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Designed peptide conjugates molecules are used to direct the synthesis and assembly of gold nanoparticles into complex 1D nanoparticle superstructures with various morphologies. Four peptide conjugates, each based on the gold-binding peptide (AYSSGAPPMPPF; PEPAu), are prepared: C12H23O-AYSSGAPPMPP ( 1), C12H23O-AYSSGAPPMPPF ( 2), C12H23O-AYSSGAPPMPPFF ( 3), and C12H23O-AYSSGAPPMPPFFF ( 4). The affect that C-terminal hydrophobic F residues have on both the soft-assembly of the peptide conjugates and the resulting assembly of gold nanoparticle superstructures is examined. It is shown that the addition of two C-terminal F residues ( 3) leads to thick, branched 1D gold nanoparticle superstructures, whereas the addition of three C-terminal F residues ( 4) leads to bundling of thin 1D nanoparticle superstructures. [ABSTRACT FROM AUTHOR]

Control of convection plays an important role in heat transfer regulation, bio/chemical sensing, phase separation, etc. Current convection controlling systems generally depend on engineered energy sources to drive and manipulate the convection, which brings additional energy consumption into the system. Here the use of human hand as a natural and sustainable infrared (IR) radiation source for the manipulation of liquid convection is demonstrated. The fluid can sense the change of the relative position or the shape of the hand with the formation of different convection patterns. Besides the generation of static complex patterns, dynamic manipulation of convections can also be realized via moving of hand or finger. The use of such sustainable convections to control the movement of a floating "boat" is further achieved. The use of human hands as the natural energy sources provides a promising approach for the manipulation of liquid convection without the need of extra external energy, which may be further utilized for low‐cost and intelligent bio/chemical sensing and separation. [ABSTRACT FROM AUTHOR]

Color change to match background has attracted particular attentions for many civil and military applications. Different from most current efforts in adaptive color change that include active color processing and generation, in this work a new passive color‐change approach without the need of color processing and generation is proposed. Such approach takes inspiration from the biological camouflage systems such as those in the midwater squid Galiteuthis, which use "leaky" fiber‐like cells to guide lights around their eyes for effective camouflage from their upward‐looking predators. In the approach, the bioinspired color‐change system directly takes the reflected light from the background, guides and displays it around the surface of the target. This bioinspired color‐change approach is dependent on a waveguide‐based system that includes light receiving, transporting, and display modules. Through the improvement of the efficiency in light collection, guiding, and display, both the experimental studies and computational modeling demonstrate the performance of such approach in the entire visible region with both spectra matching and rapid dynamic response. Through the design of pixelated modules, this new approach also shows good color matching with patterned color background and provides a feasible route to camouflage in a complex natural background. Inspired by the biological camouflage systems in the midwater squid Galiteuthis, a new color‐change approach using guided reflection is proposed and demonstrated. By directly coupling the background reflection and displaying the reflected light on the surfaces of target, the bioinspired color‐change approach achieves both the faithful spectra matching with background and rapid dynamic response in the entire visible region. [ABSTRACT FROM AUTHOR]

Rapid progresses concerning wearable electronics call for stretchable batteries. Owing to the merits of high energy density and wide operating voltage range, organic electrolyte‐based lithium‐ion batteries (LIBs) take a large proportion in the powering markets. Due to the high sensitivity to moisture and oxygen, it is difficult to obtain long‐term reliable stretchable organic electrolyte‐based LIBs when they are directly exposed to the air. Benefiting from the outstanding gas impermeability of liquid metal (LM) and relatively good barrier properties for reactive acid gas molecules by polyisobutylene (PIB), an LM‐PIB seal is demonstrated for organic electrolyte‐based LIBs. In the seal, LM can prevent the inward permeation of oxygen and water vapor, and PIB can block the outward permeation of hydrolysis acid generated from the side reactions during the operation of the organic electrolyte‐based LIBs, which helps prevent the detrimental interaction between the hydrolysis acid and LM. A specific capacity of over 120 mAh g−1 is achieved and the battery shows consistent electrochemical performances under multiple deformations. This study offers a different design approach for long‐term operation of stretchable organic electrolyte‐based LIBs. [ABSTRACT FROM AUTHOR]

With the refinement and miniaturization of integrated electronic devices, the requirements for stable operating temperature and antielectromagnetic interference are increasingly high. However, most of the current materials necessitate to develop the intelligent self‐adaptive regulation in response to external field stimuli to gratify the stipulations of different operating environments. Herein, cuttlefish‐inspired smart liquid metal based‐liquid crystal elastomer (LGN‐LCE) dual‐functional material enabling self‐adaptive electromagnetic wave interference shielding and thermal management is presented. Liquid crystal elastomer matrix endows the LGN‐LCE dynamic self‐morphing properties under thermal activation, which leads to the liquid metal network with tunable thermal/electrical conduction. The thermal conductivity of LGN‐LCE can be increased to 10.3 W m−1 K−1 with the rise of surrounding temperature, while the electrical conductivity of LGN‐LCE can be enhanced to 4.3 × 105 S m−1. Such promoted electrical conductivity helps strengthen electromagnetic interference (EMI) shielding performance of LGN‐LCE, and the minimum EMI shielding effectiveness of LGN‐LCE can be improved from 48 to 62 dB within the X‐band. This work may not only pave a new way to rationally design a self‐adaptive EMI shielding and thermal management systems, but also show good prospects for practical applications, including thermal management materials, EMI materials, flexible electronic materials, smart materials, artificial intelligence systems, biomedical, and aerospace applications. [ABSTRACT FROM AUTHOR]

This paper reports the generation of 3D thermal and electrical conductive graphene network in gallium‐based liquid metal (LM) via a simple one‐step ball‐milling approach. In this work, 2D graphene nanoplates and their derivatives were employed to construct 3D thermal and electrical conductive filler networks. It is demonstrated that the obtained composite exhibits the highest 3D thermal conductivity (44.6 W m−1 K−1) among the other gallium‐based LM composites with 2D inorganic nanofillers and distinguished electrical conductivity (8.3 S µm−1) among gallium‐based LM composites at present. The enhanced thermal conductivity and wettability of gallium‐based composite lead to its beneficial usage as thermal interface materials with exquisite texture for LED chip heat dissipation. The electrochemical and magnetic experiments confirm that these LM‐based composites can also be controlled under external electrical or magnetic field, which potentially can help extend their application in external field‐driven systems. The findings of this work offer new insight in designing LM‐based composites with enhanced thermal, electrical, and magnetic properties for a wide range of applications, including thermal management systems, 3D printing, flexible conductors, soft robotic systems, and wearable energy technologies. [ABSTRACT FROM AUTHOR]

This paper introduces an alternative approach for the synthesis of site‐specific gold‐zinc oxide (Au‐ZnO) nanorod array through the pyroelectric approach. The hydrothermally grown ZnO nanorod array on the Si substrate is served as the pyroelectric catalyst. Under rapid temperature oscillation, the gold salt precursor is reduced into gold nanoparticles around the tip of ZnO nanorods in aqueous solution. The hybrid structure shows a significant photoluminescence quenching in the visible emission spectrum of ZnO, which is due to the interaction of ZnO and gold nanoparticles. A Rhodamine B (RhB) degradation test under full spectrum sunlight illumination is conducted to demonstrate the photocatalytic performance of the Au‐ZnO nanorod array. The mechanism behind the hydrothermal growth of ZnO, pyroelectric reduction of gold nanoparticles, and photoluminescence quenching of Au‐ZnO is discussed. The findings of this work offer possible ways to the sustainable use of thermal energy, including harvesting waste heat through pyroelectric effect, and the site‐specific synthesis of various nanomaterials with enhanced photocatalytic degradation capability. [ABSTRACT FROM AUTHOR]

Hopper shape is a special type of crystal morphology. Hopper‐shaped crystals possess unique properties and show promise in many different applications. The understanding of how the building blocks (atoms, ions, and molecules) assemble into hopper‐shaped crystals and how the environmental factors influence the assembly process is critical to the properties and applications of hopper‐shaped crystals. In this review, the important interfacial instability theories that outline the underlying mechanisms for the formation of hopper‐shaped crystals are discussed. Next, the relevant experimental developments based on three categories of synthetic approaches are discussed: the growth through the control of the solute concentration, the temperature gradient, and the capping agent. At the end of the review, the applications, opportunities, and potential challenges of the hopper‐shaped crystals are discussed. [ABSTRACT FROM AUTHOR]

Human skin shows self‐adaptive temperature regulation through both enhanced heat dissipation in high temperature environments and depressed heat dissipation in cold environments. Inspired by such thermal regulation processes, an interfacial material system with self‐adaptive temperature regulation in the solar‐driven interfacial evaporation system, which can exhibit automatic temperature oscillation to enable pyroelectricity generation while producing water vapor, is reported. The bioinspired interface system is designed with the combination of a thermochromism‐based temperature regulator consisting of tungsten‐doped vanadium dioxide nanoparticles and a polymeric pyroelectric thin film of polyvinylidene fluoride. Under the simulated solar illumination with power density of 1.1 kW m−2, the bioinspired interfacial evaporation system achieves a self‐adaptive temperature oscillation with the maximum temperature difference of ≈7 °C and this system can simultaneously generate water vapor as well as electricity with an evaporation efficiency of 71.43% and a maximum output electrical power density of 104 µW m−2, respectively. The study demonstrates a design of thermal management at the interface of solar‐driven evaporation system to exhibit a self‐adaptive temperature oscillation and offers an alternative approach for the multifunctional harvesting of solar energy. [ABSTRACT FROM AUTHOR]

This work explores an alternative infrared (IR) detection mechanism that is based on the desorption of vapor molecules from the Morpho butterfly nanostructures under the stimulation of incoming IR photons, and demonstrates the use of such stimulated desorption for both broadband and wavelength selective IR detection. Compared to the structural deformation‐based IR detection using the Morpho nanostructures, this detection mechanism enables more than an order of magnitude of improvement in both the response of relative reflectance and also the signal‐to‐noise ratio at the maximum heat‐sink‐free response speed. The stimulated desorption also provides the opportunity to achieve the wavelength selective IR detection due to the wavelength selective IR absorption of the adsorbed molecules. With the demonstrated high performance in both broadband and wavelength selective IR detection, this detection approach can potentially enable other high performance sensing systems, including chemical vapor, biological, energy, and environmental sensing systems. [ABSTRACT FROM AUTHOR]

Hybrid faceted‐Ag3PO4/cube‐Cu2O composite materials have been fabricated and employed as oxygen reduction electrocatalysts for proton exchange membrane fuel cells (PEMFCs). The charge separation effect via the formation of PN junction has been demonstrated to boost the electrocatalysis toward oxygen reduction reaction. The as‐prepared rhombic dodecahedron‐Ag3PO4/cube‐Cu2O/C hybrid catalyst shows a mass‐specific activity of 109.80 mA/mgAg, which is about 6.4 times that of pure rhombic dodecahedron‐Ag3PO4/C catalyst (17.20 mA/mgAg). The density functional theory (DFT) calculation based on the density of states (DOS) further proved the optimal tunable effect, which is in pace with demonstration of electron transfer direction revealed by X‐ray photoelectron spectroscopy (XPS) analysis. Our work establishes a theoretical and practical basis for the rational design of newly non‐Pt hybrid catalysts, moreover, advances the future efficient application of PEMFCs. [ABSTRACT FROM AUTHOR]

Hopper-Shaped Crystals: Self-Assembly in Hopper-Shaped Crystals (Adv. Funct. Keywords: hopper-shaped crystals; interfacial instability; nanocrystals; self-assembly EN hopper-shaped crystals interfacial instability nanocrystals self-assembly 1 1 1 06/27/20 20200625 NES 200625 In article number 1908108, Wen Shang, Tao Deng, and co-workers show that the building blocks of crystals tend to attach at certain sites on the crystal surfaces, and the growth rates of these sites will be larger than those at the other sites. Hopper-shaped crystals, interfacial instability, nanocrystals, self-assembly. [Extracted from the article]

Platinum‐based catalysts are critical to several chemical processes, but their efficiency is not satisfying enough in some cases, because only the surface active‐site atoms participate in the reaction. Henceforth, catalysts with single‐atom dispersions are highly desirable to maximize their mass efficiency, but fabricating these structures using a controllable method is still challenging. Most previous studies have focused on crystalline materials. However, amorphous materials may have enhanced performance due to their distorted and isotropic nature with numerous defects. Here reported is the facile synthesis of an atomically dispersed catalyst that consists of single Pt atoms and amorphous Fe2O3 nanosheets. Rational control can regulate the morphology from single atom clusters to sub‐nanoparticles. Density functional theory calculations show the synergistic effect resulted from the strong binding and stabilization of single Pt atoms with the strong metal‐support interaction between the in situ locally anchored Pt atoms and Fe2O3 lead to a weak CO adsorption. Moreover, the distorted amorphous Fe2O3 with O vacancies is beneficial for the activation of O2, which further facilitates CO oxidation on nearby Pt sites or interface sites between Pt and Fe2O3, resulting in the extremely high performance for CO oxidation of the atomic catalyst. [ABSTRACT FROM AUTHOR]