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Despite the significant progress in thermoelectric composites in the last five years, examining the existing main body of publications shows the scarcity of composite systems and limited preparation strategies. Metal-organic frameworks (MOFs) have been extensively studied and have wide applications, however, MOF-related thermoelectric composites have been seldom reported mainly due to their poor electrical...
Salinity gradient power (SGP) holds great potential for electricity generation. However, the technology scale-up is hindered by the lack of high-performance membranes. Here we initiate the application of freestanding graphene oxide membranes (GOMs) in pressure retarded osmosis (PRO) to generate SGP. The freestanding GOMs have moderate water permeability coefficient and excellent mechanical strength...
Existing methodological strategies for the doping of nitrogen (N) atoms in carbon materials usually contain more than one species with indefinite N content, which made it difficult to study the role of each type of N atoms played duing the doping and severely restrict the wide application. Herein, we reported a developed synthetic strategy for preparing carbonous materials contained with specific...
Nanopolycrystalline diamond (NPD) and nanotwinned diamond (NtD) were successfully synthesized in a multianvil, high-pressure apparatus at high temperatures by using the precursors of carbon onion. It was found that distinct carbon onions with hollow or multicore microstructures lead to the formation of different diamond products, namely NPD or NtD, respectively. The Vickers hardness of high-quality...
To explore the effect of tube sizes and filling process on dielectric properties of carbon nanotubes (CNTs), CNTs with various diameters and lengths were applied to synthesize Fe-filled CNTs through wet-chemical method. The permittivities of the composites of CNTs and paraffin rely on the dispersion state (agglomeration) of CNTs in polymer matrices. During the filling process, CNTs with diverse tube...
Single-walled carbon nanohorn (CNH) has a unique structure of high electrical conductivity, which makes it potentially utilizing in energy storage. However, it is hardly used as supercapacitor alone due to enclosing internal structure and lack of faradic active sites. Here, we demonstrate the fabrication of nitrogen and oxygen dual-doped carbon nanohorn (N:CNH) via a facile arc-discharge method and...
Reproducible and in-depth studies of the electrochemical graphite intercalation and oxidation processes were carried out with the use of an electrochemical Tee-cell setup. The electrochemical method allowed simpler and greater controllability over the level of oxidation/functionalization, relative to the commonly employed chemical oxidation approach (e.g. the modified Hummers method). Extensive characterization...
To synthesize carbon nanotube/carbon matrix (CNT/C) composites rivaling or exceeding the mechanical and electrical properties of current carbon fiber/carbon matrix composites, it is essential to align carbon nanotubes in the composite. In this work, we fabricated CNT/polyacrylonitrile (PAN) precursor composites with high degree of CNT alignment, and carbonized and graphitized them at high temperatures...
The reduction of graphene oxide has been widely used to control the properties of graphene-based materials. Traditional methods thoroughly remove oxygenated functional groups in graphene oxides. We show that ethanol, ethylene glycol and glycerol can selectively reduce epoxy groups in graphene oxide while hydroxyl and carboxyl groups remain unchanged. Hydrazine hydrate can reduce oxygen functional...
Multi-wall carbon nanotubes (MWCNTs) with lengths of 0.65–1.3mm were used to fabricate aligned and continuous MWCNT/bismaleimide composites. We found that longer CNTs resulted in higher thermal and electrical conductivities of the composites. The tensile strength and Young’s modulus, however, exhibited no CNT length dependency. Investigation of the CNT morphology by transmission electron microscopy...
Electrically conductive multi-walled nanotube (MWCNT)/poly(vinylidene fluoride) (PVDF) composites with a segregated structure were prepared by high-speed mechanical mixing method. It was found that MWCNTs were uniformly dispersed on polymer particle surfaces. At the MWCNTs composition of 0.1vol.%, the composites exhibited a dramatic enhancement in electrical conductivity by 11 orders of magnitude...
A simple method for processing high-performance carbon nanotube (CNT)/poly(vinyl alcohol) (PVA) composites by coupling the spraying of a PVA solution with the continuous winding of CNT sheets from an array onto a rotating mandrel is reported. This method allows the CNT composites to have a high CNT volume fraction, while having a high degree of alignment, long CNTs, and good integration with the matrix,...
A post-growth chemical vapor deposition (CVD) treatment was used to tune the compressive mechanical properties of carbon nanotube (CNT) arrays. Millimeter tall CNT arrays with low compressive resilience were changed to a foam-like material with high compressive strength and almost complete recovery upon unloading. The foam was tuned to provide a range of compressive properties for various applications...
By adding 6wt% multi-walled carbon nanotubes (MWCNTs) or 71.7wt% micro-SiC to an epoxy resin the thermal conductivities of the composites reached maxima that were respectively 2.9 and 20.7 times that of the epoxy alone. To further improve the thermal conductivity a method that partially replaces microfiller with nanofiller was used, and a thermal conductivity, 24.3 times that of the epoxy, was obtained...
The effect of multi-walled carbon nanotubes (MWCNTs) on the cure behavior of diglycidyl ether of bisphenol-A glycidol ether epoxy resin/2-ethyl-4-methylimidazole (DGEBA/EMI-2,4) system during the cure process was studied with dynamic differential scanning calorimetry. The results showed that, at the initial curing stage, MWCNTs act as catalyst and facilitate the curing, moreover, this accelerating...
A simple solvothermal method has been used to synthesize highly graphitized lace-like carbon (GLC) using ethanol as the carbon source and Mg as reducing agent. The GLC is characterized by transmission electron microscopy, X-ray diffraction, N 2 adsorption, Raman spectroscopy and electrochemical techniques. The GLC synthesized at optimized conditions shows interlaced structure with an average...
Two phenomena were observed when a copper specimen was irradiated by normal electron beam in a transmission electron microscope. One is the growth of the rod-like carbon aggregates normally stemmed from the substrate of specimen, with their unique fir-like shape and pattern caused by the deposition of hydrocarbon molecules. These molecules come from the boiling and evaporating of the diffusion pump...
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