Metal nanoclusters (NCs) as a new class of phosphors have attracted a great deal of interest owing to their unique electronic structure and subsequently molecule-like optical properties. However, limited successes have been achieved in producing the NCs with excellent luminescent performance. In this paper, we demonstrate the significant luminescence intensity enhancement of 1-dodecanethiol (DT)-capped Cu NCs via self-assembly strategy. By forming compact and ordered assemblies, the original nonluminescent Cu NCs exhibit strong emission. The flexibility of self-assembly allows to further control the polymorphism of Cu NCs assemblies, and hence the emission properties. Comparative structural and optical analysis of the polymorphic NCs assemblies permits to establish a relationship between the compactness of assemblies and the emission. First, high compactness reinforces the cuprophilic Cu(I)···Cu(I) interaction of inter- and intra-NCs, and meanwhile, suppresses intramolecular vibration and rotation of the capping ligand of DT, thus enhancing the emission intensity of Cu NCs. Second, as to the emission energy that depends on the distance of Cu(I)···Cu(I), the improved compactness increases average Cu(I)···Cu(I) distance by inducing additional inter-NCs cuprophilic interaction, and therewith leads to the blue shift of NCs emission. Attributing to the assembly mediated structural polymorphism, the NCs assemblies exhibit distinct mechanochromic and thermochromic luminescent properties. Metal NCs-based white light-emitting diodes are further fabricated by employing the NCs assemblies with blue-green, yellow, and red emissions as phosphors.

Fluorescent CdTe nanocrystal–polymer transparent composites have been fabricated by a combination of aqueous synthesis of nanocrystals, styrene extraction using polymerizable surfactants, and radical polymerization of monomer mixture containing composite nanocrystals. The Figure shows the photoluminescence of transparent CdTe–polymer composites excited by an ultraviolet lamp.

The rapid development of modern industry and excessive consumption of petroleum‐based polymers have triggered a double crisis presenting a shortage of nonrenewable resources and environmental pollution. However, this has provided an opportunity to stimulate researchers to harness native biobased materials for novel advanced materials and applications. Nanocellulose‐based aerogels, using abundant and sustainable cellulose as raw material, present a third‐generation of aerogels that combine traditional aerogels with high porosity and large specific surface area, as well as the excellent properties of cellulose itself. Currently, nanocellulose aerogels provide a highly attention‐catching platform for a wide range of functional applications in various fields, e.g., adsorption, separation, energy storage, thermal insulation, electromagnetic interference shielding, and biomedical applications. Here, the preparation methods, modification strategies, composite fabrications, and further applications of nanocellulose aerogels are summarized, with additional discussions regarding the prospects and potential challenges in future development.

Polymer-based membranes play a key role in several industrially important gas separation technologies, e.g., removing CO 2 from natural gas, with enormous economic and environmental impact. Here, we develop a novel hybrid membrane construct comprised entirely of nanoparticles grafted with polymers. These membranes are shown to have broadly tunable separation performance through variations in graft density and chain length. Computer simulations show that the optimal NP packing forces the grafted polymer layer to distort, yielding regions of measurably lower polymer density. Multiple experimental probes confirm that these materials have the predicted increase in "polymer free volume", which explains their improved separation performance. These polymer-grafted NP materials thus represent a new template for rationally designing membranes with desirable separation abilities coupled with improved aging characteristics in the glassy state and enhanced mechanical behavior.

Increasing demand on portable and flexible electronic devices has urged on the rapid development of new electrode materials that not only possess excellent electrochemical properties but hold capabilities to be...

Liquid–solid transition is a widely used strategy to shape polymeric materials and encode their microstructures. However, it is still challenging to fully exploit liquid behaviors of material precursors. In particular, the dynamic and static liquid behaviors naturally conflict with each other, which makes it difficult to integrate their advantages in the same materials. Here, by utilizing a shear-thinning phenomenon in the dynamic hybrid hydrogels, we achieve a hydrodynamic alignment of cellulose nanocrystals (CNC) and preserve it in the relaxed hydrogel networks due to the much faster relaxation of polymer networks (within 500 s) than CNC after the unloading of external force. During the following drying process, the surface tension of hydrogels further enhances the orientation index of CNC up to 0.872 in confined geometry, and these anisotropic microstructures demonstrate highly tunable birefringence (up to 0.004 14). Due to the presence of the boundaries of dynamic hydrogels, diverse xerogels including fibers, films, and even complex three-dimensional structures with variable anisotropic microstructures can be fabricated without any external molds.

As we know, human skin is natural barrier for human being to protect the body from external substance invasion, and also biological multifunctional sensors perceiving pressure, temperature, proximity, pain, smell, friction, texture of objects, etc. [4,12,13] Admittedly, human skin also has its intrinsic drawbacks like inaccurate and indirect discernment of relative humidity which needs to be perceived by the cooperation of mechanoreceptor and thermoreceptor. [14,15] Thus, e-skin should be not only limited to imitating the structure and multifunctional sensing capabilities of human skin, but also be able to develop more excellent traits beyond the human skin. [14,16] Considering the exploitation and employment of numerous materials, versatile structures and the integration of various mechanisms and manufacturing methods, the real future e-skins would surpass human skin in most aspects and show new characteristics such as transduction of other stimuli like light, sound, and even magnetism. [17][18][19] The delicate design and integration of multifunctional flexible sensors may overcome the current shortcomings and offer new insight into the forthcoming era of omnipotent stretchable and bendable electronics.Basically, flexibility is a trait for contours with zero-Gaussian curvature, while stretchability is necessary for conformal and entire covering surfaces with non-zero Gaussian curvature when the flexible sensors are attached to irregular 3-dimensionally curvilinear human skin. [20] Thus, stretchable sensors are supposed to be flexible. In the beginning of flexible sensors, most of the elemental sensing parts were created by combining inherently inorganic and rigid active materials (e.g., Si and Au) with soft substrates via special shape designs which are partly flexible to some extent. [20][21][22][23] Nonetheless, it is far from perfect for practical use if attaching these electronic devices on arbitrarily curved human skin and robot surfaces. Actually, commercial wearables are supposed to gradually take the sense of human scale and aesthetic into consideration, i.e., they are expected to be mechanically conformal, user-comfortable, environment-friendly, biocompatible, transparent, etc. [24,25] Consequently, all-flexible/stretchable sensors mainly consisting of organic active materials and/or metal nanowires are springing up. [26] Among various signals existing in nature, forces, temperature, and humidity play essential and vital roles in our normal Multiresponsive flexile sensors with strain, temperature, humidity, and other sensing abilities serving as real electronic skin (e-skin) have manifested great application potential in flexible electronics, artificial intelligence (AI), and Internet of Things (IoT). Although numerous flexible sensors with sole sensing function have already been reported since the concept of e-skin, that mimics the sensing features of human skin, was proposed about a decade ago, the ones with more sensing capacities as new emergences are urgently demanded. However, highly integrated a...

A bowknot-like Co3O4 material has been synthesized via a gelatin-assisted hydrothermal method, which exhibits superior cyclic stability and improved rate capability.