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Wearable devices and morphing aircrafts require stretchable microwave absorbing (MA) and electromagnetic interference (EMI) shielding materials, which could work as EMI shielding clothes and battleplane coatings. Although conductive foams could work well in both microwave absorption and EMI shielding, their performances under stretching have not been studied thus far, which is possibly due to the...
It is a great challenge to fabricate lightweight microwave absorption materials (MAMs) with strong electromagnetic wave attenuation over wide frequency range. In this work, ultralight multiwalled carbon nanotube (MWCNT)/graphene foams (CGFs) are prepared through a facile solvothermal method and their microwave absorption (MA) properties are fully investigated. The CGFs exhibit tunable complex permittivity...
Macroscopic lossy foam has been expected to be the most promising candidate for lightweight high-performance microwave absorption (MA). However, inferior MA behaviors of conventional foams reported previously are disappointing. The emerging graphene foam (GF) has broken this paradoxical state of affairs. Here, series of GFs with various chemical compositions and physical structures have been prepared...
To meet the higher requirement of energy storage units, novel devices combining high power performance of supercapacitor and high energy density of Li-ion battery are in urgent demand. Herein we designed and fabricated a Li-ion capacitor device, which is composed of an electrochemical double layer capacitance electrode as the positive electrode and a Li-ion battery type electrode as the negative electrode...
Silicon is one of the most attractive anode materials for next-generation lithium-ion batteries, but generally it has poor cycle performance because of its severe volume change during lithiation/delithiation and its low intrinsic electrical conductivity. We fabricated a ternary Si-based composite Si@C/GF in which Si nanoparticles were coated on a thin carbon layer by pyrolysis of phenolic resin and...
Two major issues of conventional supercapacitors, composed of a separator, two electrodes, and liquid electrolyte, are their low package energy density and the leakage of the liquid electrolyte. Therefore, great efforts have been dedicated in development of all-solid-state supercapacitors with higher energy density. Here we demonstrate a high-performance all-solid-state supercapacitor with a graphene-doped...
N-doped graphene (NG) materials have been prepared through a one-step solvothermal reaction by using o-phenylenediamine as a double-N precursor. N-doping and reduction of graphene oxide (GO) are both achieved simultaneously during the solvothermal reaction. The results of scanning electron microscopy and high resolution transmission electron microscopy measurements indicate that NG is highly crumpled...
A feasible and scalable CO 2 -assisted arc discharge method was developed to directly synthesize single-walled carbon nanotubes (SWCNTs) with largely semiconducting species. Not only was electronic-type selectivity achieved on a large scale, with a semiconducting SWCNT (s-SWCNT) content of >90%, but also diameter selectivity was obtained, with a majority having diameters of >1.5nm. The...
The current progress on the production of aligned single-walled carbon nanotubes (SWCNTs), particularly the horizontally aligned ones, is reviewed. There are two main categories for the alignment of SWCNTs: the post synthesis assembly and the in situ growth approaches. The post synthesis assembly approach mainly involves dispersing SWCNTs in solutions and aligning SWCNTs using spin-coating, Langmuir–Blodgett...
Large-area, smooth, transparent and conductive graphene films were produced by a spin-coating method using graphene solutions. Bulk heterojunction polymer organic photovoltaic devices using these pure graphene films as a transparent anode were fabricated and studied. A direct pure graphene film electrode ensured that the device fabrication cost remained low and the processing was simple. The photovoltaic...
The synthesis of few-layered graphene sheets with controlled number of layers (3–4) on a large scale was developed using chemical exfoliation by simply controlling the oxidation and exfoliation procedure. The obtained Few-layered Graphene Oxide (FGO) was characterized by atomic force microscopy, X-ray diffraction, thermal gravimetric analysis and Ultraviolet–visible spectroscopy. It is found that...
The synthesis of graphene oxide (GO) sheets with controlled size on a large scale was developed using chemical exfoliation by simply controlling the oxidation and exfoliation procedure. The GO samples prepared under different conditions, which all have excellent water dispersion, are characterized by thermal gravimetric analysis, Ultraviolet–visible spectroscopy, X-ray diffraction and atomic force...
Boron and nitrogen co-doped single-walled carbon nanotubes (BN-SWCNTs) were directly synthesized at large scale using an electric arc discharge method. X-ray photoelectron spectroscopy, scanning electron microscopy, transmission electron microscopy and UV–vis–NIR spectroscopy were performed to investigate structure and properties of BN-SWCNTs. These results show that the band gaps of SWCNTs have been...
Composites based on graphene-based sheets have been fabricated by incorporating solution-processable functionalized graphene into an epoxy matrix, and their electromagnetic interference (EMI) shielding studies were studied. The composites show a low percolation threshold of 0.52vol.%. EMI shielding effectiveness was tested over a frequency range of 8.2–12.4GHz (X-band), and 21dB shielding efficiency...
A graphene–C 60 hybrid material has been synthesized using a chemical coupling method between graphene oxide and pyrrolidine fullerene. The formation of this hybrid material was verified by Fourier transform infrared spectroscopy, thermal gravimetric analysis and high-resolution transmission electron microscopy. Raman spectroscopy suggests a strong interaction between the C 60 cage...
Three types of single-walled carbon nanotube (SWCNT) homogeneous epoxy composites with different SWCNT loadings (0.01–15%) have been evaluated for electromagnetic interference (EMI) shielding effectiveness (SE) in the X-band range (8.2–12.4GHz). The effect of the SWCNT structure including both the SWCNT aspect ratio and wall integrity, on the EMI SE have been studied and are found to correlate well...
The electromagnetic interference (EMI) shielding of well dispersed single-walled carbon nanotube (SWCNT)/polyurethane composites was studied and the results show that they can be used as effective and lightweight shielding materials. The EMI shielding of the composite shows a reflection-dominant mechanism, while a shift from reflection to absorption was observed with increased SWCNT loading and frequency...
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