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In this letter, we present an electro-driven cylindrical actuator system composed of a bilayered liquid crystal elastomer/carbon black (LCE/CB) electro-driven soft actuator and a conductive track. The bilayered LCE/CB electro-driven actuator consists of an inner LCE circular band and several U-shaped CB conductive regions stuck on the outer surface of the LCE ring. Benefiting from the effective Joule heating of CB powder and the consequential inhomogeneous stress generated inside the bilayered LCE/CB film, the cylindrical actuator can roll forward with a rate of 1.6 mm/s along a stationary copper conductive track powered by a 50 V direct current supply. The dynamic connection between the rolling actuator and the conductive track effectively eliminates the limitation of electric wires in the complicated actuation set-ups of the LCE materials. This work might promote the development of electro-driven LCE actuators and have potential applications in the fields of soft robots and electric devices.

Bioinspired smart materials with synergistic allochroic luminescence and complex deformation are expected to play an important role in many areas of science and technology. However, it is still challenging to fabricate such soft actuators with high programmability that can be manipulated in situ with high spatial resolution. Herein, we have incorporated terminally functionalized aggregation-induced emission active tetraphenylethene derivative and photochromic spiropyran moieties into the networks of liquid crystal elastomers through covalent bonding to obtain the synergistic photochromic luminescence and programmable soft actuators. Bio-mimic functions and light-induced auxetic metamaterial-like devices were shown to be feasible based on the combination of assembly and origami-programming strategy. These bioinspired devices with synergistic photochromic luminescence and complex photodeformation abilities provide an elegant strategy to design multi-functional liquid crystal actuators.

Nanoporous materials derived from hydrogen-bonded supramolecular liquid crystal complexes present a promising and prevalent perspective in selective adsorption, water desalination, ion conductivity...

Nowadays, two-way shape memory polymeric materials with reversible shape-morphing capability exhibit extraordinary application prospects in robotic, biomedical and intelligent material technologies, and have attracted extensive scientific attention. However, the exploration of facile and efficient preparation protocols for the development of two-way shape memory polymers remains challenging. Here we report a two-step copper-catalyzed azide–alkyne cycloaddition (CuAAC) click chemistry strategy to synthesize a new type of main-chain liquid crystal elastomer (MCLCE) material directly from two small molecule monomers bearing terminal dialkyne and diazide units respectively. The azide–alkyne MCLCEs exhibit highly ordered enantiotropic smectic A phase, fully reversible thermal-actuating behavior and excellent mechanical properties. Furthermore, through doping photothermal dyes, coating electric conductive layers and complex programming protocols, the azide–alkyne MCLCE actuators can be fabricated as multifunctional two-way shape memory actuators, such as photo-responsive actuators, electric-responsive actuators and three-dimensional (3D) shape-morphing actuators, which can perform reversible 1D contraction/expansion, 2D bending/unbending, 3D helical curling/uncurling and diversified shape motion modes. This facile CuAAC in situ polymerization/crosslinking approach might bring a new perspective for the development of two-way shape memory polymeric materials with superior mechanical properties and enhanced shape morphing complexity.

With the rapid development of portable electronics, a flexible supercapacitor (SC) is highly desired for energy storage devices due to its fast charging, large capacitance and high energy density. However, inferior interfacial property is a common problem faced by many flexible electrodes, which can result in reduced electrochemical performance and limited stability. Herein, an “inverted load” strategy, which is in contrast to the traditional “forward load” method, is used to deposit the active material, the conductive layer and the flexible substrate sequentially on a glass plate, followed by peeling of the whole film, to fabricate an integrated flexible electrode. This innovative strategy contributes to the strong interlayer adhesion of the electrode, which greatly improves the electrochemical properties and stability. In the integrated electrode, a silver nanowires (AgNWs) network is tightly embedded between the PEDOT:PSS buffer layer and the colorless polyimide (CPI) substrate, which endows this electrode with excellent conductivity and bending stability. A higher specific capacitance (15.8 mF cm−2 at a current density of 0.1 mA cm−2) and an enhanced capacitance retention of 92% after 10 000 CV cycles can be achieved for the W0.71Mo0.29O3/PEDOT:PSS/AgNWs/CPI (WPAC) electrode with W0.71Mo0.29O3 as the active layer, while the PEN/ITO/PEDOT:PSS/W0.71Mo0.29O3 (PIPW) electrode prepared by the traditional “forward load” method only reaches 8.0 mF cm−2 at the same current density with a poor electrochemical cyclic stability of 48% after only 1000 CV cycles. Taking advantage of the superflexibility of the CPI substrate, the electrode can achieve outstanding flexible bending stability with the resistance of the WPAC electrode increasing less than 1% with almost no capacitance loss after 10 000 times of bending with a curvature radius of 500 μm. This novel strategy provides a new perspective on the design and fabrication of a transparent, stable and flexible electrode for electronic devices.

Ring-opening metathesis polymerization (ROMP) has been regarded as a powerful tool for sequence-controlled polymerization. However, the traditional entropy-driven ROMP of macrocyclic olefins suffers from the lack of ring strain and poor regioselectivity, whereas the relay-ring-closing metathesis polymerization inevitably brings some unnecessary auxiliary structure into each monomeric unit. We developed a macrobicyclic olefin system bearing a sacrificial silyloxide bridge on the α,β'-positions of the double bond as a new class of sequence-defined monomer for regioselective ROMP. The monomeric sequence information is implanted in the macro-ring, while the small ring, a 3-substituted cyclooctene structure with substantial ring tension, can provide not only narrow polydispersity, but also high regio-/stereospecificity. Besides, the silyloxide bridge can be sacrificially cleaved by desilylation and deoxygenation reactions to provide clean-structured, non-auxiliaried polymers.

Silicone rubber (SIR) is widely used in the field of high-voltage cable accessories insulation due to its excellent electrical properties. However, according to statistics, in 2016 alone, there were many cable accidents at home and abroad, among which cable accessories failure accounted for 85.5%. In order to fit closely with the cable, the high-voltage cable accessories adopt the installation method of pre-expanding and maintain the expanding state in the long-term operation of the cable. The silicone rubber is deteriorated by the circumferential mechanical stress, which is easy to lead to electrical tree and finally cause breakdown fault. At present, because the steel needle electrode is easy to form gas gap with the insulating material which results in the error of electrical tree experiment under the large deformation, the research on mechanical stress is mainly focused under 30% deformation, which is far less than the actual diameter expansion ratio of 45%. In this paper, in order to approach the actual working state of the insulation material of accessories, the initial voltage and morphological characteristics of silicone rubber electrical tree under large tensile ratio of 0%, 25%, 45% and 60% were studied. In order to avoid the stress concentration at the tip of the traditional steel needle electrode, a new semi conducting needle electrode was designed and successfully manufactured, and a real-time observation system of electrical tree under power frequency was built. The results showed that the initial voltage of semi conducting needle electrode was higher than that of traditional needle electrode under the same tree initiation condition. With the increase of tensile mechanical stress, the initial voltage decreased from 15.30kV to 14.33kV, and the electrical tree tended to grow in the direction of stress application. Combined with the test results of Differential scanning calorimetry and Thermogravimetric Analysis, it can be seen that the "melting point" and the temperature of maximum thermogravimetric rate increased first and then decreased with the increase of tensile ratio. At low tensile ratio, small-scale fracture of SIR molecular chain occurred, and the amorphous region increased. At high tensile ratio, the number of broken molecular chains increased. On the whole, the physical crosslinking of silicone rubber was destroyed, some molecular segments cracked, the free volume inside the material became larger, the electrical tree was more easily induced, and the electrical tree resistance of the material decreased.

Dissipative self-assembly, which requires a continuous supply of fuel to maintain the assembled states far from equilibrium, is the foundation of biological systems. Among a variety of fuels, light, the original fuel of natural dissipative self-assembly, is fundamentally important but remains a challenge to introduce into artificial dissipative self-assemblies. Here, we report an artificial dissipative self-assembly system that is constructed from light-induced amphiphiles. Such dissipative supramolecular assembly is easily performed using protonated sulfonato-merocyanine and chitosan based molecular and macromolecular components in water. Light irradiation induces the assembly of supramolecular nanoparticles, which spontaneously disassemble in the dark due to thermal back relaxation of the molecular switch. Owing to the presence of light-induced amphiphiles and the thermal dissociation mechanism, the lifetimes of these transient supramolecular nanoparticles are highly sensitive to temperature and light power and range from several minutes to hours. By incorporating various fluorophores into transient supramolecular nanoparticles, the processes of aggregation-induced emission and aggregation-caused quenching, along with periodic variations in fluorescent color over time, have been demonstrated. Transient supramolecular assemblies, which act as fluorescence modulators, can also function in human hepatocellular cancer cells., Dissipative self-assembly, which requires a continuous supply of fuel to maintain the assembled states far from equilibrium, is the foundation of biological systems but it remains a challenge to introduce light as fuel into artificial dissipative self-assemblies. Here, the authors report an artificial dissipative self-assembly system that is constructed from light-induced amphiphiles.

In recent years, sequence-controlled side-chain liquid crystal polymers (SCLCPs) have gained extensive interest because mesogenic units with different lengths and distributions can form various ord...

The pharmaceutical wastewater (PW) produced during the production of antibiotics has a huge impact on the ecological environment. The efficient removal of residual antibiotics from PW has become a great challenge. Here, a ZIF-8/GO composite film, a new material, was prepared by loading ZIF-8/GO nanosheets onto the surface of a polyethyleneimine- (PEI-) modified nylon microporous support. This new material can effectively remove tetracycline (TC) from PW with a removal rate of 99%. In addition, the layer of ZIF-8/GO nanosheets on the surface of the carrier had certain defect sites. This feature not only made the film have a relatively high flux (502 L·m−2·h−1·bar−1) but also overcame the disadvantages of the traditional membrane separation technology, such as the high operation pressure required by the easy plugging of micropores. More importantly, the abovementioned advantages enable the novel material to be applied on a larger scale. A probable adsorption mechanism was investigated and suggested.

Tooth variations in spur bevel gears have significant effects on the transmission performance, noise, and vibration and directly affect the reliability and stationarity of equipment. The hot forging process is the principal method used for the mass production of spur bevel gears owing to its high efficiency and high quality of products. However, hot forging of spur bevel gears is a high-pressure, high-temperature, and instantaneous forming process; hence, the evolution of tooth variations is extremely difficult to predict and measure. An accurate prediction of tooth variations in the hot forging process of spur bevel gears is an important precondition for tooth variation control to improve tooth accuracy. In this study, a new finite element (FE) analysis strategy of tooth variation prediction in the hot forging of spur bevel gears is proposed according to transitive relations of stress, strain, and temperature. Following this new strategy, a series of FE models are developed, so that the positional and shape variations on the tooth surface caused by die shrink-fitting (DSF), die elastic deformation (DED), die thermal expansion (DTE), gear elastic recovery (GER), and nonuniform cooling shrinkage of gear (NCSG) are comprehensively investigated. To verify the reliability of this FE analysis strategy, a hot forging experiment of a spur bevel gear was carried out, and the tooth variations of the tooth die and hot forged gear were measured using a gear-measuring machine. The results show that the factors causing the positional variation in order of importance from highest to lowest are DSF, DED, GER, NCSG, and DTE, and those for shape variation are DSF, DED, GER, DTE, and NCSG. Moreover, the shape variation of the final hot forged gear increases in the tooth profile direction and decreases in the tooth lengthwise direction. Finally, the simulation results closely agree with the experimental results, confirming the reliability of the FE analysis strategy proposed in this study.

In recent years, graphdiyne and its derivatives with fascinating electro-optic properties have attracted tremendous scientific attention. Here we design and synthesize a graphdiyne-derived discotic liquid crystal material by decorating six wedge-shaped 3,4,5-tris(dodecyloxy)benzoate groups on the fundamental structural unit of graphdiyne, the dehydrotribenzo[18]annulene core. This graphdiyne-derived liquid crystal material exhibits a cubic phase and a hexagonal columnar phase at varied temperatures. Most interestingly, this molecule displays a tunable phase-dependent photoluminescence behavior. Under the irradiation of 365 nm wavelength ultraviolet light, the luminescent material emits pale blue, green and azure light in the cubic, hexagonal columnar and isotropic phases respectively. This graphdiyne-derived discotic liquid crystal with excellent optical characteristics might have application potentials in organic optoelectronic functional materials and devices.

A snake-mimic soft actuator composed of a bilayered liquid crystal elastomer ribbon and two serrated feet is reported in this work. Under repeated on/off near-infrared light irradiation, this actuator can move forward relying on a reversible shape morphing between S-curve structure and reverse S-curve structure, which is similar to the serpentine locomotion of snakes.

Light-harvesting systems are an important way for capturing, transferring and utilizing light energy. It remains a key challenge to develop highly efficient artificial light-harvesting systems. Herein, we report a supramolecular co-assembly based on lower-rim dodecyl-modified sulfonatocalix[4]arene (SC4AD) and naphthyl-1,8-diphenyl pyridinium derivative (NPS) as a light-harvesting platform. NPS as a donor shows significant aggregation induced emission enhancement (AIEE) after assembling with SC4AD. Upon introduction of Nile blue (NiB) as an acceptor into the NPS-SC4AD co-assembly, the light-harvesting system becomes near-infrared (NIR) emissive (675 nm). Importantly, the NIR emitting NPS-SC4AD-NiB system exhibits an ultrahigh antenna effect (33.1) at a high donor/acceptor ratio (250:1). By co-staining PC-3 cells with a Golgi staining reagent, NBD C6 -ceramide, NIR imaging in the Golgi apparatus has been demonstrated using these NIR emissive nanoparticles.

The widely utilization of pharmaceutical and personal care products in the pharmaceutical therapies and agricultural husbandry has led to the worldwide pollution in the environment. However, effective purification of water contaminated by tetracycline (TC) remains a great challenge. Here, 2-dimensional (2D) zeolitic imidazolate framework-L (ZIF-L) nanoflakes with a leaf-like morphology, which could selectively adsorb TC, was successfully synthesized in aqueous media at room temperature. The removal efficiency of ZIF-L powder for TC from pharmaceutical wastewaters was greatly influenced by the solution pH, contact time, temperature and solution concentration. In order to solve these problems, ZIF-L nanoflakes were fabricated on the surface of polyethyleneimine (PEI) modified nylon microporous filter to form a 3-dimensional (3D) composite film by vacuum filtration. The result showed that this novel material could effectively remove about 99.0% of TC from pharmaceutical wastewater. Furthermore, ZIF-L film not only excluded the effects of solution pH, contact time, temperature and solution concentration on the adsorption capacity for TC, but also had a high flux (1639 L m−2 h−1 bar−1), making it suitable for a large-scale application. The probable adsorption mechanism was investigated and suggested.

Ion-exchange polymer SPEEK has been used as membrane material in proton exchange membranes and microfiltration/ultrafiltration /nanofiltration membranes. In the present study, SPEEK was synthesized by sulfonating of PEEK, afterward the SPEEKs were applied to prepare dense SPEEK/PES composite membranes for pervaporative desalination. Properties of the SPEEKs including thermal stability, ion exchange capacity and water uptake were measured. The SPEEK/PES membrane morphology and hydrophilicity were characterized. Influences of membrane prepare conditions (polymer concentration in supporting membrane, thickness of supporting membrane, sulfonation degree of SPEEK, coating layers and SPEEK concentration) and the pervaporation parameters (NaCl concentration and feed temperature) on the pervaporative desalination performance were studied. The SPEEK/PES composite membranes show high water flux up to 6 L/m2*h and salt rejection > 99.9%. During 40 h pervaporation for different NaCl concentrations (10–100 g/L) and temperatures (50–70 °C), the rejection maintains >99.9%. The permeate flux ranges to 2–6 L/m2 * h, depending on feed concentration and temperature. The total salt rejection of composite membranes is not affected by temperature and feed concentration, attributing to the supper hydrophilicity and stability of SPEEK. The results indicate that SPEEK could be considered as a candidate material for pervaporative desalination membrane.

With boron carbide (B4C) as sintering additives, silicon carbide (SiC) ceramics were prepared in 2100°C by solid-phase sintering under argon atmosphere. The change of microstructure, phase composition and density for all sintered samples were studied. The results showed that with the increase of B4C addition, the density of SiC ceramic was significantly increasing between 0-4 wt% of B4C addition and slightly increasing between 4-8 wt%. XRD analysis showed that all the ceramics without B4C were SiC-6H crystal, while those with B4C contained SiC-4H crystal, B4C turned SiC-6H to SiC-4H, and the more B4C added, the more change it made. SiC ceramic particles changed from equiaxial shape without B4C to flake shape with B4C added, and the particle sizes increased significantly with the amount of B4C additive.

A kind of supramolecular assemblies was constructed from two water-soluble and biocompatible saccharides, sulfonato-β-cyclodextrin (SCD) and chitosan, and characterized by dynamic light scattering (DLS), UV-vis, scanning electron microscopy (SEM), and transmission electron microscopy (TEM). The results showed that such nanoparticles presented good stability and controlled loading/release property, which enabled them as good drug carrier for berberine chloride (BE), a representative drug from traditional Chinese herbs. That is, the nanoparticles can load BE with high stability in a low-pH environment like that of the stomach but released BE when moved to a high-pH environment like that of the intestine.

In recent years, several cases of 220 kV silicone rubber cable joint failures have been reported in China. The faults were hypothetically attributed to air gap at insulation-semicon interface and electrical tree in insulation. It is thus important to gain a better understanding on the influence of these types of defects on the electric field distribution. In this paper, we present the simulation of 220kV cable joints under different defected cable joints. The parameters set in the simulation were based on the experimental results obtained by testing the relative permittivity, dissipation factor, volume resistivity of the silicone rubber of the defected cable. The breakdown strength of the silicone rubber was also tested to investigate whether or not the theoretical electric field obtained in the simulation is higher than the breakdown strength. The results show that the electrical field concentrates at the surface of high voltage shield and the interface between the semi-conducting stress cone and cable insulation. Air gap and electrical tree distort the electric field distribution. The strength of the electric field at the defect is much higher than the breakdown strength of silicone rubber. Therefore, defects present in cable joint are supposed to accelerate the thermal ageing of the cable insulation and hence promote the growth of electric tree which will finally lead to unexpected cable failure.

By means of solution polymerization, a series of cross-linked starch-g-polyacrylamide/ montmorillonite (St-g-PAM/MMT) nanocomposites were prepared and used to adsorb methylene blue (MB). The effects of different preparation conditions on the adsorption capacity of the nanocomposites were investigated. The experimental results demonstrated that the prepared St-g-PAM/MMT nanocomposites were effective adsorbents for removal of MB from aqueous solution. Furthermore, adsorption capacity increased with the MMT contents up to 14% and decreased as the MMT contents further increased. Adsorption capacity increased with the increasing of the ratio of starch to acrylamide, whereas adsorption capacity decreased with the increasing of crosslinking agent contents.

Montmorillonite (MMT) was applied as the modifying agent, polyethylene glycol bisglycidyl ether as crosslinking agent, Poly(γ-glutamic acid)/montmorillonite (γ-PGA/MMT) superabsorbent nanocomposite was prepared. The effects of crosslinking agent mass, MMT contents and reaction temperature on the saline water absorbency of the superabsorbent nanocomposites were studied. The experimental results demonstrated that the saline water absorbency of γ-PGA/MMT nanocomposites increased with the increasing of crosslinking agent mass firstly and decreased when the crosslinking agent mass was higher than 0.6g. The saline water absorbency of γ-PGA/MMT nanocomposites increased with the MMT contents up to 7% and decreased as the MMT contents further increased. Moreover, the saline water absorbency of γ-PGA/MMT nanocomposites increased with the reaction temperature firstly, and then decreased when the reaction temperature was higher than 50°C.

Pressboard, a common kind of electrical insulating material, is widely used in the gas insulator transformer (GIT). While a GIT was in operation, the properties of the pressboard changed under the influence of sulfur hexafluoride (SF 6 ) and heat. In this paper, pressboard was subjected to an accelerated aging test in SF 6 atmosphere at different temperatures for varying durations. In the research several tests were conducted, including thermogravimetric analysis (TGA), Fourier transform infrared spectroscopy (FTIR), a bending test, scanning electron microscopy (SEM), a dielectric properties test, and a polymerization degree test. These were carried out to research the heat stability, mechanical properties, dielectric properties, and microstructure of the pressboard at different stages of aging: The reasons for these changes could be discovered by analyzing the results. The results showed that thermal degradation of cellulose at high temperature was the main aging factor in pressboard during the thermal aging process in a SF 6 atmosphere, which also caused deterioration in the heat stability of pressboard. The mechanical properties of the pressboard deteriorated as thermal aging increased, while dielectric properties increased which were indicated by the decrease in electric inductivity and dielectric loss, and the increase in electrical resistivity. The main causes for these changes were the fracturing of the main chain of the cellulose molecules and a decrease in polar groups, such as hydroxyl, which caused a decline in the hydrophilia of the pressboard. As a consequence, the water content and the number of hydrogen bonds in the materials decreased, leading to structural degradation and a decrease in polarity of the pressboard.

Silane coupling agent KH-570 was applied to modify the surface capability of the alumina (Al2O3). The modified Al2O3were dispersed in styrene. The in-situ polymerization was used to prepare the polystyrene/alumina (PS/Al2O3) composites, in which azodiisobutyronitrile (AIBN) was used as initiator. FTIR, DSC and TG were applied to characterize the prepared composites. The solvent resistance, thermal resistance of the composites and the average molecular weight of PS in PS/Al2O3nanocomposites were studied. The experimental results demonstrated that the solvent resistance of PS/Al2O3nanocomposites was improved by the adding of Al2O3nanoparticles. The thermal resistance of the composites increased with the increasing of the Al2O3content. Meanwhile, the molecular weight of PS in the composites increased with the increasing of the Al2O3content.

The composite was prepared with montmorillonite (MMT) and poly(γ-glutamic acid) (γ-PGA). Applied the composite as the sorbent, methylene blue as the adsorbate, the influences of the initial concentrations of methylene blue, adsorption time and pH values of the solution on the adsorption capacity of methylene blue by the composite were studied. The experimental results showed that the adsorption capacity of methylene blue by MMT/γ-PGA composite both increased with the increasing of initial concentration of methylene blue and the prolonging of adsorption time, and then approached saturation respectively. The adsorption capacity of methylene blue by MMT/γ-PGA composite increased with the increasing of pH values of methylene blue solution. Meanwhile, the study of adsorption mechanism demonstrated that the adsorption of methylene blue by MMT/γ-PGA composite was Langmuir type, and the adsorption equation wasΓ=0.204c/(1+0.381C).

Ethylene vinyl acetate copolymer (EVA) and very low density polyethylene (VLDPE) blends filled with magnesium hydroxide (MH) were compounded by melt blending. Two kinds of surface treatments were used in this research, including stearic acid and epoxy silane. The composites were analyzed by scanning electron microscopy, thermogravimetric analysis, differential scanning calorimetry, limiting oxygen index (LOI), and cone calorimeter testing to study the effects of stearic acid and epoxy silane on the structure and flame-retardant properties of the MH/EVA/VLDPE composites. The results indicate that stearic acid and epoxy silane had different effects on the interfacial interaction of the MH/EVA/VLDPE composites; this made a difference in the condensed phase of the physical process. Thus, the composites with different surface treatments had different flammability characteristics, thermal degradation processes, char yields, and LOIs. © 2012 Wiley Periodicals, Inc. J Appl Polym Sci, 2012

A magnetite ferrofluid coated by dextran with a high specific absorption rate (SAR) of 75 W/g in an AC field of 55 kHz and 200 Oe was prepared by the gel crystallization method with ultrasonic treatment. For comparison, uncoated magnetite particles with a mean diameter of 50 nm were also fabricated. Several possible mechanisms such as Brownian, Neel and diffusion relaxation processes on heating effects and their influence on SAR are discussed. Several factors which can increase the value of SAR were discussed, including dextran coating, ultrasonic treatment, proper particle size and the presence of defects and disorder in the particles.

XLPE, which exhibits good electric insulation and mechanical properties due to its chemical crosslinked structure, has been used as modern extruded cable insulation materials for nearly 60 years. However, XLPE cannot be easily recycled in the end of its lifetime so that there will be a big issue in dealing with XLPE craps. New polyethylene blending materials, which have suitable recyclability and comparable dielectric and mechanical properties with XLPE, is gaining increasing attention. In this investigation, dielectric behaviors of a new blending material have been compared with XLPE. This new blend contains liner low-density polyethylene as matrix and high-density polyethylene as blending. XLPE, pure liner low-density polyethylene and highdensity polyethylene are also prepared and tested for comparison. DC resistivity, permittivity, loss tangent and breakdown strength of these materials are measured at 30°C, 45°C 60°C, 75°C, 90°C respectively. The temperature dependence of dielectric properties for these systems has been measured and discussed. The results show that temperature dependence of DC resistivity, permittivity for these materials present the similar tendency. However, the new thermo-plastic polyolefin blends show lower loss tangent and higher breakdown strength than XLPE especially the loss tangent at high temperature. The results suggest that the blend has a great potential to be used for extruded cables.

Since 1960s cross-linked polyethylene (XLPE) has become one of the most important insulation materials for extruded cables based on its excellent comprehensive performances including electrical, mechanical and thermal properties. However, the disadvantages of high level energy consuming in manufacturing process and hard to recycle at the end of lifetime have been non-negligible economic and environmental problems. Therefore, developing new insulation materials which are recyclable and low energy consuming is imperative. In this work, we study the mechanical properties of the binary blend system which contains high density polyethylene (HDPE) and linear low density polyethylene (LLDPE). The samples with different proportions are blended with rheometer and shaped in the specific moulds with press vulcanizer. The large-stress properties have been characterized by tensile tests and cantilever beam impact tests. The results show that the 70wt%LLDPE-30wt%HDPE blend exhibits the optimal mechanical properties with relatively high mechanical strength of 31MPa in tensile strength and 829% in breaking elongation (higher than XLPE) and low modulus of 450MPa (higher than XLPE) in blending system. Furthermore, the small-stress property of 70wt% LLDPE-30wt% HDPE blend is measured by dynamic thermo-mechanical analysis (DMA). In addition, the creep property of 70wt% LLDPE-30wt% HDPE blend is even better than XLPE below 130?. Therefore such a blend exhibits good mechanical behaviors and may find its potential application as an insulation material.

Three novel Ba5RNiNb9O30 (R=La, Nd and Sm) ceramics were prepared and characterized in the BaO−R2O3−NiO−Nb2O5 system. All three compounds are paraelectric phases adopting the filled tetragonal tungsten bronze (TB) structure at room temperature. At 1MHz, Ba5RNiNb9O30 ceramics have a high dielectric constants in the range 193–245.3, a low dielectric loss in range 0.0059–0.0087, and the temperature coefficients of the dielectric constant (τe) in the range −1140- −1310×10−6·°C−1. Their temperature coefficients of the dielectric constant are significantly reduced compared to those of Ba5RTi3Ta7O30 (R=La, Nd, Sm) ceramics.

Cu (In, Ga)Se2(CIGS) thin films were electrodeposited on Mo-coated soda lime glass substrate by the electrodeposition technique. The chemical bath for co-electrodeposition was prepared from copper chloride, indium chloride, gallium chloride and selenous acid. The effect of different chemical bath concentration of the CIGS films on the microstructure and electric properties has been investigated. The microstructure and morphology of the selenized CIGS thin films were investigated by X-ray diffraction and scanning electron microscopy. The composition of the selenized CIGS thin films were characterized by energy dispersive spectroscopy. Hall coefficient, Conductivity and Mobility of the selenized CIGS thin films were measured by ACCENT HL5500 Hall System. The results indicate CIGS thin films deviate little from the ideal stoichiometric one and single chalcopyrite structure. At room temperature, electrical conductivity, Hall mobility and charge-carrier concentration of the films vary from 49.63 to 64.56 (\(\Omega \cdot\)cm)‒1,271 to 386 cm2V‒1\(\cdot\)s‒1, 8.026 × 1017 to 1.4 87×1018 cm‒3, respectively, and are dependent on the composition of the films.

Amorphous silicon (a-Si) thin films were deposited on glass substrate by PECVD, and poly-crystalline silicon (poly-Si) thin films were prepared by aluminum-induced crystallization (AIC). The effects of annealing temperature on the microstructure and morphology were investigated. The AIC poly-Si thin films were characterized by XRD, Raman and SEM. It is found that a-Si thin film has a amorphous structure after annealing at 400°C for 20 min, a-Si films begin to crystallize after annealing at 450°C for 20 min, and the crystallinity of a-Si thin films is enhanced obviously with the increment of annealing temperature.

In this paper, XLPE/porous-ZnCO3 composites are prepared by melt blending method. The influences of partical content on the structure and performance of the composites are studied. Scanning electron microscopy was used to observe the particle shape of porous-ZnCO3. The differential scanning calorimetry(DSC) result indicates that porous-ZnCO3 is acting as nucleating agent to reduce the size of spherulite and then the degree of crystallinity. Thermal gravimetric analysis(TG) results show that the thermal stability of XLPE/porous-ZnCO3 composites was improved. Electrical experiments show that the dielectric constant of the composite increase with the porous particles content, but decrease with temperature.

In this paper, a series of montmorillonite/Cross-linked polyethylene nanocomposites containing different compatililizer (vinyl acetate copolymer (EVA) or ethylene-ethyl acrylate (EEA)) are prepared by melting blending method. The influence of compatibilizer on the dielectric property of the nanocomposites is studied. DSC is used to study the melting and crystallization behaviors of nanocomposites with and without compatibilizer. Dielectric spectrum of the nanocomposite is tested in room temperature. Dielectric constant and loss factor of different nanocomposites in wide frequency range are analyzed and the dynamic polarization behavior is discussed by the universal relaxation law (URL). Based on the structure characteristics, the effect of compatibilizer on the nanocomposite polarization is obtained.

In this essay the DC resistivity and high field conductive properties of nano metal/polymer composite are studied. It shows that if adding little small-sized Ag particles, the resistivity of composite increased obviously in comparison with pure epoxy resin, and the increasing of resistivity is related to the size and content of Ag particles, and the performance of polymer. High field conductive property of nano Ag/epoxy resin composite is studied. It is found that the capacitor network, which is formed by nano Ag in epoxy resin, has evident Coulomb blockade effect, and the conductance is obvious restricted in the composite, the slope of current density curve under log-log plot is less than 1; the comparative big nano metal, which tend to aggregation, will appear the space charge limitation current properties. It shows that the nano Ag particle has certain effect on the trap of composite, in high electric field a rather large space charge limitation current will appear because of the filling of the trap in composite.

Nano-Ag can be prepared through ultraviolet radiation reduction reaction and then the influence on nano-Ag particles by protecting agent, intensity of radiation and mixture ration is studied. The TEM result shows that Ag particles are dispersed evenly and the particle size is about 20 nm. Nano-dielectric with nano-Ag in epoxy resin is prepared successfully. The dielectric property of the composite is discussed. The result is that resistivity (rhov) and breakdown electric-field intensity (Eb) in room temperature of the composite are improved; the dielectric loss (tandelta) is reduced and the permittivity (epsivr) changes little. It can be seen that the dielectric property of base polymer material is improved by adding nano-Ag particles. This phenomenon is explained by Coulomb block effect

The corrosion is studied under the wet and grimy condition by acceleration test in this paper, and the lasting time is equivalent forty years of natural conditions. As a result, the main corrosion mode of metal parts in high voltage direct current is electrochemical corrosion. The rapidity of corrosion is relative to the leakage current and the processing technique. It is necessary to evaluate the corrosion resistant capability of metal parts in those support insulations which are assembled in heavy grimy areas or with high leakage current.

Zinc stannate (ZS) is a new kind of flame retardant agent. In this paper the effect caused by ZS and silicon synergistic agent to the hydroxide/polymer (EVA/LLDPE) system before and after aging process is studied by means of LOI, DSC, mechanical and dielectric properties measurements. The results show that before aging process the filling content of ZS has little influence on the flaming, mechanical and dielectric properties of the composite systems. But after aging process comparing with the composite without ZS, the strength of the composite with ZS is reduced sharply and the OI value is raised a little. The mechanism is primarily discussed in this paper.

Based on Biot's theory and the minimum potential energy principle as well as the thin plate theory, the superstructure, raft and soil are assumed to be a whole system according to the substructure method. The system must satisfy the continuity conditions at the interface between the superstructure, raft and soil surface. Considering the compatibility condition that the vertical displacement of the interface between the raft and the saturated soil should be equal, the integral equation accounting for the vertical coupling of the superstructure-raft system with the saturated soil subjected to a moving load is constructed. Using the numerical inverse transform technique, the forces and displacements of the superstructure, plate and saturated soil at any time are obtained. Some numerical results are presented to demonstrate the capacity of the proposed model. Also, the influence of load velocity on the superstructure will be investigated in this paper.

Sunlight-powered reduction of CO2 to fuels and chemicals is a promising strategy to close the carbon loop and facilitate the energy transition. In this research, we demonstrate that Au nanoparticles supported on TiO2 are an efficient plasmonic catalyst for the sunlight-powered reverse water-gas shift (rWGS) reaction. A maximum CO production rate of 429 mmol g(Au)(-1) h(-1) with a selectivity of 98 % and an apparent quantum efficiency of 4.7 % were achieved using mildly concentrated sunlight (1.44 W cm(-2) equals 14.4 sun). The CO production rate showed an exponential increase with increasing light intensity, suggesting that the process is mainly promoted by a photothermal effect. Thermal reference experiments with the same catalysts promoted CH4 formation, dropping the CO selectivity to 70 %. Thus, mildly concentrated sunlight can efficiently and selectively enhance the promotion of the rWGS reaction without using external heating. European Fund for Regional Development through the cross border collaborative Interreg V program Flanders-The Netherlands (project LUMEN); Belgian province of Limburg; Dutch province of Limburg; Dutch province of Noord-Brabant; Solliance