Multicomponent Structures Research Articles

The role of surface substitution in the atomic disorder-to-order phase transition in multi-component core-shell structures.

Intermetallic phases with atomic ordering are highly active and stable in catalysts. However, understanding the atomistic mechanisms of disorder-to-order phase transition, particularly in multi-component systems, remains challenging. Here, we investigate the atom diffusion and phase transition within Pd@Pt-Co cubic nanoparticles during annealing, using in-situ electron microscopy and ex-situ atomic resolution element analysis. We reveal that initial outward diffusing Pd partially substitutes Pt, forming a (Pt, Pd)-Co ternary system in the surface region, enabling the phase transition at a low temperature of 400 °C, followed by shape-preserved inward propagation of the ordered phase. At higher temperatures, excessive interdiffusion across the interface changes the stoichiometric ratio, diminishing the atomic ordering, leading to obvious change in morphology. Calculations indicate that the Pd-substitute in (Pt, Pd)-Co system leads to a significantly lower phase transition temperature compared to that of Pt-Co alloy and thus a lower activation energy for atomic diffusion. These insights into atomistic behavior are crucial for future design of multi-component systems.

Merged-nets enumeration for the systematic design of multicomponent reticular structures.

Rational design of intricate multicomponent reticular structures is often hindered by the lack of suitable blueprint nets. We established the merged-net approach, proffering optimal balance between designability and complexity, as a systematic solution for the rational assembly of multicomponent structures. In this work, by methodically mapping node-net relationships among 53 basic edge-transitive nets, we conceived a signature net map to identify merging net pairs, resulting in the enumeration of 53 merged nets. We developed a practical design algorithm and proposed more than 100 multicomponent metal-organic framework platforms. The effectiveness of this approach is commended by the successful synthesis of four classes of materials, which is based on merging three-periodic nets with the four possible net periodicities. The construction of multicomponent materials based on derived nets of merged nets highlights the potential of the merged-net approach in accelerating the discovery of intricate reticular materials.

Protein Cage Directed Assembly of Binary Nanoparticle Superlattices.

Inorganic nanoparticles can be assembled into superlattices with unique optical and magnetic properties arising from collective behavior. Protein cages can be utilized to guide this assembly by encapsulating nanoparticles and promoting their assembly into ordered structures. However, creating ordered multi-component structures with different protein cage types and sizes remains a challenge. Here, the co-crystallization of two different protein cages (cowpea chlorotic mottle virus and ferritin) characterized by opposing surface charges and unequal diameter is shown. Precise tuning of the electrostatic attraction between the cages enabled the preparation of binary crystals with dimensions up to several tens of micrometers. Additionally, binary metal nanoparticle superlattices are achieved by loading gold and iron oxide nanoparticles inside the cavities of the protein cages. The resulting structure adopts an AB2 FCC configuration that also impacts the dipolar coupling between the particles and hence the optical properties of the crystals, providing key insight for the future preparation of plasmonic and magnetic nanoparticle metamaterials.

Fabrication of Hierarchical Nanostructures featuring Amplified Asymmetry through Co‐assembly of Liquid Crystalline Block Copolymer and Chiral Amphiphiles

The widespread presence of hierarchical asymmetric structures in nature has sparked considerable interest because of their unique functionalities. These ingenious structures across multiple scales often emerge from the transfer and amplification of asymmetry from chiral molecules under various synergistic effects. However, constructing artificial chiral asymmetric structures, particularly in developing hierarchical multicomponent structures analogous to those formed in nature through synergistic non‐covalent interactions, still presents tremendous challenges. Herein, we propose a co‐assembly strategy to fabricate hierarchical chiral mesostructures by combining a liquid crystalline block copolymer (LC‐BCP) with a small molecular amphiphile containing chiral alanine or phenylalanine as a linker. Through a classic solvent‐exchange process, chiral amphiphiles embedded within LC‐BCP finely regulate the LC ordering effect and facilitate transfer and amplification of asymmetry. Consequently, various co‐assembled structures with significant hierarchical chirality features are obtained through synergetic effects. Remarkably, subtle alterations to the side groups of amino acids in the amphiphiles effectively adjust the hierarchical morphology transition. Moreover, the covalent bonding sequence of amino acids in the amphiphiles emerges as a critical factor governing the formation of hierarchical nanofibers and multilayered vesicles exhibiting a superhelical sense.

Fabrication of Hierarchical Nanostructures Featuring Amplified Asymmetry Through Co-Assembly of Liquid Crystalline Block Copolymer and Chiral Amphiphiles.

The widespread presence of hierarchical asymmetric structures in nature has sparked considerable interest because of their unique functionalities. These ingenious structures across multiple scales often emerge from the transfer and amplification of asymmetry from chiral molecules under various synergistic effects. However, constructing artificial chiral asymmetric structures, particularly in developing hierarchical multicomponent structures analogous to those formed in nature through synergistic non-covalent interactions, still presents tremendous challenges. Herein, we propose a co-assembly strategy to fabricate hierarchical chiral mesostructures by combining a liquid crystalline block copolymer (LC-BCP) with a small molecular amphiphile containing chiral alanine or phenylalanine as a linker. Through a classic solvent-exchange process, chiral amphiphiles embedded within LC-BCP finely regulate the LC ordering effect and facilitate transfer and amplification of asymmetry. Consequently, various co-assembled structures with significant hierarchical chirality features are obtained through synergetic effects. Remarkably, subtle alterations to the side groups of amino acids in the amphiphiles effectively adjust the hierarchical morphology transition. Moreover, the covalent bonding sequence of amino acids in the amphiphiles emerges as a critical factor governing the formation of hierarchical nanofibers and multilayered vesicles exhibiting a superhelical sense.

Effect of Nb on hydrogen storage properties of Ti–V–Cr-based alloys

This research investigates the impact of incorporating Nb into Ti–V–Cr-based alloys, with compositions ranging from Ti30-xV35Cr35Nbx (x = 0, 5, 10, 15, and 20 at. %), with the objective of enhancing hydrogen storage properties. Employing a comprehensive approach encompassing design, synthesis, and characterization, the study aimed to develop novel hydrogen storage alloys. Utilizing the CALPHAD method, the alloys were designed to anticipate the formation of multicomponent single-phase structures. Structural and microstructural analyses of the synthesized alloys were conducted using XRD, SEM, and EDS techniques. The hydrogen storage capabilities were evaluated utilizing a Sieverts’ type apparatus. The investigated alloys displayed a singular-phase BCC solid solution, characterized by dendritic microstructures. Notably, the Nb-free alloy, Ti30V35Cr35, demonstrated the highest hydrogen storage capacity, reaching 3.62 wt% (∼1.9 H/M) under 20 bar of H2 at room temperature. Among the Nb-containing alloys, Ti25V35Cr35Nb5 exhibited a capacity of 2.91 wt% (∼1.6 H/M) under identical conditions. Furthermore, the incorporation of Nb up to 10 at. % effectively bolstered cycle durability. This study underscores the presence of an optimal Nb content crucial for achieving the highest hydrogen capacity and cycle durability in these alloys.

Geometrically nonlinear static analysis of multi-component structures through variable-kinematics finite elements

Geometrically nonlinear static analysis of multi-component structures through variable-kinematics finite elements

Quaternary Dielectric Triboelectric Nanogenerator for Self-Powered Electrochemical Systems.

The energy conversion efficiency of conventional binary dielectric triboelectric nanogenerators is not satisfactory due to the limitations of material selection and triboelectrification, which motivates the design of more efficient multicomponent structures to reveal the charge accumulation mechanism for improving the energy conversion efficiency. Herein, a rotating quaternary dielectric triboelectric nanogenerator (Q-TENG) is designed to construct a self-powered system integrating illumination, sensing, and electrochemical decolorization. Through the equivalent capacitance model, the mechanisms for charge generation, transfer, and accumulation in a Q-TENG are elucidated to achieve efficient matching of quaternary dielectric materials and high output performance. At a wind speed of 3.5 m s-1, the peak power density of the Q-TENG reaches 44.94 W m-2, setting a new record for a wind-driven TENG. A 5 ppm solution of methyl orange is completely degraded by the wind-driven Q-TENG in <6 h. This work not only guides the direction for constructing more efficient TENG systems but also promotes the practical development of self-powered electrochemical systems.

1,3,5-2,4,6-Functionalized Benzene Molecular Cage: An Environmentally Responsive Scaffold that Supports Hierarchical Superstructures.

New stimulus-responsive scaffolds are of interest as constituents of hierarchical supramolecular ensembles. 1,3,5-2,4,6-Functionalized, facially segregated benzene moieties have a time-honored role as building blocks for host molecules. However, their user as switchable motifs in the construction of multi-component supramolecular structures remains poorly explored. Here, we report a molecular cage 1, which consists of a bent anthracene dimer 3 paired with 1,3,5-tris(aminomethyl)-2,4,6-triethylbenzene 2. As the result of the pH-induced ababab↔bababa isomerization of the constituent-functionalized benzene units derived from 2, this cage can reversibly convert between an open state and a closed form, both in solution and in the solid state. Cage 1 was used to create stimuli-responsive hierarchical superstructures, namely Russian doll-like complexes with [K⊂18-crown-6⊂1]+ and [K⊂cryptand-222⊂1]+. The reversible assembly and disassembly of these superstructures could be induced by switching cage 1 from its open to closed form. The present study thus provides an unusual example where pH-triggered conformation motion within a cage-like scaffold is used to control the formation and disassociation of hierarchical ensembles.

4D-printed NiTi auxetic metamaterial with enhanced functionality via deposition of nano-Ni layer

The aerospace and energy conversion industries utilize superelastic metallic metamaterials fabricated by additive manufacturing (AM). Currently, printing samples with “residual particle-free” surfaces requires post-cleaning techniques such as chemical and electrochemical etching. However, the high concentration of stress and cracking near the nodes and sharp edges can cause brittle fracture, strength reduction, and energy absorption. Moreover, topological optimization can significantly increase the weight of a structure. To overcome these challenges, in this study, we utilized the benefits of multicomponent structures and nanomaterials possessing high capillary effects and low melting points. Specifically, a thin layer of nano-Ni was deposited on the surfaces of NiTi auxetic structures printed using micro-Ni–Ti powders. The results showed that high-performance functional structures with reliable surfaces, high strength, high energy absorption, and constant Poisson’s ratios for a given deformation could be achieved. This was attributed to a low stress-induced martensite formed during laser processing and a low residual stress, computed experimentally and by simulations. Although the loss factor or dissipated energy during superelastic cycling was enhanced, the superelastic reproducibility was lowered in the samples fabricated using the developed method. This was attributed to the higher strain hardening and dislocation generation, despite the developed approach resulting in a very high superelastic recovery in the initial cycles. The findings of this study provide a framework for designing high-performance functional structures using AM and nanomaterials for energy-absorbing devices with high resistance to vibration.

A Single Component, Single Layer Flexile Foam Evaporator with the Higher Efficiency for Water Generation.

One of the greenest and promising ways to solve the problem of freshwater crisis is surface solar steam generation from seawater. A great number of photothermal materials with multi-component and multi-layered delicate yet complex structures often suffer from either low evaporation rate or high energy loss. Here, this work presents a single component foam evaporator with steam generation rate of up to 4.32kg m-2 h-1 under 1 sun irradiation. The evaporator is constructed from an aniline oligomer as a single light-absorbing component, covalent linked with polyethylene glycol to form a monolithic polymer foam. Floating on the seawater, the foam has absorbance of 99.5% over the entire solar spectral range and low thermal conductivity (0.0077W K-1m-1) that effectively retains heat in the material and at the interface. After 3 months of continuous outdoor natural sunlight irradiation, the evaporator maintains a stable and durable evaporation rate. Moreover, the materials have good mechanical properties (7.48MPa young's modulus and 57.38% elongation at break) and excellent chemical resistance in 10 common organic solvents and aqueous solutions of pH = 1 to 14. This study provides a new system and strategy for desalination, steam power generation, treatment of polluted water and sewage, etc.

Assessment of the potential structure and nucleation efficacy of multi-component heterogeneous substrate

In recent years, nucleation of multi-component heterogeneous interface structures has attracted increasing attention due to their excellent grain refinement and anti-poisoning capabilities in Al-Si alloy. In this research, a general methodology was proposed to predict the surface structure and meanwhile evaluate the grain refinement efficacy of the multi-component boride nucleants based on a comprehensive experimental and theoretical study of a novel Al-Si alloy refiner, i.e., Al-3.5 Nb-1 V-1B. By using high-resolution electron microscopy, the (Nb, V)B2 particle with a characteristic “core-shell” surface structure was observed, attributed to V adsorption driven by interfacial energy minimization, validated by ab initio calculations. A general interfacial energy-based model was then proposed which predicts the multi-component boride substrate structure, well consistent with the experimental findings. The nucleation potency of different substrates was analyzed in atomic scale and only if the interfacial atomic vibration was considered together with the nucleation-influencing factors (i.e., the lattice mismatch and the anti Si-poisoning effect), the predicted nucleation potency order can agree well with the experimental results. A thermodynamics-kinetics combined analytic model was summarized by coupling the lattice mismatch parameter, the interfacial Si adsorption energy and the interfacial atomic vibration amplitude, which accurately evaluates the multi-component boride grain refiners for the Al-Si alloys.

The strength of complex compressed reinforced concrete structures utilising hollow concrete blocks

Structures in which elements from different materials work together are successfully used in various combinations. Recently, new, effective construction materials and products have appeared. In complex or multi-component structures, elements made of materials with different physico-chemical or strain-strength characteristics should be sensibly combined for joint work. The more fully the properties of the components’ materials are utilised, the more efficient the design itself is. By analysing global practice, it can be seen that small concrete blocks have become widespread. The use of masonry made of hollow concrete blocks in modern construction differs from traditional ones in that the void area (up to 70%) makes it possible to create complex high-strength load-bearing structures by filling them with monolithic reinforced concrete. This also enables speeding up the construction process itself and reducing the cost of work on the construction site. The purpose of the study was to examine the strength of centrally compressed columns composed of hollow blocks and concrete filling with different transverse and longitudinal reinforcements, as well as to improve their calculation methodology. Experimental studies of centrally compressed columns, with different percentages of reinforcement using hollow concrete blocks as permanent formwork, have been carried out. The article presents the results of the research on strength, but the results of the strain studies were not included in this work. The proposed method of calculating complex constructions can be applied in design practice. A good correlation was observed between the experimental results and the results of the analytical model.

Exploring multicomponent perovskites ReXO[formula omitted] (Re=Sm, Eu, Gd and X=Ti, Cr, Ni and Cu): Channeling properties through alloying

Multi-component systems involving the high-entropy and the medium-entropy perovskites stimulate the incorporation of additional components to facilitate the simultaneous customization of a range of properties, thereby unlocking their potential for novel functionalities. A new class of multicomponent perovskite oxides with the participation of rare earth elements has been synthesized. The three compositions which were produced by mechanical alloying involved Sm(Ti0.18Cr0.23Ni0.29Cu0.30)O3, Eu(Ti0.18Cr0.23Ni0.29Cu0.30)O3 and Gd(Ti0.18Cr0.23Ni0.27Cu0.32)O3. The Goldschmidt’s tolerance factor predicts the stability of the multicomponent perovskite crystal structures. Furthermore, to provide a theoretical viewpoint on the above perovskites, a density-functional study of all the structures along with the single-metallic perovskites has been performed. The formation energy of the structures (three multi-component and 12 single-metallic perovskites) confirms the stability and also their formation. Furthermore, the energy gap detected in the spin-down channels of the multicomponent materials suggests a promising potential for these systems as a spin filter in spintronic applications. The magnetic characteristic could be helpful for tuning the physical characteristics of the perovskites and could modify drastically their transport properties.

The Use of Spatially Multi-Component Plasma Structures and Combined Energy Deposition for High-Speed Flow Control: A Selective Review

This review examines studies aimed at the organization of energy (non-mechanical) control of high-speed flow/flight using spatially multi-component plasma structures and combined energy deposition. The review covers selected works on the experimental acquisition and numerical modeling of multi-component plasma structures and the use of sets of actuators based on plasma of such a spatial type for the purposes of control of shock wave/bow shock wave–energy source interaction, as well as control of shock wave–boundary layer interaction. A series of works on repetitive multiple laser pulse plasma structures is also analyzed from the point of view of examining shock wave/bow shock wave–boundary layer interaction. Self-sustained theoretical models for laser dual-pulse, multi-mode laser pulses, and self-sustained glow discharge are also considered. Separate sections are devoted to high-speed flow control using combined physical phenomena and numerical prediction of flow control possibilities using thermal longitudinally layered plasma structures. The wide possibilities for organization and applying spatially multi-component structured plasma for the purposes of high-speed flow control are demonstrated.

Immune-enhancing activity of compound polysaccharide on the inactivated influenza vaccine

Traditional Chinese medicine polysaccharides have numerous biological activities with broad applications in the biomedical industries. However, a clear understanding of the pharmacological activities of compound polysaccharides with multi-component structures remain challenging. This study aimed to investigate the immune boosting effect of compound polysaccharides on the influenza vaccine and assess the preliminary structure-activity relationship. The compound polysaccharide (CP) was isolated from the combined Chinese herbs lentinan, pachymaran and tremellan, and purified by gradient ethanol precipitation to obtain its subcomponents of CP-20, CP-40, CP-60, and CP-80 with decreasing molecular weights. These polysaccharides were mainly composed of glucans with different linkage patterns, including α-(1 → 3)-glucan, α-(1 → 4)-glucan and β-(1 → 6)-glucan. A significant improvement was observed in the survival of mice vaccinated with inactivated (IAV) vaccine and the isolated polysaccharides as adjuvants. A reduction in the pulmonary virus titer and weight loss were also observed. Moreover, CP-40 and CP-60, as well as the original CP, significantly enhanced the serum anti-IAV antibody titers and interleukin IL-2, IL-5, and IL-6 concentrations. These preliminary results indicate the immune boosting effect of the compound polysaccharides is highly relevant to the specific structural properties of the subcomponent, and CP-40 is worthy of further exploration as a glycan adjuvant for the IAV vaccine.

ZIF-derived porous carbon loaded multicomponent heterostructured yolk@shell nanospheres as an ultrasensitive electrochemical sensing platform for the detection of caffeic acid in food

Multicomponent heterogeneous structures of yolk@shell nanospheres embedded in MOF-derived porous carbon are potentially excellent electrocatalytic materials. In this work, the multicomponent yolk@shell nanospheres (Au@Co3O4@CeO2) were synthesized through an autocatalytic redox reaction. The synergistic and interfacial effects between Co3O4 and CeO2 can expose more active sites and enhance the catalytic activity. Then, the electrical conductivity of Au@Co3O4@CeO2 was improved using N-doped carbon nanomaterials (NPC), which was derived from ZIF-8 by high-temperature pyrolysis. The synergistic catalytic effect between ZIF-8 derived NPC and Au@Co3O4@CeO2 resulted in the highest electrochemical response current to caffeic acid in this composite. Under optimal conditions, the prepared modified electrode showed a LOD (limit of detection) of 5.7 × 10−10 M for CA and a linear range of 1.0 × 10−9 to 3.0 × 10−6 M. Meanwhile, it showed remarkable selectivity for CA in the anti-interference experiments and can be applied to the detection in food samples (strawberry and red wine). This work has developed a novel sensing material for sensitive detection of CA, broadening the application of multi-component shell-core structured metal oxidation.

Dual-assisted high-precision tracking technique for wideband multiplexed signals in new generation GNSS

With the evolution of Global Navigation Satellite System (GNSS), new generation GNSS signals have adopted the dual-frequency multiplexing modulation techniques, which jointly modulate multiple signals located on multiple sub-frequencies into a Wideband Multiplexed Signal (WMS). Although WMSs were proposed initially to reduce the complexity of satellite transmitters and improve the transmission efficiency of signals, their multi-component structures and wide root mean square bandwidths introduced by high-frequency subcarriers also provide the possibility to improve the GNSS ranging precision. Therefore, this paper proposes a Dual-assisted Multi-component Tracking (DMT) technique, which can not only fully use high-frequency subcarriers in WMSs, but also effectively track carrier, subcarrier, and code by jointly utilizing all components in WMS. In this paper, the tracking and ranging performances of DMT are comprehensively analyzed theoretically and by simulation and real experiments. The results show that compared with existing WMS tracking methods, DMT can achieve tracking results with lower tracking jitters and ranging results with higher precision, providing a highly advantageous solution for new generation GNSS signal processing.

Advancements in Additive Manufacturing for Copper-Based Alloys and Composites: A Comprehensive Review

Copper-based materials have long been used for their outstanding thermal and electrical conductivities in various applications, such as heat exchangers, induction heat coils, cooling channels, radiators, and electronic connectors. The development of advanced copper alloys has broadened their utilization to include structural applications in harsh service conditions found in industries like oil and gas, marine, power plants, and water treatment, where good corrosion resistance and a combination of high strength, wear, and fatigue tolerance are critical. These advanced multi-component structures often have complex designs and intricate geometries, requiring extensive metallurgical processing routes and the joining of the individual components into a final structure. Additive manufacturing (AM) has revolutionized the way complex structures are designed and manufactured. It has reduced the processing steps, assemblies, and tooling while also eliminating the need for joining processes. However, the high thermal conductivity of copper and its high reflectivity to near-infrared radiation present challenges in the production of copper alloys using fusion-based AM processes, especially with Yb-fiber laser-based techniques. To overcome these difficulties, various solutions have been proposed, such as the use of high-power, low-wavelength laser sources, preheating the build chamber, employing low thermal conductivity building platforms, and adding alloying elements or composite particles to the feedstock material. This article systematically reviews different aspects of AM processing of common industrial copper alloys and composites, including copper-chrome, copper-nickel, tin-bronze, nickel-aluminum bronze, copper-carbon composites, copper-ceramic composites, and copper-metal composites. It focuses on the state-of-the-art AM techniques employed for processing different copper-based materials and the associated technological and metallurgical challenges, optimized processing variables, the impact of post-printing heat treatments, the resulting microstructural features, physical properties, mechanical performance, and corrosion response of the AM-fabricated parts. Where applicable, a comprehensive comparison of the results with those of their conventionally fabricated counterparts is provided.

Pattern recognition in the nucleation kinetics of non-equilibrium self-assembly

Inspired by biology’s most sophisticated computer, the brain, neural networks constitute a profound reformulation of computational principles1–3. Analogous high-dimensional, highly interconnected computational architectures also arise within information-processing molecular systems inside living cells, such as signal transduction cascades and genetic regulatory networks4–7. Might collective modes analogous to neural computation be found more broadly in other physical and chemical processes, even those that ostensibly play non-information-processing roles? Here we examine nucleation during self-assembly of multicomponent structures, showing that high-dimensional patterns of concentrations can be discriminated and classified in a manner similar to neural network computation. Specifically, we design a set of 917 DNA tiles that can self-assemble in three alternative ways such that competitive nucleation depends sensitively on the extent of colocalization of high-concentration tiles within the three structures. The system was trained in silico to classify a set of 18 grayscale 30 × 30 pixel images into three categories. Experimentally, fluorescence and atomic force microscopy measurements during and after a 150 hour anneal established that all trained images were correctly classified, whereas a test set of image variations probed the robustness of the results. Although slow compared to previous biochemical neural networks, our approach is compact, robust and scalable. Our findings suggest that ubiquitous physical phenomena, such as nucleation, may hold powerful information-processing capabilities when they occur within high-dimensional multicomponent systems.