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Based on the deforming technique of severe plastic deformation (SPD), the grain refinement of a Mg-9Gd-3Y-2Zn-0.5Zr alloy treated with decreasing temperature reciprocating upsetting-extrusion (RUE) and its influence on the mechanical properties and wear behavior of the alloy were studied. The RUE process was carried out for 4 passes in total, starting at 0 °C and decreasing by 10 °C for each pass. The results showed that as the number of RUE passes increased, the grain refinement effect was obvious, and the second phase in the alloy was evenly distributed. Room temperature tensile properties of the alloy and the deepening of the RUE degree showed a positive correlation trend, which was due to the grain refinement, uniform distribution of the second phase and texture weakening. And the microhardness of the alloy showed that the microhardness of RUE is the largest in 2 passes. The change in microhardness was the result of dynamic competition between the softening effect of DRX and the work hardening effect. In addition, the wear resistance of the alloy showed a positive correlation with the degree of RUE under low load conditions. When the applied load was higher, the wear resistance of the alloy treated with RUE decreased compared to the initial state alloy. This phenomenon was mainly due to the presence of oxidative wear on the surface of the alloy, which could balance the positive contribution of severe plastic deformation to wear resistance to a certain extent.

SiCNO-BN composite ceramics were synthesized by polyvinylsilazane and hexagonal boron nitride. It was found that the electrical conductivity of SiCNO-BN composites varied nonmonotonically with BN content. According to the scanning electron microscope and Raman spectroscopy analysis, we can conclude that the conductive behavior of SiCNO-BN composites was strongly related to the graphitization degree of free carbon in the SiCNO-BN composites. Compared with SiCNO ceramic, the conductivity of the SiCNO-BN composite decreased from 1.68 × 10−8 (Ω cm)−1 to 4.41 × 10−9 (Ω cm)−1 when the content of BN was 15 wt%, and the graphitization degree of free carbon also decreased dramatically. The dielectric loss of SiCNO-BN composites was also reduced as the conductivity of SiCNO ceramic decreased. In addition, one of the potential applications of polymer derived ceramics (SiCNO) is high-temperature sensors. However, its real application process is limited. In order to solve this problem, the wireless passive temperature sensors based on SiCNO-BN composite ceramics were fabricated. The results showed that the maximum measurement temperature of SiCNO-BN temperature sensor with 15 wt% BN can reach up to 1250 °C, which is higher than 900 °C of the SiCNO temperature sensor.

Due to their outstanding properties, bioadhesive hydrogels have been extensively studied by researchers in recent years. By designing the properties of bioadhesive hydrogels, they can be reasonably applied to biomedicine. Therefore, this practicality has prompted the birth of many bioadhesive hydrogels with excellent properties. In this review, by studying the progress in the field of bioadhesive hydrogels, we summarized the properties of hydrogels in bioadhesion, including adhesion, biocompatibility, degradability and antibacterial properties. In addition, we also summarized the applications of bioadhesive hydrogels in wound dressings, tissue repair, cell adhesion and wearable sensors. Finally, we summarized and outlooked the research on bioadhesive hydrogels, hoping to provide a valuable reference for the progress in the field of bioadhesive hydrogels.

A dynamic quasi-continuum model is presented to analyze free vibration of plate-type cubic crystal nano-materials. According to the Hamilton principle, fundamental governing equations in terms of displacement components and angles of rotations are given. As an application of the model, the cylindrical bending deformation of the structure fixed at two ends is analyzed, and a theoretical formula evaluating the fundamental frequency is obtained by using Galerkin’s method. Meanwhile, the solution for the classical continuous plate model is also derived, and the size-dependent elastic modulus and Poisson’s ratio are taken in computation. The frequencies corresponding to different atomic layers are numerically presented for the plate-type NaCl nano-materials. Furthermore, a molecular dynamics (MD) simulation is conducted with the code LAMMPS. The comparison shows that the present quasi-continuum model is valid, and it may be used as an alternative model, which reflects scale effects in analyzing dynamic behaviors of such plate-type nano-materials.

Graphene aerogel with good mechanical properties and elasticity were extensively investigated for oil adsorbent. Herein, polyvinyl alcohol-graphene aerogel was prepared using Pickering emulsion method with polyvinyl alcohol being used as crosslinking agent and ethylenediamine (EDA) was used as reductant. The droplets of the Pickering emulsion played the role of soft templates during the aerogel preparation, and the droplets size was adjusted by adding different amount of butanol. When the content of EDA increases from 0.5 to 0.9%, the volume of aerogel gradually increases and its outer surface becomes smoother. However, when the content of EDA reaches 1%, aerogel becomes smaller and the outer surface becomes coarser. It was found that the compression stress and EDA content are positively correlated by simple manual extrusion. Compression-rebound test and Young's modulus calculation results indicated that the mechanical properties of aerogel can be effectively influenced by pre-freezing process. The fold degree of the wall, the maximum stress and Young's modulus of the aerogel increase gradually when prolonging pre-freezing time. The polyvinyl alcohol-graphene aerogel prepared by pre-freezing for 48 h with a density of 5.07 mg cm−3, a porosity of up to 99.8%, and a pore volume of 196.84 cm3 g−1 achieved instantaneous adsorption of oil slick on water. And the pore occupancy reached 93.31% under the saturated adsorption state on pure oil.

Emulating neural activities at individual synapse level has recently attracted tremendous attention. Here, we demonstrate design and fabrication of the first digitally aligned nanowire (NW)-based three-terminal synaptic transistor. The highly-aligned and individually-position-controlled long continuous indium zinc oxide (IZO) NW arrays were directly printed on a large area with low cost using a special electrohydrodynamic nanowire printing (e-NWP) process. The NWs printed by e-NWP with a diameter of 250 nm emulated the structure of nerve fibers. The device emulates plasticity of biological synapses and showed remarkable advantages in energy consumption compared with previous reports. Unique band-edge modulation along the NW axial direction underlies makes excellent electrical properties of the device. This approach paves the way to easy fabrication of printed-NW-based artificial neural networks.

Polyacrylonitrile (PAN)/cellulose nanofibril (CNF) based carbon nanofiber membranes were produced by electrospinning and carbonization method, in which the CNF amount was 1 wt%. In order to control the spinning process, the rheological properties of the PAN/CNF suspensions were measured before electrospinning. In addition, the effects of CNF particle size on the structure and properties of carbon nanofiber membranes were investigated systematically by SEM, FTIR and mechanical test. Meanwhile, the reaction mechanism of PAN and PAN/CNF nanofiber membranes in the process of stabilization and carbonization was also fully discussed. The results show that the addition of CNFs can improve the breaking strength and conductivity of PAN carbon nanofiber membrane. Moreover, CNFs also can accelerate the carbonization rate and reduce the reaction conditions of PAN nanofiber membranes. Therefore, CNFs are effective enhancers for PAN based carbon nanofiber membranes.

Polyacrylonitrile (PAN)/cellulose nanofibril (CNF) nanofiber membranes were successfully prepared by an electrospinning method, in which the amount of CNF kept 1 wt%. The effects of CNF sizes on the morphology and properly of spinning solutions and PAN electrospun nanofiber membrane were systematically investigated by rheological property test, conductivity test, SEM, TG, DSC, contact angle test and mechanical test. The results showed that the viscosity and conductivity of the spinning solution was improved with the increasing of CNF sizes, as the formation of the strong polar interactions of nitrile groups and the hydroxyl groups between PAN and CNF. All the morphology of the PAN/CNF nanofiber membrane exhibited a uniform diameter with no visible beads or beads to the string structure, and the average diameter of the PAN/CNF nanofiber was decreased with the increasing of the CNF size. Moreover, the addition of CNF could improve the thermal stability, mechanical properly, and hydrophilicity of the PAN membrane. And the PAN/CNF-10 nanofiber membrane exhibited the optimal properties.

Electrohydrodynamic nanowire printing (e-NWP) technology can be used to print ultra-fine nanowires (NWs) in patterns at high precision. This technology has enabled advances in large-area patterned NWs, high-precision and high-integration devices, nanoelectromechanical systems, and bio-inspired devices. The electrical properties of the devices printed using e-NWP can be adjusted by controlling the gaps and diameters of the NWs. These forms have widespread application in field effect transistors, synaptic mimicry and masks. This review summarizes the basic principles, materials, printing methods and applications of e-NWP, and then outlines the research direction and obstacles that should be overcome to expand the applications of e-NWPs, and enable their commercialization.

Ultrasmall Gd2O3 nanoparticles can potentially be used as a positive magnetic resonance imaging (MRI) contrast agent owing to their high content of Gd(III), which exhibits the highest spin magnetic moment of all elements due to its seven unpaired 4f electrons. Herein, the above nanoparticles (average diameter = 2.0 nm) were coated with hydrophilic biocompatible polyacrylic acids (PAAs) of different molecular weights (Mw = 1200, 5100, 15000 Da), and the PAA-size-dependent relaxometric properties of the thus obtained composites were investigated. In addition, the biocompatibility of these composites was assessed by in-vitro cell viability measurements. Finally, dose-dependent R1 map images were acquired, proving that PAA-coated nanoparticles can be used as a T1 MRI contrast agent.

Enclosing metal clusters in zeolites can enhance their catalytic performance due to the complex effects of the zeolitic environment. However, for the first time, herein, we report the significant passivation effects of the surrounding zeolitic framework on the d-band center and catalytic performance of enclosed Pt clusters. For the dehydrogenation of propane to propylene, the Pt/NaX catalyst with Pt clusters on the exterior of X-zeolite showed a ∼1100% enhancement in TOF and largely improved selectivity for propylene compared with the corresponding Pt@NaX catalyst, in which the Pt clusters were stuck to the inside of X-zeolite. Moreover, less coke deposition and high stability were detected in Pt/NaX after the reaction for 18 h. Combining the detailed experiments and DFT calculations, it was revealed that the significant passivation effect is mainly attributed to the surrounding zeolitic framework for the enclosed Pt clusters, which decreases the d-band center of the Pt clusters and weakens the activation of propane, preventing the desorption of propylene with a reduction in propylene selectivity and increase in coke deposition. Thus, the present investigation reveals that enclosing metal clusters in zeolites may not be beneficial for some specific catalytic reactions, deepening the understanding for this type of catalyst of metal clusters enclosed in zeolites.

The work of this article is to transform the famous nonlinear space–time fractional shallow water wave equations, namely coupled Korteweg-de Vries equations into ordinary differential equations via the complex fractional traveling wave transformation, and find the exact solutions through the complete discrimination system for polynomial method. At the same time, we build the appropriate example for the identified parameters to show the existence of each solution. Besides, providing a direct perspective to show that our solutions do exist by the three-dimensional and two-dimensional graphics.

Reciprocating Upsetting-Extrusion (RUE) deformation process can significantly refine the grains size and weaken the basal plane texture by applying a large cumulative strain to the alloy, which is of great significance to weaken the anisotropy of magnesium (Mg) alloys and increase the application range. In this paper, the Mg-8.27Gd-3.18Y-0.43Zr (wt %) alloy was subjected to isothermal multi-passes RUE. The microstructure and texture evolution, crystal orientation-dependent deformation mechanism of the alloy after deformation were investigated. The results clearly show that with the increase of RUE process, the grains are significantly refined through continuous dynamic recrystallization (CDRX) and discontinuous dynamic recrystallization (DDRX) mechanisms, the uniformity of the microstructure is improved, and the texture intensity is reduced. At the same time, a large number of particle phases are dynamically precipitated during the deformation process, promoting grain refinement by the particle-stimulated nucleation (PSN) mechanism. The typical [10-10] fiber texture is produced after one pass due to the basal plane of the deformed grains with a relatively high proportion is gradually parallel to the ED during extrusion process. However, the texture concentration is reduced compared with the traditional extrusion deformation, indicating that the upsetting deformation has a certain delay effect on the subsequent extrusion texture generation. After three or four passes deformation, the grain orientation is randomized due to the continuous progress of the dynamic recrystallization process.

In this work, a core-shell-like sphere ruthenium catalyst, named as 5%Ru/&gamma, Al2O3@ASMA, has been successfully synthesized through impregnating the ruthenium nanoparticles (NPs) on the surface of the amino poly (styrene-co-maleic) polymer (ASMA) encapsulating &gamma, Al2O3 pellet support. The interaction between the Ru cations and the electro-donating polymer shell rich in hydroxyl and amino groups through the coordination bond would guarantee that the Ru NPs can be highly dispersed and firmly embedded on the surface of the support. In addition, the solid sphere &gamma, Al2O3 pellet could serve as the core to support the resulted catalysts applied in the flow process in a trickle bed reactor to promote the productivity. The resulted catalyst 5%Ru/&gamma, Al2O3@ASMA can be applied efficiently in the glucose hydrogenation and presents a steadfast sorbitol yield of almost 90% both in batch reactor and the trickle bed reactor, indicating the potential feasibility of the core-shell-like catalyst in the efficient production of sorbitol.

In the past few decades, peptide antibacterial products with unique antibacterial mechanisms have attracted widespread interest. They can effectively reduce the probability of drug resistance of bacteria and are biocompatible, so they possess tremendous development prospects. This review provides recent research and analysis on the basic types of antimicrobial peptides (including poly (amino acid)s, short AMPs, and lipopeptides) and factors to optimize antimicrobial effects. It also summarizes the two most important modes of action of antimicrobial peptides and the latest developments in the application of AMPs, including antimicrobial agent, wound healing, preservative, antibacterial coating and others. Finally, we discuss the remaining challenges to improve the antibacterial peptides and propose prospects in the field.

Hydrogels, as a kind of soft materials, are good candidates for smart skin-like materials. A double network is usually fabricated to improve the mechanical properties of hydrogels, and involves two different kinds of networks. In this work, a novel strategy for preparing single network double cross-linker (SNDCL) hydrogels was proposed and the prepared hydrogels exhibited excellent mechanical properties, including stretchability, compressibility, self-recovery, adhesion, shape memory and mechanical strength. N,N'-Methylenebisacrylamide forms covalent bonds with the network, while citric acid can form multiple weak interactions due to the polycarboxylic structure. This improves the tensile properties (6564%) and compressive properties of the hydrogel, and the hydrogels also exhibit long-lasting self-adhesion ability on various substrates. In addition, the hydrogels with multiple properties can be used as flexible strain sensors, allowing the monitoring of body movements. The hydrogels can hopefully be used in wearable electronic sensor devices and for healthcare monitoring.

C-terminated 6H-SiC (0001) single crystal substrates implanted with Pd ions with an energy of 20 keV and three fluences of 5 × 1015, 5 × 1016 and 5 × 1017 ions/cm2 at room temperature. The wetting experiments of SiC by molten Al–10Si, Al–10Si–4Cu and Al–10Si–10Zn were performed by using the sessile drop method in a high vacuum at 1323 K to determine the effects of the third element (Cu and Zn) addition and Pd ion implantation on the wettability of Al–10Si/SiC system. The experimental results showed that the wettability of Al–10Si/SiC system can be improved significantly by adding the 4% Cu with the final contact angle decreasing from ~ 60° to ~ 40°. The final contact angle of Al–10Si/SiC system decreased sharply from ~ 60° to ~ 26° after the addition of 10% Zn, which can be mainly derived from the evaporation behavior of Zn at the interface. The spreading time for reaching the equilibrium or slow spreading stage of the three Al–10Si(– 4Cu, – 10Zn)/SiC systems was prolonged more or less with the increase of Pd implantation dose, which can be mainly attributed to the variation of interfacial interactions between drops and Pd-implanted SiC substrates. Moreover, the final contact angles of Al–10Si/SiC and Al–10Si–4Cu/SiC systems decreased while that of Al–10Si–10Zn/SiC system almost kept constant with increasing the Pd implantation dose.

This paper presents the results of a study about the influence of cone angles and liner materials on shaped charge penetrating layered and spaced concrete targets. The experiments are performed using shaped charges with a fixed aspect ratio (length : diameter = 1:1) detonated at a stand-off distance of 120.0 mm (equivalent to twice the diameter of the shaped charge). The penetrating performance of three different liner materials (steel, copper and aluminium) formed with varying cone angles is evaluated in terms of diameters of entry and exit craters and depth of penetration. The results indicate that shaped charge with the aluminium liner forms the largest crater in the concrete targets. The shaped charge with the copper liner causes the deepest penetration. The results also indicate that, when the cone angle is less than 120°, the spaced target can provide better protection than the layered target in resisting the impact damage by the shaped charge with steel and copper liner. Compared with the layered target, the spaced one does not improve the level of protection against the jet formed by the aluminium cone liner. The experiments are also simulated with the commercially available software Autodyn using material parameters from four different sources. The results from the simulations are compared and evaluated in terms of depth of penetration of the target. An analytical method proposed to predict the depth of penetration of the concrete target using rod length erosion shows good correlation with the experiments.

Nanoparticles are very important in biomedical imaging because their imaging properties are superior to those of small molecules. They can be further functionalized for multimodal imaging through surface modification. In this study, we synthesized dye-coated ultrasmall gadolinium oxide nanoparticles [dye = fluorescein and fluorescein isothiocyanate (FITC)] in one-pot and investigated their dual imaging properties. The dye-coated gadolinium oxide nanoparticles exhibited excellent relaxometric properties suitable for T1 magnetic resonance imaging (MRI): r1 = 9.8 s−1mM−1 (r2/r1 = 2.6) for fluorescein-coated nanoparticles (davg = 1.6 ± 0.1 nm) and r1 = 12.3 s−1mM−1 (r2/r1 = 2.3) for FITC-coated nanoparticles (davg = 1.4 ± 0.1 nm), and strong photoluminescence (PL) in the green region (around 514 nm) suitable for fluorescent imaging (FI). The dye-coated nanoparticles exhibited strong fluorescence in cellular confocal images and high contrast in T1 MR images in mice, suggesting that they are potential dual T1 MRI-FI agents.

Stearic acid (SA) mixed with alkali in water can form different fascinating aggregates in solution. The phase behavior of SA and alkali in water was observed in this work, and the apparent viscosity was measured by rheological measurements. Fatty acid self-assembled into bilayers at pH ≈ p K a and the structure was determined by cryogenic transmission microscopy (cryo-TEM) observations. The ability of stabilizing the emulsion by the bilayers and micelles was compared. The homogeneous emulsion formed by bilayers was gained, indicating that the bilayers have a better emulsion stability. By adjusting the conditions and external stimuli, emulsification and demulsification can be achieved. Based on this background, we carried out the experiments of multi-responses of the emulsion stabilized by bilayers, including pH, CO 2 , light, and temperature.

A simple and safe one-step immersion method was developed to obtain the stable superhydrophobic copper surfaces with excellent corrosion resistance ability using fatty acids in water-medium instead of ethanol. An organic alkali, N , N -dimethylcyclohexylamine (DMCHA), was chosen to solve the poor solubility of fatty acids in water and the high Krafft point of carboxylate salts with inorganic counterions. The superhydrophobic property can be realized in a much quicker process (7.5 min) in aqueous solution than in ethanol (more than 2 d), which is universally feasible for the fabrication of superhydrophobic metal surfaces in industry scale, thereby greatly increasing the safety in industrial manufacture.

We firstly apply the trial equation method to generalized (2+1)-dimensional Gardner equation to reduce the nonlinear partial differential equation into ordinary equation. Then by the complete discrimination system for polynomial method, the classification of the exact single traveling wave solutions is presented. This is the first time that the two methods are applied to integral-differential equation. In the classification, we can see that the equation has rational function type solutions, solitary wave solutions, triangle function type periodic solutions and Jacobian elliptic functions solutions with double periodic, which are impossible to be obtained by other methods. Moreover, to ensure the existences of these solutions, concrete examples are also constructed with specific parameters. To the best of our knowledge, the results presented in the paper are brand new and can not be found in any other papers. Keywords: Exact traveling wave solutions, Complete discrimination system for polynomial, Trial equation method, Generalized (2+1) dimensional Gardner equation

In this study, the N-doping of biomass-activated carbon with dicyandiamide was performed via an ultrasonic method and a redox method. BET, SEM, EDS, FT-IR and XPS were used to determine the pore structures, morphologies and surface chemistry of the adsorbents obtained. The N-doping effect of the two modification methods on the same solid nitrogen source was evaluated and the simulated adsorption experiments of heavy metal ions in wastewater were conducted. The results showed that the N-doped biomass-activated carbon having the higher doping content was obtained by a redox method with nitric acid at 25 °C, a solid nitrogen source ratio of 1 : 1 and charring at 800 °C for 2 hours. The adsorption efficiency for the divalent copper ion of the sample obtained by the redox method was 41.15% higher than that of the ultrasonic method sample, and proved that pyridinium nitrogens and amino groups play important roles in adsorption and complexation processes. The isothermal adsorption experiments of N-doped activated carbon conformed to the Freundlich model, which mainly depended on chemical adsorption. The kinetics for copper ion adsorption followed a pseudo-second-order kinetic model. Thermodynamic experiments showed that a higher temperature was advantageous to adsorption. Simultaneously, this study further analyzed the N-doping process of the redox method sample and suggested that improvements can be implemented in the N-doping of activated carbon with solid nitrogen sources.

Ammonium persulfate modified mixed metal oxide derived from hydrotalcite with tunable acid/base properties can be prepared via thermal decomposition of Mg-Al hydrotalcite-type precursors and ammonium persulfate. By controlling the ammonium persulfate content, these sulphur mutated samples, denoted as SMgAlO-y (y = 1, 3, 5, 7), were investigated in this research. The resulted materials were characterized by XRD, SEM, FT-IR spectra, Py-IR spectra, XPS, Hammett indicator, CO2-TPD, as well as NH3-TPD. Furthermore, the acid-base property of the sample surface was determined by inverse gas chromatography measurements (IGC). Among all the obtained outcomes, the target SMgAlO-5 demonstrated the maximal Ka/Kb value, and it presented the highest activity as a catalyst in the synthesis of propylene carbonate (PC) through 1,2-propylene glycol and urea, giving the yield of 97.2% at the optimized reaction condition, which indicated that the PC yield counted on the synergic effect of the acidity and basicity on catalysts.

Incorporating impure foreign atoms or ions has been extensively utilized in materials science for generating hybrid materials with desirable properties and functions. Despite most materials consisting of cations and anions, conventional routes only focus on incorporating cations. In this work, we proposed an intentional impure anion incorporation strategy as a facile and straightforward route to adjust the properties of yielded nanocrystals. Via incorporating diverse anions, the size, morphology, uniformity and optical properties of lanthanide oxide nanocrystals could be rationally tuned. Furthermore, the obtained nanocrystals could further serve as a bioprobe for imaging deep tissue.

In this paper, compression-torsion experiments were used to study the hot deformation behavior of as-homogenized Mg-13Gd-4Y-2Zn-0.5Zr alloy at 350 °C under different equivalent strain rates. The results show that the Mg-13Gd-4Y-2Zn-0.5Zr alloy under different equivalent strain rates at 350 °C, the alloy is coordinated by the synergistic effects of multiple deformation mechanisms of lamellar long-period accumulation order (LPSO) phases kinking, dynamic recrystallization (DRX) and twinning. The degree of lamellar phase kinking and the equivalent strain rate show a positive correlation trend, while the DRX and the equivalent strain rate show a negative correlation trend. Under the condition of higher equivalent strain rate, some grains have their own hard orientation which causes the basal slip to be suppressed. At this time, they need to activate twinning to coordinate the deformation. The corresponding texture analysis shows that the activation of the lamellar LPSO phases kinking, DRX and twining will all weaken the basal texture.

Schiff base modified PAMAM dendrimer/silica hybrid materials (SG-G0-SA, SG-G1.0-SA, and SG-G2.0-SA) were synthesized and used for removing aqueous Zn(II) and Ni(II). The influence of solution pH, time, temperature, and the concentration of metal ion on the removal effect were investigated. The regeneration of the adsorbents was evaluated. The interaction mechanism between adsorbents and metal ions was revealed by density functional theory (DFT) calculation and X-ray photoelectron spectroscopy (XPS) analysis. Results show the as-prepared adsorbents display comparable adsorption property for Zn(II) and Ni(II). The optimum solution pH for Zn(II) and Ni(II) removal are 6.0 and 5.0. The adsorption kinetic follows pseudo-second-order (PSO) model, while the adsorption isotherm obeys Langmuir model. The adsorption was carried out with monolayer adsorption in chemical mechanism. 0.5 mol·L−1 HNO3–5% thiourea solution can be used as efficient eluent to regenerate the adsorbents that upload metal ions. Adsorption mechanism indicates the imino N atoms and carbonyl O atoms that play the main role in the adsorption process.

PVA hydrogel has excellent adhesion ability and biocompatibility, and is considered as a promising material in the field of wound dressings. However, the traditional PVA hydrogel has poor mechanical properties, which greatly limits its application. In this article, we obtained a PVA/PAAm interpenetrating networks (IPN) hydrogel by a one-pot free radical polymerization method, which improved the mechanical strength and retained the original properties of the PVA. The IPN hydrogel was proved to possess excellent adhesion strength and rheological properties with certain conductivity, which can be used as a human motion monitor. To achieve the application of wound dressing, a polymer antibacterial agent of polyhexamethylene guanidine (PHMG) was introduced into the hydrogel. The results showed the antibacterial properties of the PVA/PAAm IPN hydrogel were enhanced obviously on both Gram-positive and Gram-negative bacteria. The prepared PVA/PAAm IPN hydrogel may provide the possibility for the application in the field of body sensors and wound dressing.

Over the last few decades, gel with excellent characteristics and functions have attracted considerable interests of researchers for potential applications in various fields such as cosmetics, energy saving, biomedicine, electronic devices, etc. The applications of the gel are not only attributed to the biocompatible, controllability, conductivity and hydrophilic properties, but also significant rely on the strong adhesion on various substrate surfaces. When used in the field of adhesives, gel has excellent performances that ordinary adhesives cannot achieve. This review provides comprehensive information on characterizing the adhesion properties and the factors affecting the adhesion properties of gels. Several summaries of adhesion strength and the method of gel adhesion to different materials were provided. According to the different properties of the gel, the current applications of the gel in the field of biomedicine, underwater adhesion, coating and wearable devices are discussed and prospected. We also explore the latest research progress of de-bonding and classify the current ways of gel de-bonding. Finally, we emphasize the current challenges and highlight the prospects of the adhesion gel, which may provide valuable references for the subsequent researches.

The single component (SC) white-light emitting (WLE) metal-organic frameworks based on europium (Eu-MOFs), which could be applied in lighting and display, have drawn great attention but have rarely been exploited. In this work, we dedicated to design and synthesize SC-WLE Eu-MOFs via a dichromatic strategy on the balance of simultaneous ligand-based and Eu-based emissions. The Eu-MOF {[Eu4(obb)6(H2O)9]·(H2O)}∞ (IAM16–3) generated via the self-assembly of the flexible ligand 4,4′-oxybisbenzoic acid (H2obb) and europium ions displays fascinating excitation-wavelength-dependent photoluminescence (EWDP) property. Upon different excitation wavelengths, tunable WLE through manipulating the intensity ratio of characteristic emissions of Eu3+ ions and ligand-based emissions was performed. To the best of our knowledge, this is the first example for Eu-MOFs to yield SC-WLE stemming from EWDP property. Three isomorphic lanthanide-based MOFs (LnMOFs), that is, {[Ln4(obb)6(H2O)9]·(H2O)}∞ (Eu3+: IAM16–3; Tb3+: IAM16–4;...

Ultrasmall gadolinium oxide (Gd2O3) nanoparticles coated with dextran (M‾ r=1500 amu) were prepared through one-pot synthesis and their potential to act as a T1 MRI contrast agent was investigated. The dextran-coated ultrasmall Gd2O3 nanoparticles were highly water-dispersible, with an average particle diameter of 1.5 nm and an average hydrodynamic diameter of 12.4 nm, and non-toxic, as determined in a cellular cytotoxicity test. The longitudinal (r1) and transverse (r2) water proton relaxivities were estimated to be 12.2 and 29.3 s−1mM−1 (r2/r1=2.4), respectively, larger than those of commercial Gd-chelates. This r1 value is also greater than those for previously reported dextran-coated large Gd2O3 nanoparticles with particle diameter bigger than 20 nm. Positive contrast magnetic resonance (MR) images were obtained after intravenous injection of a sample solution into a mouse tail, demonstrating the potential of dextran-coated ultrasmall Gd2O3 nanoparticles as a T1 MRI contrast agent.

A new series of N-methylfulleropyrrolidines bearing oligo(poly(ethylene oxide))-appended Percec monodendrons (fulleromonodendrons, 4a-f) have been synthesized. The substituted position of the oligo(poly(ethylene oxide)) chain(s) on the phenyl group of the Percec monodendron for 4a-f was varied, which is at the 4-, 2,4-, 3,5-, 3,4,5-, 2,3,4- and 2,4,6- position, respectively. 4a-e are obtained as solids at 25 °C and can self-organize into lamellar phases as revealed by X-ray diffraction (XRD) and small-angle X-ray scattering (SAXS) measurements, while 4f appears as a viscous liquid. The substitution patterns of the oligo(poly(ethylene oxide)) chain(s) also significantly influence the solubility of 4a-f, especially in ethanol and water. Formation of self-organized supramolecular structures of 4d and 4e in water as well as 4d in ethanol is evidenced from UV-vis and dynamic light scattering (DLS) measurements. Further studies in water using various imaging techniques including transmission electron microscopy (TEM), freeze-fracture TEM (FF-TEM), cryo-TEM and atomic force microscopy (AFM) observations revealed the formation of well-defined vesicles for 4d and plate-like aggregates for 4e, indicating that the aggregation behavior of the fulleromonodendrons is highly dependent on their molecular structures. For 4d in ethanol, only irregular aggregates were noticed, indicating the solvent also plays a role on regulating the aggregation behavior. After functionalization with the Percec monodendrons, 4a-f can preserve the intriguing electrochemical properties of pristine C60 as revealed by cyclic voltammetries. The thermotropic properties of 4a-f have also been investigated. It was found that all of them show good thermal stability, but no mesophases were detected within the investigated temperature ranges.

The design of the first p-i-n junction synaptic transistor (JST) based on n-type TiO2 film covered with poly(methyl methacrylate) (PMMA) and with a p-type P3HT/PEO nanowire (NW) on top. Except for basic synaptic functions that can be realized by a single neurotransmitter, the electronic device emulates the multiplexed neurotransmission of different neurotransmissions, i.e., glutamate and acetylcholine, for fast switching between short- and long-term plasticity (STP and LTP). This is realized by the special p-i-n junction with hole transport in the p-type P3HT NW to form STP, and electron transport in the n-type TiO2 layer and trapped under the PMMA inversion layer to form LTP. Altering the external input induces changes of the polarity of the charge carriers in the conductive channel, promoting fast switching between STP and LTP modes. When stimulated using two parallel inputs, the response of PMMA/TiO2 emulates the synergistic effect of taste and aroma on the control of food-intake in the brain. Because of the bipolarity, the p-i-n JST has excellent reconfigurability, which importantly is attributed to simulate the plasticity of synapses and to mimic how distinct types of gustatory receptor neurons respond to different concentrations of salt. The electronic device lays the technical foundation for the realization of the future complex artificial neural networks.

Heavy metal ions pollution in water system has been imposing serious damage to aquatic ecosystem and public health. Efficient and selective capture of targeted metal ion from water is a great challenge and the focus of extensive research. Herein, sulfur-functionalized polyamidoamine (PAMAM) dendrimer/magnetic Fe3O4 hybrid materials were constructed for capturing Hg(II) and Ag(I) from water solution. The as-prepared adsorbents were fully characterized and the factors that influence the adsorption performance were investigated. The maximum adsorption of Fe3O4@SiO2-M2 were 0.8 and 1.29 mmol∙g−1 for Hg(II) and Ag(I). The hybrid materials display good adsorption selectivity and 100% selective adsorb Hg(II) with the presence of Ni(II), Mn(II), and Zn(II). Adsorption mechanism suggests sulfur groups play the predominant role during the capture of Hg(II). These hybrid materials exhibit excellent regeneration property and can be reused with practical application value.

Dynamic covalent bonds (DCBs) have received widespread attention due to their unique reversibility and stimulus responsiveness. The introduction of DCBs often endows materials with good controllability and self-healing properties, which greatly improves the limitations of some current researches. This review summarizes the characteristics and reaction mechanisms of different types of DCBs, and provides a variety of typical dynamic covalent reactions and their reaction conditions. Finally, we summarize the latest developments in the application of DCBs, including tissue adhesives, tissue regeneration, drug delivery, sensors, 3D printing, fluorescent probes and coatings, and propose existing challenges and future development directions in this field.

The decreasing temperature reciprocating upsetting-extrusion (RUE) deformation experiment was carried out on Mg-Gd-Y-Zr alloy to study RUE deformation on the influence of microstructure of the alloy. This work showed that with the gradual increase of RUE deformation passes, the continuous dynamic recrystallization (CDRX) process and the discontinuous dynamic recrystallization (DDRX) process occurred at the same time, and the grain refinement effect was obvious. Particulate precipitation induced the generation of DRX through particle-stimulated nucleation (PSN). In addition, after one pass of RUE deformation, the alloy produced a strong basal texture. As the RUE experiment proceeded, the basal texture intensity decreased. The weakening of the texture was due to the combined effect of DRX and alternating loading forces in the axial and radial directions. After four RUE passes, the mechanical properties of the alloy had been significantly improved, which was the result of the combined effect of dislocation strengthening, fine grain strengthening, and second phase strengthening.

Schiff-base functionalized magnetic Fe3O4 were prepared by feasible one-pot subsequent homogeneous method (Fe3O4@SiO2–HO–S) and heterogeneous method (Fe3O4@SiO2-HE-S), respectively. The as-prepared adsorbents were used for the adsorption of aqueous Hg(II) and Ag(I). The effects of solution pH, time, temperature, coexisting metal ions, and initial metal ion concentration on the adsorption were investigated. The as-synthesized adsorbents were characterized by transmission electron microscope, scanning electron microscope, and X-ray photoelectron spectroscopy. The effect of solution pH indicates the optimal adsorption pH is 6. The adsorption equilibrium time are 180 and 220 min for both Hg(II) and Ag(I) under the concentration of 0.002 and 0.004 mol L−1, respectively. The adsorption kinetic process is proved to be dominated by film diffusion process and follows pseudo-second-order kinetic model. The adsorption isotherm process is proceeded by chemical mechanism and can be described by Langmuir model. Thermodynamic parameters indicate that the adsorption process is spontaneous, endothermic, and entropy increase. Adsorption selectivity demonstrates Fe3O4@SiO2-HE-S and Fe3O4@SiO2–HO–S exhibit good adsorption selectivity for Hg(II). The adsorption mechanism demonstrates the N atoms of Schiff base functional group mainly dominate the adsorption of Fe3O4@SiO2-HE-S and Fe3O4@SiO2–HO–S for metal ions. The regeneration property indicates the adsorbents can be reused with practical value.

The presence of metal ion in N,N-dimethylformamide (DMF) would bring adverse effect for its practical application in the fields of chemical industry and advanced functional materials. Adsorbents for the effective metal ion purification in DMF are needed. Herein, amino-capped polyamidoamine (PAMAM) dendrimer decorated silica particles (G1.0-SG, G2.0-SG, and G3.0-SG) were prepared for removing of Zn(II) and Co(II) from DMF. The influence effects on the adsorption performance were revealed. The adsorption mechanism was indicated by density functional theory (DFT) calculation. The maximum adsorption amount of G1.0-SG, G2.0-SG and G3.0-SG for Zn(II) are 0.35, 0.42 and 0.38 mmol·g−1, while those for Co(II) are 0.31, 0.36 and 0.22 mmol·g−1, respectively. The adsorption is proceeded with film diffusion process as rate-controlling step and can be well depicted by the pseudo-second-order model. Adsorption isotherm reveals the adsorption can be enhanced by the metal ion concentration and temperature. The adsorption was conducted spontaneously in chemical mechanism by monolayer behavior. Theoretical calculation reveals the chelation between primary and second amino groups with metal ion dominates the adsorption. The adsorbents can be efficiently regenerated by thiourea-HNO3 solution. As the adsorbents exhibit good adsorption performance and regeneration property, they can be potentially used for the purification of metal ion in DMF solvent with practical application.

In this study, an analytic derivation is made for the truncated Cauchy-Lorentz velocity distribution experimentally observed in freestanding graphene membranes. Three methods are used and discussed, including the Fokker-Planck-Kolmogorov equation, the maximum nonsymmetric entropy principle, and the Bayesian inference. From these results, a physical mechanism is provided for the non-Gaussian velocity distribution in terms of carbon atom arrangement in freestanding graphene. Moreover, a new theoretical foundation is proposed for future studies of the anomalous dynamics of carbon atoms in graphene membranes.

Using large amounts of bio-optical data collected in the South China Sea (SCS) from 2003 to 2016, this study checks the consistency between well-known semi-analytical algorithms (SAAs)—the quasi-analytical algorithm (QAA) and the default generalized inherent optical property (GIOP-DC)—in retrieving the non-water absorption coefficient (anw(λ)), phytoplankton absorption coefficient (aph(λ)) and particulate backscattering coefficient (bbp(λ)) from remote-sensing reflectance (Rrs(λ)) data at 412, 443, 490, 531, and 555 nm. The samples from the SCS are further separated into oligotrophic and mesotrophic water types for the comparison of the SAAs. Several findings are made: First, the values of anw(λ) derived from the two SAAs deliver similar performance, with R2 values ranging from 0.74 to 0.85 and 0.74 to 0.87, implying absolute percent error differences (APDs) from 37.93% to 74.88% and from 32.32% to 71.75% for the QAA and GIOP-DC, respectively. The QAA shows a value of R2 between 0.64 and 0.91 and APDs between 43.57% to 83.53%, while the GIOP-DC yields R2 between 0.76 to 0.89 and APDs between 44.65% to 79.46% when estimating aph(λ). The values of bbp(λ) derived from the QAA are closer to the in-situ bbp(λ) values, as indicated by the low values of the normalized centered root-mean-square deviation and normalized standard deviation, which are close to one. Second, a regionally tuned estimation of aph(λ) is proposed and recommended for the SCS. This consistency check of inherent optical properties products from SAAs can serve as reference for algorithm selection for further applications, including primary production, carbon, and biogeochemical models of the SCS, and can provide guidance for improving aph(λ) estimation.

Molecular self-assembly has become a popular tool to prepare nanomaterials with potential applications, such as ion-responsive detection of Hg(2+) in aqueous solutions. In this study, FFACD aromatic pentapeptides, whose N-terminuses were protected by carboxyl (Ac-FFACD) or a 9-fluorenylmethoxycarbonyl group (Fmoc-FFACD), were chosen as building blocks to produce nanostructures in solutions. Based on the preliminary determination of the critical aggregation concentration (CAC) of Ac-FFACD and Fmoc-FFACD aromatic pentapeptides in water, the order of magnitude of which is 10(-5) mol·L(-1), self-assembled spiral and networked nanowires can be easily obtained over a range of concentrations. These nanowires were characterized by transmission electron microscopy (TEM), scanning electron microscopy (SEM), and atomic force microscopy (AFM). The self-assembled spiral and networked nanowires were designed to be used as templates for preparing CdS quantum dots (QDs) in-situ at room temperature. The peptide-functionalized, nanowire-encapsulated CdS QDs can be used for rapid, sensitive, and selective detection of trace amounts of mercuric ions (Hg(2+)) in aqueous solutions. This method enables rapid, linear detection (the linear correlation coefficients are 0.9972 of ΔF = 257.09 + 3.58 cHg(2+) for Ac-FFACD and 0.9994 of ΔF = 48.13 + 32.96 cHg(2+) for Fmoc-FFACD) with the Hg(2+) limit of detection at 300.85 ng·L(-1) and 32.09 ng·L(-1) for Ac-FFACD and Fmoc-FFACD, respectively. The supramolecular, self-assembled nanowires, fabricated from the two aromatic pentapeptides and having encapsulated QDs, exhibit superior properties attributable to the large loading capacity and the coordination sites of these peptides with Hg(2+). These structures can serve as novel Hg(2+) sensors and have possible applications for detection of various targets in scientific and engineering systems.

An amino poly (styrene-co-maleic anhydride) polymer (ASMA) encapsulated γ-Al2O3 pellet material has been synthesized successfully. After loading with Pd species and modified with morpholine, the inorganic-organic hybrid material shows an excellent catalytic property in the selective hydrogenation of p-chloronitrobenzene (p-CNB) to p-chloroaniline (p-CAN). In this procedure, morpholine can connect with the polymer layer in a form of amide bond and acts as an unparalleled immobilized dechlorination inhibitor, which can avoid further dechlorination efficiently and keeps stability due to the repulsive effect from the surviving C-O-C bond. The catalyst as prepared was characterized by using XRD, TGA, SEM, TEM, FT-IR, and ICP-OES, and it was further tested in the selective hydrogenation of p-CNB. It shows a supreme catalytic activity (almost 100%) and selectivity (up to 99.51%) after recycling for even 10 times, much superior to the blank alumina supported palladium (47.09%).

Schiff base decorated magnetic composites (Fe3O4@SiO2-HO-S and Fe3O4@SiO2-HE-S) were synthesized via homogeneous and heterogeneous method, respectively. The adsorption property for Co(II) and Zn(II) from ethanol was investigated systematically by considering the effects of contact time, temperature, initial metal ion concentration, and coexisting metal ion. Result shows that the magnetic composites exhibit better adsorption performance toward Co(II) and Zn(II) as compared with Fe(III), Cd(II), and Cu(II). The adsorption of Co(II) and Zn(II) can reach equilibrium at about 175 and 200 min, respectively. Adsorption kinetic can be well fitted by pseudo-second-order model and is controlled by film diffusion process. Adsorption isotherm indicates that the adsorption favors high initial metal ion concentration and temperature. The adsorption isotherm suggests the adsorption proceeds by monolayer behavior and chemical mechanism. Thermodynamic parameters demonstrate that the adsorption is exothermic, spontaneous, and entropy increased process. Fourier transform infrared spectroscopy (FTIR), X-ray photoelectron spectroscopy (XPS) and density functional theory (DFT) calculation demonstrate the participation of nitrogen and oxygen atoms during the adsorption, and nitrogen atoms play the dominant role for the adsorption. Regeneration indicates Fe3O4@SiO2-HE-S and Fe3O4@SiO2-HO-S can be reused as promising adsorbents for the removal of metal ion from ethanol.

The excitation-wavelength-dependent photoluminescence (EWDP) property of flexible organic ligand 1,4-bis(2-methyl-imidazol-1-yl)butane (Bmib) was observed. Herein, Bmib was chosen as a bridge linker to react with AgX (X = Br and I) to synthesize novel coordination network compounds (CNCs) with interesting EWDP properties. As anticipated, under the same hydrothermal synthesis conditions, two new isomorphic CNCs, i.e. [Ag2(Bmib)Br2]∞ (IAM16-1) and [Ag2(Bmib)I2]∞ (IAM16-2), as the first examples of CNCs showing EWDP properties, have been obtained. The EWDP properties may be attributed to the stretch and rotation of the long -(CH2)4- chains of Bmib and the spatial orientation adjustment of the methyl group of each imidazole ring at different excitation wavelengths. It is a great challenge to point out the emission mechanisms of CNCs merely from the experimental results due to their multiple charge transfer routes. To address this issue, we adopt DFT calculations to pursue in-depth investigation of the emission mechanisms for IAM16-1 and IAM16-2, respectively.

The self-assembly of an amphiphilic peptide molecule to form nanofibers facilitated by Ag(+) ions was investigated. Ultrafine AgNPs (NPs=nanoparticles) with an average size of 1.67 nm were synthesized in situ along the fibers due to the weak reducibility of the -SH group on the peptide molecule. By adding NaBH4 to the peptide solution, ultrafine AgNPs and AuNPs were synthesized with an average size of 1.35 and 1.18 nm, respectively. The AuNPs, AgNPs, and AgNPs/nanofibers all exhibited excellent catalytic activity toward the reduction of 4-nitrophenol, with turnover frequency (TOF) values of 720, 188, and 96 h(-1) , respectively. Three dyes were selected for catalytic degradation by the prepared nanoparticles and the nanoparticles showed selective catalysis activity toward the different dyes. It was a surprising discovery that the ultrafine AuNPs in this work had an extremely high catalytic activity toward methylene blue, with a reaction rate constant of 0.21 s(-1) and a TOF value of 1899 h(-1) .

The relaxometric properties of ultrasmall Gd2O3 nanoparticles coated with various ligands were investigated. These ligands include small diacids with hydrophobic chains, namely, succinic acid (Mw = 118.09 amu), glutaric acid (Mw = 132.12 amu), and terephthalic acid (Mw = 166.13 amu), and large polyethylenimines (PEIs) with hydrophilic chains, namely, PEI-1300 ( M ¯ n = 1300 ) and PEI-10000 ( M ¯ n = 10000 ). Ligand-size and ligand-chain hydrophilicity effects were observed. The longitudinal (r1) and transverse (r2) water proton relaxivities generally decreased with increasing ligand-size (the ligand-size effect). The ligand-size effect was weaker for PEI because its hydrophilic chains allow water molecules to access the nanoparticle (the ligand-chain hydrophilicity effect). This result was explained on the basis of the magnetic dipole interaction between the dipoles of the nanoparticle and water proton. In addition, all samples were found to be non-toxic in cellular cytotoxicity tests.

Bilayers at high pH in the fatty acid systems of palmitic acid/KOH/H2O, palmitic acid/CsOH/H2O, stearic acid/KOH/H2O and stearic acid/CsOH/H2O can form spontaneously (Xu et al., 2014, 2015). In this work, the bilayers can still be observed at 25°C with an increase of the concentration of fatty acids. We found that wormlike micelles can also be prepared in the fatty acid soap systems at high pH, even though the temperature was increased to be 50°C. The viscoelasticity, apparent viscosity, yield stress of the bilayers were determined by the rheological measurements. Wormlike micelles were identified by cryogenic transmission electron microscopy (cryo-TEM) and emphasized by the rheological characterizations, which are in accordance with the Maxwell fluids with good fit of Cole-Cole plots. The phase transition temperature was determined by differential scanning calorimetry (DSC) and the transition process was recorded. The regulating role of counterions of fatty acids were discussed by (CH3)4N(+), (C2H5)4N(+), (C3H7)4N(+), and (C4H9)4N(+) as comparison, concluding that counterions with appropriate hydrated radius were the vital factor in the formation wormlike micelles.

Water-soluble and biocompatible D-glucuronic acid coated Na2WO4 and BaCO3 nanoparticles were synthesized for the first time to be used as x-ray computed tomography (CT) contrast agents. Their average particle diameters were 3.2 +/- 0.1 and 2.8 +/- 0.1 nm for D-glucuronic acid coated Na2WO4 and BaCO3 nanoparticles, respectively. All the nanoparticles exhibited a strong x-ray attenuation. In vivo CT images were obtained after intravenous injection of an aqueous sample suspension of D-glucuronic acid coated Na2WO4 nanoparticles, and positive contrast enhancements in the kidney were clearly shown. These findings indicate that the nanoparticles reported in this study may be promising CT contrast agents.

A salt-free surfactant system formed by a peptide amphiphile with short headgroup (PA,C16-GK-3) and a zwitterionic surfactant (dodecyldimethylamine oxide, C12DMAO) in water has been systematically investigated. The microstructures and properties of C16-GK-3/C12DMAO mixed system were characterized using a combination of microscopic, scattering and spectroscopic techniques, including transmission electron microscopy (TEM), field emission-scanning electron microscopy (FE-SEM), atomic force microscopy (AFM), Fourier transform infrared (FT-IR), circular dichroism (CD) and rheological measurements. Rich phase transitions have been observed by adjusting the concentration of C16-GK-3. Investigation of the hydrogels of C16-GK-3/C12DMAO with TEM, SEM and AFM showed that all of these hydrogels form nanobelts. The nanobelt formation is performed in a hierarchical manner: β-sheet peptides and C12DMAO first interact each other to form small aggregates, which then arrange themselves to form one dimensional (1D) left-handed ribbons. The ribbons further aggregated into flat and rigid nanobelts. We proposed a mechanism to interpret the self-assembly process according to the specific peptide structure as well as multiple equilibria between the hydrogen bonding interactions between the headgroups of C16-GK-3, between C12DMAO molecules and the headgroups of C16-GK-3, chirality of the amino acid residues and hydrophobic interactions of the alkyl chains.