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The development of synthetic polymers that mimic the double-stranded helical structure of DNA is a fascinating topic in polymer science. In this study, we designed and synthesized two chiral norbor...

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.

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.

Liquid-crystal elastomer (LCE) materials, which have been developed and investigated for 4 decades, still lack real industrial applications. The fundamental obstacle is the modest force of LCEs generated in the LC-to-isotropic phase transition process, which is the most important actuation moment. Here, we report an interpenetrating liquid-crystal polyurethane/polyacrylate elastomer material, consisting of one main-chain polyurethane LCE and another liquid-crystal polyacrylate thermoset network, which are simultaneously polymerized. This two-way shape memory material can reversibly shrink/expand under thermal stimulus and show ultrastrong actuation-mechanics properties. With a maximum shrinkage ratio of 86% at 140 °C, which is beyond the LC-to-isotropic phase transition, its actuation blocking stress, actuation work capacity, breaking strength, and elastic modulus reach 2.53 MPa, 1267.7 kJ/m

In recent years, click chemistry has drawn intense research attention for the fabrication of main-chain liquid crystal polymers (MCLCPs) because of its vast technical advantages, such as ease of operation, green processes, atomic economy and high reaction yields. However, current click chemistry approaches (thiol–ene, thiol–yne and azide–alkyne polyadditions) and all other previous polycondensation methods have to prepare liquid crystal (LC) monomers first and then link LC monomers together to give the designed MCLCPs, efficient synthesis and rapid screening of novel MCLCP materials are still challenging. In this manuscript, a series of fluorosulfate-functionalized monomers and aryl silyl ether-containing monomers are polymerized via the newly-emerged sulfur(VI) fluoride exchange (SuFEx) click chemistry reaction, to form four MCLCPs P1, P2, P3 and P4, bearing sulfate ester groups in the polymer backbones. The chemical structures of these monomers and MCLCPs are confirmed by GPC and NMR techniques. The combination of DSC, POM and WAXS data indicates that although most of the monomers lack liquid crystallinity, their corresponding MCLCPs all exhibit LC phases. P1 and P3 have a nematic phase with a smectic fluctuation, while P2 and P4 show a nematic phase. Compared with all the previous polycondensation routes which must synthesize mesogenic monomers first and then prepare the corresponding MCLCPs, this novel SuFEx click chemistry strategy can synthesize MCLCP products from two orthogonal non-LC monomer groups, which might provide a new perspective for efficient synthesis and rapid screening of novel MCLCP materials.

A photo-responsive supramolecular assembly was successfully constructed through the stoichiometric 2 : 1 non-covalent association of two 4-(anthracen-2-yl)pyridine-2,6-dicarboxylic acid (1) units in one γ-cyclodextrin (γ-CD) cavity, followed by the subsequent coordination polymerization of the γ-CD·12 (12 = two 1) inclusion complex with Eu(III). Interestingly, owing to the photodimerization behavior of anthracene units and the excellent luminescence properties of Eu(III), the Eu3+⊂γ-CD·12 system showed multicolor fluorescence emission from cyan to red by irradiation for 0–16 minutes. Moreover, white light emission with CIE coordinates (0.32 and 0.36) was achieved at 4 min. Importantly, white light-containing multicolor emission could be obtained in water, solid films and living cells. Especially, the Eu3+⊂γ-CD·12 system could tag living cells with marvelous white fluorescence and display no obvious cytotoxicity. Thus, this supramolecular assembly offers a new pathway in the fields of tunable photochromic fluorescent ink and cell labelling.

Background As a pattern recognition receptor, Toll‐like receptor 7 (TLR7) widely presented in the endosomal membrane of various cells. However, the precise role and mechanism of TLR7 in septic cardiomyopathy remain unknown. This study aims to determine the role of TLR7 in cardiac dysfunction during sepsis and explore the mechanism of TLR7 in septic cardiomyopathy. Methods We generated a mouse model of septic cardiomyopathy by challenging with lipopolysaccharide (LPS). TLR7‐knockout (TLR7−/−), wild‐type (WT) mice, cardiac‐specific TLR7‐transgenic (cTG‐TLR7) overexpression, and littermates WT (LWT) mice were subjected to septic model. Additionally, to verify the role and mechanism of TLR7 in vitro, we transfected neonatal rat ventricular myocytes (NRVMs) with Ad‐TLR7 and TLR7 siRNA before LPS administration. The effects of TLR7 were assessed by Ca2+ imaging, western blotting, immunostaining, and quantitative real‐time polymerase chain reaction (qPCR). Results We found that TLR7 knockout markedly exacerbated sepsis‐induced systolic dysfunction. Moreover, cardiomyocytes isolated from TLR7−/− mice displayed weaker Ca2+ handling than that in WT mice in response to LPS. Conversely, TLR7 overexpression alleviated LPS‐induced systolic dysfunction, and loxoribine (TLR7‐specific agonist) improved LPS‐induced cardiac dysfunction. Mechanistically, these optimized effects were associated with enhanced the adenosine (cAMP)‐protein kinase A (PKA) pathway, which upregulated phosphorylate‐phospholamban (p‐PLN) (Ser16) and promoted sarco/endoplasmic reticulum Ca2+ ATPase (Serca) and Ryanodine Receptor 2 (RyR2) expression in the sarcoplasmic reticulum (SR), and ultimately restored Ca2+ handling in response to sepsis. While improved Ca2+ handling was abrogated after H89 (a specific PKA inhibitor) pretreatment in cardiomyocytes isolated from cTG‐TLR7 mice. Consistently, TLR7 overexpression improved LPS‐induced Ca2+‐handling decrement in NRVMs. Nevertheless, TLR7 knockdown showed a deteriorative phenotype. Conclusions Our data demonstrated that activation of TLR7 protected against sepsis‐induced cardiac dysfunction through promoting cAMP‐PKA‐PLN pathway, and we revealed that TLR7 might be a novel therapeutic target to block the septic cardiomyopathy and support systolic function during sepsis., Our study explored the effect of TLR7 activation, by which TLR7 modulated Ca2+ handling in septic cardiomyopathy. TLR7 protected against sepsis‐induced cardiac dysfunction through activation of cAMP‐PKA‐PLN pathway. Targeting this newly identified TLR7 may yield novel interventional solutions against septic cardiomyopathy.

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.

A supramolecular nanoparticle that realized the loading and sustained release of ATP was successfully constructed from sulfato-β-cyclodextrin (SCD) and polyethylenimine (PEI). The assembly and disassembly behaviors of supramolecular nanoparticle were investigated by means of Tyndall effect, UV–vis spectroscopy, dynamic light scattering (DLS), zeta potential and transmission electron microscopy (TEM). Significantly, the resulting nanoparticle was disrupted with the increasing of pH and recovered to the spherical nanoparticle as the pH decreased to initial value. Owing to the positive zeta potential, the supramolecular nanoparticle showed the good loading and sustained release abilities towards ATP.

Supramolecular hydrogels, which are usually used to develop excellent smart soft materials, are widely applied in miscellaneous fields due to their inherent reversible properties, unique functions and mechanical properties. Compared with covalently linked hydrogels, supramolecular hydrogels have advantages of easy preparation, stimulus responsiveness and good biocompatibility. Herein, after threading amino-modified β-cyclodextrins onto poly(propyleneglycol)bis(2-amionopropylether) (PPG-NH2) chains, the resultant pseudorotaxanes non-covalently interacted with a clay nanosheet (CNS) matrix to construct supramolecular hydrogels bearing negative charges, and the mechanical properties of these hydrogels were positively correlated with the number of amino groups on the pseudorotaxane. Significantly, these hydrogels presented good adsorption properties for cationic dyes. The adsorption capacity (Qe) of the hydrogels towards rhodamine B (RhB), crystal violet (CV), and methylene blue (MB) could reach 181–228 mg g−1, and most of the dyes were adsorbed within 5 min. Thus, these hydrogels may have potential applications in the field of waste water treatment.

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.

By means of grafting polymerization, cross-linked starch-g-polyacrylamide (starch-g-PAM) was prepared and used to adsorb methylene blue (MB). Adsorption isotherm and kinetic of the sorption process were studied. The experimental results demonstrated that the prepared starch-g-PAM was an effective adsorbent for removal of MB from aqueous solution. The adsorption of MB by starch-g-PAM was Freundlich type, and the adsorption equation was caculated to be . Furthermore, the adsorption kinetics analysis demonstrated that the adsorption process followed the pseudo-second-order model.

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.

A supramolecular hydrogel was successfully constructed by the noncovalent association of cucurbit[8]uril (CB[8]) with a tetraphenylethylene (TPE) derivative bearing four monocharged viologens (TPE-4Q). Due to the attractive photophysical behaviours of TPE and its rigid complexation with CB[8], the obtained hydrogel emits bright orange fluorescence and is highly thermostable even at 200 °C. Rheological analyses and microscopic investigations jointly confirm that the supramolecular hydrogel possesses good rheological properties and well-organised lamellar structures. Significantly, the assembly/disassembly process of this supramolecular hydrogel can be efficiently modulated by several external stimuli, including pH, mechanical force and competitive guests. Moreover, as investigated by UV/Vis and fluorescence titrations, this two-dimensional self-assembly can specifically adsorb π-conjugated anionic dyes in water with high adsorption efficiency, mainly through the π-stacking interaction with TPE backbones and the electrostatic interaction with monocharged viologen sites.

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).

By using grafting reaction, starch-g-poly (acrylic acid) (starch-g-PAA) hydrogel was prepared and used to adsorb methylene blue (MB). Adsorption isotherm and kinetic of the sorption process were studied. Meanwhile, various thermodynamic parameters were calculated. The absorption experimental results demonstrate that the prepared starch-g-PAA is an effective adsorbent for removal of MB from aqueous solution. The adsorption of MB by starch-g-PAA is Freundlich type. Furthermore, the adsorption kinetics analyze demonstrates that the adsorption process follows the pseudo-second-order model, and the adsorption is a multi-step process. Moreover, the calculated thermodynamic parameters indicate the spontaneous and endothermic nature of the adsorption process. The values of adsorption activation energy demonstrate that the adsorption is mainly diffusion-controlled process.

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

Circularly polarized luminescence (CPL) induced by host-guest complexation remains a challenge in supramolecular chemistry. Herein, a couple of CPL-silent enantiomeric guest binaphthylbis(4,4'-bipyridinium) salts can emit obvious CPL in the presence of cucurbit[8]uril in aqueous media, due to the restriction of molecular rotation limitation effect. Such CPL can be reversibly adjusted by the addition of acid and base. Furthermore, the resultant supramolecular systems can interact with DNA, accompanied by the morphological conversion from branched supramolecular nanowires to exfoliated nanowires, which can enable to the exploration of such supramolecular systems as DNA markers by CPL signals.

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.

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, 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.

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.