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Gaining an in-depth understanding of the effect of the Ba/Ti ratio on the performance of BaTiO3 (BT)-based multilayer ceramic capacitors (MLCCs) from the viewpoint of defect chemistry is challenging owing to the doping diversity and complexity. This study focused on the dielectric properties based on the Ba/Ti ratio, which are mainly determined by reversible and irreversible domains. The sample with Ba/Ti < 1 had a larger shell proportion and lower reversible domain concentration than that with Ba/Ti > 1, which is attributed to Ba vacancies having a higher diffusion rate than Ti vacancies. Furthermore, different pinning abilities resulted in different irreversible domain concentrations. When Dy was doped in Ti sites for materials with Ba/Ti > 1, it formed defects , , and , exhibiting a stronger pinning ability than and formed in the case of Ba/Ti < 1 and Dy doped in the Ba site. [ABSTRACT FROM AUTHOR]

The rapid advancements in high-density packaging underscore the critical demand for advanced thermal interface materials (TIMs). Developing TIMs with exceptional mechanical flexibility, robust interfacial adhesion, minimal thermal resistance, and superior thermal stability presents a significant challenge. Here, we introduce poly(ionic liquid)s (PILs) as the matrices for TIMs, representing an initial investigation into the feasibility of PIL-based TIMs. Specifically, poly(1-octyl-3-vinylimidazole) bis(trifluoromethanesulfonyl)imide (P[OVIm]NTf2) shows a remarkable tensile elongation (>2300%), strong interfacial adhesion (6.9 MPa with steel, 6.6 MPa with copper), elevated thermal decomposition temperature (>240 °C in air), excellent thermal stability (no mass loss at 150 °C), rapid self-healing capability, and reprocessability. As a proof of concept, liquid metal (LM) was utilized as a filler within P[OVIm]NTf2 matrix to fabricate TIMs containing a substantial LM content (>60 vol%). The P[OVIm]NTf2/LM visco-elastomers achieve a remarkable thermal conductivity of 3.2 W m−1 K−1. Furthermore, the composites display an elongation of 109% while maintaining strong interfacial adhesion (0.95 MPa) with steel. In a practical application scenario, the P[OVIm]NTf2/LM visco-elastomers efficiently disperse heat, highlighting their potential practical utility. This study presents a novel approach by advocating the use of PILs as an alternative to conventional silicone matrices, thereby validating the potential application of PILs in the TIM domain. [ABSTRACT FROM AUTHOR]

Most tough elastomer composites are reinforced by introducing sacrificial structures and fillers. Understanding the contribution of fillers and sacrificial bonds in elastomer composites to the energy dissipation is critical for the design of high-toughness materials. However, the energy dissipation mechanism in elastomer composites remains elusive. In this study, using a tearing test and time-temperature superposition, we investigate the effect of fillers and sacrificial bonds on the energy dissipation of elastomer composites consisting of poly(lipoic acid)/silver-coated Al fillers. We found that the fillers and sacrificial bonds mutually enhance both the intrinsic fracture energy and the bulk energy dissipation, and moreover the sacrificial bonds play a more important role in enhancing fracture toughness than the fillers. It is unreasonable to rely solely on the loss factor for bulk energy dissipation. The addition of sacrificial bonds results in a chain segment experiencing greater binding force compared to the addition of fillers. This suggests that the chain segment consumes more energy during its movement. By calculating the length of the Kuhn chain segment and the Kuhn number, it is evident that the addition of sacrificial bonds results in a greater binding force for the chain segment than the addition of fillers, and this enhanced binding force increases the energy consumption during the motion of the chain segment. [ABSTRACT FROM AUTHOR]

As stringent demands for PI materials with low-temperature curable properties have increased in the high-frequency communication era, the introduction of flexible structures has gained prominence for enhancing molecular chain mobility. However, systematic studies on the effect of flexible structures on low-temperature curing ability remain limited. In this work, we designed a new dianhydride monomer with isopropylidene and ester groups named TABPP. Low-temperature curable polyimides with different molecular chain flexibility were prepared by choosing different diamines and anhydrides. Surprisingly, the degree of imidization was not straightforwardly aligned with molecular chain flexibility. An exemplar instance was PI-9-200, exhibiting the greatest flexibility among the samples, yet possessing the lowest degree of imidization (ID) of 68.59%. Based on the analysis of experimental results and front-line orbital energy levels, it could be seen that the mismatch between the ID and the flexibility may originate from the influence of electronic effects of the monomers. Notably, when enough flexible structures were introduced into the polyimide backbone, the effect of increasing the free volume appeared to outweigh the influence of incomplete imidization, thereby favoring the preparation of low-temperature curable PI films with outstanding dielectric properties. In particular, the dielectric constant of the prepared low-temperature curable PI films was as low as 2.50, which is the best performance among the low-temperature curable PI films. This work throws new light on the correlation between flexibility and low-temperature curing ability and offers fresh perspectives on the preparation of low-temperature curable PIs with excellent dielectric properties. [ABSTRACT FROM AUTHOR]

A new pair of multifunctional Zn(II)–Dy(III) enantiomers based on the chiral Schiff-base ligands [R,R-ZnLDy(H2O)(NO3)3] (1R2R-ZnDy) and [S,S-ZnLDy(H2O)(NO3)3] (1S2S-ZnDy) (H2L = phenol, 2,2′-[[(1R,2R/1S,2S)-1,2-diphenyl-1,2-ethanediyl]bis[(E)-nitrilomethylidyne]]bis[6-methoxy]) was synthesized and characterized. Magnetic studies indicate that 1R2R-ZnDy behaves as a single-molecule magnet. Enantiomers 1R2R-ZnDy and 1S2S-ZnDy show chiroptical activity and circularly polarized luminescence in the N,N-dimethylformamide (DMF) solution. The chiral Zn(II)–Dy(III) complexes display magnetic circular dichroism signals at room temperature. Accordingly, these complexes will inspire intriguing research on single-molecule magnets with circular polarization of luminescence activity and magneto-optic effects, which will give new clues to design multifunctional molecular magnetic materials. [ABSTRACT FROM AUTHOR]

New applications of elastomers, such as flexible electronics and soft robotics, have brought great attention to tear resistance since elastomers are prone to shear failure. Most elastomers contain chemical cross-links and entanglements. The effects of both on their mechanical properties have been intensively studied, while how they cope with tearing remains elusive. Here, in polybutadiene elastomers, we find that the energy release rate of tearing (Gtearing), often employed as a measure of tear resistance, is influenced synergistically by chemical cross-linking and entanglements, while its threshold (G0) is only related to the chemical cross-linking. At a low tear speed, the polybutadiene elastomers with low cross-linking density have Gtearing up to 4 times higher than their G0 compared to highly cross-linked ones. Different from conventional reinforcement due to volume dissipation of a polymer network, enhancement of Gtearing significantly depends on the degree of cross-linking. The enhancement of Gtearing at low cross-linking degrees may be related to a novel mechanism, the friction-strengthening phenomenon, which was possibly caused by the pull-out of the chains at a high degree of orientation. [ABSTRACT FROM AUTHOR]

Two-dimensional copper sheets were introduced as the catalyst and bridge to enhance the electrical and thermal conductivity of graphene films prepared from graphene oxide nanosheets via a thermal reduction method. The effects of adding different amounts of copper sheets in the composite films were investigated, and the results show that the electrical and thermal conductivity of the graphene films could be increased by 3 times and 64.9%, respectively. The two-dimensional copper sheets not only play an important role as a catalyst toward improving the graphitization degree of reduced graphene oxide, but also act as a bridge and promote the interconnection of the electrical and thermal conduction paths in the composite films due to the good electrical and thermal conductivity of copper. Moreover, the heat dissipation experiment shows that this enhanced graphene composite film has potential applications in the heat management of electronics. [ABSTRACT FROM AUTHOR]

To date, low-temperature curable polyimide (PI) materials have been in great demand in the field of advanced packaging. However, their synthesis is still a challenge due to the distinct structural design contradiction between the low-temperature curing ability and other desired properties. In this work, we designed and synthesized two novel diamines with different side groups (phenyl and pyrimidine rings), named PhNH2 and SPMNH2, and applied them to construct high-performance PI. Inspired by our previously reported pyrimidine based diamine PMNH2 (X. Lv, S. Qiu, S. Huang, K. Wang and J. Li, Polymer, 2022, 261, 125418), we tried to explore the impact of nitrogen heterocycle position (in the side group or main chain) on low-temperature curing ability. Compared with the typical diamine complex with nitrogen heterocycles in the main skeleton, the well-designed pyrimidine side group endowed the PI films with a highly improved imidization degree (ID) and excellent thermal and mechanical properties at a low curing temperature (200 °C). It should be noted that the configurations and the side group effects of diamine could modulate the temperature of polymerization and the structure of polymers, which further influenced the final performance of PI films. The copolyimide films based on SPMNH2 exhibited a high elongation of 103.4%, Young's modulus of 3.20 GPa, tensile strength of 147 MPa, 5wt % decomposition temperature (Td5%) of 524 °C, and a glass transition temperature (Tg) of 359 °C, which was much better than that for PI film copolymerization with PhNH2 or PMNH2 cured at 200 °C. Experimental results and theoretical calculations showed that the introduction of pyrimidine side groups allowed for a better catalytic effect in the reaction system, and stronger intermolecular force between the polymer chains. This is the first report about the side-group effects on low-temperature curable PI films, which should be enlightening for the design of novel and high-performance diamines applied for advanced packaging and other fields. [ABSTRACT FROM AUTHOR]

Thermally conductive polymer-based composites with the combination of superior stretchability, efficient self-healing, recyclability and high thermal conductivity have long been pursued in the modern electronics industry. However, integrating these attractive properties remains challenging due to the complexity of the composite structure and composition. In this work, by fabricating covalent adaptable networks and introducing supramolecular interactions, we prepared a poly(thioctic acid)/aluminum (poly(TA)/Al) composite elastomer. The prevalent supramolecular interactions provide the poly(TA)/Al with enhanced interfacial interaction and a stretchable covalent adaptable network, leading to superior stretchability (1640%), enhanced thermal conductivity (1.83 W mK−1) and excellent self-healing efficiency (96% and 98% at 80 °C for tensile elongation and thermal conductivity, respectively). Moreover, the dynamically reversible covalent adaptable network ensures solid-state plasticity and thermally induced recyclability of the poly(TA)/Al, which can maintain desirable mechanical and thermal conductivity. The current work provides a practical method to design thermally conductive self-healing composites with stretchability and recyclability, which are needed for the heat dissipation of advanced electronic devices. [ABSTRACT FROM AUTHOR]

Prussian blue analogues (PBAs) as a class of metal–organic frameworks demonstrate a promising platform to develop cost-effective high-performance electrocatalysts. However, the construction of delicate micro/nanostructures and controllable doping are still a challenging task for the fabrication of highly efficient copper-based electrocatalysts. Herein, we report a facile synthesis of copper foam supported Cu3P@Co-Cu3P (CH@PBA-P/CF) sub-microwire arrays as an active electrocatalyst for alkaline water splitting. The Co-Cu3P shell derived from the Cu3[Co(CN)6]2 PBA serves as the source of active sites. Co doping and construction of core–shell structures endow the CH@PBA-P/CF electrocatalyst with abundant catalytic sites, enhanced intrinsic activity, and low charge transport resistance. The catalytic electrode integrated with 3D copper foam and 1D sub-microwire arrays is highly conductive and stable, which promotes the charge transport and improves the structural stability. As a consequence, CH@PBA-P/CF shows impressive catalytic performances toward the HER and OER in terms of low overpotentials of 231 and 312 mV at a current density of 50 mA cm−2 in 1 M KOH, respectively. Notably, the water electrolyzer using the CH@PBA-P/CF electrode exhibits better water splitting performance than the one using noble metal-based couples. [ABSTRACT FROM AUTHOR]

Correction for 'Electromagnetic interference shielding materials: recent progress, structure design, and future perspective' by Xiao-Yun Wang et al., J. Mater. Chem. C, 2022, 10, 44–72, https://doi.org/10.1039/D1TC04702G. [ABSTRACT FROM AUTHOR]

With the rapid development of advanced microelectronic equipment, thermal interface materials with high thermal conductivity and excellent mechanical properties have become an urgent need. Adding traditional thermally conductive fillers to polymers often leads to poor mechanical properties of thermal interface materials. In this paper, a liquid metal (LM) is used as an auxiliary filler to fill spherical boron nitride (SBN) polymer thermal interface materials. The liquid metal bridges the spherical boron nitride distributed in "islands", endowing the thermal interface materials with high thermal conductivity (4.00 W m−1 K−1, an increase of 227.66%), and excellent mechanical properties (elongation at break up to 198.96%, an increase of 81.24%). These experimental results show that the liquid metal, a flexible filler, can not only replace rigid fillers to reduce the contact thermal resistance between fillers through surface contact, but also improve the mechanical properties to a certain extent, breaking through the defects of traditional rigid fillers, and provides ideas for the future development of thermal interface materials. [ABSTRACT FROM AUTHOR]

The rapid development of electronic equipment and the sharp increase in the demand for wireless communication have resulted in a substantial increase in electromagnetic pollution. Consequently, electromagnetic interference (EMI) shielding materials have been developed to solve the grim problem of electromagnetic pollution. However, 5G communication technology and modern electronic products demand shielding materials with higher requirements in terms of EMI shielding performance, weight, flexibility, and reliability. This review focuses on the recent research progress in the structural design, characterization, and properties of various EMI shielding materials including metal type, carbon type, and MXene type. The basic theory of EMI shielding is introduced in detail and the current testing technologies for EMI shielding effectiveness are summarized, which can help elucidate the structural design principles for shielding materials. The effect of different types of carbon materials, which are classified as zero-dimensional, one-dimensional, two-dimensional, and three-dimensional, on the shielding performance, and the corresponding shielding mechanism are discussed. Moreover, near-field shielding and its application in the field of electronic packaging are introduced. Based on our comprehensive analysis, we present the main challenges and outlook of EMI shielding materials in future research. [ABSTRACT FROM AUTHOR]

Employing external stimuli to manipulate the synergy between the magnetic behaviour and proton conductivity has stimulated extensive scientific interest due to potential applications in information storage, sensors, fuel cells, etc. Herein, we report the assembly of a unique dysprosium compound, {[DyL(Cl)(CH3OH)]·CH3CN}n(1) (H2L = N′-(5-fluoro-2-hydroxybenzylidene)pyrazine-N-oxide-carbohydrazide), which exhibits a humidity-induced reversible single-crystal to single-crystal transformation involving the cleavage and formation of multiple coordination bonds, generating a water-rich form of {[DyL(H2O)3]Cl}n (1′). Both phases are composed of layered structures based on {Dy2} dimeric units and extended by pyrazine-N-oxide groups of the ligand. In particular, the presence of water molecules not only changes the coordination environment of Dy3+ ions, but also releases a lattice chloride ion that alters hydrogen bonding between the layers, resulting in a synergetic switch of the dynamic magnetic behaviour and proton conductivity. [ABSTRACT FROM AUTHOR]

While assembling superparamagnetic units in a controlled manner is crucial for future applications of molecular nanomagnets, optimizing their magnetic properties while achieving directional assembly of these units still remains a formidable challenge. Herein, we demonstrate how the assembly of two dysprosium chain complexes, namely, [Dy2(L)2Cl2(CH3OH)3]n·nCH3OH (1) and [Dy(L)Cl(DMF)]n (2) (H2L = N'-(5-bromo-2-hydroxybenzylidene)pyrazine-N-oxide-carbohydrazide), can be successfully manipulated using an appropriate bridging ligand design. Both complexes contain similar dimeric units bridged by two alkoxido oxygens from an L2− ligand, but extended by its pyrazine-N-oxide group exhibiting two distinct coordination modes, namely, single and double pyrazine-N-oxide bridges, respectively. Magnetic studies reveal that both complexes display typical slow magnetic relaxation under zero direct-current field; however, the anisotropy barrier and the coercive field at 2 K for complex 2 are twice as much as that of 1. A further theoretical study indicates that switching the coordination mode from a single pyrazine-N-oxide bridge to double bridges can enhance both the magnetic anisotropy of dysprosium ions and magnetic coupling within the dimeric cores. The synergistic effect between the magnetic anisotropy of dysprosium ions and magnetic interactions among them directly contributes to the overall better performance of complex 2. [ABSTRACT FROM AUTHOR]

Stretchable micro-supercapacitors (MSCs) with high power density and small size have been intensively researched in the recent years. However, to date, the stretchability of the overall device is still limited by the lack of a stretchable electrode material, which results in significant performance degradation, particularly in the highly stretched state. Herein, a new method for designing natively stretchable MSCs capable of maintaining high electrochemical performance in a highly (200%) stretched state is presented. The electrode is based on the novel incorporation of the bis(trifluoromethane) sulfonamide lithium salt (LiTFSI) and poly(vinyl alcohol) (PVA) into a PEDOT:PSS hydrogel. The resultant PEDOT:PSS-LiTFSI-PVA hydrogel is operated with a PVA/H2SO4 electrolyte to deliver an unprecedented level of combined performance such as a large areal capacitance of 44.5 mF cm−2, a power density of 0.04 mW cm−2 at an area energy density of 0.004 mW h cm−2, and an excellent stretchability of 200% while retaining 93% of the original capacitance. The MSCs deliver highly stable performance even under extensive stretching, showing a high 92% capacitance retention after 2000 cycles of 100%-strain stretching. The proposed MSC architecture is compatible with laser patterning, which enables rapid fabrication, and reflects a highly practical approach for realizing high performance, mechanically robust micro energy storage devices. [ABSTRACT FROM AUTHOR]

By utilizing the hybrid-ligand conception, three novel dysprosium complexes Dy(2-py-4-pmc)(L)(H2O) (H2-py-4-pmc = 2-(2-pyridyl)pyrimidine-4-carboxylic acid; L = fumarate (fum, 1), succinate (suc, 2), or pimelate (pim, 3)) have been successfully synthesized. Structural analysis reveals that the dicarboxylate ligands connect 2-py-4-pmc−-protected Dy3+ to form one-dimensional molecular ribbons. Magnetic measurements indicate that the three complexes exhibit typical slow magnetic relaxation under a zero dc field with effective reversal barriers Ueff of 180 K, 145 K and 137 K for 1–3, respectively, which is mainly attributed to the strong Ising anisotropy of dysprosium ions induced by the appropriate arrangement of carboxylate groups. Ab initio calculations demonstrate that the charge distribution around dysprosium ions and the magnetic interactions between them are key contributions to their different dynamic behaviour. [ABSTRACT FROM AUTHOR]

Over the last few years, low-temperature curing polyimide (PI) has turned out to be a significant target for the advanced electronic package. Although the curing accelerators have been confirmed to be capable of significantly decreasing the curing temperature, their effects on properties have not been comprehensively examined. In this study, polyamide acid is synthesized by pyromellitic dianhydride (PMDA) and 4,4′-oxydianiline (ODA), and the process of low-temperature imidization is investigated by introducing six accelerators, i.e., quinoline (QL), isoquinoline (IQL), 2-methyl quinoline (2-QL), 4-methyl quinoline (4-QL), 8-methyl quinoline (8-QL), as well as 5,6,7,8-tetrahydroquinoline (THQL). As revealed from the results, the polyimide films formed using 4-QL and QL have exhibited prominent mechanical, thermal, and electrical properties. For the PI-4-QL, the tensile strength is 151.87 MPa, elongation-at-break reaches 161.36%, and the weight loss of 5% is observed at 533 °C; for the PI-QL, the tensile strength is 134.82 MPa, elongation-at-break reaches 145.16%, and the weight loss of 5% reaches 545 °C. As indicated from the results, the boiling point, acidity and molecular structure of the low-temperature curing accelerators show significant effects. Lower acidity and steric hindrance between the accelerator and amide bond facilitate the low-temperature imidization of polyamide acid. Furthermore, the as-prepared low-temperature cured PIs of 4-QL and QL would exhibit wide applications in advanced packaging industry. [ABSTRACT FROM AUTHOR]

Two-dimensional (2D) multilayered graphitic carbon nanosheets are prepared via a facile, green, and mild method of one-pot hydrothermal carbonization at a temperature below 300 °C. Copper with a 2D structure is formed in situ and serves as both a template and catalyst. The obtained multilayered carbon nanosheets exhibit well-defined shapes and a radius-to-thickness ratio as high as 104, with monolayer thickness as small as 2.86 nm. [ABSTRACT FROM AUTHOR]

Rheumatoid arthritis is a chronic systemic autoimmune disease that causes joint swelling and cartilage damage. The objective of the present work was to develop a temperature-sensitive hydrogel (D-NGel) containing nanoparticles (D-NPs), which could simultaneously deliver combination indomethacin and methotrexate. D-NPs were formed by multiple non-covalent interactions between PEI-SS and the carboxyl-containing hydrophobic small molecule drugs IND and MTX, which were then loaded into a temperature-sensitive hydrogel matrix. The Tsol/gel of the temperature-sensitive hydrogel matrix composed of 27% F127 and 10% F68 was 33 °C and the gelation time was less than 15 s. The resultant D-NGel was injected into the articular cavity of collagen-induced arthritis rats and quickly transformed in situ into gels which slowly released drug in the joint fluid for up to 72 h. The D-NGel effectively reduced joint swelling, bone erosion and expression of inflammatory cytokines in the ankle fluid and knee joint fluid. In addition, liver and kidney function tests and histopathological examination indicated there was a good biological safety for D-NGel. In conclusion, this work has demonstrated the great potential of the D-NGel for sustained co-delivery of IND and MTX for the synergistic treatment of rheumatoid arthritis, treating both the symptoms and the root causes of rheumatoid arthritis. [ABSTRACT FROM AUTHOR]

Recently, it has become highly desirable but remains a challenge to design strain-sensing materials with rational geometric structures that endow the strain sensors with high sensitivity, large stretchability and a broad sensing range simultaneously. Herein, core–shell Cu–Ag nanowires (NWs) with tunable morphology and oxidation-resistance are achieved by an effective galvanic replacement reaction between Cu NWs and Ag(NH3)2+ without any additional heating, stirring or reducing agent. When the mass ratio of Cu NWs to AgNO3 is 8 : 6, Cu–Ag NWs exhibit the best oxidation-resistance and electrical conductivity retention in harsh environments. Nacre-mimetic conductive composites are achieved by embedding porous conductive networks composed of Cu–Ag NWs/reduced graphene oxide (rGO) in a poly(styrene-block-butadiene-block-styrene) (SBS) matrix, enabling the process to be simple, energy-saving, and scalable. They can detect both tiny and large deformations with a wide sensing range (up to 374% strain), high sensitivity (a gauge factor up to 87 362), high break elongation (up to 660% strain), and excellent reliability and stability. This successful combination of huge sensing range and high sensitivity is attributed to the high stretchability of the SBS “mortar”, the hierarchical architecture and the synergistic effects of sensitive two-dimensional (2D) rGO, and the conductive stretchable one-dimensional (1D) Cu–Ag NW “brick”. In addition, the composites can be used as patterned conductive interconnects for light-emitting diodes. [ABSTRACT FROM AUTHOR]

A flexible pressure sensor with high sensitivity has been proposed which consists of a typical sandwich structure by integrating a polydimethylsiloxane (PDMS) substrate with a micro-arrayed PDMS dielectric layer. A PDMS flexible substrate coated with silver nanowires (AgNWs) is used as a top/bottom electrode material, and a PDMS dielectric layer with micro-array structure is used to ensure high sensitivity of the pressure sensor. As a result, compared with conventional parallel board capacitive sensors, such sensors exhibit good performance, high sensitivity (2.04 kPa−1) in low pressure ranges (0–2000 Pa), low detection limits (＜7 Pa) and fast response times (＜100 ms). Furthermore, the integration of the sensor electrode and the dielectric layer ensures good bending stability and cycling stability of the sensor. Flexible capacitive pressure sensors can be used to measure the pressure distribution of finger tips when holding an object and grabbed with fingers. The spatial distribution of the applied pressure can also be clearly identified by fabricating a pressure sensor array. Due to its outstanding performance, the flexible pressure sensor shows bright application prospects in wearable sensing devices, electronic skins and humanoid robotics. [ABSTRACT FROM AUTHOR]

Fluorescence light microscopy (FLM) is commonly used for localizing specific cellular and subcellular targets. Electron microscopy (EM), on the other hand, can reveal ultrastructural details of cellular architectures beyond the limit of optical resolution. Correlative light and electron microscopy (CLEM) that combines the two techniques has proven valuable in various cell biological applications that require both specificity and resolution. Here, we report an efficient and easy-to-use CLEM system, and its applications in studying neuronal synapses. The system utilizes patterned symbols to encode coordinates on micro-fabricated polydimethylsiloxane (PDMS) substrates, on which dissociated primary hippocampal neurons grow and form synaptic connections. After imaging and localizing specifically labeled synapses with FLM, samples are embedded in resin blocks and sectioned for EM analysis. The patterned symbols on PDMS substrates provide coordinate information, allowing efficient co-registration between FLM and EM images with high precision. A custom-developed software package achieves automated EM image collection, FLM/EM alignment, and EM navigation. With this CLEM system, we have obtained high quality electron tomograms of fluorescently labeled synapses along dendrites of hippocampal neurons and analyzed docking statistics of synaptic vesicles (SVs) in different subtypes of excitatory synapses. This technique provides an efficient approach to combine functional studies with ultrastructural analysis of heterogeneous neuronal synapses, as well as other subcellular structures in general. [ABSTRACT FROM AUTHOR]

Exploring effective electrocatalysts is in urgent demand to boost their large-scale applications for direct ethanol fuel cells. Herein, for the first time, we report nanoparticle-assembled Pd nanocages with efficient catalytic activity towards ethanol electrochemical oxidation. The catalysts are prepared from the second template of a nanosheet surface of amorphous Co(OH)2 octahedral nanocages, which are prepared from the original template of octahedral Cu2O. These Pd octahedral nanocages exhibit a porous rough surface, which consists of smaller Pd nanoparticles, endowing them with highly active surface area and many active sites. For the electrochemical oxidation of ethanol, the Pd nanocages demonstrate superior activity (3765 mA mgPd−1), 4.8 times and 5.9 times those of commercial Pd/C and Pd nanocatalysts, respectively, prepared directly from an octahedral Cu2O original template. Furthermore, the Pd nanocages demonstrate excellent long-term durability. [ABSTRACT FROM AUTHOR]

Flexible and stretchable electronics, which could function properly under different deformations, have attracted extensive attention recently, due to their widespread application potential. Among them, flexible and stretchable conductors have played a significant role in bridging stretchable electronics (e.g., flexible strain sensors and stretchable energy storage devices) and measured targets (e.g., human motion detection and multifunctional output devices). Although various types of fabrication method for flexible conductors have been reported, the fabrication of stretchable conductors exhibiting stretchability, conductive stability, and durability remains a challenge. Here, we developed a flexible and stretchable three-dimensional (3D) conductor by the electroless plating technique. The prepared flexible and stretchable conductor combines two strengths including the excellent conductivity of 3D gold–nickel@graphene coated polyurethane sponge (Au–Ni@GPUS) conductive networks and the flexibility of casting encapsulated PDMS. The resistance of the conductor ranges from original 2.5 Ω to 4.0 Ω when the applied strain increased from 0% to 30% for the first stretching–releasing cycle. And after 1000 stretching–releasing cycles, the original resistance exhibited a small increase to 3.1 Ω, while the resistance under 30% applied strain was 6.0 Ω which well illustrates the conductive stability and durability. Besides, the resistance of the conductor is retained even after 1000 cycles of bending (the bending angle ranges from 0° to 180°) and twisting (the twisting angle ranges from 0° to 180°), confirming the excellent conductivity of the conductor. Additionally, the fabricated flexible and stretchable conductor has been successfully applied as a flexible interconnect of light-emitting diodes and a stretchable mobile phone charging interconnect. [ABSTRACT FROM AUTHOR]

Ge-Doped Li0.33La0.56TiO3 (Ge-LLTO) perovskites are synthesized with various GeO2 contents by solid-state reactions as Li-ion conductive electrolytes for rechargeable all-solid-state Li batteries. After the addition of GeO2, the sinterability and Li ion conductivity are enhanced for the perovskite solid electrolyte. The Li0.43La0.56Ti0.95Ge0.05O3 electrolytes exhibit the highest sinterability and Li ion conductivity among the as-prepared Li0.33+2xLa0.56Ti1−xGexO3 electrolytes. The improvement of Li ion conductivity might be attributed to the improvement of the densification and structural integrity of the LLTO solid electrolyte. The lithium transference number (tLi+) of Ge-doped LLTO is close to 1. Moreover, the Ge-LLTO electrolytes are stable in the potential range of 0–10 V vs. Li/Li+. [ABSTRACT FROM AUTHOR]

Developing highly efficient and low-cost oxygen evolution reaction (OER) electrocatalysts is highly demanded, as the OER is recognized as a key half-reaction in water splitting for producing hydrogen; however, this still remains a great challenge. Herein, we design three-dimensional (3D) tubular hierarchical core–shell electrocatalysts for the OER using a simple and highly controllable two-step method. The large-scale tubular Cu(OH)2 arrays are directly grown on Cu foam (CF) at room temperature, followed by the growth of highly porous CoNi carbonate hydroxides (CH) via a low-temperature hydrothermal method on the walls of these Cu(OH)2 nanotubes (NTs). The hollow and open-structured core–shell hierarchical Cu(OH)2@CoNiCH NTs/CF electrode with a large surface area and numerous mesoporous and short diffusion paths can provide many active sites, fast electron transport and easy accessibility of water, leading to an excellent OER activity in an alkaline electrolyte with an overpotential of 288 mV and 326 mV at a current density of 30 mA cm−2 and 100 mA cm−2, respectively, also with robust durability. This new structure would open an avenue for the advancement of highly efficient OER electrocatalysts. [ABSTRACT FROM AUTHOR]

In the development of nanotechnology, the creation of new nanomaterials consistently feeds back into efforts to design and fabricate novel macroscopic materials with specific properties. Despite recent progress in preparing numerous types of nanomaterials, it remains a prodigious challenge to assemble tiny building blocks into functional macroscale architectures suitable for practical applications. Herein, we report a facile strategy suitable for common nanomaterials, in which ice-templated assembly and liquid nitrogen-assisted rotation are coupled, for fast processing of uniform spongy millispheres with tunable microstructures. Such spheres possess a hierarchical structure with an interpenetrating, open-porous, urchin-like network and abundant external voids, which can be continuously fabricated on a large scale by employing an automatic propeller. To demonstrate the great potential of the unique three-dimensional network in the energy and environmental field, boron nitride plates and graphene based spheres are fabricated to be utilized in oil/solvent adsorption and supercapacitors, respectively. With such useful features, we believe that this strategy may serve as a valuable tool for the assembly of nanomaterials for various applications. [ABSTRACT FROM AUTHOR]