvent extraction. High sensitivity and strong π-Au interaction between PAHs and Au nanodimers are observed. Additionally, the density functional theory calculation confirmed the interactions of PAHs physically absorbed on the Au surface; the binding energy and differential charge further theoretically indicated the correlation between the sensitivity and the number of PAH rings, which is consistent with SERS experimental results. This work provides a new method to understand the interactions between aromatic molecules and noble metal surfaces in an ambient environment, also paving the way for designing the interfaces in the fields of catalysis, sensors, and molecular electronics.

Controlled Growth of Pd Nanocrystals by Interface Interaction on Monolayer MoS2: An Atom-Resolved in Situ Study.

The crystal growth kinetics is crucial for the controllable preparation and performance modulation of metal nanocrystals (NCs). However, the study of growth mechanisms is significantly limited by characterization techniques, and it is still challenging to in situ capture the growth process. Real-time and real-space imaging techniques at the atomic scale can promote the understanding of microdynamics for NC growth. Herein, the growth of Pd NCs on monolayer MoS2 under different atmospheres was in situ studied by environmental transmission electron microscopy. Introducing carbon monoxide can modulate the diffusion of Pd monomers, resulting in the epitaxial growth of Pd NCs with a uniform orientation. The electron energy loss spectroscopy and theoretical calculations showed that the CO adsorption assured the specific exposed facets and good uniformity of Pd NCs. The insight into the gas-solid interface interaction and the microscopic growth mechanism of NCs may shed light on the precise synthesis of NCs on two-dimensional (2D) materials.

Van der Waals Epitaxy, Superlubricity, and Polarization of the 2D Ferroelectric SnS.

Tin monosulfide (SnS) is a two-dimensional layered semiconductor that exhibits in-plane ferroelectric order at very small thicknesses and is of interest in highly scaled devices. Here we report the epitaxial growth of SnS on hexagonal boron nitride (hBN) using a pulsed metal-organic chemical vapor deposition process. Lattice matching is observed between the SnS(100) and hBN{11̅0} planes, with no evidence of strain. Atomic force microscopy reveals superlubricity along the commensurate direction of the SnS/hBN interface, and first-principles calculations suggest that friction is controlled by the edges of the SnS islands, rather than interface interactions. Differential phase contrast imaging detects remnant polarization in SnS islands with domains that are not dictated by step-edges in the SnS. The growth of ferroelectric SnS on high quality hBN substrates is a promising step toward electrically switchable ferroelectric semiconducting devices.

Quantitative x ray phase contrast imaging of oblique shock wave–interface interactions

Oblique shock wave–interface interactions of gases and liquids have been extensively studied in shock tubes using optical methods to measure equation-of-state (EOS) parameters. However, this is difficult with solids due to their opaqueness to visible light. X ray phase contrast imaging (XPCI) has the penetrative strength to probe solids while still being sensitive to mass density and enhancing the visibility of material boundaries. We investigate the accuracy and repeatability of measuring the mean value of the average mass density (areal density divided by thickness) over region S (BS) and flow deflection angle (θ) from XPCI images of a sample. To that end, a Hough transform-based method for measuring θ is developed. To measure BS, the XPCI image intensity probability density function (PDF) is modeled accounting for the spatial distribution of x ray energy, scintillator response, and pulse-to-pulse variation in the x ray intensity. In addition, a Monte Carlo-based algorithm for computing the BS PDF is developed. Both methods are validated on an impact-generated oblique shock wave interacting at a solid polymer-to-polymer interface. This is accomplished through a comparison to hydrodynamic simulations using well-established EOS. Under the modeling framework for the XPCI image intensity, BS is computed with an accuracy of <0.1% and precision of 3%–5%, while θ has an uncertainty of 0.2°, respectively. This shows that the XPCI-based model that is developed here could be an invaluable tool for high-fidelity testing of hydrodynamic models in shock polar configurations.

Flexible Pressure Sensors in Human-Machine Interface Applications.

Flexible sensors are highly flexible, malleable, and capable of adapting todifferent shapes, surfaces, and environments, which opens a wide range ofpotential applications in the field of human-machine interface (HMI). Inparticular, flexible pressure sensors as a crucial member of the flexiblesensor family, are widely used in wearable devices, health monitoringinstruments, robots and other fields because they can achieve accuratemeasurement and convert the pressure into electrical signals. The mostintuitive feeling that flexible sensors bring to people is the change ofhuman-machine interface interaction, from the previous rigid interaction suchas keyboard and mouse to flexible interaction such as smart gloves, more inline with people's natural control habits. Many advanced flexible pressuresensors have emerged through extensive research and development, and to adaptto various fields of application. Researchers have been seeking to enhanceperformance of flexible pressure sensors through improving materials, sensingmechanisms, fabrication methods, and microstructures. This paper reviews the flexible pressure sensors in HMI in recent years, mainlyincluding the following aspects: current cutting-edge flexible pressuresensors; sensing mechanisms, substrate materials and active materials; sensorfabrication, performances, and their optimization methods; the flexiblepressure sensors for various HMI applications and their prospects.

Interfacial interactions and optoelectronic properties of Cs2AgInCl6/J-TMDs heterojunctions for photovoltaic applications

The photoelectric performance of double perovskites is relatively poor compared to traditional perovskite materials, constructing heterojunctions to improve its optoelectronic properties is an effective strategy for designing high-performance double perovskite optoelectronic applications. In this study, we undertook a comprehensive investigation into the electronic and optical characteristics of Cs2AgInCl6/janus transition-metal dichalcogenides (J-TMDs) heterojunctions based on density functional theory (DFT) calculations. Our findings reveal that the construction of van der Waals heterojunctions is only feasible when the Cs-Cl (001) surface of the double perovskite comes into contact with J-TMDs. The nature of the heterojunction formed between Cs2AgInCl6 Cs-Cl surface and J-TMDs (MXY) relies on the disparity in atomic numbers between X and Y, thereby influencing the charge transfer and interface interaction. Moreover, the Cs-Cl/WXY heterojunction exhibits the most promising features for optoelectronic applications due to its lower effective mass and lower exciton binding energy. The optical absorption coefficients of Cs-Cl/J-TMDs heterojunctions surpass those of corresponding Cs2AgInCl6 monolayers, signifying their potential utility in solar cells. Additionally, we computed the power conversion efficiency (PCE) of Cs2AgInCl6/MXY heterojunctions and found that the Cs-Cl/WSeTe-Se heterojunction demonstrates the highest PCE (11.25 %) among all Cs2AgInCl6/MXY heterojunctions, positioning it as a promising material for photovoltaic applications. These results provide valuable insights into the design and optimization of Cs2AgInCl6/MXY heterojunctions for the development of high-performance optoelectronic devices.

GproteinDb in 2024: new G protein-GPCR couplings, AlphaFold2-multimer models and interface interactions.

G proteins are the major signal proteins of ∼800 receptors for medicines, hormones, neurotransmitters, tastants and odorants. GproteinDb offers integrated genomic, structural, and pharmacological data and tools for analysis, visualization and experiment design. Here, we present the first major update of GproteinDb greatly expanding its coupling data and structural templates, adding AlphaFold2 structure models of GPCR-G protein complexes and advancing the interactive analysis tools for their interfaces underlying coupling selectivity. We present insights on coupling agreement across datasets and parameters, including constitutive activity, agonist-induced activity and kinetics. GproteinDb is accessible at https://gproteindb.org.

Importing Antibonding-Orbital Occupancy through Pd-O-Gd Bridge Promotes Electrocatalytic Oxygen Reduction.

The active-site density, intrinsic activity, and durability of Pd-based materials for oxygen reduction reaction (ORR) are critical to their application in industrial energy devices. This work constructs a series of carbon-based rare-earth (RE) oxides (Gd2 O3 , Sm2 O3 , Eu2 O3 , and CeO2 ) by using RE metal-organic frameworks to tune the ORR performance of the Pd sites through the Pd-REx Oy interface interaction. Taking Pd-Gd2 O3 /C as a representative, it is identified that the strong coupling between Pd and Gd2 O3 induces the formation of the Pd-O-Gd bridge, which triggers charge redistribution of Pd and Gd2 O3 . The screened Pd-Gd2 O3 /C exhibits impressive ORR performance with high onset potential (0.986 VRHE ), half-wave potential (0.877 VRHE ), and excellent stability. Similar ORR results are also found for Pd-Sm2 O3 /C, Pd-Eu2 O3 /C, and Pd-CeO2 /C catalysts. Theoretical analyses reveal that the coupling between Pd and Gd2 O3 promotes electron transfer through the Pd-O-Gd bridge, which induces the antibonding-orbital occupancy of Pd-*OH for the optimization of *OH adsorption in the rate-determining step of ORR. The pH-dependent microkinetic modeling shows that Pd-Gd2 O3 is close to the theoretical optimal activity for ORR, outperforming Pt under the same conditions. By its ascendancy in ORR, the Pd-Gd2 O3 /C exhibits superior performance in Zn-air battery as an air cathode, implying its excellent practicability.

Importing Antibonding‐Orbital Occupancy through Pd−O−Gd Bridge Promotes Electrocatalytic Oxygen Reduction

AbstractThe active‐site density, intrinsic activity, and durability of Pd−based materials for oxygen reduction reaction (ORR) are critical to their application in industrial energy devices. This work constructs a series of carbon‐based rare‐earth (RE) oxides (Gd2O3, Sm2O3, Eu2O3, and CeO2) by using RE metal–organic frameworks to tune the ORR performance of the Pd sites through the Pd−RExOy interface interaction. Taking Pd−Gd2O3/C as a representative, it is identified that the strong coupling between Pd and Gd2O3 induces the formation of the Pd−O−Gd bridge, which triggers charge redistribution of Pd and Gd2O3. The screened Pd−Gd2O3/C exhibits impressive ORR performance with high onset potential (0.986 VRHE), half‐wave potential (0.877 VRHE), and excellent stability. Similar ORR results are also found for Pd−Sm2O3/C, Pd−Eu2O3/C, and Pd−CeO2/C catalysts. Theoretical analyses reveal that the coupling between Pd and Gd2O3 promotes electron transfer through the Pd−O−Gd bridge, which induces the antibonding‐orbital occupancy of Pd−*OH for the optimization of *OH adsorption in the rate‐determining step of ORR. The pH‐dependent microkinetic modeling shows that Pd−Gd2O3 is close to the theoretical optimal activity for ORR, outperforming Pt under the same conditions. By its ascendancy in ORR, the Pd−Gd2O3/C exhibits superior performance in Zn‐air battery as an air cathode, implying its excellent practicability.

Review of SPEEK Amphoteric Proton Exchange Membranes in All Vanadium Flow Batteries

Sulfonated polyether ether ketone (SPEEK) membranes have been widely used in the field of all vanadium flow batteries (VFRB) due to their simple structure, convenient preparation, good thermal and mechanical stability, low cost, and easy modification. However, its membrane performance largely depends on the degree of sulfonation. As the degree of sulfonation increases, the proton conductivity increases, but it also increases water uptake, leading to excessive swelling and vanadium ion penetration, thereby reducing the stability of the membrane and the performance of the battery. The introduction of alkaline functional groups can serve as proton acceptors to promote proton transport through the Grotthus mechanism, and on the other hand, they can form acid-base pairs with sulfonic acid groups. The resulting hydrogen bonds, acid-base interactions, ion bonds, and other interface interactions are beneficial for reducing the swelling rate of SPEEK membranes, and can also adjust the size of proton transport channels, constructing efficient proton transport channels that are both conducive to proton transport and can hinder the passage of vanadium ions, Improve the ion selectivity of membranes. Therefore, this article reviews the basic research and practical development status of SPEEK amphoteric membranes in VRFB, including the latest progress in various modification strategies. And evaluated the challenges and potential future research directions faced by the development of SPEEK membranes.

Pullout behavior of geogrid reinforcement in calcareous sand

This study conducts a series of large-scale pullout tests to explore the pullout behavior of the biaxial geogrid-calcareous sand interface. It investigates the effects of normal stress, relative density, and embedded length on the interface pullout behavior of geogrid reinforcement in calcareous sand. In addition, this research examines changes in interface shear strength and the interface friction coefficient. The interface interaction mechanism of geogrid reinforcement in calcareous sand and the evolution of pullout force-clamp displacement curves are determined. The results indicated that the pullout force-clamp displacement curve primarily exhibits softening and hardening behaviors. The passive resistance of the geogrid mesh significantly influences the softening behavior, while shear friction predominantly affects the hardening behavior. The interface friction coefficient ranged from 0.28 to 0.88 for embedded lengths of 300 − 460 mm. The effects of relative density and embedded length on interface cohesion are more pronounced than those on the interface friction angle. When the embedded length increased from 300 to 460 mm, the rise in interface cohesion ranged from 42.0% to 47.7%, whereas the increase in internal friction angle ranged from 9.5% to 14.5%.

Designing a 3D structure and a self‐healing technique for advanced polymer composites with outstanding mechanical properties and healing ability

AbstractWe designed three‐dimensional (3D) structures through a combination of glass fiber cloth and in situ formation of nano polyphenylene oxide (PPE) fibers during the fabrication process of thermosetting cyanate ester/bismaleimide composites and developed a self‐stitching technique based on PPE fiber and interpenetrating polymer networks (IPNs) for aiding the crack self‐healing. The building of 3D structure effectively improves the interface interaction between fiber and matrix and suppresses the crack propagation process in composite, leading to significant enhancement in the mechanical properties. When PPE content is 20%, the interlaminar shear strength, flexural strength, impact strength, and tensile strength of the resulting composite are 98%, 74%, 95%, and 101% higher than those of the composite without PPE. The resulting composites possess excellent thermomechanical and lower dielectric properties. Because IPNs within composites can create interspaces and easily deform above glass‐transition temperature, PPE components may penetrate through the interspaces under thermal expansion force, and the contraction stresses of polymers generate strong locking effects in composite after cooling to room temperature, then the crack surfaces of composites can be stitched by PPE fibers, significantly recovering the mechanical properties. The healing efficiency of the composite with 30% PPE after impact and then heating at approximately 280°C can reach 96%.Highlights 3D structures were constructed during the fabrication process of glass‐fiber‐reinforced thermosetting cyanate ester/bismaleimide composite. A self‐stitching technique was developed for aiding the crack self‐healing of composite. 3D structures significantly improved the interface interaction between fiber and matrix in laminated composite. The mechanical properties of the resulting composite could be significantly improved by 3D structures. The healing efficiency of the healed composite could reach 96%.

Interfacial engineering of hierarchical MoNi4/NiO heterostructure nanosheet arrays as bifunctional electrocatalysts for urea-assisted energy-saving hydrogen production

Employing urea oxidation reaction (UOR) to substitute slow oxygen evolution reaction (OER) is an effective technique to accomplish high-efficiency hydrogen production. The exploitation of inexpensive and highly active bifunctional catalyst still remains a considerable challenge. We report the hybrid nanosheet arrays constructed of MoNi4/NiO heterojunction with hierarchically crosslinked network architecture by hydrothermal reaction and subsequent annealing process under H2/Ar atmosphere. The special heterostructure with neoteric morphology can promote electron shift and interface interaction through the powerful coupling interface between MoNi4 and NiO, increasing charge transfer speed, intrinsic activity and electrolyte transport. Only 31 mV overpotential and 1.37 V potential are needed to arrive 10 mA cm−2 for hydrogen evolution reaction (HER) and UOR, respectively. For the two-electrode urea-assisted electrolyzer, the lower potential of 1.41 V is required to reach 10 mA cm−2. Moreover, it displays superior stability with unceasing working for 54 h at the cell voltage of 1.41 V without obvious activity degeneration. This research provides an insight on the construct of high-efficiently bifunctional catalyst by synergistic coupling of NiMo-based alloys with metal oxides.

AIN particles/BN whiskers co-doped epoxy composites modified with polydopamine with high thermal conductivity

In this work, aluminum nitride particles (AlN) and boron nitride whiskers (BNw) were surface-functionalized by polydopamine, and then novel composites were prepared by co-doping. By observing with transmission electron microscopy, we clearly saw that the surfaces of AlN and BNw were successfully coated with a thin polydopamine coating. This is beneficial to enhance the filler-matrix interface interaction and the filler dispersion. The co-doping of the two thermally conductive fillers increases the chance of contact between the filler and the filler, and reduces the interfacial thermal resistance, thereby forming a thermal conduction network more efficiently. The results show that at a frequency of 1 MHz at room temperature, the dielectric constant of 30 wt%AlN@PDA/6 wt%BNw@PDA/EP composites is 4.74 and the dielectric loss tangent is 0.0171. Its thermal conductivity is 0.40 W/(m·K), the glass transition temperature reaches 250.2°C, the impact strength reaches 6.89 kJ m−2, and the breakdown field is 10.93 kV/mm.

MPA-Pred: A machine learning approach for predicting the binding affinity of membrane protein-protein complexes.

Membrane protein-protein interactions are essential for several functions including cell signaling, ion transport, and enzymatic activity. These interactions are mainly dictated by their binding affinities. Although several methods are available for predicting the binding affinity of protein-protein complexes, there exists no specific method for membrane protein-protein complexes. In this work, we collected the experimental binding affinity data for a set of 114 membrane protein-protein complexes and derived several structure and sequence-based features. Our analysis on the relationship between binding affinity and the features revealed that the important factors mainly depend on the type of membrane protein and the functional class of the protein. Specifically, aromatic and charged residues at the interface, and aromatic-aromatic and electrostatic interactions are found to be important to understand the binding affinity. Further, we developed a method, MPA-Pred, for predicting the binding affinity of membrane protein-protein complexes using a machine learning approach. It showed an average correlation and mean absolute error of 0.83 and 0.91 kcal/mol, respectively, using the jack-knife test on a set of 114 complexes. We have also developed a web server and it is available at https://web.iitm.ac.in/bioinfo2/MPA-Pred/. This method can be used for predicting the affinity of membrane protein-protein complexes at a large scale and aid to improve drug design strategies.

Mechanism of bubble cutting by fibers: Experiment and simulation

Bubble fragmentation plays a crucial role in plenty of industrial applications. The incorporation of fiber mechanism enhances fluid turbulence and facilitate bubble fragmentation in gas–liquid flows. However, the bubble cutting mechanism associated with fibers is not fully understood. Here, we sought to elucidate the underlying mechanisms and characteristics of bubble fragmentation by varying solution type, bubble impact velocity, fiber diameter, and surface wettability. Based on the experimental outcomes observed under these varied conditions, a mathematical model describing the bubble fragmentation pattern was developed. Further analysis of velocity, gas–liquid interfacial area liquid film, and dissipation energy by CFD simulations proved instrumental in explicating the results observed in our visual experiments. The interface area of bubble increases from 0.8 × 10-4 m2 to 1.45 × 10-4 m2 with the enhancement of fiber hydrophilicity. This investigation enriches our understanding of bubble fragmentation facilitated by fibers, thereby guiding the optimal design of fibers for enhanced gas–liquid interface interactions.

A-C/GeTe superlattices: Effect of interfacial impedance adaptation modeling on the thermal properties

Recently, nanostructuration has been proposed to improve the performance of phase change memories. This is the case of superlattices composed of amorphous carbon and crystalline germanium telluride, which we have investigated by molecular dynamics. For this, a modified Stillinger–Weber potential is adapted to reproduce their stiffness contrast/impedance ratio. In order to study the effect of the interface interaction, two sets of parameters are used to model the interfaces with different interactions between the two materials using the properties of the softer material or the average properties between the two creating an adaptation of impedance across the layers. The effects of interface roughness and carbon diffusion at grain boundaries are studied. Using equilibrium molecular dynamics as well as the propagation of wave-packets, we show first that without impedance adaptation, the anisotropy is high, and the roughness has a marked impact on the properties. However, the introduction of impedance adaptation destroys those effects on the thermal conductivity. Finally, we show that the periodic texturing of the interface increases the transmission of in-plane transverse phonons.

GelMA-catechol coated FeHAp nanorods functionalized nanofibrous reinforced bio-instructive and mechanically robust composite hydrogel scaffold for bone tissue engineering

Critical bone defects complicate tissue graft-based surgeries, raising healthcare expenditures and underscoring scaffold-based tissue-engineering strategies to support bone reconstruction. Our study highlighted that the phase-compatible combination of inorganic nanorods, nanofibers, and hydrogels is promising for developing biomimetic and cell-instructive scaffolds since the bone matrix is a porous organic/inorganic composite. In brief, methacrylated gelatin (GelMA) was reacted with dopamine to form catechol-modified GeLMA (GelMA-C). The GelMA-C was nanocoated onto an iron-doped hydroxyapatite (FeHAp) nanorod via metal-catechol network coordination. The modified nanorod (FeHAp@GelMA-C) was loaded onto GelMA-based nanofibers. The nanorods loaded pre-fibers were electrospun onto GelMA solution and photochemically crosslinked to fabricate a fiber-reinforced hydrogel. The structural, mechanical, physicochemical, biocompatibility, swelling properties, osteogenic potential, and bone remodelling potential (using rat femoral defect model) of modified nanorods, simple hydrogel, and nanorod-loaded fiber-reinforced hydrogel were studied. The results supported that the interface interaction between GelMA-C/nanorods, nanorods/nanofibers, nanorods/hydrogels, and nanofiber/hydrogels significantly improved the microstructural and mechanical properties of the scaffold. Compared to pristine hydrogel, the nanorod-loaded fiber-reinforced scaffold better supported cellular responses, osteogenic differentiation, matrix mineralization, and accelerated bone regeneration. The nanorod-loaded fiber-reinforced hydrogel proved more biomimetic and cell-instructive for guided bone reconstruction.