Multicomponent Materials Research Articles

In-Plane Adaptive Heteroepitaxy of 2D Cesium Bismuth Halides with Engineered Bandgaps on c-Sapphire.

The heteroepitaxy of 2D materials with engineered bandgaps are crucial to broaden the spectral response for their integrated optoelectronic devices. However, it is a challenge to achieve the high-oriented epitaxy and integration of multicomponent 2D materials with varying lattice constants on the same substrate due to the limitation of lattice matching. Here, in-plane adaptive heteroepitaxy of a series of high-oriented 2D cesium bismuth halide (Cs3Bi2X9, X = I, Br, Cl) single crystals with varying lattice constants from 8.41 to 7.71 Å is achieved on c-plane sapphire with distinct lattice constant of 4.76 Å at a low temperature of 160°C in an air ambient, benefiting from tolerable interfacial strain by switching compressive stress to tensile stress during a 30° rotation of crystal orientation. First-principles calculation demonstrates that those are all thermodynamically stable phases, deriving from multiple minima of interfacial energy between single crystals and sapphire substrate. The detectivity of Cs3Bi2I9 photodetector reaches up to 3.7 × 1012 Jones, deriving from high single-crystal quality. This work provides a promising experimental strategy and basic theory to boost the heteroepitaxy and integration of 2D single crystals with varying lattice constants on low-cost dielectric substrate, paving the way for their applications in integrated optoelectronics.

Asymmetric supercapacitors assembled by hollow N, s co-doped carbon spheres decorated FeOOH and Co3S4 nanoparticles

Exploiting advanced anode and cathode materials with distinctive architectures and multi-component participation is of great significance to boosting the energy density of asymmetric supercapacitors. Herein, ultra-fine FeOOH nanoparticles are in situ grown on the hollow N, S co-doped carbon (HNSC) spheres using a facile solvothermal strategy and subsequent calcination process. Benefiting from the attractive hollow architecture and the synergistic effect between FeOOH and HNSC, the FeOOH/HNSC composite as anode for supercapacitors delivers an optimal capacity of 588.2C g−1 (1 A g−1) and remains 88.3 % of its initial value after 10,000 cycles at 15 A g−1 in 6 M KOH. Furthermore, the HNSC-supported Co3S4 nanoparticles are also prepared through a one-step solvothermal strategy. The obtained Co3S4/HNSC composite as cathode achieves a capacity of 420C g−1 (1 A g−1) and maintains a high retention of 95.3 % after 10,000 cycles at 15 A g−1. The constructed asymmetric supercapacitor using FeOOH/HNSC and Co3S4/HNSC as anode and cathode appears to possess a superior energy density of 82.3 Wh kg−1 at 821.6 W kg−1 with retention of 84.9 % after 10,000 cycles at 10 A g−1. These attainments demonstrate that constructing multi-component electrode materials with unique structures is an effective method to optimize the electrochemical characteristics of asymmetric supercapacitors.

Enhancing the Surface Mechanical Properties of AL2618 Alloy Turbochargers Using a PLD Device with AI2O3

Abstract Pulsed laser deposition (PLD) has become a widespread technology for the fabrication of multicomponent thin films Material. In this research, the Microstructure phase, composition and effect of paint made from A nanomaterial (Alfa- Al2O3) were study, A Pulsed laser deposition used in order to improving mechanical performance of aluminum alloy (AL-2618) of turbocharger blades, The main advantages of using it in the manufacture of turbocharger blades to reduce corrosion and erosion, and to ensure high hardness and long-life fatigue, The Pulsed laser deposition used for turbocharger blade, to deposit a layer of aluminum dioxide (10 m) on the surface of the aluminum alloy. The mechanical properties of the blade improved where the hardness of the samples examined and conducted an (EDX) test before and after the deposition process. It was found that after depositing a Nano-layer of aluminum dioxide (Al2O3), the hardness increased and the corrosion and erosion were reduced.

Study on improving the performance of engineered cement-based composites by modifying binder system and polyethylene fiber/matrix interface

In this study, cement, rice husk ash (RHA), silica fume, mineral powder and fly ash were used as multi-component cementing materials, and the polyethylene (PE) fiber was modified by cellulose nanocrystal (CNC) to develop an Engineered Cementitious Composites (ECC) with high ductility and strength. The hydration heat and X-ray diffractometer (XRD) results indicate that RHA delays the early hydration of cement, its pozzolanic effect refines the internal porosity of hydration matrix and improves the compactness of ECC samples. Moreover, RHA increases the interfacial properties between fiber and cement matrix, reduces the first cracking strength and significantly improves the tensile strain rate of ECC. With the increasing content of RHA, its reinforcement effect becomes more obviously. The strain rate of ECC samples that uses RHA to replace 40 % of cement can reach 6.81 %. However, once the content of RHA is too high, the quality of cement involved in hydration will be significantly weakened, which reduces the amount of hydration products and has a negative impact on the compressive strength. By CNC coating, the active groups can be coated to the fiber surface to improve the fiber’s wettability. Which has promoted the growth of hydration products on the fiber surface, enhancing the fiber/matrix interface properties, and improved the ductility of ECC. CNC coating can also make up for the loss of compressive strength caused by RHA. The molecular dynamics simulation results show that unmodified PE fiber hardly to form a stable bond with C-S-H. However, CNC can adsorb with C-S-H through hydrogen and Ca-O bonding, and can also interaction with PE fiber by hydrogen bonding. Herein, CNC acts as an intermediate to connect PE and C-S-H, increase the interface stability of fiber/cement matrix, improve the interface bonding, and thus enhance the ductility of ECC. Developing multi-binder system and reinforced fiber/interface can significantly reduce the amount of cement used in ECC, and understanding the enhancement mechanism is beneficial to guide the optimal design of ECC.

Preparation and Characterization of Apixaban Cocrystals with Coformers for Improving Physical Properties

Background: Cocrystals are stoichiometric, multicomponent crystalline materials composed of an active pharmaceutical ingredient (API) and a coformer arranged in a crystalline structure. Apixaban (APX) is an oral blood thinner that has a low aqueous solubility of 0.028mg/mL at 24 °C and a weak oral bioavailability of about 50% for doses below 10 mg, decreasing as doses above 25 mg are taken. Objectives: To develop and assess APX cocrystal to improve its solubility. Methods: Cocrystals of APX with diverse coformers were synthesized using the solvent evaporation technique in varying molar ratios. The structure of the synthesized cocrystals was validated by DSC, PXRD, and FTIR analyses. Saturation solubility of APX and cocrystals in water was also investigated. Results: APX cocrystals with diverse coformers exhibited distinct physicochemical features. The co-crystal of APX with oxalic acid at a 1:1 ratio exhibited a 2.54-fold enhancement in solubility relative to that of pure APX in water. Each coformer enhanced the solubility of the APX co-crystals. The FTIR spectra of the cocrystals indicated no interaction between the APX and the coformers. The DSC analysis revealed distinct endothermic peaks corresponding to its melting point, indicating the development of cocrystals. The PXRD diffractogram demonstrated fluctuation of 2 theta values of peaks and confirmed cocrystallization of APX. Conclusions: Cocrystallization may serve as a potential method to improve the solubility of APX.

Multishell hierarchical GCNF/PANI/NiCo-LDH nanofibers film for high-performance supercapacitors

In the domain of supercapacitor investigation, nickel cobalt layered double hydroxides (NiCo-LDH), regarded as a promising battery material, have garnered significant attention. However, the inherent drawbacks of low conductivity and pronounced agglomeration in single-component NiCo-LDH hinder the achievement of satisfactory overall performance. Thus, a key challenge remains in the rational design of multi-component composite materials incorporating NiCo-LDH, carbon materials, and conductive polymers to enhance their electrochemical properties. In this study, we successfully fabricated multishell hierarchical fiber films of GCNF/PANI/NiCo-LDH through simple wet-chemical approach. This novel architecture features graphene-coated electrospun carbon nanofibers (GCNF) serving as a self-supporting carbon framework, polyaniline (PANI) acting as the conductive layer, and NiCo-LDH contributing a high faraday capacity. Utilizing the enhanced cooperative effects between the various components, the enhanced GCNF/PANI/NiCo-LDH electrode exhibits remarkable specific capacity (347.1 mAh g-1, 2499 F g-1 at 1 A g-1) alongside exceptional rate performance (maintaining 56.5% capacity at 20 A g-1). Moreover, when an asymmetric supercapacitor (ACS) is constructed using active carbon (AC) as the cathode and GCNF/PANI/NiCo-LDH as the anode, it demonstrates remarkable energy storage capabilities. Specifically, it achieves an impressive energy capacity of 43.8 Wh kg-1, along with a high power exceptional durability, with a capacitance retention of 88.8% even after 2000 cycles. This study presents a novel approach for designing high-performance density of 937.5 W kg-1. Additionally, it exhibits core-triple-shelled hierarchical materials in the field of energy storage devices.

The thermodynamics of multicomponent high-entropy materials

AbstractHuman development has been based for millennia on manufacturing materials using a conventional alloying strategy of selecting a principal component for the primary property requirement of the material and then adding one or two minor alloying components at relatively low concentrations, either to enhance the primary property or to provide additional secondary properties. We have discovered relatively recently that, with sufficiently large numbers of alloying elements added in sufficiently large concentrations, the configurational entropy of mixing can often become large enough to suppress the formation of brittle compound phases, leading instead to the formation of multicomponent high-entropy solid solutions. In fact, there are literally billions of multicomponent high-entropy single-phase solid-solution materials, with a wide range of exciting new properties, in most cases relatively straightforward to manufacture by conventional processing methods. There seems, however, to be an upper limit to these effects, so that, beyond about ten or twelve alloying components, the inevitable increase in chemical diversity prevents the configurational entropy of mixing from suppressing the increasingly strong chemical reactions between them. This paper discusses in more detail the thermodynamic balance between: (1) increasing configurational entropy and promoting high-entropy solid solutions; and (2) increasing chemical diversity and promoting the formation of brittle compound phases. This is discussed on the basis of regular solution thermodynamics, without the need for more complex, semi-empirical Calphad calculations that can sometimes obscure the underlying key physical and chemical principles. The results show: (1) why large single-phase solid-solution regions are relatively common in multicomponent phase space; (2) why single-phase solid solutions are often favoured over stoichiometric compounds for large numbers of chemically similar components, in concentrated rather than dilute proportions, at high temperatures, and after quenching to room temperature; and (3) the difficulty of detailed thermodynamic analysis in multicomponent materials because of the large numbers of thermodynamic parameters that need to be known and the corresponding lack of underlying thermodynamic measurements.

Embedment of Molybdenum Disulfide in Electrospun Fibers as an Integrated Cathode for Lithium-Ion Batteries

As an important component of LIBs, the electrode material plays a crucial role in determining the lithium (Li) storage performance in LIBs. In this study, MoS2 nano-flowers were synthesized using a one-pot hydrothermal method. The resulting MoS2 nano-flower, along with PAN, were used as raw materials for electrospinning. After annealing treatment, MoS2/(carbon nanofibers) CNFs nano-composites coated with carbon fibers were formed. The CNFs coating exhibited electrical conductivity and enhanced structural stability of the MoS2 due to the stabilizing effect of the carbon fibers. Additionally, electrochemical tests, including CV and GCD, indicated that the optimal capacity and cycling stability were achieved when the MoS2 content was 10%. The results indicated that the charge/discharge capacity of MoS2/CNFs-10% at a current density of 100 mA/g was ~650 mAh/g. After the cycling current returned to 100 mA/g, the current recovery was ~600 mAh/g, thereby indicating outstanding cycling stability. Accordingly, our fabrication technique and new insight could both widen design strategy of multicomponent composite electrode materials and promote the practical applications of the latest emerging transition metal sulfides in next-generation high-performance lithium-ion batteries.

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.

Electrostatic Assembly of Gold Nanoclusters in Reverse Emulsion Enabling Nanoassemblies with Tunable Structure and Size for Enhanced NIR-II Fluorescence Imaging.

The precise control of the assembly structure and size of gold nanoclusters (AuNCs) can potentially amplify their near-infrared II (NIR-II) fluorescence imaging and targeting properties. However, the conventional electrostatic assembly of AuNCs and charged molecules faces challenges in balancing the inherent electrostatic repulsions among charged units and regulating the diffusion of assembly units. These difficulties limit precise control over assembly size and structure, along with limited options for coassembled molecules, thereby restricting imaging properties and targeting capability. To circumvent this challenge, we developed a reverse emulsion-confined electrostatic assembly method. This technique efficiently constructs AuNC nanoassemblies with diverse coassembled molecules, allowing for the fine-tuning of assembly size and structure, including both core-satellite and homogeneous AuNC nanoassemblies. The development of two distinct nanoassemblies can be partially attributed to the varying diffusive rates of AuNCs or the AuNCs/polymer complex within the fused emulsion droplets. This variance arises from steric hindrances encountered during the emulsion fusion process. Interestingly, core-satellite nanoassemblies exhibit the strongest NIR-II fluorescence enhancement. Finally, the introduction of a hyaluronic acid coating on the surfaces of nanoassemblies with varying sizes enables the nanoprobes to achieve enhanced lymph node imaging through size modulation and macrophage targeting, which are used for surgical navigation to remove lymph node metastases. We envision that this self-assembly strategy can be extended to a wide range of electrostatic assembly systems for the development of multicomponent functional materials.

Electrochemical Biosensor Based on Dual-Ligand Functionalized Lanthanide-Encapsulated Polyoxometalate Conductive Polymer Film for Detecting Broad-Spectrum Tumor Marker MicroRNA-155.

In this work, a dual-ligand functionalized lanthanide-encapsulated selenotungstate [H2N(CH3)2]16Na2H10[Ho6(H2O)10(HPACA)4W10O28(Ac)2][SeW9O33]6 · 60H2O (1, HPACA = 2-pyrazinecarboxylic acid, HAc = acetic acid) was successfully acquired by simultaneously incorporating rigid HPACA and flexible Ac- ligands to one reaction system. Interestingly, the polyanion [Ho6(H2O)10(HPACA)4W10O28(Ac)2][SeW9O33]628- of 1 is composed of six trivacant Keggin-type [B-α-SeW9O33]8- units interconnected through an organic-inorganic hybrid dual-ligand bimetallic [Ho6(H2O)10(HPACA)4W10O28(Ac)2]20+ cluster. Moreover, the 1@PNMPy film (PNMPy = poly(N-methylpyrrole)) was successfully prepared through an electrochemical polymerization strategy. The doping of 1 significantly narrows the bandgap in the 1@PNMPy film, which enables the 1@PNMPy film to exhibit remarkable conductivity and rapid electron transfer capability. Then, the 1@PNMPy film-modified glassy carbon electrode was used to construct a 1@PNMPy-based electrochemical biosensor (ECBS), which achieves sensitive electrochemical detection (a low limit of detection of 0.108 fM and a wide concentration detection range of 10-8-10-15 M) for broad-spectrum tumor marker microRNA-155. Also, the 1@PNMPy-based ECBS has a good specific recognition performance for microRNA-155 in a variety of interfering media. The research not only contributes to a deeper understanding of the synthetic chemistry of multicomponent polyoxometalate (POM)-based materials but also can further expand innovative applications of multicomponent POM-based materials in electrochemical detection and electrochemical devices.

Quantifying Heterogeneous Interface Effect of Fe3O4(111)/C for Enhanced Low-Frequency Electromagnetic Wave Absorption

How to tailor electromagnetic parameters of multi-component materials is the fundamental issues for low-frequency electromagnetic wave absorbers (EMA). However, there remains a challenge to accurately elucidate the impact of respective components at heterogeneous interfaces on the EMAs, not to mentioning the further quantitative contribution of the interfacial effect to the electromagnetic loss. In this paper, we for the first time separated the Fe3O4(111)/C heterogeneous interface of Fe3O4@C via a controllable interfacial separation strategy, meanwhile ensuring the consistent microstructure and the ratio of each component, as well as the unchanged macroscopic structure of the particles. Once all potential influences on electromagnetic parameters have been independently studied, the unique difference in heterogeneous interfaces enabled us to quantitatively evaluate the effect of them on electromagnetic parameters. Both experimental and density functional theory (DFT) calculation results consistently demonstrate that the Fe3O4(111)/C heterointerface increases carrier concentration and conductivity, thereby enhancing the imaginary part of the dielectric constant. Very distinguished from traditional interfacial polarisation mechanism presented in previous publications, this study introduces a novel interfacial loss mechanism primarily characterized by conductivity loss, which is rigorously investigated in a quantitative way. This discovery offers a novel approach for designing controllable heterogeneous interfaces and manipulating electromagnetic parameters in multicomponent EMAs.

Mechanism of Thermodynamically Rationalized Selective Growth of a Two-Dimensional Ternary Ferromagnet on Insulating Substrates.

Two-dimensional (2D) semiconducting ferromagnet Fe3GeTe2 holds great promise for advanced spintronic applications because of its gate-tunable ferromagnetic ordering at room temperature, whereas the controllable growth of large-area single crystals remains very challenging due to its ternary nature and variable stoichiometry inducing many competitive phases. Here, we theoretically probe the mechanism of selective growth of monolayer Fe3GeTe2 on various epitaxial substrates. Thermodynamic analysis shows that the corresponding phase-pure chemical potential windows for the selective growth of Fe3GeTe2 can be reasonably attained in ternary phase space on insulating and chemically inert c-plane sapphire and Ga2O3(0001) substrates by properly modulating the interfacial interaction and employing suitable feedstocks to avoid competitive growth of possible impurity phases with different stoichiometry ratios. It is also revealed that both the weak edge-substrate interaction and interlayer coupling of Fe3GeTe2 together lead to a surface-dominated nucleation behavior and, thereby, energetically favor lateral growth of the monolayer rather than vertical growth of the multilayer. Importantly, straight protocols for the experimentally selective growth of phase-pure ternary Fe3GeTe2 are also provided by establishing the relationship between the feedstock chemical potential and growth parameters on a thermochemical basis. Our insightful study can also be reasonably extended to guide future experimental design for the selective growth of other multicomponent 2D materials.

Recent advances in additive manufacturing of refractory high entropy alloys (RHEAs): A critical review

Refractory High Entropy alloys (RHEAs) have evolved as a superior multicomponent material having a unique combination of microstructures and mechanical properties. RHEAs are a particular grade of high entropy alloys (HEAs) known for their outstanding high-temperature properties achieved thorough their constituent refractory elements. To date, majority of the RHEAs have been manufactured through several conventional methods, but are limited by certain limitations. Additive manufacturing (AM) has the potential to revolutionize the manufacturing industry by providing excellent opportunities to fabricate RHEAs while providing opportunities for enhancing the design freedom and complex geometrical shapes. As the field is rapidly evolving, a systematic examination of our comprehension is beneficial, and this article attempts to address this issue. To find the right place in industrial markets, additively manufactured RHEAs require further advancements. The present review provides a comprehensive overview of the additively manufactured RHEAs in terms of microstructural characterization, mechanical behaviour and other environmental properties published so far. This review article is presented lucidly with an aim of better understanding for the readers in this domain. To this end, future works and current challenges are also included and discussed briefly.

Simultaneous achieving color‐tuning long persistent luminescence and phosphorescent quantum yield of 81.05% in 2D organic metal halide perovskite

AbstractIonically bonded organic metal halide perovskite‐like luminescent materials, which incorporate organic cations and metal halides, have emerged as a versatile multicomponent material system. However, these materials still face challenges in terms of low phosphorescence quantum yields and limited long persistent luminescence (LPL) colors. Herein, we present the design and synthesis of an intraligand charge‐transfer organic‐based metal halide perovskite‐like material, in which organic cations form a compact supramolecular hydrogen‐bonded organic framework (HOF) structure, exhibiting crystallization‐induced phosphorescence emission of ligand, while metal halides form a unique two‐dimensional (2D) structure that displays intrinsic self‐trapped excitons (STE) emission under the radiation of UV light. Notably, the metal halide hybrid is found to exhibit enhanced phosphorescent photoluminescence efficiency of up to 81.05% and tunable LPL from cyan to orange compared to the pristine organic phosphor, due to the structural distortion and scaffolding effects of 2D metal halides as well as a well‐packed HOF structure. Optical characterizations and theoretical calculations reveal that charge transfer from organic cations and halogen to ligand as well as STE from inorganic layers are responsible for the tunable LPL. Meanwhile, the high‐efficiency phosphorescent quantum yield is attributed to stronger hydrogen bond stacking as well as structural distortion of metal halogen bands. Thus, the obtained LPL provides potentials in anti‐counterfeiting, security systems, and so on.

Dual-color fluorescent multi-component hybrid materials for copper ion detection, NADH regeneration and cell imaging

Gold nanoclusters (AuNCs) exhibit unique physical, chemical and photoelectric properties with various advantages. On the other hand, small organic fluorescent molecules show alternative specialized characteristics. To overcome their weaknesses and integrate strengths, we propose here a workable platform to fabricate protein-gold-dye multifunctional hybrid materials. Briefly, protein skeleton bovine serum albumin (BSA), AuNCs, and organic molecule dye Thioflavin T (ThT) are co-assembled mutually to form a dual-color fluorescent material BSA-AuNCs@ThT. This approach is simple, cost-effective, green and environmental friendly. To tackle their biological application, we coat BSA-AuNCs@ThT with cationic polyethyleneimine (PEI). The prepared BSA-AuNCs@ThT@PEI hybrid materials can be used to fluorescence imaging of microbial cells as well as HeLa cells. Due to the unique background of BSA-AuNCs@ThT@PEI, the hybrid materials work well in differentiate heavy metal ions such as Hg2+ and Cu2+ ions. Moreover, this system is also suitable to do the photocatalytic transformation and regeneration of coenzyme NADH. Therefore, we propose this platform to build new nano-dye hybrid materials for copper ion detection, NADH regeneration and cell imaging, or potentially other applications.

Dual electron transfer path and Ti3C2Tx LSPR photothermal enhancement in 2D/2D/2D Ti3C2Tx MXene@TiO2/CdIn2S4 ternary heterojunction for enhanced photocatalytic H2 production: Construction, kinetics, and mechanistic insights

It is an inherent problem in the field of photocatalytic hydrogen (H2) production to realize the effective coordination and mutual promotion between multi-component materials. In this work, using the monolayer plasmonic Ti3C2Tx as substrate, the first example of a 2D/2D/2D Ti3C2Tx MXene@TiO2/CdIn2S4 (MTC) ternary heterojunction nanocomposite containing O and S dual vacancies is synthesized. Dual high density electron transfer path and Ti3C2Tx LSPR photothermal effect synergistically enhance light absorption, photogenerated charge carrier separation, and surface reaction rates. At room temperature, the photocatalytic H2 production rate of MTC50 reaches 6762.1 μmol·g−1·h−1. Through DFT and FDTD methods, it is proved that high density electron transfer and large area strong plasmon coupling effectively enhance the photothermal effect of Ti3C2Tx LSPR, which provides reasonable inspiration for the design of photocatalysts in extremely cold environment. This work provides important insights into the construction of 2D multi-component systems and the explanation of the LSPR enhancement mechanism.

Spatial Variations in Hydrogen Bonding Interaction within Polymer Blends Revealed by Infrared Nanoimaging.

Hydrogen bonding plays a crucial role in enhancing the miscibility of polymer blends, allowing for the tailoring of their physicochemical properties to meet diverse application demands. However, nanoscale imaging of its impact on the phase-separation behavior of multicomponent polymeric materials remains largely unexplored. In this work, we introduce scattering-type scanning near-field optical microscopy (s-SNOM) equipped with a broadly tunable quantum cascade laser as a tool for investigating spatial variations in hydrogen-bonding interactions within blends of polyvinyl acetate (PVAc) and polyvinylphenol (PVPh), spin-coated from tetrahydrofuran solution. Our multiwavelength s-SNOM imaging approach reveals distinct features, namely, the hydrogen bonding mediated miscible PVAc/PVPh blend and the phase-separated PVAc domain. These results provide a more detailed understanding, indicating that hydrogen bonding may not lead to a completely uniform blend throughout the film, as previously believed, based on far-field spectroscopy. Furthermore, through comparisons between topography and near-field images, we find that the PVAc/PVPh hydrogen-bonded domain exhibits a strong affinity for the Si surface with its native oxide, while the free (non-hydrogen-bonded) PVAc film is vertically phase-separated atop the blend. Overall, our work demonstrates that s-SNOM is an effective and efficient tool for studying intermolecular interactions relevant to various chemical and biological phenomena.

Highly enhanced electrocatalytic OER with facile electrodeposition of MIL–53(Fe)/NiAl–LDH/NF and NiAl–LDH/MIL–53(Fe)/NF

This research investigates a new approach to improve the electrocatalytic rate of the Oxygen Evolution Reaction (OER), a key step in water electrolysis. The study focuses on two promising materials: MIL–53(Fe) and NiAl–LDH. MIL–53(Fe) offers several advantages: high catalytic activity, large surface area, and good chemical stability. NiAl–LDH is attractive due to its layered structure, tolerance to a wide range of pH levels, scalability, and cost-effectiveness. However, their limitations like low conductivity and restricted accessibility of active sites hinder their performance in water splitting applications. To address these limitations, novel composite thin films were created using a technique called layer–by–layer (LBL) electrophoretic deposition. These films, built on nickel foam (NF) substrates, included two configurations: MIL–53(Fe)/NiAl–LDH/NF and NiAl–LDH/MIL–53(Fe)/NF. The MIL-53(Fe)/NiAl-LDH/NF composite exhibited remarkable OER activity in alkaline electrolytes, requiring overpotentials of only 200, 270, and 370 mV to reach current densities of 20, 50, and 100 mA cm−2, respectively. The Tafel slope of 54.86 mVdec−1 suggests rapid reaction kinetics. Additionally, it demonstrated excellent long-term stability, lasting for at least 20 h. The success of the MIL–53(Fe)/NiAl–LDH/NF composite can be attributed to the LBL technique. This method creates a composite with a larger surface area, significantly improving OER efficiency. In contrast, the MIL–53(Fe)/NiAl–LDH/NF configuration had the opposite effect. The NF pores became blocked by the MIL–53(Fe) layer, reducing the overall surface area, hindering electron transfer, and thereby limiting oxygen production. The LBL deposition method used in this study proves its effectiveness in designing efficient electrocatalysts. This opens up possibilities for creating other multicomponent materials for energy applications. The findings provide valuable insights for future research on these promising composite materials, potentially leading to the development of cost-effective and high-performance catalysts for various electrochemical applications.

Probing the influence of composition and cross-linking degree on single-chain nanoparticles from poly(tetrahydrofuran-ran-epichlorohydrin) copolymers: Insights from neutron scattering, calorimetry, and dielectric spectroscopy

The industrial sector has made significant strides in the development of multicomponent and multiphasic polymer materials, including polymer blends, composites (such as nanocomposites), and various copolymers. Random copolymers, characterized by their statistical arrangement of repeating units, are particularly noteworthy due to their tunability from amorphous to semicrystalline states. In this study, we focus on poly(tetrahydrofuran-ran-epichlorohydrin) (P(THF-ran-ECH)) copolymers, which serve as precursors for single-chain nanoparticles (SCNPs). These SCNP-based materials are of particular interest as they bridge the gap between traditional polymers and colloids. This research comprehensively investigates how the type and degree of internal cross-linking influence the structure and dynamics of P(THF-ran-ECH) copolymers and their SCNPs. Techniques such as quasielastic neutron scattering (QENS), differential scanning calorimetry (DSC), and broadband dielectric spectroscopy (BDS) were employed to study copolymers with varying compositions and levels of cross-linking. By analyzing two samples with different epichlorohydrin (ECH) contents (13 mol% and 27 mol%), we aim to control crystallization and explore its effects on dynamic behavior. Our results show that both the composition and the degree of cross-linking significantly impact the dynamics of the SCNPs, with SCNPs exhibiting slower dynamics compared to their precursor copolymers. Furthermore, semicrystalline samples display faster dynamics in SCNPs than amorphous samples. These findings provide valuable insights for the design and optimization of advanced multicomponent polymer systems.