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Abstract The 3D microsheets contain cobalt particles and numerous interlaced carbon nanotubes (denoted as Co-NCNTs) with different pyrolysis temperature (700 °C, 800 °C and 900 °C) were successfully fabricated by a novel solution phase method. That is, polyolized the prepared g-C 3 N 4 to form a g-C 3 N 4 @Co-glycolate hybrid precursor microsheets, which was then subjected to pyrolysis treatment under an inert gas. The effects of pyrolysis temperature in the range of 700°C–900 °C on the microwave absorption properties of the Co-NCNTs were investigated in detail. As an absorber, Co-NCNTs with the pyrolysis temperature of 800 °C exhibit superior electromagnetic wave absorption properties with the optimal reflection loss (R L) value of −46 dB in the thickness of 2.5 mm, wide effective bandwidth (R L ≤ −10 dB) of 7.2 GHz. This excellent performance attributed to the special microsheet structures, uniform Co particle distribution and the better impedance matching. Highlights • The 3D Co-NCNTs microsheets were fabricated by a novel solution phase method. • The MW absorption properties at different pyrolysis temperature were investigated. • Many interlaced N-CNTs and Co particles are entwined on the surface of microsheets. • The maximum R L of Co-NCNTs/800 °C is −46 dB at the thickness of 2.5 mm. • The uniform Co particle distribution contribute to the enhancement of ability. [ABSTRACT FROM AUTHOR]

Abstract The hierarchical hollow framework involving interconnected highly conductive N-doped carbon nanotube networks and CoS 2 particles were successfully prepared by metal-organic framework (MOF) derived method. After the two pyrolysis process in the atmosphere of reducing gas and inert gases, numerous carbon nanotubes interlaced on the surface of framework and CoS 2 nanoparticles also attached on the surface. The electromagnetic parameters of CoS 2 /NCNTs composites can be well controlled by regulating the loadings of sample in sample-paraffin mixture. The results demonstrate that CoS 2 /NCNTs with 50% loadings show superior electromagnetic wave absorption properties in the wide frequency range, almost covering the whole X bands (8–12 GHz) only with a relative thin thickness of 1.6 mm. Hierarchical hollow structure and better impedance matching performance between N-doped carbon nanocube and CoS 2 nanoparticles contribute to the enhancement of microwave absorption ability. Our work confirms that hollow framework CoS 2 /NCNTs composites can provide a novel idea for designing high-absorbability microwave absorbers. [ABSTRACT FROM AUTHOR]

• CMC treatment was proved as a physical or noncovalent CNT functionalization method. • CMC treatment was effective in modifying CNT dispersion. • CMC treatment achieved better mechanical properties of CNT reinforced cementitious composites. • CMC treatment had superior piezoresistive properties of CNT reinforced cementitious composites. Controlling CNT dispersion has been the key challenge for CNT nanocomposites. This study investigated the dispersion, mechanical and piezoresistive properties of CNT reinforced cementitious composites using carboxymethyl cellulose (CMC) treatment by comparing with three other existing mixing methods, including direct mixing, surface treatments using octenyl succinic anhydride (OSA) modified tapioca starch as a polymeric additive, and sodium dodecylbenzene sulfonate (NaDDBS) as a surfactant. The experimental results first indicated that the CMC treatment was categorized as a noncovalent functionalization and showed effectiveness in improving CNT dispersion, compressive strength, modulus of elasticity, Poisson ratio, and piezoresistive sensitivity of CNT reinforced cementitious composites. [ABSTRACT FROM AUTHOR]

Hybrid hollow urchin-like cobalt and copper silicate constructed by nanotubes encapsulated in graphene nanosheets composites were successfully prepared using graphene oxide as carrier and silica spheres as template, which were done through a well-known Stȍber process and a hydrothermal method. In fact, the synthesis of hybrid urchin-like silicate constructed by nanotubes through onestep hydrothermal reaction has rarely been reported.The electrochemical performances of the composites as lithium-ion battery anode materials were studiedfor the first time. As novel anode materials of Li-ion batteries, the special hollow urchin-like structure not only could facilitate the Li + diffusion and electron transport but alsocouldaccommodate the volume variation during the conversion reactions. In addition, the introduction of graphene can make the electrical conductivity better. Graphene wrapped hollow urchin-like silicate compositespossesses superior electrochemical cycling properties. The first discharge capacity is1955.2mAh/g with a current density of 300 mA/g. The unique well-designed configuration presents a beneficial method to synthesize efficient and high performance electrode materials for advanced power applications. [ABSTRACT FROM AUTHOR]

Three-dimensional graphene@carbon nanotube (G@CNT) composite was coated on polypropylene separator as an interlayer for high performance of lithium-sulfur batteries. In this study, the novel G@CNT nanotubes coated separator offers not only fast electron pathway for insulating sulfur, but also outstanding restriction of dissolving polysulfides. The heat impregnation of sulfur in carbon black also plays an auxiliary role on the cycling performance of the G@CNT interlayer assisted cathodes. As the dual sulfur locking strategy by heat impregnation and G@CNT interlayer, the prepared Li-S cells exhibited high rate capacity and sustainably enhanced cycling stability. Excellent cycling performance with a high capacity 935.1 mAh g −1 at 0.2C and 755.6 mAh g −1 at 1C after 200 cycles is achieved. Moreover, the cell delivers reversible discharge capacities up to 669.7 mAh g −1 and 555.1 mAh g −1 after 200 cycles even at 2C and 4C. [ABSTRACT FROM AUTHOR]

A novel graphene/carbon nanotube (GN-CNT) hybrid was synthesized by thermal pyrolysis of urea on the surface of graphene at 800, 900 and 1000 °C. The effects of pyrolysis temperature on yield of carbon nanotubes and electrochemical properties of the GN-CNT hybrid were investigated carefully. The production rate of pyrolysis gas was increased as temperature rising. The GN-CNT hybrid reached the largest surface area and the generation of a mass of pores at the pyrolysis temperature of 900 °C due to the carbon nanotubes cracking during pyrolysis at 1000 °C. The properties of favorable 3D architecture, the generation of a mass of pores during the release of carbon nitride gases and outstanding mechanical flexibility, showed pronounced effects on the fast and steady transfer of electrons and sodium-ion. Consequently, the GN-CNT hybrid pyrolysized at 900 °C exhibit a very high reversible capacity of up to 269.14 mAh g −1 after 100 cycles at a current density of 300 mA g −1 . Even up to 5 A g −1 , a rate capacity of 195.37 mA h g −1 can be obtained after 700 cycles. [ABSTRACT FROM AUTHOR]

Three-dimensional (3D) graphene@CNTs@MnO 2 (GCM) nanocomposites materials have been fabricated by a facile two-step method. The structure, morphology and electrochemical properties of the 3D nanocomposites were investigated by XRD, TG, Raman, SEM, TEM and electrochemical measurements. The 3D forest-like rGO@CNTs (GC) serves as both the backbone and ideal electron pathway for MnO 2 . With this sophisticated configuration, the 3D GCM nanocomposites exhibit a specific capacitance of 245 F g −1 at 0.5 A g −1 , excellent cycling stability (91.4% retention after 2000 cycles at 1 A g −1 ) and high rate capability. These excellent capacitive performances may make the as-prepared nanocomposites as promising electrode materials for supercapacitors. [ABSTRACT FROM AUTHOR]

Carbon nanotubes (CNTs) are widely added into polymeric materials as additives to improve the mechanical properties of the composites. The great variances of CNTs in geometries including different diameters and lengths may inevitably result in extensive differences on material properties and reinforcing efficiencies in CNT reinforced epoxy composites. This paper investigated the dispersion characterizations and adhesion properties of CNT reinforced epoxy composites with different CNT geometries including three different CNT diameters and two different lengths by particle size analysis, single lap shear (SLS) tests, transmission and scanning electron microscopy (TEM and SEM). The experimental results showed that CNTs with larger diameter (50–100 nm) had a greater ability to achieve more uniform dispersion which further led to better adhesion properties. Although CNT length did not have an evident effect on the CNT dispersion, epoxy composites reinforced by normal-length CNTs (5–20 µm) had higher lap shear strength and toughness than those by shorter CNTs (0.5–2 µm). [ABSTRACT FROM AUTHOR]

To improve the dispersion effectiveness of carbon nanotubes (CNTs) in epoxy and the adhesion of the resulted composites on steel substrates, this paper proposed to surface treat CNTs using carboxymethyl cellulose (CMC) in the epoxy-CNTs composite. The dispersion characterizations and adhesion properties of epoxy composites reinforced by CMC surface treated CNTs were then systematically investigated. CNTs with three different weight fractions (0.5%, 1%, and 2%) were surface treated by CMCs to improve their dispersion in epoxy-CNTs composites. It was found by Raman spectroscopy, particle size analysis, transmission and scanning electron microscopy that the CMC surface treatment was effective in reducing the size of CNT clusters to achieve a better dispersion of CNTs in such epoxy-based composite. The experimental results of contact angle and single lap joint tests indicated that better CNT dispersion resulted from the CMC surface treatment significantly improved the wettability and adhesion properties of the epoxy-CNTs composites. [Display omitted] • CMCs were attached on the surface of CNTs forming a thin amorphous layer. • CNT dispersion was improved by reducing the size of CNT clusters after CMC surface treatments. • CMC surface treatments had a positive effect on adhesion properties of CNT epoxy composites. [ABSTRACT FROM AUTHOR]

The improved physicochemical immobilization and catalytic redox conversion of lithium polysulfides (LiPSs) intermediates are considered to be a desirable solution to enhance the sulfur electrochemistry in lithium-sulfur (Li–S) batteries. Herein, we for the first time, reported the fabrication of the core-shell structure composed of cobalt-doped carbon nano-tube (CNT) assembled polyhedron core derived from the cobalt metal-organic frameworks (Co-MOFs)@graphitized porous carbon aerogel shell as the sulfur reservoir material for Li–S batteries. The obtained sulfur cathodes exhibited excellent electrochemical performance, including a high reversible capacity (939.9 mAh g−1 at 0.1C), outstanding areal capacity (3.35 mAh cm−2 after 50 cycles, under a low electrolyte/8.3 μL m g s − 1 ), and superior cycling stability (the capacity decay rate of 0.087% per cycle after 500 cycles at 1C). The improvement in electrochemical performance could be attributed to the unique core-shell architecture: the multiple polyhedron Co–C cores not only provide a multiple-point catalytic center for LiPS conversion, but also serves as the polar material to inhibit the migrating of polysulfides by chemical interaction; More importantly, the graphitized porous carbon aerogel shell provides a fast transport channel for Li+/e− diffusion, and also sufficient free space for the sulfur reservoir and Li 2 S 2 /Li 2 S deposition. [Display omitted] • Co–C polyhedra reduced the formation of non-graphitic carbon in carbon aerogel. • Core-shell structures provided adequate accommodation capacity for sulfur species. • Multipoint Co–C polyhedron cores accelerated polysulfide redox reaction kinetics. • The S/Co-GC@GPCA cathode delivered outstanding cycling stability. [ABSTRACT FROM AUTHOR]

Abstract: Strontium ferrite particles were firstly prepared by sol–gel method and self-propagating synthesis, and then the polyaniline/strontium ferrite/multiwalled carbon nanotubes composites were synthesized through in situ polymerization approach. Structure, morphology and properties of the composite were characterized by various instruments. XRD analysis shows that the output of PANI increases with the increase of the content of MWCNTs, due to the large surface area of MWCNTs. Because of the coating of PANI, the outer diameter of MWCNTs increases from 10nm to 20–40nm. The electrical conductivity of the composites increases with the amount increase of MWCNTs and reaches 7.2196S/cm in the presence of 2g MWCNTs. The coercive force of the composites prepared with 2g MWCNTs is 7457.17Oe, which is much bigger than that of SrFe12O19 particles 6145.6Oe, however, both the saturation magnetization and the remanent magnetization of the composite become much smaller than those of SrFe12O19 particles. The electromagnetic properties of the composite are excellent in the frequency range of 2–18GHz, which mainly depend on the dielectric loss in the range of 2–9GHz, and mainly on the magnetic loss in the range of 9–18GHz. [Copyright &y& Elsevier]

Carbon nanotubes (CNTs) are generally considered as a promising particle reinforcement of incorporating advanced properties and characteristics into epoxy nanocomposites. This paper investigated the bonding performances of CNT-reinforced epoxy adhesively bonded joints on steel substrates using the single lap shear (SLS) tests. The bonding performances (including bonding strength, fracture strain, toughness, and failure mode) were studied with three adhesive thicknesses (1 mm, 0.5 mm, and 0.25 mm) and three CNT weight fractions (0%, 0.375%, and 0.75%). The experimental results indicated that thinner bondlines and higher CNT additions could significantly improve the bonding performances and modify the failure mode of CNT-reinforced epoxy adhesively bonded joints. However, the effects of adhesive thickness became less significant with the increase of CNT weight fractions. In addition, the plastic behaviour of CNT-reinforced epoxy, CNTs pulling-out, and the aggregation of CNTs were observed by scanning electron microscopy (SEM) image analysis on the fracture surfaces of CNT-reinforced epoxy adhesively bonded joints, indicating the potential effectiveness of the CNT reinforcement. • Bonding performances of epoxy joints improved with the increase of CNTs up to 0.75%. • Thinner bondlines showed better bonding performances than thicker ones. • The influence of bondline thickness became less significant as the addition of CNTs. [ABSTRACT FROM AUTHOR]

Carbon nanotubes (CNTs) with a honeycomb arrangement were designed onto graphene as the electrochemical electrodes. The honeycomb arrangement provided a relatively larger surface area to store more ions with a stronger structure to maintain long-term surface morphology. The combination of CNTs and graphene exhibited robust durability during electrochemical performance. The pseudo-capacitive property of IrO 2 was coated onto the CNT surface to enhance the capacitance. Cyclic voltammetry and charging–discharging measurements were used to examine the electrochemical behaviors. The CNTs/graphene and IrO 2 /CNTs/graphene capacitances were 3.93 and 129.40 F/g, respectively. The designed electrode demonstrates excellent characteristics and is appropriate for electrochemical applications. [ABSTRACT FROM AUTHOR]

Highlights: [•] Graphene was grown on Cu foil by mobile thermal chemical vapor deposition system. [•] CNT was synthesized on graphene for RuO2 nanostructure growth by thermal chemical vapor deposition system. [•] The CNT growth location was fixed through the use of photolithography technique, thereby increasing the specific area. [•] RuO2 nanostructures were coated onto CNT bundle arrays through metal organic chemical vapor deposition, in order to utilize its pseudo capacitive property. [ABSTRACT FROM AUTHOR]

Abstract: Large surface area IrOx nanofoils (IrOxNF) were deposited on multi-wall carbon nanotube (MWCNT) templates, forming IrOx/MWCNT nanocomposites, by reactive radio frequency magnetron sputtering using Ir metal target. The structural and spectroscopic properties of IrOxNF were characterized. The micrographs of field emission scanning electron microscopy showed the formation of foil-like structure for the as-deposited samples. Transmission electron microscopy analysis revealed the contiguous presence of glassy iridium oxide, iridium metal, and iridium dioxide nanocrystals in the foil. X-ray photoelectron spectroscopy analysis provided the information of the oxidation states and the stoichiometry of IrOxNF. Raman spectra revealed the amorphous-like phase of the as-deposited IrOxNF. The nanofoil structure provided ultra-high surface area for electrical charge storage which made the IrOx/MWCNT nanocomposites as an attractive candidate for the supercapacitor applications. [Copyright &y& Elsevier]

Polyaniline materials are widely utilized as electrodes for supercapacitors because of low cost, facile synthesis, high mechanical flexibility and theoretical high specific capacitance. However, the poor cycle stability and low rate capability restrict their practical applications. Integration of polyaniline with carbon materials is an effective strategy to solve the aforementioned limitations. In this review, polyaniline electrode materials, especially in the forms of different nanostructures, are firstly summarized to demonstrate the general merits of polyaniline-carbon composites for supercapacitors. Subsequent emphasis focuses on the rational design of the composites with various carbon materials, including activated carbon, porous carbon, carbon nanotubes, carbon fibers, graphene or their hybrids. The importance of the compositions, desired architectures and synergistic interactions on the enhanced electrochemical properties is emphasized. In particular, the research trends in the configurational design of unconventional devices, such as flexible, stretchable, compressible and asymmetric supercapacitors with excellent performance at different states (bending, stretching, compressing and/or folding). The review ends with a summary and discusses the perspectives and challenging issues regarding the rational design of flexible supercapacitors in future studies, along with the current outlook for the integrated electronic devices. • Polyaniline electrodes with different nanostructures are summarized. • Influence factors on the performance of PANI-carbon electrodes are emphasized. • The configurational design of unconventional devices is highlighted. [ABSTRACT FROM AUTHOR]

Integrating polyaniline (PANI) with different dimensional carbon materials is considered as a promising strategy to solve the disadvantages of PANI electrodes, such as low rate capability and poor cyclic stability. In this work, a novel layer-by-layer sandwiched graphene/PANI nanorods/carbon nanotubes (G/PANI/CNTs) heterostructure has been synthesized. The morphology of the heterostructures has been characterized by XRD, Raman spectroscopy, N 2 adsorption-desorption, XPS, FESEM and TEM. The obtained new layer-by-layer sandwiched heterostructures exhibit intimate interface contacts, fully network-structured CNTs coating, dual physical supports and synergistic effects, which can effective host the electrochemical properties of PANI with the electrolyte and restrain the volumetric changes of PANI. As a result, the electrodes exhibit high specific capacitance (638 F g -1  at 0.5 A g −1 ), good rate capability (88.2% retention from 0.5 A g −1 to 10 A g −1 ) and long cycle stability (93% of the initial specific capacitance after 2000 cycles) when the amount of CNTs is 2 mg. Moreover, a possible mechanism for good performance of the layer-by-layer sandwiched heterostructures has been systematically studied. We believe that this strategy will open up an avenue for the rational design of sandwich structured electrodes for high performance supercapacitors and other electronic devices. [ABSTRACT FROM AUTHOR]

The carbon nanotube (CNT) has replaced palladium oxide (PdO) as the electrode material for surface-conduction electron-emitter (SCE) applications. Vertically aligned CNT arrays with a delta-star arrangement were patterned and synthesized onto a quartz substrate using photolithography and thermal chemical vapor deposition. Delta-star shaped VACNT arrays with 20° tips are used as cathodes that easily emit electrons because of their high electrical field gradient. In order to improve the field emission and secondary electrons (SEs) in SCE applications, magnesium oxide (MgO) nanostructures were coated onto the VACNT arrays to promote the surface-conduction electron-emitter display (SED) efficiency (η). According to the definition of η in SCE applications, in this study, the η was stably maintained in the 75–85% range. The proposed design provides a facile new method for developing SED applications. [ABSTRACT FROM AUTHOR]

Amorphous carbon nanorods (CNRs) were deposited directly using radio frequency magnetron sputtering. The synthesized CNR electrochemical properties were investigated using graphene as the current collector for an electric double layer capacitor. The CNRs were vertically aligned to the graphene to achieve higher specific surface area. The capacitor performance was characterized using electrochemical impedance spectroscopy, cyclic voltammetry, and galvanostatic charge-discharge testing in 1 M KOH electrolyte at 30°C, 40°C, 50°C, and 60°C. The CNR specific capacitance was observed to increase with increasing measurement temperature and could reach up to 830 F/g at 60°C. Even after extensive measurements, the CNR electrode maintained good adhesion to the graphene current collector thereby suggesting electrode material stability. [ABSTRACT FROM AUTHOR]

Abstract: Top-down fabrication strategies are proposed and demonstrated to realize arrays of vertically-aligned silicon nanowire bundles and bundle arrays of carbon nanotube–silicon nanowire (CNT–SiNW) heterojunctions, aiming for releasing the electrostatic screening effect and improving the field emission characteristics. The trade-off between the reduction in the electrostatic screening effect and the decrease of emission sites leads to an optimal SiNW bundle arrangement which enables the lowest turn-on electric field of 1.4V/μm and highest emission current density of 191μA/cm2 among all testing SiNW samples. Benefiting from the superior thermal and electrical properties of CNTs and the flexible patterning technologies available for SiNWs, bundle arrays of CNT–SiNW heterojunctions show improved and highly-uniform field emission with a lower turn-on electric field of 0.9V/μm and higher emission current density of 5.86mA/cm2. The application of these materials and their corresponding fabrication approaches is not limited to the field emission but can be used for a variety of emerging fields like nanoelectronics, lithium-ion batteries, and solar cells. [Copyright &y& Elsevier]

Highlights: [•] We have successfully designed the honeycomb patterns on glass substrate by photolithography technique. [•] Honeycomb-VACNTs were synthesized successfully onto glass substrate by using thermal CVD and covered different Ti films on VACNTs by e-beam evaporation. [•] After coating the Ti films, the current density reached 7mA/cm2 when the electric field was 2.5V/μm. [•] The fluorescence of VACNTs with Ti 15nm films exhibits the high brightness screen and emission uniformity. [Copyright &y& Elsevier]

Abstract: Two miniature electrochemical capacitors, of high power and sufficient energy capacity, are prepared using photolithography and transferred to a plastic substrate. The preparation procedure involves, inverting a 60μm thick interdigital pattern of multi-walled carbon nanotubes (CNT) with a Scotch tape, such that the pre-sputtered gold layer at the bottom effectively collects interfacial charge. The equivalent series resistance (ESR) of the symmetric CNT capacitor measures 0.40Ωcm2, while that of the asymmetric capacitor with a positive α-Co(OH)2/CNT electrode measures 0.45Ωcm2, much less than the as-grown CNT capacitor. Electrodeposited α-Co(OH)2 enhances the cell capacitance significantly, especially in a wide potential window. When operated at current density 20Ag−1 and window 1.8V, the cell capacitance of asymmetric capacitor measures 62.6Fg−1, much higher than that of symmetric capacitor 8.7Fg−1. But the symmetric CNT capacitor displays a better power performance because of a lower ESR. At current density 30Ag−1, its power density reaches 20.6kWkg−1 with energy density 2.2Whkg−1. In contrast, the asymmetric capacitor stores more energy, at 30Ag−1, it exhibits power density 11.4kWkg−1 and energy density 7.8Whkg−1. [Copyright &y& Elsevier]

Abstract: MnO2 and carbon nanotubes (CNT) composite electrodes have been built on the interdigital stack layers of Fe–Al/SiO2 and Fe–Al/Au/Ti/SiO2 for the electrochemical micro-capacitors, using photolithography and thin-film technologies. The electrode properties and the performance of micro-cells are measured and analyzed with cyclic voltammetry (CV), impedance spectroscopy, and galvanostatic charge/discharge test in 0.1M Na2SO4 electrolyte. The vertically aligned CNT, grown on Fe–Al/SiO2, is more suitable for supporting the pseudocapacitive MnO2 than the random CNT on Fe–Al/Au/Ti/SiO2, but ohmic resistance of the former electrode is higher. We have prepared three cells on each stack layer with different electrode materials. The Ragone plot shows systematic variations in power and energy performance, reflecting their differences in electrode structure and polarization loss. The asymmetric cell of a pseudocapacitive positive electrode, loaded with MnO2 and CNT, exhibits a small IR drop and a high specific energy during discharge. Built on Fe–Al/SiO2, this asymmetric cell discharges at specific power 0.96kWkg−1 with specific energy 10.3Whkg−1; while on Fe–Al/Au/Ti/SiO2, the asymmetric cell discharges at power 1.16kWkg−1 with energy 5.71Whkg−1. [Copyright &y& Elsevier]

Abstract: In this study, the electrochemical capacitor characteristics of vertically aligned carbon nanotubes (VACNTs) with different nitrogen content were investigated. The pristine VACNTs and nitrogen-doped VACNTs were synthesized by thermal chemical vapor deposition (CVD) with a mixture of C2H2 and NH3 gases. The content of nitrogen doped into VACNTs played an important role in enhancing the capacitance characteristics. With increasing the NH3 pressure, the nitrogen content of VACNTs increased. However, the capacitance did not increase with the increase in nitrogen content of VACNTs entirely. There was an optimal NH3 pressure for synthesizing the nitrogen-doped VACNTs to obtain the maximum capacitance. Furthermore, for the real practice of supercapacitor, the stability of capacitance was tested for 500 cycles. The results revealed that the nitrogen-doped VACNT was a promising supercapacitance device material. [ABSTRACT FROM AUTHOR]

Abstract: Carbon nanotubes (CNTs) were used as the electric double layer capacitor (EDLC) material and were synthesized by using thermal chemical vapor deposition (TCVD). To enhance the EDLC capacity, the ruthenium dioxide (RuO2) nanorods were grown on CNTs by using metal organic chemical vapor deposition (MOCVD). The synthesized CNTs were the principal part and template, and the RuO2 nanorods were grown outwardly from CNTs. The increase of effective specific area between electrode and electrolyte played an important role in enhancing the capacitance. Different concentrations of KOH were used as electrolyte to measure the capacitance to find the variation of capacitance. Moreover, the RuO2/CNT composites demonstrated a stable cycle life. The results showed that the RuO2/CNT composites were a promising supercapacitor device material. [Copyright &y& Elsevier]

[Display omitted] Polymer-matrix composites containing hybrid fillers can exhibit electric performance due to synergistic conductive effect. In this work, the nonlinear synergistic enhancement electric conductive effect (NSECE) in nanocomposites containing carbon nanotubes (CNTs) and graphene nanoplatelets (GNPs) is studied by the 3D Monte Carlo simulation. The 3D model with random distribution based on tunnel theory for nanocomposites filled with cylindrical CNTs and disc-shaped GNPs is developed. The morphology of CNTs and GNPs are researched for the NSECE in percolation threshold. The results show that the reason of NSECE is the different network construction ability of CNTs and GNPs with different morphology. When the monofiller nanocomposites of each of those exact fillers have similar percolation thresholds and the length of CNTs is smaller than the diameter of GNPs, hybrid nanocomposites filled with CNTs and GNPs is more likely to exhibit NSECE in their electrical performance. [ABSTRACT FROM AUTHOR]

Abstract: To achieve the maximum area utilization ratio for a parallel electrode capacitor, an Archimedean spiral was used to design the capacitor pattern. Multi-walled vertically aligned carbon nanotubes (VACNTs) were used for the capacitor electrodes because of their metallic properties and their endurance toward various chemical reagents. In contrast to the parallel plate capacitor, the total capacitance was formed by parallel connections of all unit cells of the individual VACNT capacitors, so that a relatively higher capacitance was obtained. This design can provide a new approach to fill diverse dielectrics into a spiral capacitor to obtain different capacitances for various applications. [Copyright &y& Elsevier]

Abstract: Carbon nanotubes (CNTs) have been widely applied in field emission (FE) due to their high geometric aspect ratio and low work function. More recently, researchers have introduced ruthenium dioxide (RuO2) as a field emitter because of its excellent chemical and thermal stability due to its oxide nature. This study used the surface morphology of CNTs and the field emission (FE) stability of RuO2 to improve FE characteristics. Since the work functions of CNTs and RuO2 are very close, this study combined these two elements by applying a thin film of RuO2 on the CNT surface. In the process of covering the tips of CNTs with a thin film of RuO2 eventually obtained the best matching of these two elements. The study not only enhanced the FE performance of CNTs but also extended FE lifetime by applying a thin film of RuO2 on the CNT tips. [Copyright &y& Elsevier]

Abstract: To enhance the field emission characteristics, needle-like ruthenium dioxide (RuO2) nanocrystals (NCs) were grown on vertically aligned carbon nanotubes (VACNTs) using metal organic chemical vapor deposition (MOCVD). The VACNTs were the principal part and template with the needle-like RuO2 NCs grown outwardly from the VACNTs. Each needle-like RuO2 NC can be regarded as an individual field emitter, resulting in field emission site enhancement. The results demonstrated that the RuO2/VACNTs composite is an emitter material with great potential. [Copyright &y& Elsevier]