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In this work, a novel design and modeling method is proposed to obtain hierarchical structures with non-uniform lattice microstructures based on density-based topology optimization. First of all, a parametric concept is proposed to generate a family of parameterized lattice microstructures that present similar topological features. In order to balance the structural performance and computational efficiency, we construct a Parameterized Interpolation for Lattice Material (PILM) model and the mathematical formulation incorporates two new design variables. At the macroscale, the relative density variable is applied to describe material volume fraction in the design domain, instead of using the pseudo-density in the Solid Isotropic Material with Penalization (SIMP) model. At the microscale, each macroelement is regarded as an individual microstructure controlled by an aspect ratio variable. The equivalent properties of parameterized lattice microstructures can be derived by interpolating the effective elastic matrixes of several typical microstructure unit cells, which avoid expensive iterative homogenization calculations during optimization procedure. Hence, the multiscale concurrent design method can optimize the macroscopic distribution and their spatially varying microstructural configurations simultaneously at an affordable computation cost. Several numerical examples are presented to demonstrate the effectiveness of the proposed approach. Furthermore, the obtained hierarchical structures with non-uniform lattice microstructures show good manufacturability and remarkably improved structural performance by means of the additive manufacturing and experimental testing, compared to the designs with uniform lattice microstructures. [ABSTRACT FROM AUTHOR]

Carbon nanofibers with hierarchical structure were synthesized by combining Co-containing zeolitic imidazolate frameworks (ZIF-67) with natural eggshell membranes (ESMs). Benefiting from the hierarchical structure and element modification of Co/N, the obtained nanofibers exhibited excellent oxygen reduction reaction (ORR) performance. The reusing of ESMs trash made this strategy meaningful for environment. [ABSTRACT FROM AUTHOR]

Spider silk fibers (SSF) have a hierarchical structure composed of proteins with highly repetitive sequences and biomineralization is sophisticated in hierarchical organic–inorganic constructions. By using inorganic hydroxyapatite (HAP) and organic polyvinyl alcohol (PVA) to simulate the rigid crystalline and flexible amorphous protein blocks of SSF, respectively, biomimetic mineralization is herein attempted for the large‐scale preparation of SSF‐like macrofibers with a hierarchical ordered structure, a superhigh tensile strength of 949 ± 38 MPa, a specific toughness of 296 ± 12 J g−1, and a stretch ability of 80.6%. The hybrid macrofibers consist of microfibers, and their outstanding performance (e.g., extreme tolerance to temperatures ranging from −196 to 80 °C and superior ability to inhibit the transverse growth of cracks) is attributed to the hierarchical arrangement as well as the organic–inorganic integrated structure within the oriented mineralized polymer chains. The biomineralization‐inspired technique provides a promising tactic that can be used to synthesize functional organic–inorganic fibers that are structurally complex and, furthermore, industrially manufacture SSF‐like artificial fibers with a supertoughness. [ABSTRACT FROM AUTHOR]

Biomimetic superhydrophobic surfaces display many excellent underwater functionalities, which attribute to the slippery air mattress trapped in the structures on the surface. However, the air mattress is easy to collapse due to various disturbances, leading to the fully wetted Wenzel state, while the water filling the microstructures is difficult to be repelled to completely recover the air mattress even on superhydrophobic surfaces like lotus leaves. Beyond superhydrophobicity, here we find that the floating fern, Salvinia molesta, has the superrepellent capability to efficiently replace the water in the microstructures with air and robustly recover the continuous air mattress. The hierarchical structures on the leaf surface are demonstrated to be crucial to the recovery. The interconnected wedge-shaped grooves between epidermal cells are key to the spontaneous spreading of air over the entire leaf governed by a gas wicking effect to form a thin air film, which provides a base for the later growth of the air mattress in thickness synchronously along the hairy structures. Inspired by nature, biomimetic artificial Salvinia surfaces are fabricated using 3D printing technology, which successfully achieves a complete recovery of a continuous air mattress to exactly imitate the superrepellent capability of Salvinia leaves. This finding will benefit the design principles of water-repellent materials and expand their underwater applications, especially in extreme environments. [ABSTRACT FROM AUTHOR]

Hollow metal‐organic frameworks (MOFs) and their derived materials have shown fascinating structural complexity, such as diverse morphology, tunable porosity and hierarchical structure, which largely extends their intrinsic applications, especially in electrochemical energy storage and conversion. Herein, a hollow and hierarchical Co–MOF@CoCr2O4 microplate array on nickel foam was successfully prepared through a simple one‐step in situ conversion strategy, in which Co–MOF served both as self‐supporting etching template and as a self‐sacrificing ion‐exchange template. When used as a battery‐type electrode for advanced hybrid supercapacitors, the Co–MOF@CoCr2O4 composite expressed a high specific capacity of 596.8 C g−1 at 0.4 A g−1, excellent rate properties (72.6 % retention rate at 10 A g−1 compared with the initial capacitance at 0.4 A g−1) and good cycling stability (85.1 % retention over 5000 cycles). Furthermore, a fabricated hybrid supercapacitor device reached a high energy density of 0.4 mWh cm−2 (34.36 Wh kg−1) at a power density of 2.34 mW cm−2 (201.03 W kg−1), and superior cycle stability (96.2 % retention over 5000 cycles). These enhanced electrochemical behaviors indicated that this advanced approach can be extended to design various hollow and hierarchical structural MOF/bimetallic‐oxide‐based composite arrays for high‐performance hybrid supercapacitors. [ABSTRACT FROM AUTHOR]

The block copolymer with functional small molecules formed via non-covalent interactions has tremendous appeal in various fields of applications. When the functional small molecules were attached to one of the blocks of the block copolymer, it can produce hierarchical structures with built-in functionality. This technique enables for the generation of controlled nanostructures in the solid-state, and also creates nanoporous templates by selective dissolution of small molecules. In this featured paper, we review the recent trends of block copolymer-based supramolecules in the self-assembly process of organic semiconductors and nano-particles within the block copolymer domains in bulk and thin films. [ABSTRACT FROM AUTHOR]

Functional surfaces have been investigated widely due to different applications in industries. In this paper, the surface functionality was the contrast generated by surfaces orthogonally textured with micro ridges. The principle to generate contrast was the anisotropic reflection led by the bevel surfaces of micro ridges. The surface quality of the micro bevels determined the reflection of the features. In the authors' previous work, such a functionality was successfully achieved on flat and cylinder surfaces of tool steel samples by micro milling. However, due to the limitation of micro milling process for microstructure fabrication, this study investigated the manufacturing of 3D functional surfaces of RSA 905 by diamond engraving. The 3D surface was shaped with hierarchical structures of micro bricks and micro ridges on the bricks: the surface was divided into micro grids then each grid was machined into a flat basic cell by using a round-tipped tool; the micro ridges were engraved on the basic cells with a sharp-tipped tool. In order to determine the feasibility of the microstructures to achieve contrast generation on 3D surfaces, a data matrix consisting of such micro ridges was patterned on a spherical concave and a freeform surface. The surface integrity was evaluated by measuring the surface roughness of the bevels on the micro ridges, characterizing the burr formation and detection of possible defects left on the micro features that affect the surface functionality. The successful scanning of the data matrix proved the microstructures successfully generated enough contrast to form readable codes. Furthermore, the contrast generated by the microstructures was quantified for process optimization by using a customized robotic measuring system. [ABSTRACT FROM AUTHOR]

This study was to explore the internal reasons for the changes in oil absorption performance of tigernut starch (TS) by revealing the high-temperature induced variations of structural and functional properties of TS. The results showed that as the temperature increased from 80 °C to 140 °C, the degree of starch gelatinization increased, while the proportion of double helix structures, the total proportion of B1 and B2 chains, the relative crystallinity and the molecular weight decreased, accompanied by the fragmentation and swelling of TS granules. The oxidation of tigernut oil (TNO) led to a decrease in oil density and an increase in total polar component content. These phenomena could result in an increase of oil absorption capacity of TS and starch-lipid complex index. With further increase in temperature from 170 °C to 200 °C, the disruption of the crystalline structure and chain structure increased, resulting in the melting and disintegration of TS granules. This caused a decrease in the starch-oil contact area and capillary absorption of TNO by the TS granules. The results will contribute to revealing the effect of high-temperature induced changes in the structural and functional properties of TS on its oil absorption properties. [Display omitted] [ABSTRACT FROM AUTHOR]

This study proposes a combined strategy of defect engineering and construction of S-scheme heterojunction that produces synergistic photovoltaic effects and significantly enhances photocatalysis degradation of organic pollutants under visible-light. A three-dimensional hierarchical flower-like photocatalyst CdS@Gd-ZnO featuring S-scheme heterojunction was rationally constructed. CdS@Gd-ZnO was able to degrade 99 % of rhodamine B (RhB) (10 mg/L, 75 min) and 95 % of methylene blue (MB) (10 mg/L, 60 min) under visible-light. Also, it has an excellent ability to degrade antibiotics, with 93 % of tetracycline hydrochloride (TCH) (20 mg/L, 60 min) and 90 % of oxytetracycline (OTC) (20 mg/L, 60 min), respectively. It was found that a small amount of Gd3+ doping was not only conducive to introducing more oxygen defects, which provides a powerful tool for trapping electrons for charge transfer, but also caused the change of energy band structure, and ultimately enhanced the degradation of cationic pollutants. Accordingly, this strategy enhances the photocatalytic performance of CdS@Gd-ZnO, and the combined effect is significantly stronger than either alone. This work provides a new idea for the design of efficient heterojunction photocatalysts for energy and environmental applications. [Display omitted] • A synergistic effect between defective energy levels and S-scheme heterojunction enhance photocatalytic performance. • Core-shell-like structure based on 3D hierarchical structure ensures tight interfacial contacts. • 0D/3D structure (self-assembled from 2D ultrathin nanosheets) favors charge transfer. • Fine tuning of oxygen vacancy concentration can be achieved by Gd3+ ion doping. [ABSTRACT FROM AUTHOR]

Developing advanced sorbents for selective carbon dioxide (CO 2) sequestration with minimal energy consumption remains a pivotal challenge. This study presents a novel strategy through transforming 3D bulk zirconium-porphyrin frameworks into the corresponding 2D nanosheet-assembled superstructures for enhanced CO 2 capture. The hierarchical frameworks with well-organized nanosheet architectures exhibit significantly increased specific surface area from 600 m2/g to 2400 m2/g while providing kinetic benefits for gas diffusion. Compared to the adsorption behavior of the bulk counterparts, the nanosheet-assembled frameworks demonstrate a 1.5-fold increase in CO 2 adsorption capacity without compromising CO 2 /N 2 selectivity. Theoretical calculation reveals that the coordination unsaturated Zr-O clusters, electron delocalized environments both in interlayer gaps and micropores provided binding sites for CO 2 capture. Our research demonstrates an adaptable structure-directed approach for the crystal engineering of metal-organic frameworks which would inspire the creation of state-of-the-art crystalline porous materials for broadened applications. [Display omitted] Transforming 3D zirconium-porphyrin frameworks into 2D nanosheet-assembled superstructures enabling enhanced CO 2 adsorption capacity while providing kinetic benefits in gas diffusion. The 2D superstructures exhibited increased CO 2 adsorption capacity by 2.5 times compared to the bulk counterparts without sacrificing the CO 2 /N 2 selectivity. • A strategy to fabricate nanosheet-assembled zirconium-porphyrin superstructures. • Significantly increased specific surface area up to 2400 m2/g. • Enhanced CO 2 capture ability without compromising CO 2 /N 2 selectivity. • Theoretical calculation revealing the CO 2 adsorption mechanism. [ABSTRACT FROM AUTHOR]

[Display omitted] • Cu-TCPP nanosheets and TiO 2 nanoclusters form a unique Z-scheme heterostructure. • The heterostructure shows excellent photocatalytic activity for ROS generation. • This novel material shows excellent antibacterial performance in vitro / in vivo. • The sufficient ROS and Cu ion ensure the long-term antibacterial activity. Bacterial infections pose a huge threat to human health due to the inevitable emergency of drug resistance. Metal-organic frameworks (MOFs) consisting of metal ions and organic linkers, as emerging efficient antibacterial material, have the merits of structural flexibility and adjustable physicochemical property. With assistance of photosensitive agents as organic linkers, MOFs have great potential in antibacterial application through photocatalytic therapy by the generation of reactive oxygen species (ROS). However, the limited light use efficiency and short lifespan of ROS are two obstacles for their applications. Inspired by the semiconductor heterostructure in photocatalysis, we rationally design and precisely synthesize MOFs based heterostructures, in which the TiO 2 nanoclusters are filled into the pores of Cu-TCPP nanosheets (i.e. TiO 2 NCs@Cu-TCPP HSs). And the composite materials possess three-dimensional (3D) hierarchical architectures, which have advantages of large surface area, excellent light-absorbing ability and photocatalytic efficiency. Significantly, this novel material displays >99.99 % antibacterial efficiency against E. coli and S. aureus within 30 min and preserves the excellent antibacterial ability during reusing three times, which is superior to recently reported photocatalystic-based antibacterial materials. Our study provides new insights into the energy band engineering for enhanced antibacterial performance, paving a way for designing advanced clinical wound dressings. [ABSTRACT FROM AUTHOR]

[Display omitted] • A novel bio-inspired tapered structure mimicking the hierarchical architecture of barnacle is designed. • The SEA and mean crushing force show a significant improvement as the number of substructures increases. • The mean crushing force reaches maximum value when the ratio of external to internal wall thickness is the lowest. • The theoretical model effectively predicts the mean crushing force of the proposed structure. This paper introduces a new type of energy-absorbing hierarchical tapered structure, mimicking the hierarchical architecture of barnacle. The proposed structures are designed by iteratively incorporating sub-tapered tubes at the junctions of primary ribs aiming to enhance the crashworthiness performance. The finite element models of the proposed structures are constructed in Abaqus software and validated using experimental testing. The effects of the geometrical parameters including the number of substructures and the external-to-internal wall thickness ratio on the energy absorption characteristics of the proposed structures are investigated. The results demonstrate that as the number of substructures increases, the specific energy absorption (SEA) and mean crushing force of the proposed design show a significant improvement. Specially, the SEA of the proposed structures with four substructures can reach 32.78 kJ/kg, which is 85.8 % higher than the conventional tapered tube. Additionally, decreasing the ratio of external to internal wall thickness leads to enhanced performance. After optimizing the wall thickness ratio, the maximum SEA can reach 40.87 kJ/kg, which is 26.0 % higher than that before optimization. To complement the findings, a theoretical study is presented, which exhibits excellent agreement with the numerical results, further validating the effectiveness of the proposed design. This study highlights the potential of incorporating hierarchical and tapered features into tapered structures, offering promising prospects for advancements in energy absorption technology across diverse industries. [ABSTRACT FROM AUTHOR]

Hollow nanoparticles doped hierarchical hexagonal star shaped cobalt (Co) phosphosulfides (CoS/P) have been prepared with sulphidation and phosphorization of Co-based hydroxides as precursors sequentially. Each corner of a hexagonal star is composed of many branched nanorods. Hollow nanoparticles with an average size of 50 nm are observed on these branches. The resulting CoS/P catalyst shows efficient water splitting activity. These hollow nanoparticles provide more exposed active sites with enhanced reaction activity and reaction rate. The CoS/P could serve as a bifunctional OER and HER catalyst with an overpotential of 320 mV and 210 mV, respectively, at j = 10 mA cm−2. The CoS/P exhibited an overpotential of 470 mV for overall water splitting at j = 10 mA cm−2. Theoretical calculations also confirm the beneficial effect of CoS/P compared with CoS. This novel hierarchical structure is a promising electrocatalyst for overall water splitting. [Display omitted] • Hierarchical 3D CoS/P doped with hollow nanoparticles was constructed. • The sulphidation and phosphorization process of Co-based hydroxide led to the formation of hollow structures. • CoS/P exhibited efficient water splitting activity in alkaline media. • Hollow nanoparticles provide more exposed active sites and enhance the reaction activity. • Theoretical calculations confirmed the beneficial effect of CoS/P compared to CoS. [ABSTRACT FROM AUTHOR]

The extent of utilization of magnesium silicate hydrate (MSH) in construction is limited partly because of insufficient data ascertaining the kinetics of its precipitation. Here, MSH grown homogeneously or heterogeneously in the range of magnesium to silicon solution molar concentration ratios, [Mg]/[Si] = 0.5–1.5, and temperature = 25–80 °C was analyzed for its chemical structure and morphology. Infrared spectroscopy and geochemical modeling show that increasing the [Mg]/[Si] ratio results in less silicate polymerization in MSH. Atomic force microscopy reveals the presence of nanoparticles that aggregate and fuse to form films. Oriented attachment of nanoparticles and features indicative of enhanced crystallinity were observed at higher temperatures and longer reaction times. These data provide direct evidence for the persistence of hierarchical structures (i.e., nanoparticles forming 3D microparticles and 2D film layers) at the nanoscale to mesoscale. These findings offer insights into the precise chemical synthesis of MSH and its widespread use as a binder for construction purposes. [ABSTRACT FROM AUTHOR]

Plant and animal surfaces have become a model for preparing special synthetic surfaces with low wettability, reflectivity, or antibacterial properties. Processes that lead to the creation of replicas of natural character use two-step imprinting methods. This article describes a technique of synthetic polymer surface preparation by the process of two-stage imprinting. The laboratory-prepared structure copies the original natural pattern at the micrometer and sub-micrometer levels, supplemented by a new substructure. The new substructure identified by the scanning electron microscope is created at the nanometer level during the technological process. The nanostructure is formed only under the conditions that a hierarchical structure forms the surface of the natural replicated pattern, the replication mold is from a soft elastomeric material, and the material for producing the synthetic surface is a polymer capable of crystallizing. A new nanometer substructure formation occurs when the polymer cools to standard laboratory temperature and atmospheric pressure.

Detailed and accurate three-dimensional (3D) information about the morphology of hierarchically structured materials is derived from multi-scale X-ray computed tomography (XCT) and subsequent 3D data reconstruction. High-resolution X-ray microscopy and nano-XCT are suitable techniques to nondestructively study nanomaterials, including porous or skeleton materials. However, laboratory nano-XCT studies are very time-consuming. To reduce the time-to-data by more than an order of magnitude, we propose taking advantage of a monitored tomographic reconstruction. The benefit of this new protocol for 3D imaging is that the data acquisition for each projection is interspersed by image reconstruction. We demonstrate this new approach for nano-XCT data of a novel transition-metal-based materials system: MoNi4 electrocatalysts anchored on MoO2 cuboids aligned on Ni foam (MoNi4/MoO2@Ni). Quantitative data that describe the 3D morphology of this hierarchically structured system with an advanced electrocatalytically active nanomaterial are needed to tailor performance and durability of the electrocatalyst system. We present the framework for monitored tomographic reconstruction, construct three stopping rules for various reconstruction quality metrics and provide their experimental evaluation.

Purpose – This paper aims to apply an integrated data envelopment analysis (DEA) and analytic hierarchy process (AHP) approach to a multi-hierarchy grey relational analysis (GRA) model. Consistent with the most real-life applications, the authors focus on a two-level hierarchy in which the attributes of similar characteristics can be grouped into categories. Nevertheless, the proposed approach can be easily extended to a three-level hierarchy in which attributes might also belong to different sub-categories and further be linked to categories. Design/methodology/approach – The procedure of incorporating the DEA and AHP methods in a two-level GRA may be broken down into a series of steps. The first three steps are under the heading of attributes and the latter three steps are under the heading of categories as follows: computing the grey relational coefficients of attributes for each alternative using the basic GRA model which further provides the required (output) data for an additive DEA model; computing the priority weights of attributes and categories using the AHP method which provides a priori information on the adjustments of attributes and categories in additive DEA models; computing the grey relational grades of attributes in each category for alternatives using an additive DEA model; converting the grey relational grades of attributes to the grey relational coefficients of categories; computing the grey relational grades of categories for alternatives using an additive DEA model; computing the dissimilarity grades of categories for the tied alternatives using an additive DEA exclusion model. Findings – The proposed approach provides a more reasonable and encompassing measure of performance in a hierarchy GRA, based on which the overall ranking position of alternatives is obtained. A case study of a wastewater treatment technology selection verifies the effectiveness of this approach. Originality/value – This research is a step forward to overcome the current shortcomings in a hierarchy GRA by extracting the benefits from both the objective and subjective weighting methods.

Abstract The direct assembly of functional nanoparticles into a highly crystalline mesoporous semiconductor with oriented configurations is challenging but of significance. Herein, an evaporation induced oriented co‐assembly strategy is reported to incorporate SnO2 nanocrystals (NCs) into a 3D branched mesoporous TiO2 framework by using poly(ethylene oxide)‐block‐polystyrene (PEO‐b‐PS) as the template, SnO2 NCs as the direct tin source, and titanium butoxide (TBOT) as the titania precursor. Owing to the combined properties of ultrasmall particle size (3–5 nm), excellent dispersibility and presence of abundant hydroxyl groups, SnO2 NCs can easily interact with PEO block of the template through hydrogen bonding and co‐assemble with hydrolyzed TBOT to form a novel hierarchical branched mesoporous structure (SHMT). After calcination, the obtained composites exhibit a unique 3D flower‐like structure, which consists of numerous mesoporous rutile TiO2 branches with uniform cylindrical mesopores (≈9 nm). More importantly, the SnO2 NCs are homogeneously distributed in the mesoporous TiO2 matrix, forming numerous n–n heterojunctions. Due to the unique textual structures, the SHMT‐based gas sensors show excellent gas sensing performance with fast response/recovery dynamics, high sensitivity, and selectivity toward ethanol.

A percolation model of gas sensors is proposed, on the basis of which the effect of material porosity, pore size and pore size distribution on the gas detection threshold is analyzed. It is shown that micropores exert the greatest influence on gas sensitive properties. An increase in the percolation threshold leads to an increase in the detection threshold of reducing gases. The developed percolation model is used to explain high sensitivity values of sensor structures obtained by the chemical co-precipitation method.

The study of biological materials and bio-inspired materials science is well established; however, surprisingly little knowledge is systematically translated to engineering solutions. To accelerate discovery and guide insights, an open-source autoregressive transformer large language model (LLM), BioinspiredLLM, is reported. The model is finetuned with a corpus of over a thousand peer-reviewed articles in the field of structural biological and bio-inspired materials and can be prompted to recall information, assist with research tasks, and function as an engine for creativity. The model has proven that it is able to accurately recall information about biological materials and is further strengthened with enhanced reasoning ability, as well as with Retrieval-Augmented Generation (RAG) to incorporate new data during generation that can also help to traceback sources, update the knowledge base, and connect knowledge domains. BioinspiredLLM also has shown to develop sound hypotheses regarding biological materials design and remarkably so for materials that have never been explicitly studied before. Lastly, the model shows impressive promise in collaborating with other generative artificial intelligence models in a workflow that can reshape the traditional materials design process. This collaborative generative artificial intelligence method can stimulate and enhance bio-inspired materials design workflows. Biological materials are at a critical intersection of multiple scientific fields and models like BioinspiredLLM help to connect knowledge domains., (© 2023 The Authors. Advanced Science published by Wiley-VCH GmbH.)

The synergistic effect of hollow cavities and multiple hetero-interfaces displays huge advantages in achieving lightweight and high-efficient electromagnetic wave absorption, but still confronts huge challenges. Herein, hierarchical Co 2 P/CoS 2 @C@MoS 2 composites via the self-sacrificed strategy and a subsequent hydrothermal method have been successfully synthesized. Specifically, ZIF-67 cores first act as the structural template to form core-shell ZIF-67@poly(cyclotriphosphazene-co-4,4'-sulfonyldiphenol) (ZIF-67@PZS) composites, which are converted into hollow Co 2 P@C shells with micro-mesoporous characteristics because of the gradient structural stabilities and preferred coordination ability. The deposition of hierarchical MoS 2 results in phase transition (Co 2 P→Co 2 P/CoS 2 ), yielding the formation of hierarchical Co 2 P/CoS 2 @C@MoS 2 composites with hollow cavities and multiple hetero-interfaces. Benefiting from the cooperative advantages of hollow structure, extra N,P,S-doped sources, lattice defects/vacancies, diverse incoherent interfaces, and hierarchical configurations, the composites deliver superior electromagnetic wave capability (-56.6 dB) and wideband absorption bandwidth (8.96 GHz) with 20 wt.% filler loading. This study provides a reliable and facile strategy for the precise construction of superior electromagnetic wave absorbents with efficient absorption attenuation., (© 2023 Wiley-VCH GmbH.)

The low mechanical strength of conductive hydrogels (<1 MPa) has been a significant hurdle in their practical application, as they are prone to fracturing under complex conditions, limiting their effectiveness. Here, this work fabricates a strong and tough conductive hierarchical poly(vinyl alcohol) (PEDOT:PSS/PVA) organo-hydrogel (PPS organo-hydrogel) via a facile combining strategy of self-assembly and stretch training. With PVA/PEDOT:PSS microlayers and aligned PVA/PEDOT:PSS nanofibers, PVA and PEDOT:PSS nanocrystalline domains, and semi-interpenetrating polymer networks, PPS organo-hydrogels display outstanding mechanical performances (strength: 54.8 MPa, toughness: 153.97 MJ m -3 ). Additionally, PPS organo-hydrogels also exhibit powerful sensing capabilities (gauge factor (GF): 983) due to the aligned hierarchical structures and organic liquid phase of DMSO. Notably, with the synergy of such mechanical and sensing properties, organo-hydrogels can even detect objects as light as 1 gram, despite bearing a tensile strength of ≈23 MPa. By incorporating these materials into human-machine interfaces, such as controlling artificial arms for grabbing objects and monitoring sport behaviors in soccer training, this work has unlocked a new realm of possibilities for these high-performance hierarchical organo-hydrogels. This approach to designing hierarchical structures has the potential to lead to even more high-performance hydrogels in the future., (© 2023 Wiley-VCH GmbH.)

The sustainable and scalable fabrication of low-cost, efficient, and durable electrocatalysts that operate well at industrial-level current density is urgently needed for large-scale implementation of the water splitting to produce hydrogen. In this work, an integrated carbon electrode is constructed by encapsulating Ni nanoparticles within N-doped carbonized wood framework (Ni@NCW). Such integrated electrode with hierarchically porous structure facilitates mass transfer process for hydrogen evolution reaction (HER). Ni@NCW electrode can be employed directly as a robust electrocatalyst for HER, which affords the industrial-level current density of 1000 mA cm -2 at low overpotential of 401 mV. The freestanding binder-free electrode exhibits extraordinary stability for 100 h. An anion exchange membrane water electrolysis (AEMWE) electrolyzer assembled with such freestanding carbon electrode requires only a lower cell voltage of 2.43 V to achieve ampere-level current of 4.0 A for hydrogen production without significant performance degradation. These advantages reveal the great potential of this strategy in designing cost-effective freestanding electrode with monometallic, bimetallic, or trimetallic species based on abundant natural wood resources for water splitting., (© 2023 Wiley-VCH GmbH.)

The high demand for micro-/nanohierarchical structures as components of functional substrates, bioinspired devices, energy-related electronics, and chemical/physical transducers has inspired their in-depth studies and active development of the related fabrication techniques. In particular, significant progress has been achieved in hierarchical structures physically engineered on surfaces, which offer the advantages of wide-range material compatibility, design diversity, and mechanical stability, and numerous unique structures with important niche applications have been developed. This review categorizes the basic components of hierarchical structures physically engineered on surfaces according to function/shape and comprehensively summarizes the related advances, focusing on the fabrication strategies, ways of combining basic components, potential applications, and future research directions. Moreover, the physicochemical properties of hierarchical structures physically engineered on surfaces are compared based on the function of their basic components, which may help to avoid the bottlenecks of conventional single-scale functional substrates. Thus, the present work is expected to provide a useful reference for scientists working on multicomponent functional substrates and inspire further research in this field., (© 2023 Wiley-VCH GmbH.)

Cellular structures (CSs) have been used extensively in recent years, as they offer a unique range of design freedoms. They can be deployed to create parts that can be lightweight by introducing controlled porous features, while still retaining or improving their mechanical, thermal, or even vibrational properties. Recent advancements in additive manufacturing (AM) technologies have helped to increase the feasibility and adoption of cellular structures. The layer-by-layer manufacturing approach offered by AM is ideal for fabricating CSs, with the cost of such parts being largely independent of complexity. There is a growing body of literature concerning CSs made via AM; this presents an opportunity to review the state-of-the-art in this domain and to showcase opportunities in design and manufacturing. This review will propose a novel way of classifying cellular structures by isolating their Geometrical Degrees of Freedom (GDoFs) and will explore the recent innovations in additively manufactured CSs. Based on the present work, the design inputs that are common in CSs generation will be highlighted. Furthermore, the work explores examples of how design inputs have been used to drive the design domain through various case studies. Finally, the review will highlight the manufacturability limitations of CSs in AM.

Auxetic materials or structures, especially 3D cellular lattice architectures with negative Poisson's ratio (NPR) have attracted great attention due to their unprecedented mechanical behaviors and promising applications in recent years. Many 3D auxetic architected cellular materials have been manufactured and characterized with polymers and metals using additive manufacturing technology as well as some fibre reinforced polymers (FRP) composites via assembly method, however metal 3D printed auxetic structures with high-quality are rarely reported and FRP composites using assembly method contain a variety of defects which result in a knock-down effect on mechanical properties. Auxetic structures made from polymers are normally of low stiffness and strength and FRP composites are of low toughness and impact resistance, which causes limitations on their structural and functional applications. If rationally designed structures can be made from high-performance metal materials the specific stiffness and strength of which are much higher than polymers, their specific stiffness and strength can be significantly increased which will make them more suitable for various potential applications. This paper presents novel 3D double-U hierarchical structures (DUHs) based on double-V hierarchical structures (DVHs) with tunable Poisson's ratio and Young's modulus by tailoring the geometry parameters. Experimental, numerical and theoretical results show that DUHs have smooth geometry that can reduce manufacturing damage and stress concentration under elastic loading. Another advantage of DUHs is that the curved configurations have enhanced auxetic behavior and higher static collapse stress than DVHs under crushing. The advanced 3D printing technology and those excellent mechanical properties of 3D DUHs meet the requirements of structural and functional applications. [ABSTRACT FROM AUTHOR]

The process for preparing SnO2 nanocrystalline microspheres via synthesis in microemulsions combined with hydrothermal treatment of the resulting suspensions was studied. Tin acetylacetonate, whose n‑butanol solution is more convenient for use compared to classical reagents, was shown to have a promise for use as a precursor. Simultaneous thermal analysis and IR spectroscopy showed the transformation of a hydrated powder under heating to yield anhydrous tin dioxide. SEM analysis of the prepared SnO2 powder microstructure elucidated a two-level organization of oxide particles—nanoparticles with a size of about 25 nm were hierarchically organized in the form of medium-sized microspheres of about 1.5 µm, were formed during microemulsion synthesis upon tin acetylacetonate hydrolysis. [ABSTRACT FROM AUTHOR]

Nickel oxide nanosheets were manufactured using sol–gel technology and hydrothermal treatment. The effect of hydrothermal treatment on the hierarchical organization character of the thus-manufactured oxide powder was shown. The microstructural parameters of the powder were studied by transmission (TEM) and scanning (SEM) electron microscopy; The homogeneity of the powder and the absence of impurities of another chemical composition were verified by energy dispersive elemental microanalysis (EDX). [ABSTRACT FROM AUTHOR]

In this update of Clark and Watson (1995), we provide a synopsis of major points of our earlier article and discuss issues in scale construction that have become more salient as clinical and personality assessment has progressed over the past quarter-century. It remains true that the primary goal of scale development is to create valid measures of underlying constructs and that Loevinger's theoretical scheme provides a powerful model for scale development. We still discuss practical issues to help developers maximize their measures' construct validity, reiterating the importance of (a) clear conceptualization of target constructs, (b) an overinclusive initial item pool, (c) paying careful attention to item wording, (d) testing the item pool against closely related constructs, (e) choosing validation samples thoughtfully, and (f) emphasizing unidimensionality over internal consistency. We have added (g) consideration of the hierarchical structures of personality and psychopathology in scale development, discussion of (h) codeveloping scales in the context of these structures, (i) "orphan," and "interstitial" constructs, which do not fit neatly within these structures, (j) problems with "conglomerate" constructs, and (k) developing alternative versions of measures, including short forms, translations, informant versions, and age-based adaptations. Finally, we have expanded our discussions of (l) item-response theory and of external validity, emphasizing (m) convergent and discriminant validity, (n) incremental validity, and (o) cross-method analyses, such as questionnaires and interviews. We conclude by reaffirming that all mature sciences are built on the bedrock of sound measurement and that psychology must redouble its efforts to develop reliable and valid measures. (PsycINFO Database Record (c) 2019 APA, all rights reserved). [ABSTRACT FROM AUTHOR]

Three-dimensional hierarchical morphologies widely exist in natural and biomimetic materials, which impart preferential functions including liquid and mass transport, energy conversion, and signal transmission for various applications. While notable progress has been made in the design and manufacturing of various hierarchical materials, the state-of-the-art approaches suffer from limited materials selection, high costs, as well as low processing throughput. Herein, by harnessing the configurable elastic crack engineering-- controlled formation and configuration of cracks in elastic materials--an effect normally avoided in various industrial processes, we report the development of a facile and powerful technique that enables the faithful transfer of arbitrary hierarchical structures with broad material compatibility and structural and functional integrity. Our work paves the way for the cost-effective, large-scale production of a variety of flexible, inexpensive, and transparent 3D hierarchical and biomimetic materials. [ABSTRACT FROM AUTHOR]

Advanced methods, allowing the controllable synthesis of ordered structural nanomaterials with favourable charges transfer and storage, are highly important to achieve ideal supercapacitors with high energy density. Herein, we report a microliter droplet‐based method to synthesize hierarchical‐structured metal–organic framework/graphene/carbon nanotubes hybrids. The confined ultra‐small‐volume reaction, give well‐defined hybrids with a large specific‐surface‐area (1206 m2 g−1), abundant ionic‐channels (narrow pore of 0.86 nm), and nitrogen active‐sites (10.63 %), resulting in high pore‐size utilization (97.9 %) and redox‐activity (32.3 %). We also propose a scalable microfluidic‐blow‐spinning method to consecutively generate nanofibre‐based flexible supercapacitor electrodes with striking flexibility and mechanical strength. The supercapacitors display large volumetric energy density (147.5 mWh cm−3), high specific capacitance (472 F cm−3) and stably deformable energy‐supply. [ABSTRACT FROM AUTHOR]

Hierarchical nanostructures based on rodlike particles of the composition CeO2–10% Y2O3 were obtained by programmed direct coprecipitation of metal hydroxides in the presence of polyvinyl alcohol. The effect of the concentration of the structure-forming polymer template on the morphology of the formed oxides was shown. The dependence of the particle size and microstructure of the products on the polyvinyl alcohol concentration in the reaction system was identified. Simultaneous thermal and X-ray powder diffraction analyses determined that the polymer during precipitation is incorporated into the structure of the produced nanopowder, preventing coarsening of particles during heat treatment. [ABSTRACT FROM AUTHOR]

The significance of graphene and its two-dimensional (2D) analogous inorganic layered materials especially as hexagonal boron nitride (h-BN) and molybdenum disulphide (MoS2) for "clean energy" applications became apparent over the last few years due to their extraordinary properties. In this review article we study the current progress and selected challenges in the syntheses of graphene, h-BN and MoS2 including energy storage applications as supercapacitors and batteries. Various substrates/catalysts (metals/insulator/semiconducting) have been used to obtain graphene, h-BN and MoS2 using different kinds of precursors. The most widespread methods for synthesis of graphene, h-BN and MoS2 layers are chemical vapor deposition (CVD), plasma-enhanced CVD, hydro/solvothermal methods, liquid phase exfoliation, physical methods etc. Current research has shown that graphene, h-BN and MoS2 layered materials modified with metal oxide can have an insightful influence on the performance of energy storage devices as supercapacitors and batteries. This review article also contains the discussion on the opportunities and perspectives of these materials (graphene, h-BN and MoS2) in the energy storage fields. We expect that this written review article including recent research on energy storage will help in generating new insights for further development and practical applications of graphene, h-BN and MoS2 layers based materials. [ABSTRACT FROM AUTHOR]

The controlled formation of complex and functional 1‐, 2‐, and 3D hierarchical assemblies from molecular building blocks represents a key current challenge. Herein, we report the use of a seeded growth approach for a series of perylenediimide‐based molecules (PDIs 1–4) to access otherwise inaccessible self‐assembly pathways that yield complex hierarchical structures. The key to the new approach is to use hetero‐seeds which possess a different composition and morphology from that of the molecular building block. For example, a nanotube seed (from PDI 3) and a microribbon seed (from PDI 4) were found to initiate different self‐assembly pathways for PDI 1, which normally assembles to yield nanocoils. This led to the formation of unprecedented 3D scroll‐like and scarf‐like hierarchical nanostructures, respectively. Also, the hetero‐seeds from PDI 3 initiate hidden self‐assembly pathways of PDI 2 to generate 1D tubular heterojunctions. Significantly, this new strategy offers new opportunities to create emergent and functional hierarchical and complex structures from small molecule precursors. [ABSTRACT FROM AUTHOR]

The superhydrophobic surfaces have many applications, including skin friction reduction, antiicing, anti-fouling, and self-cleaning surfaces. Also, with the precise design of these surfaces, it is possible to increase the heat transfer coefficient in the condensation heat transfer. In recent years, a variety of methods have been proposed for the fabrication of the superhydrophobic surfaces, some of which are very complex and not applicable for industrial uses. In this paper, a nanocomposite superhydrophobic coating is produced in a simple and applicable way for large surfaces. Using this method, a superhydrophobic surface with surface structures in multi-scale and with a sliding angle of less than 5 degrees is obtained. After evaluating the specification of superhydrophobic surfaces, slip length measurement of the coating is performed using a fabricated measurement system. It should be noted that the slip length of the superhydrophobic surface is a characteristic feature of these surfaces and always its measurement is associated with challenges. In this research, the slip length of the created coating was measured by use of the proposed measurement system. The results show that the slip lengths of about 40-500 microns can be achieved by use of the proposed measurement system. [ABSTRACT FROM AUTHOR]

Features of the synthesis and physicochemical properties of a new class of materials— hierarchical MWW zeolites (HZ-MWW), prepared via recrystallization—are studied. Recrystallization is done in two stages in an alkaline solution containing cetyltrimethylammonium bromide. The effect the type of precursor and the concentration of alkali have on the morphological, textural, and acidic properties of HZ-MWW is studied. It is shown the recrystallization of a layered precursor under mild conditions in a 0.5 M NaOH solution slightly alters the porous structure while preserving the morphology of the zeolite crystal. It is established that an increase in the degree of recrystallization in 1 and 2 M NaOH solutions is accompanied by the fragmentation of crystals, growth of the external surfaces of materials, and the formation of a mesoporous phase formed by ordered pores around 3 nm in size. The evolution of the HZ-MWW porous structure is traced during the preparation of the hydrogen form with acidic properties. It is concluded that the ion exchange of HZ-MWW in ammonium nitrate solution washes out the amorphous phase and changes the texture of the H-forms of HZ-MWW, compared to the detemplated Na-forms. The acidic properties of HZ-MWW correlate with the Si/Al ratio and samples of the micropore volume. [ABSTRACT FROM AUTHOR]

Within the green chemistry context, heterogeneous catalysis for the synthesis of N‐heterocycles from renewable resources using non‐precious metals has garnered great interest in terms of economic and environmental perspectives. Herein, we present a triazine functional hierarchical mesoporous organic polymer (HMOP) with nanorod morphology together with large BET surface area ∼1218 m2 g−1, huge pore volume&γτ";6 mL g−1 and dual micro/mesopore architectures. Subsequent Cu‐coordination with nitrogen atoms of the HMOP provides a robust catalyst (Cu‐HMOP) to accomplish multi‐step cascade reactions for preparation of N‐heterocycles by different routes. For instance, the Cu‐HMOP efficiently catalyzes one‐pot sequential multi‐step oxidative dehydrogenative coupling of 2‐aminobenzyl alcohol with diverse aromatic ketones to afford corresponding quinolines in excellent isolated yields (up to 97 %). Secondly, the present catalyst exhibits good aerobic oxidative dehydrogenation activity of amines to imines. Thirdly, for "click" reaction involving azides‐alkynes, the Cu‐HMOP produced quantitative yield for 1,4‐disubstituted 1,2,3‐triazole derivatives at room temperature using water as solvent. Verification of active metal leaching by a hot filtration test as well as reusability of the retrieved Cu‐HMOP catalysts shows a consistent activity in the multi‐component quinoline synthesis as model reaction. [ABSTRACT FROM AUTHOR]

• BiOBr hierarchical structures are synthesized by solvothermal process. • Crystal growth and morphology structures of BiOBr can be regulated. • BiOBr hierarchical structures are assembled by numerous porous nanosheets. • The anisotropic growth of BiOBr particles is along the (110) plane. • BiOBr hierarchical structures exhibit excellent photocatalytic performance. BiOBr hierarchical structures were successfully synthesized through a solvothermal process assisted with citric acid using methanol as a solvent. The as-synthesized BiOBr hierarchical structures have diameters of ca. 1 μm, and assembled by numerous porous nanosheets with exposed (110) facets. Results indicated that the crystal growth and morphology structures of BiOBr were significantly influenced by the amount of citric acid, the solvothermal time and the solvent used in reaction. In addition, the as-synthesized BiOBr hierarchical structures exhibited high photocatalytic activity on the degradation of methyl orange under either UV light or simulated sunlight illumination, due to the larger specific surface area and unique hierarchical structures assembled by numerous BiOBr porous nanosheets. [ABSTRACT FROM AUTHOR]

Efficient touch feedback, capable of monitoring the magnitude of force and identifying active location, is significant to artificial intelligence and interactive robotics. It generally needs the integration of multitudinous sensing elements and intricate manufacturing procedures. Here we propose a multifunctional paper-based touch sensor to realize touch trajectory recognition as well as achieve pressure information. The asymmetric and symmetric structures are designed to skillfully construct localization layer and pressure sensing layer. These functional layers effectively assemble a scalable touch sensor and, thus, greatly simplify the device's architecture with the competitive advantages of easiness in fabrication, cost-effectiveness, self-switching characteristic, and programmability in interactive function. Through coding and using the electrical signals, human-computer interaction, human-machine interaction, and force-enhanced cryptographic matrix are explored and demonstrate the feasibility of the proposed touch sensor. This work provides a novel mechanosensational sensing paradigm to leverage the complex physics of a feasible strategy for advancing human-related interactive electronics. Image 1 • The touch sensor based on synergistic sensing of stratified structures can identify touch track and detect pressure signal. • Design of hierarchically symmetric and asymmetric structures enables to greatly simplify the architecture of touch sensor. • Touch sensor constructed on paper substrate features low cost, portability, and environmental friendliness. • Multifarious human-related interactions demonstrate the programmability and potential of the proposed touch sensor. [ABSTRACT FROM AUTHOR]