The growing interest to develop modern digital displays and colour printing has driven the advancement of colouration technologies with remarkable speed. In particular, metasurface-based structural ...colouration shows a remarkable high colour saturation, wide gamut palette, chiaroscuro presentation and polarization tunability. However, previous approaches cannot simultaneously achieve all these features. Here, we design and experimentally demonstrate a surface-relief plasmonic metasurface consisting of shallow nanoapertures that enable the independent manipulation of colour hue, saturation and brightness by individually varying the geometric dimensions and orientation of the nanoapertures. We fabricate microscale artworks using a reusable template-stripping technique that features photorealistic and stereoscopic impressions. In addition, through the meticulous arrangement of differently oriented nanoapertures, kaleidoscopic information states can be decrypted by particular combinations of incident and reflected polarized light.
Liquid‐crystal fork gratings are demonstrated through photopatterning realized on a DMD‐based microlithography system. This supplies a new strategy for generating fast switchable, reconfigurable, ...wavelength‐tolerant and polarization‐insensitive optical vortices. The technique has great potential in broad fields such as OAM‐based quantum computations, optical communications, and micromanipulation.
We review recent work done on thermosensitive core–shell particles that consist of a solid core onto which a shell of crosslinked polymer as, e.g., poly(N-isopropylacrylamide) (PNIPA) has been ...grafted. Immersed in cold water the shell of these particles having dimensions of typically 150
nm in diameter will swell. At ca. 32
°C a volume transition takes place in the PNIPA-network and the shell shrinks considerably. In this review we present a survey of recent work done with these particles. The synthesis by a two-step route as well as by photo-emulsion polymerization will be discussed. Recent progress in the characterization of the systems by cryogenic transmission electron microscopy is presented and compared to work employing scattering methods. The phase diagram of the thermosensitive network and its description in terms of the Flory-Rehner-theory is reviewed. Moreover, the internal dynamics of the network could be studied by depolarized dynamic light scattering (DDLS). Since the degree of swelling can be reversibly adjusted by temperature, the effective volume fraction in aqueous solution can be adjusted within a wide range. Thus, the particles act as inflatable spheres and have been used for an in-depth study of the rheology of concentrated suspensions. As a final point, we present an overview of the use of these particles as nanoreactors. Here metal nanoparticles and enzymes are immobilized in the shell of the particles and used for catalysis. All results obtained so far demonstrate that thermosensitive core–shell particles present a class of model colloids with excellent stability and great versatility.
The development of high-performance anode materials for next-generation lithium-ion batteries (LIBs) is vital to meeting the requirements for large-scale applications ranging from electric vehicles ...to power grids. Conversion-type transition-metal compounds are attractive anodes for next-generation LIBs because of their diverse compositions and high theoretical specific capacities. Here, we provide an overview of the recent development of some representative conversion-type anode materials (CTAMs) in LIBs. In this review, we start with an introduction to typical CTAMs and their lithium storage mechanisms. Then, we present the obstacles to their widespread implementation and the corresponding nanoengineering strategies for high-performance CTAMs, including the use of low-dimensional nanostructures, hierarchical porous nanostructures, hollow structures, and hybridization with various carbonaceous materials. Particularly, we highlight the relationship between these nanostructures and the lithium storage properties. Lastly, we present some perspectives on the current challenges and possible research directions for nanostructured CTAMs.
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Despite the successful commercialization of lithium-ion batteries (LIBs) in portable electronic devices, intensive research on high-energy density batteries is still ongoing to meet the energy demand for upcoming large-scale applications ranging from electric vehicles to power grids. Hence, high-energy density electrode materials have become the research emphasis for next-generation LIBs. Among various candidates, transition-metal compounds based on the conversion reaction mechanism have attracted great interest because of their high theoretical specific capacities. In this review, recent advances on the design and synthesis of nanostructured conversion-type anode materials (CTAMs) in LIBs are presented. The CTAMs covered in this review are transition-metal oxides, sulfides, selenides, fluorides, nitrides, and phosphides. Various advanced strategies toward high-performance CTAMs in LIBs, including structural engineering and carbon hybridization, are discussed.
Numerous strategies have been developed to improve the lithium storage properties of conversion-type anode materials (CTAMs) for lithium-ion batteries (LIBs). In this review, we highlight the recent progress in nanoengineering strategies for advanced CTAMs in LIBs. Specifically, the nanostructures obtained are summarized into four categories, including low-dimensional materials, hierarchical porous configurations, unique hollow architectures with diverse features, and hybridization of CTAMs with various carbonaceous materials. Moreover, some challenges and personal perspectives of nanostructured CTAMs are presented.
Climate change is triggering more frequent and intense hydrological disasters, which significantly impact society and economy. This paper discusses the specific impacts of these changes on ...hydrological hazards. It analyzes the early warning mechanism, risk assessment, and coping strategies to provide a scientific basis for effective response. This paper aims to explore the impact of climate change on hydrological disasters and develop effective prediction and response strategies. The effects of climate change on the mechanisms of hydrological disasters, risk assessment theory, influencing factors, and early warning mechanisms is studied through a comprehensive analysis method. According to the study, climate change significantly impacts the frequency and intensity of hydrological disasters. In a particular region, there has been a 30% increase in the frequency of floods caused by heavy rainfall over the past 20 years, leading to a 40% increase in economic losses. In addition, climate model-based risk assessment methods effectively predicted the potential impacts of these disasters. The study revealed that enhancing early warning systems and raising public awareness can reduce catastrophe risk. Climate change significantly impacts hydrological hazards, and more systematic and integrated management strategies are needed to reduce their impacts.
Ubiquitous nanoplastics (NPs) increase exposure risks to humans through the food chain and/or other ways. However, huge knowledge gaps exist regarding the fate and adverse impact of NPs on the human ...cardiovascular system. Autophagy is an important catabolic pathway that disposes of cytoplasmic waste through the lysosomes. In this study, we pursued to determine the interaction and autophagy effect of polystyrene nanoplastics (PS-NPs) (100 and 500 nm in size) on human umbilical vein endothelial cells (HUVECs). The results showed both sizes of PS-NPs interacted with almost all the treated HUVECs in a time- and concentration-dependent manner, and 500 nm PS-NPs were only bound to the surface of cell membranes, whereas 100 nm PS-NPs were taken up by HUVECs and aggregated in the cytoplasm. Furthermore, exposure to 25 μg/mL of 500 nm PS-NPs for 48 h significantly increased lactate dehydrogenase release from HUVECs, while internalized 100 nm PS-NPs not only caused cell membrane damage, but also induced autophagy initiation and autophagosome formation. By a mCherry-GFP-LC3 lentivirus infection assay, we also demonstrated that autophagic flux level was impaired in response to 100 nm PS-NPs. Herein, our results provide new insight into the size-dependent internalization and autophagy response to PS-NPs in HUVECs.
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•PS-NPs (100 nm and 500 nm in size) can interact with HUVECs efficiently.•500 nm PS-NPs bound to the surface of cell membranes causing cell membrane damage.•100 nm PS-NPs aggregate in the cytoplasm and block the autophagic flux in HUVECs.
Carbon-based materials, as one of the most important electrode materials for supercapacitors, have attracted tremendous attention. At present, it is highly desirable but remains challenging to ...prepare one-dimensional carbon complex hollow nanomaterials for further improving the performance of supercapacitors. Herein, we report an effective strategy for the synthesis of hollow particle-based nitrogen-doped carbon nanofibers (HPCNFs-N). By embedding ultrafine zeolitic imidazolate framework (ZIF-8) nanoparticles into electrospun polyacrylonitrile (PAN), the as-prepared composite nanofibers are carbonized into hierarchical porous nanofibers composed of interconnected nitrogen-doped carbon hollow nanoparticles. Owing to its unique structural feature and the desirable chemical composition, the derived HPCNFs-N material exhibits much enhanced electrochemical properties as an electrode material for supercapacitors with remarkable specific capacitance at various current densities, high energy/power density and long cycling stability over 10 000 cycles.
Active planar optical devices that can dynamically manipulate light are highly sought after in modern optics and nanophotonics. The geometric phase derived from the photonic spin-orbit interaction ...provides an integrated strategy. Corresponding elements usually suffer from static functions. Here, we introduce an inhomogeneously self-organized anisotropic medium featured by photo-invertible chiral superstructure to realize geometric phase elements with continuously tunable working spectrum and light-flipped phase profile. Via preprograming the alignment of a cholesteric liquid crystal mixed with a photo-responsive chiral dopant, we demonstrate light-activated deflector, lens, Airy beam and optical vortex generators. Their polychromatic working bands are reversibly tuned in an ultra-broadband over 1000 nm covering green to telecomm region. The chirality inversion triggers facile switching of functionalities, such as beam steering, focusing/defocusing and spin-to-orbital angular momentum conversion. This work offers a platform for advanced adaptive and multifunctional flat optics with merits of high compactness, low loss and broad bandwidth.
In recent years, the integration of graphene and related two-dimensional (2D) materials in optical fibers have stimulated significant advances in all-fiber photonics and optoelectronics. The ...conventional passive silica fiber devices with 2D materials are empowered for enhancing light-matter interactions and are applied for manipulating light beams in respect of their polarization, phase, intensity and frequency, and even realizing the active photo-electric conversion and electro-optic modulation, which paves a new route to the integrated multifunctional all-fiber optoelectronic system. This article reviews the fast-progress field of hybrid 2D-materials-optical-fiber for the opto-electro-mechanical devices. The challenges and opportunities in this field for future development are discussed.
Cholesteric liquid crystal (CLC) chiral superstructures exhibit unique features; that is, polychromatic and spin‐determined phase modulation. Here, a concept for digitalized chiral superstructures is ...proposed, which further enables the arbitrary manipulation of reflective geometric phase and may significantly upgrade existing optical apparatus. By encoding a specifically designed binary pattern, an innovative CLC optical vortex (OV) processor is demonstrated. Up to 25 different OVs are extracted with equal efficiency over a wavelength range of 116 nm. The multiplexed OVs can be detected simultaneously without mode crosstalk or distortion, permitting a polychromatic, large‐capacity, and in situ method for parallel OV processing. Such complex but easily fabricated self‐assembled chiral superstructures exhibit versatile functionalities, and provide a satisfactory platform for OV manipulation and other cutting‐edge territories. This work is a vital step towards extending the fundamental understanding and fantastic applications of ordered soft matter.
Digitalized chiral superstructures enable the generation, detection, and demultiplexing of optical vortices in a polychromatic, large‐capacity, and in situ way. Such complex but easily fabricated self‐assembled cholesteric liquid‐crystal superstructures provide a versatile platform for various cutting‐edge territories. This work brings new insights to both fundamental understanding and innovative applications of ordered soft matter.
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