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A hydrogel strain sensor can successfully transform its deformation into resistance changes, offering novel options for the Internet of Things (IoT) and artificial intelligence (AI). However, it remains challenging to prepare hydrogel sensors with superior performance (e.g., high conductivity). Here, we produced a conductive hydrogel (named PPC hydrogel) utilizing only three components, PVA (poly(vinyl alcohol)), PAAS (polyacrylate sodium), and CaCl

Photothermal deicing is a noncontact, economically, efficient, and environmentally friendly melting/preventing ice method. Obtaining a cheap, easily fabricated material with high photothermal conversion and deicing efficiency is a challenge. Here, carbon-based photothermal superhydrophobic materials with thermal insulation micropores were prepared by using the salt-template. We demonstrate that the microholes array structure can enhance light absorption and hydrophobicity of the material, and the micropores structure can inhibit the heat transfer from the surface to the subcooled substrate, which synergistically greatly enhances the photothermal conversion. A heat transfer model was established to clarify the influence mechanisms of air cushion on interfacial heat transfer during the photothermal anti-icing and deicing process. The self-cleaning, flexibility, mechanical, and chemical stability tests show that the material has the potential for outdoor application. The prepared materials with high photothermal deicing efficiency provide a new way for the anti-icing and deicing of outdoor equipment.

The presence of room temperature phosphorescence emission in metalloporphyrin, via the transition from the excited triplet state (T

The refractive index (RI) is a fundamental physical property of materials. Although measurement of the RI of biological nanoparticles (BNPs) in aqueous media is of great importance to basic research and biomedical applications, it is hampered by their tiny size, large intrinsic heterogeneity, and weak scattering. Here, we report the development of a label-free technique that can determine the RI of individual viruses and small extracellular vesicles (sEVs) with high precision and an analysis rate up to 10 000 particles per minute. This was achieved via the combination of high-sensitivity light-scattering detection by nanoflow cytometry (nFCM) and the Mie theory calculation. With the measured RIs for T7 virions, T7 capsids, and sEVs, the concentrations of nucleic acid in viral particles and protein in the lumen of sEVs were estimated. Furthermore, building upon a simplified core-shell model, the RIs of sEVs ranging from 40 to 200 nm were obtained. By using these RIs, a statistically robust size distribution of sEVs was acquired in minutes with accuracy and resolution matched closely with those of cryo-TEM measurements. Our approach could become an important tool in the RI determination of single BNPs.

Considering disadvantages such as the low thermal stability and environmental pollution of existing gel inhibitors, a green and stable intumescent nanoinhibitor (INI) was prepared and tested. First, polyacrylamide (PAM), nano-silica, and intumescent flame retardant (IFR) were selected as raw materials. The INI was prepared by nanoparticle modification and cross-linking polymerization. Then, the structure and physical properties of INI were tested by Fourier transform infrared spectroscopy, scanning electron microscopy, and rheological experiments. Meanwhile, the inhibition performance of INI was studied through thermogravimetric analysis-Fourier transfer infrared spectroscopy (TGA-FTIR) analysis. The results suggest that the nanomodification improved the dispersibility of INI particles. The addition of modified nano-silica (MNS) and IFR enhances the strength of the reticular structure, thereby improving the transport convenience and covering ability of the INI gel. At high temperatures, IFR can generate a porous foamed carbon layer that further coats the coal. After INI inhibition treatment, the characteristic temperature and activation energy of coal were significantly improved, and the production of carbon monoxide and carbon dioxide decreased. Hence, irrespective of physical properties, physical inhibition performance, or chemical inhibition performance, INI performed well. Research results can provide valuable references for the preparation and performance study of a coal spontaneous combustion inhibitor.

The development of high quality magnetic self-healing hydrogels containing well-dispersed magnetic nanoparticle has been a challenging procedure due to unavailable methods of facilely introducing groups that can efficiently stabilize these magnetic nanoparticles in the self-healing hydrogels. In this research, a polymer containing both phenylboronic acid (PBA) and phosphonic acid (PA) groups has been developed by the Kabachnik-Fields (KF) reaction. This polymer well disperses iron oxide nanoparticles (IONPs) through the strong interactions between the PA groups and the surface of the IONPs; thus, this polymer effectively mixed IONPs and poly(vinyl alcohol) (PVA) to form a hydrogel containing well-dispersed IONPs. The resulting hydrogel is self-healing, owing to the dynamic borate ester linkages. Moreover, the presence of the IONPs endowed the hydrogel with magnetic properties, also making it heat-responsive in an alternating magnetic field and expanding its application as a contrast agent for magnetic resonance imaging. The magnetic self-healing hydrogel showed excellent biosafety properties in animal experiments, suggesting its potential as an injectable implant material for biological and medical applications. This research exploits a biocompatible magnetic self-healing hydrogel with well-dispersed IONPs, demonstrating the value of the KF reaction in the development of functional polymers and smart materials, which might prompt a broad study of multicomponent reactions in interdisciplinary fields.

High permittivity materials for a gigahertz (GHz) communication technology have been actively sought for some time. Unfortunately, in most materials, the dielectric constant starts to drop as frequencies increase through the megahertz (MHz) range. In this work, we report a large dielectric constant of ∼800 observed in defect-mediated rutile SnO2 ceramics, which is nearly frequency and temperature independent over the frequency range of 1 mHz to 35 GHz and temperature range of 50-450 K. Experimental and theoretical investigations demonstrate that the origin of the high dielectric constant can be attributed to the formation of locally well-defined Zn2+-Nb4+ defect clusters, which create hole-pinned defect dipoles. We believe that this work provides a promising strategy to advance dipole polarization theory and opens up a direction for the design and development of high frequency, broadband dielectric materials for use in future communication technology.

Here, we report (C4H9)4NCuCl2 single crystals with a luminous intensity that remains largely the same after soaking in water for 24 h. (CH9)4NCuCl2 has a new type zero-dimensional framework, in which the isolated [CuCl2]- anions are wrapped by organic (C4H9)4N+ cations. As expected, (C4H9)4NCuCl2 shows a broad emission band at 508 nm with a photoluminescence quantum yield of approximately 82% at room temperature, stemming from self-trapped exciton (STE) emission. Temperature-dependent photoluminescence measurement reveals that there is an energy barrier ΔE (24.0 meV) between the intrinsic state and STE state, which leads to the increase in emission intensity with an increase in temperature (98-278 K), while the emission intensity begins to decrease when the temperature is higher than 278 K due to the effects of both thermal quenching and carrier scattering. Our findings provide a new idea for the design of lead-free anti-water stability metal halide materials.

Chalcopyrite (CuFeS2), a natural copper–iron bimetallic sulfide, has shown great promise as an active material for lithium-ion batteries because of its superior electrochemical performance, high ab...

Through specific structural modification of a 4-phenylindoline precursor, new 4-arylindolines containing a thiazole moiety were developed and found to be promising modulators of the programmed cell death-1 (PD-1)/programmed cell death-ligand 1 (PD-L1) axis. Compound A30 exhibited outstanding biochemical activity, with an IC50 of 11.2 nM in a homogeneous time-resolved fluorescence assay. In the cell-based assay, A30 significantly promoted IFN-γ secretion and rescued T-cell proliferation, which were inhibited by PD-1 activation. Furthermore, A30 showed favorable in vivo antitumor activity in a mouse 4T1 breast carcinoma model. Moreover, in mouse CT26 colon carcinoma models, A30 potently suppressed the growth of CT26/PD-L1 tumor but did not obviously affect the growth of CT26/vector tumor. The results of flow cytometry analysis indicated that A30 inhibited tumor growth by activating the immune microenvironment. We concluded that A30 is a new starting point for further development of PD-1/PD-L1 interaction inhibitors as antitumor agents.

Herein, Cu-modified SAPO-34 catalysts with various copper loadings are synthesized via a pH-controlled ion-exchange method. Cu exists predominantly as isolated cations at lower loadings, located at octahedrally coordinated sites in the ellipsoidal cavity of SAPO-34 zeolites, while CuO is gradually generated on the external surface at higher loadings. Our results reveal that the isolated Cu cations are the active sites for C₃H₆-SCR. The presence of CuO species enhances the C₃H₆ activation ability of the catalysts, which thus, improves the C₃H₆-SCR performance at medium and low temperatures (below 400 °C). At high temperatures, however, the formation of CuO accelerates the nonselective oxidation of C₃H₆ and causes activity decline. These findings suggest that the active temperature window for hydrocarbons-selective catalytic reduction (HC-SCR) reactions over Cu/SAPO-34 catalysts can be tailored by tuning the proportion of various copper species to fit the need in real applications, which provide new insights into understanding and designing highly efficient Cu-based zeolite catalysts.

The crystallization methodology of DNA origami frames has found salient utility in large-scalely integrating multifarious functional components following organized arrangements, thus opening up the possibilities for optical, biological, and other interdisciplinary applications. However, the single strand-dominated spacing region between adjacent DNA origami units has extremely restricted the adjustment of DNA origami separations, leading the soft crystals susceptible to environmental influences. Herein, we developed a cocrystallization pathway by incorporating rigid DNA rods into a DNA origami assembly system to achieve mutually ordered bridging on a three-dimensional scale. The intervention of DNA rods significantly improved the rigidity and crushing resistance of entire cocrystals and rendered DNA origami units exhibiting different spacing distances within the obtained crystal phase when varying DNA rod structures artificially. Such a tuning strategy that uses DNA rods as allosteric factors would provide a rational method for accessing diverse crystalline states and even modulating the tailorable properties of materials on demand.

The self-assembly of block copolymers in a confined space has been proven to be a facile and robust strategy for fabricating assembled structures with various potential applications. Herein, we employed a new pH-responsive polymer self-assembly method to regulate ion transport inside artificial nanochannels. The track-etched asymmetric nanochannels were functionalized with PS22k-b-P4VP17k/hPS4k blend polymers, and the ionic conductance and rectification properties of the proposed system were investigated. The pH-actuated changes in the surface charge and wettability resulted in the selective pH-gated ionic transport behavior. The designed system showed a good switching property to the pH stimulus and could recover during the repetitive experiments. The gating ability of the polymer-nanochannel system increased with increasing the weight of the homopolymer, and the proposed platform demonstrated robust stability and reusability. Numerical and the dissipative particle dynamics simulations were implemented to emulate the pH-dependent self-assembling behavior of diblock copolymers in a confined space, which were consistent with the experimental observations. As an example of the self-assembly of polymers in nanoconfinements, this work provides a facile and robust strategy for the regulation of ion transport in synthetic nanochannels. Meanwhile, this work can be further extended to design artificial smart nanogates for various applications such as mass delivery and energy harvesting.

Dispersions of magnetic nanoparticles (MNPs) can exhibit paramagnetic ferrofluid or ferromagnetic liquid behavior. By modifying the surface functionality of MNPs, ferrofluids have been used to fabricate novel magnetically actuated devices. If the surface-functionalized MNPs interact with complementary ligands at a fluid-fluid interface, MNP surfactants form and in situ assemble at the interface. When jammed interfacially, MNP surfactants give rise to ferromagnetic behavior of the liquid (droplet), which is endowed with permanent magnetic dipoles while maintaining all of the characteristics of a fluid system. Here, we give a brief overview of the developments in the dispersion of MNPs in liquids from ferrofluids to ferromagnetic liquid droplets, their responses to external fields, and the manipulation of these responses for end uses. The reversible room-temperature para-to-ferro transformation of magnetic liquids is highlighted. We discuss challenges in the synthesis and characterization of these unusual liquids along with potential technological applications.

Zero-dimensional lead-free organic-inorganic hybrid metal halides have drawn attention as a result of their local metal ion confinement structure and photoelectric properties. Herein, a lead-free compound of (Gua)3Cu2I5 (Gua = guanidine) with a different metal ion confinement has been discovered, which possesses a unique [Cu2I5]3- face-sharing tetrahedral dimer structure. First-principles calculation demonstrates the inherent nature of a direct band gap for (Gua)3Cu2I5, and its band gap of ∼2.98 eV was determined by experiments. Worthy of note is that (Gua)3Cu2I5 exhibits a highly efficient cool-white emission peaking at 481 nm, a full-width at half-maximum of 125 nm, a large Stokes shift, and a photoluminescence quantum efficiency of 96%, originating from self-trapped exciton emission. More importantly, (Gua)3Cu2I5 single crystals have a reversible thermoinduced luminescence characteristic due to a structural transition scaled by the electron-phonon coupling coefficients, which can be converted back and forth between cool-white and yellow color emission by heating or cooling treatment within a short time. In brief, as-synthesized (Gua)3Cu2I5 shows great potential for application both in single-component white solid-state lighting and sensitive temperature scaling.

Cobalt sulfide is favorable for supercapacitors, but its application is inhibited by the inherent slow charge transfer kinetics and poor stability in alkaline solution. Herein, zeolitic imidazole f...

Exploring a convenient method to solve the stability problem of all-inorganic halide perovskite nanocrystals (NCs) has become an urgent task in their practical application. In recent years, cesium ...