The Infona portal uses cookies, i.e. strings of text saved by a browser on the user's device. The portal can access those files and use them to remember the user's data, such as their chosen settings (screen view, interface language, etc.), or their login data. By using the Infona portal the user accepts automatic saving and using this information for portal operation purposes. More information on the subject can be found in the Privacy Policy and Terms of Service. By closing this window the user confirms that they have read the information on cookie usage, and they accept the privacy policy and the way cookies are used by the portal. You can change the cookie settings in your browser.
Functionalization is widely used to improve the dispersion of graphene in a polymer matrix when fabricating composites. However, there is no consensus on whether functionalization of graphene enhances thermal conductivities (TCs) of composites. Herein, we discover that although functionalization is effective in improving TCs of composites when the lateral size of graphene is small, the opposite is...
MgO supported monometallic Fe (FeMgO) and bimetallic FeMn (FeMnMgO) catalysts were developed for growing carbon nanotubes using CO as carbon source. Characterizations on the FeMgO catalyst revealed that Fe cations were well-dispersed in the porous MgO support, forming a solid solution. Since most Fe cations in the solid solution are difficult to reduce, FeMgO can only catalyze the growth of single-walled...
Char is produced during pyrolysis of biomass and it could be valorised as soil amendment, activated carbon or to produce syngas or heat by further oxidation. The mechanisms of biochars formation have to be better understood in order to tailor their properties. For this purpose, the pyrolysis of biomass was conducted in a fixed bed reactor allowing a good control of pyrolysis conditions. Miscanthus...
In this work we demonstrate that at the same pyrolysis temperature, higher graphitization can be attained in carbon nanofibers (CNFs) with hollow core compared to solid nanofibers, resulting in higher electrical conductivities in hollow CNFs. Through controlled electrospinning, single polymeric (PAN/PMMA) nanofibers are suspended across the walls of a photolithographically patterned SU8 microstructure,...
In this paper, a novel three-dimensional-linked (3D-linked) carbon fiber-carbon nanotube (Cf-CNT) hybrid structure is presented to improve the through-thickness thermal properties of polymer derived silicon carbonitride matrix composites. Comparing with pristine plain woven carbon fiber, the pores in the criss-cross position are fully filled with carbon nanotubes (CNT) in the presented Cf-CNT hybrid...
Graphene oxide (GO), prepared using Hummers method, is used to fabricate nanofiltration membranes by pressure-assisted self-assembly method. The reasons for the formation of wrinkles on the surface of GO membranes are analyzed in this paper. GO membranes have serious flux attenuation and obvious changes in surface morphology due to hydraulic pressure. At 1.0 MPa, the water flux of GO membranes decreases...
We have systematically studied the radiation effects on both p-type and n-type single-walled carbon nanotube (SWCNT) thin film transistors (TFTs) using aligned CNT arrays and semiconducting CNT networks as conductive channels. The main electrical parameters were extracted and studied statistically to help determine both the radiation effects and the underlying physical mechanisms. We found that the...
The use of graphene for microelectronics and spintronic applications requires strategies for metals to wet graphene and to grow layer-by-layer. This is especially important when metals will be used as electrical contacts or as spin filters. Extensive work in the literature so far has shown that this is very challenging, since practically all metals grow 3D, with multi-height islands forming easily...
As-synthesised single-walled carbon nanotubes (SWCNTs) are often contaminated with amorphous carbon and residual catalyst particles. These contaminants have a detrimental effect on the effective mechanical and electronic properties, limiting their performance in many applications. A comparative series of SWCNT purifications including acid treatments, gas phase purifications and recently-developed...
Both carbon nanotubes (CNTs) and graphene are important pillars in the ongoing efforts to devise new applications in nanotechnology. One of their most promising applications is building devices such as sensors and biosensors, which is important step for the development of personalized medical healthcare devices. Mediators are usually used and sought to modify the physicochemical properties of these...
The formation of a bead-shaped microstructure of poly{[3-octylthiophene-2,5-diyl]-[p-amino-azobenzylidenequinomethane]}bonded SWNT (PDTAABQ-SWNT) reveals the inhomogeneous distribution of reactive sites along a SWNT in a covalent functionalization. The bead-shaped microstructure arises from the twisting and entangling of polymer chains due to spatial confinement and geometrical restriction, as a result...
Lithium–sulfur (LiS) battery, as a high energy-density storage system, has attracted great attention for next generation rechargeable battery applications. However, the fast capacity decay caused by lithium polysulfides (LiPSs) dissolution impedes its prospect for commercialization. In this work, nitrogen-doped graphene, as a chemical immobilizer, was designed to bind LiPSs and stabilize sulfur in...
Raman spectroscopy is widely used to evaluate the nature and potential origins of carbonaceous matter in Earth's oldest rocks and minerals. It is also the tool that will be used for organic detection on the next vehicles to remotely explore the surface of Mars. Here we present, for the first time, a novel quantitative method in which previously neglected Raman spectral features are correlated directly,...
Nanostructured carbon materials have outstanding physical properties and high aspect ratios. They have attracted much attention for use as polymer composite reinforcements. In this study, alkylated and reduced graphene oxide nanoribbons (A-rGONRs) were prepared by unzipping multi-walled carbon nanotubes (MWCNTs), followed by a simple alkylation/chemical reduction process using a Dean-Stark trap. A-rGONRs...
Mechanical energy dissipation is important for vibration damping and sound absorption. This paper provides an analytical model for the interfacial-friction-based viscous behavior of exfoliated graphite, thereby establishing a methodology that may be applied to such behavior of materials in general. This model is in contrast to the conventional bulk viscous deformation model. It can be used to predict...
Among all of the requirements for carbon materials used in electric double-layer capacitors (EDLCs), specific surface area (SSA) and electrical conductivity is a pair of mutual competing demands. In this paper, a series of frame-filling structural nanoporous carbons were prepared using an amphiphilic mixture of graphite oxide and a coal tar pitch-based carbonaceous material as precursor ensuring a...
In this work, a new poly(9,9-dioctylfluorene) (PFO) derivative (named PFIID) with the large conjugated planar surfaces was designed and synthesized, and the ability to sort sc-SWCNTs was investigated in detailed. The absorption spectra of sorted SWCNT solutions demonstrated that PFIID exhibited the ability to selectively and efficiently sort sc-SWCNTs from commercial arc discharge carbon nanotubes...
Nitrogen-doped carbon nanotubes (CNx-NTs), platinum (Pt)-based catalysts supports, were prepared by pyrolysis of polypyrrole nanotubes (PPy-NTs), which were synthesized using a self-degraded template method. The morphology, structure and physicochemical properties of CNx-NTs supports and Pt/CNx-NTs catalysts were investigated by scanning electron microscope, Brunauer-Emmett-Teller surface area, transmission...
In this study, we developed a simple approach, using a nanocavity structure, to increase the light absorption of graphene in an ultra-broadband and omnidirectional manner. We determined the light absorption of graphene by calculating the surface electric fields (E-fields) of various underlying substrates. Although the surface E-field was maximized for both one-dimensional photonic crystals and a metal/dielectric...
We report on angular-resolved x-ray photoelectron spectroscopy (XPS) studies of magnetron sputtered CNx thin films, first in situ (without air exposure), then after air exposure (for time periods ranging from minutes to several years), and finally after Ar ion etching using ion energies ranging from 500 eV to 4 keV. The as-deposited films typically exhibit two strong N1s peaks corresponding to pyridine-like,...
Set the date range to filter the displayed results. You can set a starting date, ending date or both. You can enter the dates manually or choose them from the calendar.