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Composited materials (NC/PDTDA) of nitrogen-doped porous carbon (NC) and partial poly (2, 2′-dithiodianiline) (PDTDA) have been successfully synthesized by in-situ polymerization and can be utilized in alkaline electrolytes as electrodes for supercapacitors. The physiochemical properties of NC/PDTDA composites materials are characterized by field emission scanning electron microscope, transmission electron microscope, Fourier transform infrared spectroscopy, Raman spectrum, X-ray electron spectrum, and X-ray diffraction. In addition, the electrochemical properties of NC/PDTDA composites materials are tested in 3 M KOH aqueous solution with a representative three-electrode system. It shows the highest specific capacitance when the mass ratio of NC to PDTDA is 1:2 (NC/PDTDA-2), and the specific capacitance is 490.5 F/g at a current density of 1 A/g. More significantly, the asymmetric supercapacitor is also assembled with an extended operating voltage window of 1.4 V in PAM-PVA- KOH electrolyte. It exhibits an energy density of 13.49 Wh/Kg at a power density of 699.8 W/Kg.

Aminated polyethylene glycol (PEG-NH2) functionalized graphene nanosheets (PEG-rG) were successfully introduced into epoxy resin as a core-shell nanostructure to prepare the epoxy based dielectric composite. The overall mechanical and dielectric performances of the PEG-rG/epoxy nanocomposites were greatly improved in comparison with its counterparts employing with untreated graphene. The dielectric constant of PEG-rG/epoxy 1.5 wt% nanocomposites reached 84.3 at 100 Hz, two times higher than that of rG/epoxy 1.5 wt% system. What’s more, the dielectric loss is effectively reduced to a very low level (tan δ = 0.21).

Percolative poly(vinylidene fluoride) (PVDF) composites with high dielectric constant and low dielectric loss was successfully achieved by incorporating reduced graphene oxide (rGO) decorated with magnetic iron oxide (Fe3O4) (rGO@Fe3O4) nano-fillers. The morphology, structure, thermal, electrical and magnetic properties of the composites were investigated systematically by using SEM, XRD, FTIR, TGA, DSC, impedance analyzer and magnetometer, respectively. The presence of a tiny amount of poly(sodium 4-styrene sulfonate) (PSSNa) facilitated the homogeneous distribution of rGO@Fe3O4 nanoparticles and prevented the formation of an electrical conductive network within the PVDF matrix, resulting in an excellent dielectric performance of the rGO@Fe3O4/PVDF nano-composites. With 1.0 wt% rGO@Fe3O4 incorporated in PVDF, the nanocomposite exhibited a high dielectric constant of 1297 and a low dielectric loss of 0.26 at 100 Hz. Percolation model revealed that such improvements could be attributed to the synergistic effect of the inorganic Fe3O4 and rGO, whereby the electric charges were accumulated by forming many mini-capacitors in the bulk PVDF matrix. The structure-property behavior of the final nanocomposites was discussed.

Carbon-composited ferroferric oxide (Fe3O4@C-1) was synthesized through a thermal decomposition of the chelate (Fe)2(C4H4O6)3, which can be served as the sources for both Fe3O4 and carbon. After etching in hydrochloric acid (HCl) solution for 20 min, the pyrolytic Fe3O4@C-1 turned into Fe3O4@C-2 gaining a higher specific surface area and a better electrochemical performance. As anode materials for lithium-ion batteries, the Fe3O4@C-2 sample delivers a reversible capacity of 1047 mAh g−1 at a current density of 200 mA g−1 and remains the capacity at 837 mAh g−1 after 200 cycles, while the capacity of the Fe3O4@C-1 electrode fades to only 94 mAh g−1 after 200 cycles.

Fe2O3 nanomaterials with a mesoporous structure are prepared via a heat treatment of natural rust obtained from a rusty switch of tap water at 500 °C for 3 h in air atmosphere. As an anode material for lithium-ion batteries, the Fe2O3 electrode delivers a reversible capacity over 1000 mAh g−1 at a current density of 0.5 A g−1 after 1000 cycles. Samples obtained at different heat treatment temperatures (400 and 600 °C) also show good electrochemical performance.

The aluminum foils for high voltage aluminum electrolytic capacitors were DC etched in HCl–H2SO4 hybrid acids and the effects of in-situ mechanical attrition on the etching were studied in this work. Compared with the conventional etching, the distribution of etch tunnels was, under in-situ mechanical attrition, more uniform with high density of etch pits and long tunnels, which expands the surface area of etched Al electrode and greatly increases its capacitance. This effect is probably due to the mechanical attrition effects which are beneficial for the breakdown of the protective film and reducing concentration polarization in the bulk etchant solutions, inducing higher pit and tunnel density and increasing the survival rate of tunnels.

High performance Graphene-MnO2-polyaniline (Graphene/MnO2/PANI) nanocomposite was synthesized by hydrothermal process. The structure and morphology of Graphene/MnO2/PANI nanocomposite were characterized by scanning electron microscopy (SEM), transmission electron microscopy (TEM), X-ray powder diffraction (XRD) and Fourier-transform infrared spectroscopy (FT-IR). The electrochemical properties of composite were evaluated by constant current charge–discharge, cyclic voltammetry and AC impedance, respectively. The results show that the prepared Graphene/MnO2/PANI nanocomposite exhibits greatly enhanced specific capacitance (305 F g−1) as compared to that of pristine graphene (155 F g−1) and MnO2/PANI (240 F g−1) in 1 M Na2SO4 solution. In addition, the capacity of the Graphene/MnO2/PANI nanocomposite still maintains 90 % after 1000 charge–discharge cycles at a current density of 1 A g−1, exhibiting potential applications in electrode materials for supercapacitors.

High-performance porous carbon is an essential electrode materials for high-specific energy supercapacitors because it has a high specific surface area on the electrode surface and stores charge through electrolyte-ion adsorption. In this article, N, S co-doped porous carbon was successfully prepared through carbonization and activation of partial poly (2, 2′-dithiodianiline) (PDTDA). The N, S co-doped porous carbon material was used to prepare the electrode for supercapacitor. The three-electrode system was used to test its electrochemical performance. The results show that the suitable carbonization temperature was 600 °C (ASNC-600–800), which showed excellent capacitance performance. The specific capacitance of ASNC-600–800 is 500.10 F/g at 1 A/g. In addition, N, S co-doped porous carbon possess the specific energy of 21.15 Wh/kg at specific power of 450 W/kg. A new path has been opened for the preparation of low cost and high-performance porous carbon electrode materials.

Nitrogen-doped porous carbon materials for supercapacitor was successfully fabricated from precursor of polyacrylamide gel through freeze drying, carbonization and KOH activation process. The precursor of polyacrylamide gel was prepared using acrylamide and N,N-methylene diacrylamide as monomers and cross-linking agents, respectively. The nitrogen-doped porous carbon was tested by field emission scanning electron microscope, transmission electron microscope, Fourier transform infrared spectroscopy, Raman spectrum, X-ray electron spectrum and specific surface analysis, respectively. Further, the electrochemical performance of nitrogen-doped porous carbon was tested by using a three-electrode system, which exhibited large specific capacitance of 302.1 F/g at 1 A/g, good rate property (71.8%, 217 F/g at 20 A/g) and cycle property (96% after 8000 cycles). Symmetrical supercapacitor was also assembled with an extended operating voltage window of 1.8 V in 1 M Na2SO4 electrolyte. More significantly, the nitrogen-doped porous carbon maintains an energy density of 23.27 Wh/kg in the case of a power density of 450 W/kg.

High performance actived carbon–MnO2–polyaniline (AC/MnO2/PANI) composite was synthesized via a two-step method. AC/MnO2 was firstly obtained by a chemical co-precipitation procedure, and then exposed to an in situ polymerization process of aniline under acidic conditions to form the AC/MnO2/PANI composite. The structures and morphologies of the products were characterized by X-ray powder diffraction, scanning electron microscopy, and Fourier-transform infrared spectroscopy. Results show that the AC/MnO2/PANI hybrid exhibits better capacitance than that of pure AC and the AC/MnO2 electrodes.

The morphology of etched aluminum foil was observed using scanning electron microscopy, which led to the establishment of a cubic tunnel etch model and a trench tunnel etch model. With these two modes, the theoretical maximum specific capacitance values for the anode foil used in aluminum electrolytic capacitors were calculated with Matlab at various formation voltages. The corresponding optimum values for tunnel size, density, distribution and geometrical shape were also given as a function of oxide thickness. The experimental and theoretical capacitance values are compared. It is concluded that the theoretical maximum specific capacitance for trench etch tunnel model is higher than that for cubic etch tunnel one at fixed formation voltage. Promoting tunnel-merging in rows rather than in clusters is preferred during electro-etching process, leading to formation of trench tunnels on the Al foil. For high formation voltages, measured capacitances approach the optimum values and enlargement of surface area by electrochemical etching was faced with the limit. But for low formation voltages, the experimental capacitance value obtained is far behind the optimized one and the tunnels size, distribution, shape and density must be optimized to achieve high capacitance.

The applications of Fe3O4 in lithium-ion batteries are greatly restricted due to the low electrical conductivity, and poor cycling stability that is owing to the large volume expansion. To overcome these drawbacks, Fe3O4@C nano-composite was designed and synthesized via a one-step thermal decomposition of C4H4FeO6 served as the precursor for both Fe3O4 and carbon. As an anode material for lithium-ion batteries, the Fe3O4@C composite exhibits a reversible capacity of 680 mAh/g at a current density of 0.2 A/g, and after 600 times, the discharge capacity of the as-prepared Fe3O4@C networks is determined to be 590 mAh/g, showing superior cycling stability. The simple synthetic procedure and excellent performances makes Fe3O4@C a promising candidate as the potential anode material for lithium-ion batteries.

Micrometer- and nanometer-Al2O3-particle-filled poly(phthalazine ether sulfone ketone) (PPESK) composites with filler volume fractions ranging from 1 to 12.5 vol % were prepared by hot compression molding. We evaluated the tribological behaviors of the PPESK composites with the block-on-ring test rig by sliding PPESK-based composite blocks against a mild carbon steel ring under dry-friction conditions. The effects of different temperatures on the wear rate of the PPESK composites were also investigated with a ball-on-disc test rig. The wear debris and the worn surfaces of the PPESK composites were investigated with scanning electron microscopy, and the structures of the PPESK composites were analyzed with IR spectra. The lowest wear rate, 7.31 × 10−6 mm3 N−1 m−1, was obtained for the composite filled with 1 vol %-nanometer Al2O3 particles. The composite with nanometer particles exhibited a higher friction coefficient (0.58–0.64) than unfilled PPESK (0.55). The wear rate of 1 vol %-nanometer-Al2O3-particle-filled PPESK was stable and was lower than that of unfilled PPESK from the ambient temperature to 270°C. We anticipate that 1 vol %-nanometer-Al2O3-particle-filled PPESK can be used as a good frictional material. We also found that micrometer-Al2O3-particle-filled PPESK had a lower friction coefficient at a filler volume fraction below 5%. The filling of micrometer Al2O3 particles greatly increased the wear resistance of PPESK under filler volume fractions from 1 to 12.5%. © 2005 Wiley Periodicals, Inc. J Appl Polym Sci 95: 993–1001, 2005

Graphene hybrid aerogels have attracted attention as electrode materials because of their unique porous architectures. However, their electrochemical performance is limited by the intrinsic hydrophobicity and the ease of aggregation of graphene nanosheets. We demonstrate a unique methodology to produce graphene hybrid aerogels through assembly of graphene nanosheets, nanometer-scale ferroferric oxide (Fe3O4), and hydrophilic poly(vinyl alcohol) (PVA) into three-dimensional hierarchical macrostructures. Electrochemical performance measurements exhibit a significant improvement in the specific capacitance of this ternary hybrid aerogel with remarkable cycling stability. Specifically, the specific capacitance is nearly 6.6 times higher than that of the neat graphene aerogel, and a cycling capacitance retention rate of 99% was achieved after 2000 cycles at a high current density of 0.5 A g−1. Electrochemical impedance spectroscopy measurements demonstrate a lower resistance in the Fe3O4/graphene/PVA aerogel electrode compared with that of both neat graphene and Fe3O4/graphene aerogel electrodes. The obtained graphene hybrid aerogels with outstanding cycling performance and high energy density are very promising as electrode materials for supercapacitors. © 2017 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2017, 134, 45566.

In the title mol-ecule, C(22)H(16)N(2)OS(2), which demonstrates non-crystallographic C(2) pseudosymmetry [C-O-C angle = 121.0 (3)°], the two benzene rings make a dihedral angle of 62.09 (14)°. The crystal packing exhibits no significantly short inter-molecular contacts.