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BP anodes prepared in the ambient atmosphere are susceptible to reaction with copper current collectors to form Cu3P, thereby exhibiting significantly different electrochemical activity from those prepared in an inert environment.

Ionic polymer-Carbon nanotube composite (IPCC) actuators based on black phosphorus (BP)-Nafion composite membranes were fabricated. BP-Nafion composite was used as the ionic matrix with functional ...

In the field of flame retardant polymer, it is an important challenge by the addition of a small amount of flame retardant to obtain the flame retardancy that meet the application requirements. In ...

As a new member of 2D materials, the phosphorene possesses many unique characteristics compared with other carbon-based materials, which is strongly correlated to the structure and the electronic properties of phosphorus, can enable its use in electrochemical energy storage devices. Herein, we present a simpler approach to prepare phosphorene and then use it as an electrode in a new supercapacitor, which has a battery performance but works via the redox reaction of iodide ions on the interface of phosphorene electrode and electrolyte. The phosphorene is prepared by an electrochemical cathodic exfoliation method and the exfoliation mechanism is discussed. The high-quality phosphorene can be obtained within 5 min without ultrasonication and the yield is ∼93.1%. The dimension of phosphorene reaches micrometer grade. By virtue of the merit of the great electrocatalysis effect of phosphorene to iodide ions, the specific discharge capacity reaches to 3181.5 F/g in a three-electrode system and the largest specific energy density is 203.7 Wh/kg in an asymmetric hybrid system.

A 2D porous multifunctional Zn(II) metal–organic framework (MOF) [ZnL(H2O)3]·3H2O·DMF (BIPT-1·3H2O·DMF) has been successfully synthesized by using bis-(3-carboxy-phenyl)furan-2,5-dicarboxamide (H2L) as organic linkers under solvothermal conditions and characterized by single crystal X-ray diffraction analysis, IR spectroscopy, thermogravimetric analyses (TGA) and powder X-ray diffraction spectra (PXRD). The participation of long chain flexible organic ligands (H2L) not only offered BIPT-1·3H2O·DMF larger pore size and stronger fluorescence emission as expect, but also introduced more functional groups and active sites into the MOF structure which is conducive to its further applications. The luminescence analysis indicated that BIPT-1·3H2O·DMF exhibited a high selectivity and sensitivity fluorescence quenching toward to Fe3+ ions in water medium, which can be observed by naked eyes under UV light. This remarkable quenching effect can be explained by the competitive absorption of excited energy mechanism and the impediment of energy transfer mechanism. Meanwhile, BIPT-1·3H2O·DMF exhibited a rare capability of neutral MOF, i.e., to selectively adsorb cationic dyes, especially for methylene blue.

A novel supercapacitor system with an ultrahigh electrochemical performance was prepared by applying a multi-walled carbon nanotubes (MWCNTs) - polyaniline (PANI) composite electrode and a redox potassium iodide (KI) electrolyte. The composite electrode possessed a good conductivity and a consecutive 3D conductive network. The amazing electrochemical performance came from the simultaneous redox reaction in both electrode and electrolyte. The maximum discharge specific capacitance was up to 4960 F/g (0.1 A/g) when the concentration of KI electrolyte was only 0.05 M in a three-electrode system. After 1000 charge-discharge cycles, it still reached to 1550 F/g when the current density was increased to 1.5 A/g. Furthermore, the specific capacitance, energy density and power density of 726 F/g, 100.8 Wh/kg and 499.8 W/kg, respectively, were also obtained in an asymmetric two-electrode system.

The mesoporous manganese dioxide with high specific surface area was obtained through a one-pot prepare procedure at ambient temperature under acidic conditions. And the graphene/mesoporous manganese dioxide composite was synthesized by a simple hydrothermal approach. As a comparison, silver nanowires also as a conductor was added to the mesoporous manganese dioxide. Both of the graphene and silver nanowires can increase the capacitance of the mesoporous manganese dioxide-based composite electrode materials. Compared with the graphene/mesoporous manganese dioxide composite, the silver nanowires/mesoporous manganese dioxide mixture has a better electrochemical performance, the specific capacitance and energy density is almost 2.2 times larger than that of the composites. The morphology and detail structure were investigated by the Scanning electron microscopy, X-ray diffraction, Raman spectra, Fourier transform infrared spectrometry and Nitrogen adsorption–desorption isotherms. The electrochemical performance was assessed by the cyclic voltammograms, galvanostatic charge/discharge and electrochemical impedance spectroscopy.

A facile method to fabricate ionic polymer-metal composite (IPMC) actuators is proposed. A blend of mesoporous graphene (MG) and Nafion is used as the ionic matrix, which is sandwiched by two layers of blend of reduced graphene oxide (rGO) and Nafion as the electrodes. When subjected to an electrical field of 3 V, the IPMC actuator exhibits a blocking force of 10 gf g−1 for 20 s, and the same behavior can be repeatedly played for hundreds of cycles. MG improves the mechanical properties of Nafion-based IPMC, more importantly, the mesopores in graphene provide additional pathway for the diffusion of cationic clusters and thus enhance the actuation speed. In addition, the surface electrodes of rGO protect the interlamellar liquid from evaporation thus ensure the durability.

High performance electrodes for supercapacitor usually are achieved by compositing conductive and redox materials, the former such as multi-walled carbon nanotubes (MWCNTs), graphene, etc., provide the electrical double-layer capacitances that far less than pseudo-capacitances of the later (metal oxide, polyaniline, and so on). Here, carbonaceous composite electrode of MWCNTs and the redox electrolyte are combined into an electrochemical system for high synergetic effect of capacitance. MWCNT is activated by acid treatment and its structures are characterized by scanning electron microscope, X-ray diffraction, and Infrared spectroscopy analyses. The electrochemical measurements of resultant electrodes showed an excellent synergetic effect. The acid-activated MWCNTs electrode exhibited the maximum specific capacitance of 682 F/g in 0.2 M KI redox electrolytes, which is about 2–20 times larger than MWCNTs and its composite electrode in universal electrolyte without KI.

Nanostructured polyaniline was prepared using the template method in the mixed solvent that was composed of dimethyl formamide and distilled water. A series of tests were performed to examine the structural and electrical performance of polyaniline, including X-ray diffraction, scanning electron microscopy, Fourier-transform infrared spectrometry, nitrogen adsorption–desorption, cyclic voltammetry and galvanostatic charge–discharge tests. Results indicated that the mixed solvent could lead to a different morphology and influence the electrical performance of polyaniline in the system. The specific surface area of polyaniline was greatly improved and the electrical properties were enhanced correspondingly.

Phosphorene is a promising candidate for the pseudocapacitive electrode material, because it offers a huge number of ion-accessible sites for multiphase active materials. A high working temperature is bound to deteriorate the electrochemical behavior of supercapacitors due to exothermic redox reactions during the charge–discharge process. To address this problem in supercapacitors, a self-thermoregulatory electrode material is designed and constructed to enhance the electrical energy-storage performance of supercapacitors for use in a wider temperature range. This electrode material is fabricated by microencapsulating n-docosane phase-change material (PCM) with a SiO2 inner shell and then coating a polyaniline/phosphorene hybrid outer layer as an electrochemical active material. A well-defined core-shell microstructure and expected components of the resultant electrode material are confirmed by morphological observations and structural characterizations. In this electrode material, while the polyaniline/phosphorene hybrid layer performs charge storage/release behaviors according to the faradic mechanism, the PCM core can effectively regulate the microenvironmental temperature for the electrode system in situ through phase transitions, thus improving the rate capability and specific capacitance of the electrode system. Furthermore, the hybridization of polyaniline and phosphorene contributes to the enhancement of capacitive behavior and charge–discharge cycle stability by offering more ion-accessible site in the polyaniline active material. In view of a unique combination of phosphorene and PCM, the novel electrode material developed by this work exhibits a potential application for high-performance supercapacitors suitable for use at high working temperatures.

Phosphorus oxide modified graphene was prepared by one-step electrochemical anodic exfoliation method and utilized as electrode in a redox supercapacitor that contained potassium iodide in electrolytes. The whole preparation process was completed in a few minutes and the yield was about 37.2%. The prepared sample has better electrocatalysis activity for I−/I−3 redox reaction than graphite due to the good charge transfer performance between phosphorus oxide and iodide ions. The maximum discharge specific capacitance is 1634.2 F/g when the current density is 3.5 mA/cm2 and it can keep at 463 F/g after 500 charging–discharging cycles when the current density increased about three times.

In recent years, manganese dioxide has become a research hotspot as an electrode material because of its low price. However, it has also become an obstacle to industrialization due to its low ratio of capacitance and the low rate performance which is caused by the poor electrical conductivity. In this study, a KI solution with electrochemical activity was innovatively applied to the electrolyte, and we systematically investigated the rate performance of the mesoporous manganese dioxide and the composite electrode with silver nanowires in supercapacitors. The results showed that when mesoporous manganese dioxide and mesoporous manganese dioxide/silver nanowires composite were used as electrodes, the strength of the current was amplified five times (from 0.1 to 0.5 A/g), the remaining rates of specific capacitance were 95% (from 205.5 down to 197.1 F/g) and 92% (from 208.1 down to 191.7 F/g) in the KI electrolyte, and the rate performance was much higher than which in an Na2SO4 electrolyte with a remaining rate of 25% (from 200.3 down to 49.1 F/g) and 60% (from 187.2 down to 113.1 F/g). The morphology and detail structure were investigated by Scanning electron microscopy, X-ray diffraction, Fourier transform infrared spectrometry and Nitrogen adsorption-desorption isotherms. The electrochemical performance was assessed by cyclic voltammograms, galvanostatic charge/discharge and electrochemical impedance spectroscopy.

Conventional ionic polymer–metal composite actuator had two major drawbacks: (i) complicated and time-consuming fabrication of noble metal electrode and (ii) degradation of electromechanical property in open air. In this study, we proposed a facile method to fabricate graphene oxide (GO)-based electromechanical actuators with surface-reduced graphene oxide (rGO) as its electrodes. Such GO actuators were fabricated by evaporating the aqueous dispersion of exfoliated GO nanosheets, followed with in situ reduction of the surface of the GO nanosheets by hydrogen iodide (HI). When subjected to a 3 V electrical field, the GO actuator performed electromechanical bending action with a tip displacement of 5 mm and exhibited a blocking force of 10 gf g−1 for 10 s. In addition, the GO actuator showed an almost identical actuating behavior in cyclic measurements. The durable actuation could be attributed to both the unique lamellar structure of the GO film which blocked the diffusion of cationic clusters and the surface rGO electrodes which protected the interlamellar water from evaporation.

A novel high specific capacitance mesoporous polyaniline (PANI)/silica platelet nanocomposite electrode material for supercapacitors was prepared by an impregnation polymerization. The initiator was embedded firstly in the mesoporous silica pores and channels and then initiated the polymerization of aniline (AN). Compared with the other mesoporous silica materials, the mesoporous silica platelets possess a relative shorter mesoporous channels, leading an easier penetration process of initiator and AN to the inner of mesoporous silica platelets. The structures, morphologies and electrochemical properties of the nanocomposites were thoroughly studied by a series of methods, such as X-ray diffractometry, scanning electron microscope, nitrogen adsorption-desorption tests, infrared spectroscopy, thermogravimetric analysis, and electrochemical measurements. The results revealed that the PANI existed both in the inner and surface of the mesoporous silica platelets, leading a continual conductive network and a large specific surface area. These features provide the nanocomposites an excellent electrochemical performance. The biggest specific capacitance is 1598 F g−1 at a current density of 0.5 A g−1. POLYM. COMPOS., 2015. © 2015 Society of Plastics Engineers

The high gallium content and ordered mesoporous Ga-SBA-15 materials were prepared via a direct sol–gel hydrothermal approach. X-ray fluorescence, wide angle X-ray diffraction, nitrogen adsorption–desorption analysis, transmission electron microscopy, small-angle X-ray scattering and scanning electron microscopy are used to characterise the materials, and analysis of these results shows that the structure of these materials with different Si/Ga ratios is excellently ordered. Furthermore, the data of small-angle X-ray scattering and nitrogen adsorption–desorption analysis proved that the wall thickness of mesoporous Ga-SBA-15 materials was decreased by increasing the gallium content. Adsorption of xylene and hydroquinone over the different Si/Ga molar ratios of these materials was explored and the findings showed that SBA-15 did not perform as well.

Dielectric elastomers (DEs), which are capable of displaying considerable stress and strain in response to an applied electric field, have shown the closest similarity in performance to natural muscles. However, the high operating voltage of DEs limits their practical application. A reduction of the operating voltage can be achieved through increasing the dielectric constant and/or decreasing the elastic modulus. Here, an all-organic non-percolative dielectric composite with enhanced electromechanical actuating performance was prepared by introducing polyaniline (PANI) and epoxidized soybean oil (ESO) into a nitrile-butadiene rubber (NBR) matrix. A small amount of PANI was used to increase the dielectric constant through adding electron movement which is similar to dipole polarization, while ESO was used to decrease the elastic modulus of the composite through weakening intermolecular interactions in NBR and molecular interaction between NBR and PANI. Finally, an actuated strain of 2.5% was obtained at 4.5 V μm−1 by 4 phr PANI/NBR composite filled with 50 phr ESO, a 700% improvement in actuated strain compared with the actuated strain (0.31%) of pure NBR at 4.5 V μm−1 without any pre-strains. In comparison with other dielectric composites filled with conductive filler, the ESO/PANI/NBR composite also displays a relative advantage under conditions of no pre-strain and low electric field.

In order to improve compatibility between the dielectric filler and polymeric matrix, we used bio-inspired polydopamine (PDA) to modify titanium dioxide (TiO2) nano-particles. The PDA coated TiO2 (TiO2-PDA) nano-particles were incorporated into nitrile-butadiene rubber (NBR) which contains a large amount polar groups to obtain a dielectric elastomer composite with a large actuated strain under a low electric field. The relatively soft insulating PDA layer on the TiO2 nano-particles led to the composites filled with TiO2-PDA nano-particles displaying better filler dispersion, much lower elastic modulus, lower dielectric loss, and higher electric breakdown field compared with the composites filled with pristine TiO2 nano-particles, resulting in a high electromechanical sensitivity (β). At last, an actuated strain of 5.2% at a relatively safe electric field of 12.5 kV mm−1 without any pre-strains was obtained by the 10 phr TiO2-PDA/NBR composite, a 140% increase in actuated strain compared with the actuated strain (0.69%) of pure NBR at 20 kV mm−1 without any pre-strains. This biomimetic method is simple, efficient, nontoxic, and easy to control, which can be used in other dielectric fillers to improve electromechanical properties of dielectric elastomers.

The cooperative effects between the PANI (polyaniline)/nano-NiO (nano nickel oxide) composite electrode material and redox electrolytes (potassium iodide, KI) for supercapacitor applications was firstly discussed in this article, providing a novel method to prepare nano-NiO by using β-cyelodextrin (β-CD) as the template agent. The experimental results revealed that the composite electrode processed a high specific capacitance (2122.75 F·g−1 at 0.1 A·g−1 in 0.05 M KI electrolyte solution), superior energy density (64.05 Wh·kg−1 at 0.2 A·g−1 in the two-electrode system) and excellent cycle performance (86% capacitance retention after 1000 cycles at 1.5 A·g−1). All those ultra-high electrical performances owe to the KI active material in the electrolyte and the PANI coated nano-NiO structure.

A novel interpenetrating structural ultrafine polypropylene-silica nanocomposite particles were synthesized by a modified sol–gel approach in the presence of the melt polypropylene emulsion. A series of samples with different polypropylene content was prepared to investigate the unique characteristics of this original nanocomposite. The thermal gravimetric analysis and differential scanning calorimetry results showed that the nanocomposites had the interpenetrating structure and good thermal stability, and the crystallization behavior of polypropylene was confined by the silica matrix. The interpenetrating structure of nanocomposites was also suggested by the nitrogen adsorption–desorption measurement results. The scanning electronic microscope and transmission electron microscopy images indicated that the nanocomposites had irregular particle morphology. The nanoparticle tracking analysis results show that the mean size of the nanocomposites was around 160 nm. According to the results obtained from different measurements, a reasonable formation mechanism was proposed.

Conventional shape memory polymers suffer the drawbacks of low thermal stability, low strength, and low shape recovery speed. In this study, main-chain liquid crystalline polyurethane (LCPU) that contains polar groups was synthesized. Graphene oxide (GO)/LCPU composite was fabricated using the solution casting method. The tensile strength of GO/LCPU was 1.78 times that of neat LCPU. In addition, shape recovery speed was extensively improved. The average recovery rate of sample with 20 wt % GO loading was 9.2°/s, much faster than that of LCPU of 2.6°/s. The enhancement in mechanical property and shape memory behavior could be attributed to the structure of LCPU and GO, which enhanced the interfacial interactions between GO and LCPU.

We reported a real-time single carrier 400Gb/s system with baud rate of 61GHz. The reality challenges and corresponding DSP solutions are discussed. We show back-to-back as well as propagation performance of the system.

Insufficient energy density and poor cyclic stability is still challenge for conductive polymer-based supercapacitor. Herein, high performance electrochemical system has been assembled by combining poly (3,4-ethylenedioxythiophene) (PEDOT):poly (styrene sulfonate) (PSS) redox electrode and potassium iodide redox electrolyte, which provide the maximum specific capacity of 51.3 mAh/g and the retention of specific capacity of 87.6% after 3000 cycles due to the synergic effect through a simultaneous redox reaction both in electrode and electrolyte, as well as the catalytic activity for reduction of triiodide of the PEDOT:PSS.

Finely ordered SBA-15-type mesoporous silica materials were synthesized by templating with an amphiphilic block copolymer under various conditions, and their internal two-dimensional hexagonal mesostructures were confirmed by X-ray diffraction patterns, transmission electronic microscopy and nitrogen adsorption–desorption isotherms. Evaluation on morphological dependence of the synthetic conditions demonstrated that, for the samples synthesized through a one-step route, a variety of morphologies (e.g. short columns, spheres, hexagonal platelets, etc.) were achieved by means of adjusting acid species, reaction temperature, acidity and the concentration of inorganic salt. For the samples synthesized through a two-step route under mildly acidic conditions, the morphologies can be controlled by acidity of the solutions, and exhibits the irregularly faceted particles, the spherical ones, and the aggregated spheres by varying the pH from 1.02 to 2.61.

Well-ordered mesoporous silica materials were synthesized by using poly(ethylene oxide- b -propylene oxide- b -ethylene oxide) triblock copolymer as template through two-step pathway under mildly acidic conditions (pH 2.2–4.1). The highly ordered cage-like mesoporosity of the prepared materials having cubic Fm 3 m mesostructure was evidenced by the well-defined small angle X-ray diffraction patterns combined with transmission electron microscopy. Scanning electron microscopy observation exhibits a macron-sized spherical morphological structure for the prepared materials at pH 2.2, and a variation trend to small amount of spheres on the surface of randomly shaped agglomerations with increasing the pH value. The nitrogen adsorption–desorption analysis reveals that the prepared mesoporous silica materials have a uniform moderate-sized pore diameter (5.6–6.5 nm) and a very thick pore wall (4.96–6.10 nm). These features may lead to a much higher thermal, hydrothermal, and mechanical stability. The mesoporous silica materials synthesized in this study will favor the incorporation of catalytically active heteroatoms in silica frameworks, and the functionalization of organic groups for applications in catalysis, sensor and separation. The two-step synthetic method under mildly acidic conditions can also be extended to the production in the industrial scale as an environmentally friendly way.

Highly ordered mesoporous silica materials have been synthesized under mildly acidic conditions by templating with a nonionic triblock copolymer (Pluronic P104) in a two-step process. It was found that a transformation from the SBA-15 type 2-dimensional (2D) hexagonal channel mesostructure (p6mm symmetry) to the MSU-X type 3-dimensional (3D) worm-like mesostructure could be induced by varying the pH whilst keeping all other conditions constant. The transformation between two types of mesoporous silica materials can be attributed to the effect of varying proton concentration on the interaction between organic micelles and inorganic species. Both types of mesoporous materials have high surface areas, large pore volumes, thick pore walls, large mean pore sizes, and narrow pore size distribution.

The PANI/Mesoporous MnO2 composites were prepared through a simple one step method and we introduced the KI-H2SO4 solution as the electrolyte of PANI/MnO2 composites creatively. The characterization of structure, morphology, and composition are obtained by X-ray diffraction, Fourier transform infrared spectroscopy, thermal gravity analysis, Raman spectra, and scanning electron microscope. The electrochemical performances were investigated by constant-current charge–discharge, the voltammetry curve, and alternating current (AC) impedance technique. The specific capacitance of composites is 1405 F/g, which is almost 10 times larger than MnO2 (158 F/g). We also find that the iodide concentration is closely related to the specific capacitance. Therefore, we explored the specific capacitance at different iodide concentration (0.05, 0.1, 0.2, 0.5, and 1 M), the results indicated that the specific capacitance reached a maximum value (1580 F/g) at 0.5 mol/L. Additionally, the PANI/Mesoporous MnO2 composites not only exhibited a good ratio discharge property (857 F/g) at high current density, but also revealed an excellent cycling stability after 500 cycles, which retained 90% of the original specific capacitance.

Monodispersed SBA-15 equilateral hexagonal platelets with thick silica wall have been synthesized at high yield (∼ 100%) by a static self-assembly strategy in the presence of commercial non-ionic block copolymer P104 and inorganic salt under acidic conditions. The results of the experiments show that the synthesized materials have a uniform internal structure of the well-ordered hexagonal mesoporous channels arrayed vertically to the platelet face, and a high monodispersity both in external morphology and particle size. An external morphological evolvement from hexagonal corona to crystal-like hexagonal platelet and then to biscuit-like hexagonal plate, as well as an increase of the pore size and a decrease of the silica wall thickness with increasing K 2 SO 4 concentrations in the template solution, has been found.

Ordered and cubic mesoporous silica materials were synthesized by using poly(ethylene oxide-b-propylene oxide-b-ethylene oxide) triblock copolymer as template under a moderately acidic condition of 0.5 mol/l HCl solution. These mesoporous materials were characterized by Fourier transform (FT) IR spectroscopy, thermo-gravimetric analysis (TGA), X-ray diffraction (XRD) pattern, scanning electron microscopy (SEM), transmission electron microscopy (TEM), and nitrogen adsorption–desorption measurements. The three-dimensional cage-like microporosity of the prepared mesoporous silica having ordered hexagonal mesoporous structure was evidenced by the well-defined XRD patterns combined with TEM photographs. SEM observation shows a highly regular cubic crystal structure for the prepared mesoporous silica. The size of these crystallites was maintained within the range between 4 and 6 μm, which is fairly important for the application to the stationary phase for separation. The nitrogen adsorption–desorption analysis reveals that the prepared mesoporous silica possesses a small pore diameter of 3.68 nm, a total surface area of 363.648 m2/g, a total pore volume of 0.379 cm3/g, and a pore-wall thickness of 6.63 nm. These features may lead to higher thermal and hydrothermal stability, excellent microporosity, and good connectivity. The mesoporous silica prepared in this study exhibits potential applications to catalysis, sensoring, and separation.

The multilamellar barrier materials based on the blends of high-density polyethylene (HDPE) and copolyester (PETG) were prepared via melt extrusion, and poly(ethylene-co-acrylic acid) (EAA) as a compatibilizer was incorporated into the blends. A systematic investigation was carried out, with regard to morphology and properties. Scanning electron microscopy observation displayed the laminar morphology for the blends with the whole compositions, and the thinner laminas of the PETG phase formed in the HDPE matrix by incorporating EAA into the blends. In addition, the number and the size of the laminas of the dispersed phases were also dependant on the die temperature and screw speed, respectively. Evaluation of the mechanical properties demonstrated that incorporation of the EAA resulted in an improvement of the mechanical properties. These behaviors are attributed mainly to better adhesion and compatibility between HDPE and PETG, which has been confirmed by thermal analysis and the rheological properties. On the basis of these premises, it is reasonable to suggest that the improved barrier properties of the ternary blends with increasing concentration of the EAA be attributed to both the increase in the number of the laminas of the PETG and the decrease in their thickness, which prohibits the organic solvent molecules from entering into and permeating through the amorphous regions of the blends. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 101: 3791–3799, 2006

Under new mild conditions, above the isoelectric point of silica (pH = 2–5), SBA-15 mesoporous silica with ordered hexagonal pores were prepared by pre-hydrolyzing of tetraethyl orthosilicate in the presence of poly(ethylene glycol)-block-poly(propylene glycol)-block-poly(ethylene glycol) as a template. Small angle X-ray scattering (SAXS), nitrogen adsorption and desorption experiments, and transmission electron micrograph (TEM) measurements showed well-ordered hexagonal array structure, though there are some changes in wall thickness and density with the increase of pH value from 2 to 5.