Characterization Of Interface Research Articles

Characterization of the soybean oil body interface: revealing the mechanism of changes in the interfacial protein composition, structure, and function of oil bodies extracted under different denaturation conditions

We investigated the stability and rheological properties of extracts from soybean oil bodies (OB) obtained under different denaturing conditions (heating, guanidine hydrochloride, urea, and sodium dodecyl sulfate (SDS)). Differences in the interfacial and antioxidant properties exhibited by the different compositions of interfacial proteins in the extracted OB were also assessed. SDS disrupted the interfacial structure of OB, whereas the treatments under the other three denaturing conditions effectively increased the ability of the OB proteins to form a network structure. The analysis of the secondary and tertiary structures of proteins showed that all denaturation conditions affected both hydrogen bonding and hydrophobic interactions of the protein molecules, with urea leading to the most pronounced structural unfolding and rearrangement of the OB proteins. The microstructure results of the protein indicated that the protein treated with GuHCl and urea exhibited a 'shell-like' structure and structural decomposition, which can promote the pre-encapsulation of active substances through hydrogen bonding or hydrophobic interactions. The electrophoretic results further confirmed that SDS could displace 24-kDa proteins and disrupt the original membrane structure of OB, whereas urea removed most of the extrinsic proteins. The interfacial proteins extracted from OB using the four denaturing methods were different but all had enhanced interfacial and antioxidant properties compared to the control. Therefore, the extraction of OB under different denaturation conditions facilitated the hierarchical extraction of its interfacial proteins, thereby broadening its application in the food industry.

New insights of the imprint at the catalyst-layer/ microporous-layer interface in PEMFC after heavy duty operation of commercial vehicles

Structural degradation and property decay of membrane electrode assemblies (MEAs) are primary causes for the stack performance and lifetime degradation. This study particularly investigates the structural damage and properties evolution of the catalyst-layer/microporous-layer (CL/MPL) interface in the MEA by conducting real-vehicle heavy-duty operational durability test and interfacial structure characterization. This research presents the first report and revelation of the causes and effects of CL/MPL interface imprints, and provides targeted advice for relieving MEA interfacial degradation. Results indicate that excessive assembly stress and stress variation during operation of stack causing the detachment of MPL materials at the region below the bipolar plate ridges is the essential cause of the imprints. The average surface contact angles of the aged CLs generally increase and the imprinted region exhibit stronger hydrophobicity than non-imprinted region due to the attachment of MPL materials. While the opposite is observed in MPL. Carbon corrosion induce structural degradation of the CL/MPL interface, leading to significant loss of carbon support and hydrophobic agent. The surface of aged CL become rougher and the pore size become more larger compared to the fresh CL. The formation of the interface imprint makes the contact between CL and MPL at the imprint region tighter, which reduces the interface resistance and inhibits the increase in ohmic polarization.

Shell-Isolated Nanoparticle-Enhanced Raman Spectroscopy: Toward High Sensitivity and Broad Applicability.

As a nondestructive and ultrasensitive technique, surface-enhanced Raman spectroscopy (SERS) has captivated the attention of the global scientific community for over 50 years. Among the various spectroscopic techniques derived from SERS, shell-isolated nanoparticle-enhanced Raman spectroscopy (SHINERS) stands as a cutting-edge advancement. The innovative and versatile core-shell nanoparticle structures used in SHINERS have emerged as an ideal platform for interfacial research, offering high sensitivity and broad applicability across diverse materials and single-crystal surfaces. Consequently, SHINERS has seen widespread adoption in pivotal fields, such as interface chemistry, electrocatalysis, biomedicine, materials, and food safety. In this Perspective, we outline the evolutionary journey of SHINERS, delve deep into its applications in fundamental research for interface characterization and catalysis, and explore its practical utility in critical areas of food safety and biomedicine analysis. Additionally, we map out the prospective trajectory and future milestones that await SHINERS as it continues to revolutionize the landscape of scientific exploration.

Engineering DNA Nanocube SAM Scaffolds for FRET-Based Biosensing: Interfacial Characterization and Sensor Demonstration.

Decorating a gold surface with molecular-level control over the positioning of DNA probes was demonstrated using a self-assembled monolayer (SAM) of wireframe DNA nanocube structures. The DNA nanocubes were specifically adsorbed and oriented using thiol-modified DNA on one face of the cube. The DNA nanocube SAM had a uniform coverage over the gold single crystal bead electrode with a separation of 20-30 nm measured by AFM. The face of the nanocube furthest from the gold surface was designed to hybridize with two different sequences of a 50 base single-stranded DNA probe that was modified with a fluorophore. The first 20 bases were hybridized with the DNA nanocube. One of a pair of FRET fluorophores was used for each probe strand. The dimensions of the nanocube controlled the relative spacing between these fluorophores. When the DNA probes were single-stranded, a FRET signal was observed. FRET decreased to background levels when a complementary DNA target was hybridized to either probe, resulting in a turn-off sensor with little cross-talk between the individual hybridization events. Hybridization isotherms for one target gave KA = 170 pM and a detection limit <50 pM. In addition, the DNA nanocube SAM was configured to be used as a turn-on NeutrAvidin sensor using biotinylated DNA targets hybridized to each probe resulting in an increase in FRET. We show that the wireframe DNA nanocube can be an effective scaffold for preparing biosensors with controlled separation between surface-bound probes facilitating precise sensor surface design and enabling a wide range of sensing modalities with more than one signal available for correlative confirmation of the target binding.

Interfacial microstructure evolution and mechanical characterization of brazed Al2O3 joints with Ni‒Ti interlayer: An experimental and theoretical approach

Reliable brazing joints of Al2O3 ceramics were obtained using an active Ni‒Ti interlayer under vacuum conditions. The interfacial microstructure and mechanical properties of the joints were studied. The structural, electronic, and elastic properties of the primary interfacial reaction phases were determined using first–principles calculations. After brazing at 1320 °C for 30 min, Ni2Ti4O layer and columnar AlNi2Ti formed at the interface adjacent to the Al2O3 substrate. With increasing brazing temperature between 1300 °C and 1380 °C, Ni2Ti4O layer thickened gradually, and the AlNi2Ti became increasingly longer. As brazing temperature reached 1400 °C, TiO was formed at the interface, and the Ni2Ti4O content decreased significantly; moreover, bulk AlNi2Ti and TiNi3 were distributed in the brazing seam. The highest shear strength of 129 MPa was achieved when brazed at 1350 °C for 30 min. According to the first–principles calculations, Ni2Ti4O is more readily formed than AlNi2Ti, whereas AlNi2Ti exhibits greater stability than Ni2Ti4O. Both AlNi2Ti and Ni2Ti4O possess metallic bonds, contributing to the adhesion of the filler metal to the Al2O3 substrates. The calculated modulus and Poisson’s ratio indicate that both AlNi2Ti and Ni2Ti4O exhibit ductile characteristics, which assist in relieving residual stress within the joint.

Characterization of Interface Transition Zone in Asphalt Mixture Using Mechanical and Microscopic Methods.

An enormous surge in the pavement sector requires the evaluation of interface bonding in asphalt composite, since the assessment of bonding brings considerable cost savings. Microscopic and mechanical analyses were performed to study the status of the interface transition zone of four groups of asphalt mixtures, using thin-slice preparation to obtain asphalt mixture slices with a flat surface for microscopic analysis. The interface transition zones were characterized using good knowledge of blending or diffusion phenomena by conducting tests both at the micro and macro levels to determine mixture quality. Asphalt mixture components were observed using fluorescence microscopy imaging and evaluated by the gray value change law. Asphalt mixture groups, (virgin, recycled of 30% aged and 70% unaged, 6%, and 4% rejuvenator dosage mixtures) under the same process parameters, which are a mixing time of 270 s and a mixing temperature of 150 °C, been considered optimum for component fusion in a hot asphalt mixture were used. This study relied on the influence of morphology law, assessed through rutting tests for high temperature performance, semi-circular bending tests for low temperature performance, and pull-off tests for interface bonding strength. The relationship between interface transition zones and macro performance was studied. The self-developed pull-off method was a research innovation which can be used as an alternative to study interface transition zones in asphalt mixtures, and provides the necessary data needed with 3D surface failure mode calculations. The device measured the bonding strength of a single aggregate in distinct positions using the bitumen penetration test method. The main goals were to determine a correction factor, identify the appropriate alteration, and compute the actual fracture surface area. Using scanning electron microscopy for interface characterization and micro-morphologies of mortar transition zone, our analysis provides adequate knowledge about interface position and the components present. The applied approaches to characterize asphalt mixture interfaces proved workable and reliable, as all methods have similar trends with useful information to determine asphalt pavement quality.

Fabrication of Bimetallic Structure (SS 316L/SS 308L) via Wire + Arc Additive Manufacturing: A Detailed Characterization of Interface

Fabrication of Bimetallic Structure (SS 316L/SS 308L) via Wire + Arc Additive Manufacturing: A Detailed Characterization of Interface

Solar Fuel Synthesis Using a Semiartificial Colloidal Z-Scheme.

The integration of enzymes with semiconductor light absorbers in semiartificial photosynthetic assemblies offers an emerging strategy for solar fuel production. However, such colloidal biohybrid systems rely currently on sacrificial reagents, and semiconductor-enzyme powder systems that couple fuel production to water oxidation are therefore needed to mimic an overall photosynthetic reaction. Here, we present a Z-scheme colloidal enzyme system that produces fuel with electrons sourced from water. This "closed-cycle" semiartificial approach utilizes particulate SrTiO3:La,Rh and BiVO4:Mo (light absorbers), hydrogenase or formate dehydrogenase (cocatalyst), and a molecular cobalt complex (a redox mediator). Under simulated solar irradiation, this system continuously generates molecular hydrogen or formate, while co-producing molecular oxygen for 10 h using only sunlight, water, and carbon dioxide as inputs. In-depth analysis using quartz crystal microbalance, photoelectrochemical impedance spectroscopy, transient photocurrent spectroscopy, and intensity-modulated photovoltage spectroscopy provides mechanistic understanding and characterization of the semiconductor-enzyme hybrid interface. This study provides a rational platform to assemble functional semiartificial colloidal Z-scheme systems for solar fuel synthesis.

Role of Pin Profile and Offset in Interfacial Characterization and Mechanical Behavior of Dissimilar Friction Stir Welded T-Lap Joints

Role of Pin Profile and Offset in Interfacial Characterization and Mechanical Behavior of Dissimilar Friction Stir Welded T-Lap Joints

The fabrication, microstructure, rheological properties and interactions of soft solid oleogels of hazelnut oil body

Trans and saturated fatty acids in dietary solid fats have negative effects on human health, such as chronic diseases, making the development of a fat substitute an urgent matter. The plant derived oil body-hazelnut oil body (HOB) as the oil droplets, and the hydrogel formed by xanthan gum (XG) and type B gelatin (GEL) as the outer layer were used to encapsulate HOB and construct the oleogel. The OBC, microstructure, and rheological results indicated that the XG-GEL formed a sponge-like, tightly packed three-dimensional network structure on the surface of HOB, effectively preventing oil leakage. The hazelnut oil body oleogel exhibited 100% OBC, excellent deformation resistance, and thixotropic recovery ability. FTIR spectroscopy results revealed that changes in the amide I, II, III, and A bands indicated the formation of hydrogen bonds, with pronounced hydrogen bonding occurring between the amino/hydroxyl groups of HOB and the hydroxyl/carboxyl groups of XG-GEL. Raman spectroscopy results suggested that HOB-XG-GEL likely exhibited stronger hydrophobic interactions, while XG-GEL had no significant impact on the unsaturation level, membrane composition, or lipid acyl chain disorder of HOB. XRD results showed a single broad diffraction peak at 2θ = 19.6°, corresponding to π-π stacking interactions between HOB and XG-GEL. Interfacial characterization and zeta potential results demonstrated that HOB-XG-GEL had stronger surface activity and electrostatic repulsion. XRD and DSC results confirmed that the hazelnut oil body oleogel displayed an amorphous structure and good thermal stability. This study provides a new strategy for fabricating oil bodies to produce edible oleogels instead of solid fats.

Thermal characterization of vertical interface by scanning photothermal radiometry.

In this work, scanning photothermal radiometry is used for imaging and to characterize a submicron crack. From the thermal images, the evolution of the crack is mapped in the space with micrometer resolution. A vertical contact interface at the steel-steel junction is used to represent a micro-crack with a thickness less than 0.5μm. The thermal quadrupole approach is used to model the heat transfer within the semi-infinite vertical crack. Then, using the phase mapping and that calculated from the model, the estimation of both the equivalent thermal boundary resistance of the interface and the average interface thickness was done.

Interfacial characterization of spinning water film along a concave wall

Abstract Thin liquid film flowing down the inner concave surface of a vertical cylindrical vessel is examined. At the top of the vessel, the water is injected horizontally at high speed circumferentially along the vessel wall and flows downwards due to the action of gravity. This turbulent film flow is modeled using the large eddy simulation (LES) and Reynolds averaged Navier–Stokes (RANS) approaches combined with the volume-of-fluid method. The results of both methods are validated with direct numerical simulation. The Favre-filtered two-phase LES, which is implemented and studied in this paper, can reasonably predict the film thickness similarly to that of the RANS approach using the elliptic blending Reynolds stress model, although it requires fine resolution in the wall region. The effect of volume flow rate on the film structure and thickness is investigated. The film thickness is shown to be nearly constant when the wall is partially wetted and changes as the cubic root of the volume flow rate when the spinning film encloses the entire circumference of the vessel.

Wettability and Interfacial Reaction between the K492M Alloy and an Al2O3 Shell.

In this study, wettability behavior and the interaction between the K492M alloy and an Al2O3 shell were investigated at 1430 °C for 2~5 min. The microstructural characterization of the alloy-shell interface was carried out by optical microscopy (OM) and scanning electron microscopy (SEM). The results indicated that the interaction could cause a sand adhesion phenomenon affecting the alloy, and the attached products were Al2O3 particles. In addition, the wetting angles of the alloys located on the shell were 125.2°, 109.4°, 97.0°, and 95.0°, respectively, as the contact time was increased from 2 to 5 min. Apparently, the wettability of the alloy in relation to the shell had a relationship with the contact time, where a longer contact time was beneficial to the permeation of the alloy into the shell and the interaction between the two components. No significant chemical products could be detected in the interaction layer, indicating that only the occurrence of the physical dissolution of the shell took place in the alloy melt.

Interface migration and grain growth in NbC-Ni cemented carbides with secondary carbide addition

Cemented carbides are widely used for cutting and drilling tools. They usually combine a WC hard carbide phase and a Co-based ductile binder. NbC-Ni materials are considered as a possible alternative, especially for wear applications. The advantageous economic situation for raw materials sourcing, their interesting mechanical properties and low density have raised a new interest for these materials. However, mechanical properties can be limited by the rapid grain growth during liquid phase sintering, as compared to WC-Co. Grain growth can be controlled by the addition of secondary carbides. In this paper, a quantitative EBSD analysis of grain growth is performed for NbC-12 vol%Ni materials sintered at 1450 °C with controlled addition of Mo2C and WC. The average grain size decreases continuously with Mo2C addition. The results are discussed based on a more detailed interface characterization and on a previous model for the cooperative migration of phase boundaries and grain boundaries.

Synthesis of lubricant additive for castor oil: A green and fast approach

The realization of industrial applications of plant-based lubricants depends on well-dispersed lubricant additives. Herein, microwave-assisted ball milling directly grafted L-phenylalanine (LP) onto graphene oxide. The reaction does not require a pretreatment step and avoids high temperatures and catalyst involvement. The prepared LP-functionalized graphene oxide (LP-GO) exhibited hydrophobicity with a water contact angle of up to 133° and could maintain stable dispersion in castor oil for more than 80 days. 0.2 wt% of LP-GO improved the thermal conductivity of castor oil by 11.1 % and contributed to the enhancement of tribological performance under three different conditions. In particular, wear and friction decreased by 7.31 % and 11.54 % under the medium speed medium load condition, respectively. The friction decreased by 25.27 % in the low-speed high-load condition, and the wear decreased by 18.65 % under the high-speed low-load condition. The characterization of the tribological interface revealed that the lubrication mechanism of LP-GO was attributed to its protective and repairing effects at the friction interface. The surface functionalization approach in this paper is rapid and green. It can be extended to other functionalizing agents and nanomaterials, facilitating further applications of vegetable oils in tribology.

Anion‐Engineering Toward High‐Voltage‐Stable Halide Superionic Conductors for All‐Solid‐State Lithium Batteries

AbstractHalide solid electrolytes (SEs) are attracting strong attention as one of the compelling candidates for the next‐generation of inorganic SEs due to their high ionic conductivity. Nevertheless, unsatisfactory high‐voltage stability restricts the further applications of halide SEs. Herein, the anion‐engineering of F−/O2− is evolved to construct the high‐voltage stable zirconium‐based halide superionic conductors (Li2.5ZrCl5F0.5O0.5, LZCFO). Benefiting from the thermodynamic/kinetic high‐voltage stability of F‐containing SE and the disordered localized structure introduced by O2−, LZCFO displays a practical electrochemical limit of 4.87 V versus Li/Li+ and an ionic conductivity of 1.17 mS cm−1 at 30 °C. With LZCFO and NCM955, the all‐solid‐state lithium battery exhibits a high discharge capacity of 207.1 mAh g−1 at 0.1C and a capacity retention of 81.2% after 500 cycles at 0.5C. The interfacial characterization further demonstrates the formation of the F‐rich cathode–electrolyte interphase (CEI), which inhibits side reactions between the cathode and the SE and boosts excellent cycling stability. This work affords fresh insights on the engineering of SEs with high‐voltage stability, high ionic conductivity, and stable CEI in all‐solid‐state lithium batteries.

Deconvoluting Effects of Lithium Morphology and SEI Stability through Interface Engineering

The widespread use of renewable energy resources and electrification is mandatory for transitioning into a fossil-fuel-free world. Currently, Li-ion battery (LIB) is the universal mode of electrochemical energy storage, but it is reaching the theoretical limit, creating the urgency of more efficient batteries for next-generation applications. Li-metal batteries (LMBs) are considered a key technology to overcome the current energy density limitations of LIBs. In the most energy-dense LMB configuration, the anode-free LMB, Li is directly plated on and stripped from the Cu current collector (CC), subjecting it to the most stringent cycling conditions and making performance regulation crucial. Therefore, engineering the Cu-electrolyte interface is both fundamentally and practically significant.The two most crucial performance modulators in LMBs are electrodeposited Li morphology and solid electrolyte interphase (SEI). The literature has shown that low surface area morphology and anion-derived SEIs are usually beneficial for improved performance. However, it is difficult to deconvolute the individual impact of low surface area morphology and anionic SEI species on performance as they coexist and are correlated. One reported approach to understand the decoupled effects of morphology and SEI is ultrafast electrodeposition of lithium outpacing SEI formation (>100 mA cm-2). Our work establishes a new approach applicable at regular plating and stripping conditions (1 mA cm-2) that uses interface engineering with atomic layer deposited (ALD) thin films to deconvolve Li morphology and SEI stability effects. First, we modify the Cu CC surface using two different thin films with distinct characteristics: resistive, acidic HfO2; and conductive, acidic ZnO.Leveraging ALD, we precisely control the thickness of the nanofilms and establish that increasing the film resistance results in improved performance due to resistance-derived Li morphology. Our approach of decoupling the impact of SEI species from morphology is to preform the SEI before cycling using a simple potential hold step for both these acidic films with opposite electrical properties at different thicknesses. We find that with increasing film thickness, generally, the preformed SEI has more anionic species due to the surface acidity of the thin films. Despite being anion-rich, the preformed SEI does not improve performance, which we attribute to its evolution into an organic-rich SEI during plating. Moreover, the impact of the preformed SEI is statistically insignificant during long-term cycling, whereas the role of resistance becomes more apparent. The effects are demonstrated through interface characterization and performance measurements in three different electrolytes, with at least a twofold increase in cycle life and improved capacity retention achieved in practical anode-free pouch cells. Our results thus indicate that morphological control is more effective for improved battery cyclability due to the inherent challenges with preformed SEI preservation, and as a result the resistance of the thin films is more important than surface acidity for CC modification.

Approaching the Multiphase Interface of Ir-Based PEM Electrolyzers Using Operando ‘Tender’ X-Ray AP-XPS

Electrochemical water splitting is a promising pathway for the renewable production of hydrogen as an alternative fuel and chemical feedstock. Yet, the process is plagued by slow kinetics of the essential oxygen evolution reaction at the anode. Further, large-scale hydrogen production from such devices will require reduced platinum group metal (PGM) loadings (often iridium-based anodes) and/or new materials due to factors such as PGM scarcity, cost and loss during operation. In the hopes of enabling progress of rational design for OER catalysts, effective characterization of the electrode-liquid interface is crucial. Synchrotron-based X-ray Photoelectron Spectroscopy (XPS) offers a versatile way to obtain surface chemical and elemental characterization of these materials. The use of X-rays in the ‘tender’ regime (~2-6 keV) allows for deeper probing than the conventional ‘soft’ x-ray (< 2000 eV) set up that is common at synchrotrons and lab-based sources. The photoelectrons generated from tender x-rays have enough energy to penetrate tens of nanometers through low density components such as a layer of liquid or polymeric electrolyte. This opens the door to access the chemistry at the interface of liquid and ionomer electrolyte-electrocatalyst materials. With the use of a fully operational two-electrode system, we are able to study these membrane electrode assemblies under active water splitting conditions.My talk will explain our specific approach, which is often crucial for successful collection of accurate data, highlighting elements of cell design and experimental setup that are helpful for this process. I will also show recent AP-XPS results on iridium-based polymer electrolyte membranes for water splitting. With application of elevated potential, we can correlate the iridium valency and surface species with the appearance of product traces in a mass spectrum. Figure 1

Interfacial characterization and bonding mechanism of W/ODS-316 L steel multi-material structure fabricated by laser powder bed fusion

Interfacial characterization and bonding mechanism of W/ODS-316 L steel multi-material structure fabricated by laser powder bed fusion

Interfacial Dynamics Study of NCM523-Based Semi-Solid-State Lithium-Ion Batteries by Electrochemical Impedance Spectroscopy.

The use of solid electrolytes (SE) in solid-state batteries holds the promise of achieving higher energy densities and enhancing safety. However, current solid-state batteries face significant interface impedance issues, mainly dealing with the effect of the evolution of the solid-solid interface on ion transport. Semi-solid-state batteries (SSB), containing a small amount of liquid electrolyte, serve as appropriate transitional products in the development process of solid-state batteries. More importantly, the clarity of the relevant interface dynamics can provide theoretical guidance for the subsequent all-solid-state batteries. Therefore, this paper investigates SSB through Electrochemical Impedance Spectroscopy (EIS), primarily employing a combination of theoretical modeling, simulation predictions, and experimental analyses to elucidate the complex electrochemical processes within these batteries. Based on detailed exploration of the complex electrochemical processes within SSB, we have discovered additional electrochemical processes beyond Li+ penetration through the solid-electrolyte interphase (SEI) film and charge transfer. We attribute the additional electrochemical reaction processes to the resistance present at the SE/SEI interface of SSB on account of numerical analysis and interface characterization. Furthermore, this interface resistance exhibits a trend of initial decrease followed by continuous increase, elucidating the attribution and numerical variations of various impedance components within the EIS. The application of EIS techniques to analyze ion transport processes in SSB serves as a suitable transition toward achieving all-solid-state batteries as well as provides guidance for subsequent interface optimization of solid-state batteries and propels their transition from laboratory experimentation to commercialization.