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• GNP and MWCNT collectively affect mechanical stability and electrical property of the PFHD. • Optimized PFHD contains 67 wt% MWCNT and 33 wt% GNT. • Paper-based low cost and rapid heating device shows a T max of 116.3 ℃ at 2.5 V. • Flexible and lightweight heating device ideal for PEMFC driven aerial vehicle can serve as a disposable container for hydrogen fuel. A paper-based flexible heating device (PFHD - paper-based flexible heating device) composed of a cellulose paper substrate and a carbonaceous functional electrode is reported. The functional composite electrodes containing graphene nanoplatelets (GNP - graphene nanoplatelets) and multi-walled carbon nanotubes (MWCNT) in various compositional ratios were prepared by dip-coating the oxygen plasma-treated paper substrate into the composite ink, and subsequently dried at 110 ℃ for 30 min to prepare PFHDs. The electrochemical characteristics and heat generation properties of PFHDs indicated that the GNP component in the functional electrode enhanced the electrical conductivity of the electrode, and the physical stability was enhanced mainly by the MWCNT component. Accordingly, PFHD 0.33 which contains 33 % GNP and 67 % MWCNT in the functional electrode shows excellent heating performance with high stability and areal rated power of 0.68 W cm−2 (specific rated power = 45 W g−1). The measured sensitivity of PFHD 0.33 is 31.50 ℃ V−1 at the applied DC voltage of 0.1–2.0 V. [Display omitted] [ABSTRACT FROM AUTHOR]

A facile strategy is designed for the fabrication of flexible and free-standing ternary CoSnO 3 /graphene/carbon nanotubes (CoSnO 3 /GN/CNTs) composite papers through a simple filtration, followed by annealing process. The CoSnO 3 /GN/CNTs composite papers with high flexibility and tailorability can be easily fabricated. The CoSn(OH) 6 nanoparticles/graphene oxide/carbon nanotubes (CoSn(OH) 6 /GO/CNTs) composite papers obtained by a simple filtration method are transformed into CoSnO 3 /GN/CNTs composite papers after a thermal treatment process. In this unique composite structure, CoSnO 3 nanoparticles (nanocubes and nanoboxes) are embedded homogenously into the 3D framework of graphene and carbon nanotubes, respectively, in which offers not only a 3D conductive network and a dual restriction on the aggregation of CoSnO 3 nanoparticles, but also accommodates the large volume expansion of CoSnO 3 nanoparticles. When used directly as binder- and conductive agent-free anodes for lithium-ion batteries, the CoSnO 3 /GN/CNTs composite papers exhibit superb electrochemical properties including extraordinary reversible capacities, superior rate capabilities and stable cycle performances compared to CoSnO 3 nanoparticles and GN/CNTs paper, suggesting a new pathway for the rational engineering of anode materials. [ABSTRACT FROM AUTHOR]

The increasing demands for portable, wearable, and implantable sensing devices have stimulated growing interest in innovative electrode materials. In this work, we have demonstrated that printing a conductive ink formulated by blending three-dimensional (3D) porous graphene–carbon nanotube (CNT) assembly with ionic liquid (IL) on two-dimensional (2D) graphene paper (GP), leads to a freestanding GP supported graphene–CNT–IL nanocomposite (graphene–CNT–IL/GP). The incorporation of highly conductive CNTs into graphene assembly effectively increases its surface area and improves its electrical and mechanical properties. The graphene–CNT–IL/GP, as freestanding and flexible substrates, allows for efficient loading of PtAu alloy nanoparticles by means of ultrasonic-electrochemical deposition. Owing to the synergistic effect of PtAu alloy nanoparticles, 3D porous graphene–CNT scaffold, IL binder and 2D flexible GP substrate, the resultant lightweight nanohybrid paper electrode exhibits excellent sensing performances in nonenzymatic electrochemical detection of glucose in terms of sensitivity, selectivity, reproducibility and mechanical properties. [ABSTRACT FROM AUTHOR]

The review presents the results of modeling of the solvation of nanoparticles with deep eutectic solvents that act as stabilizers of metal nanoparticles, which provide a new platform for nanoparticle technology. It is calculated that there is a slower dynamics of solvent molecules, i.e., a slowing down of water near solutes. Such water has limited movement and cannot be organized into tetrahedral forms, in contrast to water in volume. Also, the paper describes systematic studies of the adsorption configuration, distribution density and adsorption energy of molecules H$_{2}$O, CO$_{2}$, CH$_{4}$, N$_{2}$, C$_{8}$H$_{18}$ and fluorocarbons C$_{3}$F$_{8}$ and C$_{5}$F$_{12}$ on the surface of kaolinite (0 0 1). Water adsorption is initiated and occurs due to the growth of clusters around surface groups, which is mainly regulated by the interactions of hydrogen bonds. Further, the paper investigates theoretically physical and mechanical properties of nanoscale systems, in particular, nanotips, amorphous carbon monolayer and nanoparticles. It is shown that the single-layer amorphous carbon is surprisingly stable and is deformed with a high ultimate strength without the propagation of cracks from the point of failure. The sliding on amorphous polyethylene and silicon studied using the method of molecular dynamics is described. The paper also discusses the dependencies of the friction force, acting on nanoparticles, on their velocity and sizes, in particular, the contact area, the structure and the type of the material, as well as on the direction of their shear and temperature. At an angle of rotation $ 45^\circ $, the silicon friction forces reach a minimum value, which can be termed superlubricity. The molecular dynamics modeling of the surface of carbon nanotubes, chitosan, polyvinyl acetate, titanium dioxide, $α$-quartz and zeolite is described to solve application problems ranging from reaction control to targeted delivery and creation of new drugs. The general principles have been identified that artificial water channels made of carbon nanotubes porins must satisfy, which can serve as a basis for further experiments. The organic modification mainly forms a modifier layer by crosslinking the hydrogen bond with the substrate, the flatness of the modified layer is strongly influenced by the type and concentration of the modifier. [ABSTRACT FROM AUTHOR]

[Display omitted] • Pulsed laser radiation forms a graphene/SWCNT hybrid film with a developed surface. • Functionalization of graphene/SWCNT film with BaO nanoparticles reduces the work function. • Emission current of carbon film increased by 42 times due to functionalization with BaO. • Hybrid carbon film with BaO nanoparticles can be used as efficient field cathode. This paper presents the manufacturing technology of hybrid nanostructures based on a buffer layer of reduced graphene oxide (rGO) flakes with vertical single-walled carbon nanotubes (SWCNTs) and their bundles functionalized with BaO nanoparticles. Using density functional theory (DFT) calculations, supercells of rGO/SWCNT/BaO films were constructed and the patterns of the electron work function were revealed. It has been demonstrated that the electron work function is influenced by both the mass fraction of BaO nanoparticles and the inter-tube distance. Branched carbon nanostructure was formed using a pulsed laser irradiation. Fragmentation of BaO nanoparticles on the carbon surface was achieved. It was shown that after laser treatment, Ba(NO 3) 2 particles up to 200 nm in size were fragmented into smaller BaO nanoparticles with sizes of a few nanometers, covering the nanotubes. The field emission current–voltage characteristics (CVCs) were measured and showed a 42-fold increase in emission current compared to the nanostructure without BaO functionalization and laser treatment. BaO-functionalized hybrid carbon nanostructures are predicted to be efficient field cathodes, with a current density of at least 2 A/cm2, for use in X-ray tubes, field emission displays, and vacuum microwave devices. [ABSTRACT FROM AUTHOR]

The aim of the paper is to investigate the effect of size of multiwalled carbon nanotubes (MWCNTs) as additives for dispersion in gear oil to improve the tribological properties. Since long pristine MWCNTs tend to form clusters compromising dispersion stability, they are mildly processed in a ball mill to shorten the length and stabilized with a surfactant before dispersing in lubricant. Investigations are made to assess the effect of ball milling on the size and structure of MWCNTs using electron microscopy and Raman spectroscopy. The long and shortened MWCNTs are dispersed in EP 140 gear oil in 0.5% weight. The stability of the dispersed multiwalled carbon nanotubes is evaluated using light scattering techniques. The antiwear, antifriction, and extreme pressure properties of test oils are evaluated on a four-ball wear tester. It is found that ball milling of MWCNTs has a strong effect on the stability and tribological properties of the lubricant. From Raman spectroscopy, it is found that ball milling time of up to 10 hours did not produce any defects on the surface of MWCNTs. The stability of the lubricant and the antiwear, antifriction, and extreme pressure properties have improved significantly with dispersion shortened MWCNTs. Ball milling for longer periods produces defects on the surface of MWCNTs reducing their advantage as oil additives. [ABSTRACT FROM AUTHOR]

• G-CNTs-FeCo grown by vertically electrochemical exfoliation and hydrothermal. • FeCo growing on graphene can enhance electrochemical performance. • FeCo acts as catalyst for growing CNTs on graphene. • Electrochemical performance of G-CNTs-FeCo is better than pure graphene. • CNTs and FeCo growing on the graphene enhance conductivity and capacity. In this work, we grow CNTs on electrochemical exfoliation graphene with few FeCo(G-CNTs-FeCo) by hydrothermal as a new supercapacitors electrode. It has excellent specific capacitance (560.26 F/g at 1 mV/s) and low charge transfer resistance (30.79 Ω). The supercapacitor electrode exhibits better electron conductivity and electrochemical performance than pure graphene which was found to combine the merit of graphene, CNTs and FeCo metals. This paper would help to provide a method to improve graphene SCs performance. [ABSTRACT FROM AUTHOR]

Nano-sized carbons, such as graphene nanoparticle (GNP) and multiwall carbon nanotube (MWCNT), have attracted a great deal of attention due to their extraordinary intrinsic properties. Extensive research has been done on each carbon material for epoxy nanocomposites but only a few have ventured into a comparison study. In this paper, the effect of GNP and MWCNT, at various filler loadings, on the mechanical, thermal and dielectric properties of epoxy nanocomposites have been investigated. The experimental results demonstrate that GNP filled epoxy nanocomposites showed higher thermal and dielectric properties, but slightly lower mechanical properties compared to the MWCNT filled epoxy nanocomposites. The tensile strength, flexural strength, thermal conductivity and dielectric constant of GNP filled epoxy nanocomposites improved up to 11%, 17%, 126%, and 171% respectively, and MWCNT filled epoxy nanocomposites improved up to 26%, 29%, 60%, and 73% respectively. [ABSTRACT FROM AUTHOR]

Abstract: SnO2–graphene–carbon nanotube (SnO2–G–CNT) mixture is synthesized using graphene oxide as precursor for application as anode material in rechargeable Li ion batteries. It is shown that the SnO2 nanoparticles of 3–6nm in diameter are not only attached onto the surface of graphene sheets by anchoring with surface functional groups, but they also are encapsulated in pore channels formed by entangled graphene sheets. The incorporation of carbon nanotubes reduces the charge transfer resistance of the anode made from the mixture through the formation of 3D electronic conductive networks. The SnO2–G–CNT anodes deliver remarkable capacities of 345 and 635mAhg−1 at 1.5 and 0.25Ag−1, respectively. Flexible electrodes consisting of highly-aligned SnO2–G–CNT papers are also prepared using a simple vacuum filtration technique. They present a stable capacity of 387mAhg−1 at 0.1Ag−1 after 50 cycles through the synergy of the high specific capacity of SnO2 nanoparticles and the excellent cycleability of G–CNT paper. [Copyright &y& Elsevier]

The addition of SiC or TiC nanoparticles to polycrystalline alumina matrix has long been known as an efficient way of improving the mechanical properties of alumina-based ceramics, especially strength, creep, and wear resistance. Recently, new types of nano-additives, such as carbon nanotubes (CNT), carbon nanofibers (CNF), and graphene sheets have been studied in order not only to improve the mechanical properties, but also to prepare materials with added functionalities, such as thermal and electrical conductivity. This paper provides a concise review of several types of alumina-based nanocomposites, evaluating the efficiency of various preparation methods and additives in terms of their influence on the properties of composites. [ABSTRACT FROM AUTHOR]

Nanotechnology is a dynamically developing field of science, due to the unique physical, chemical and biological properties of nanomaterials. Innovative structures using nanotechnology have found application in diverse fields: in agricultural and food industries, where they improve the quality and safety of food; in medical and biological sciences; cosmetology; and many other areas of our lives. In this article, a particular attention is focused on carbon nanomaterials, especially graphene, as well as carbon nanotubes and carbon quantum dots that have been successfully used in biotechnology, biomedicine and broadly defined environmental applications. Some properties of carbon nanomaterials prevent their direct use. One example is the difficulty in synthesizing graphene-based materials resulting from the tendency of graphene to aggregate. This results in a limitation of their use in certain fields. Therefore, in order to achieve a wider use and better availability of nanoparticles, they are introduced into matrices, most often polysaccharides with a high hydrophilicity. Such composites can compete with synthetic polymers. For this purpose, the carbon-based nanoparticles in polysaccharides matrices were characterized. The paper presents the progress of ground-breaking research in the field of designing innovative carbon-based nanomaterials, and applications of nanotechnology in diverse fields that are currently being developed is of high interest and shows great innovative potential. [ABSTRACT FROM AUTHOR]

Abstract: In this paper we report the effect of Fe film thickness on the growth, structure and electron emission characteristics of carbon nanotubes (CNTs) and multilayer graphene deposited on Si substrate. It is observed that the number of graphitic shells in carbon nanostructures (CNs) varies with the thickness of the catalyst depending on the average size of nanoparticles. Further, the Fe nanoparticles do not catalyze beyond a particular size of nanoclusters leading to the formation of multilayer graphene structure, instead of carbon nanotubes (CNTs). It is observed that the crystallinity of CNs enhances upon increasing the catalyst thickness. Multilayer graphene structures show improved crystallinity in comparison to CNTs as graphitic to defect mode intensity ratio (I D /I G ) decreases from 1.2 to 0.8. However, I 2D /I G value for multilayer graphene is found to be 1.1 confirming the presence of at least 10 layers of graphene in these samples. CNTs with smaller diameter show better electron emission properties with enhancement factor (γC  = 2.8 × 103) in comparison to multilayer graphene structure (γC  = 1.5 × 103). The better emission characteristics in CNTs are explained due to combination of electrons from edges as well as centers in comparison to the multilayer graphene. [Copyright &y& Elsevier]

Abstract: Carbon nanofibres (CNFs) obtained by plasma-enhanced chemical vapour deposition are made of cone-shaped graphene layers, the opening angle of which has a significant influence on their properties: the smaller the angle, the closer the properties to those of carbon nanotubes. That angle is determined by the shape of the metal nanoparticle used to catalyse the growth. We show in this paper that the shape of Ni nanoparticle catalysts, and in turn the CNF properties, can be tuned during plasma-enhanced chemical vapour deposition, by the choice of the etchant gas. We show in particular that a water-containing etchant (H2O or H2O+H2) increases the growth rate by an order of magnitude at 600°C compared to an ammonia-containing etchant (NH3 or NH3 +H2), and leaves more elongated Ni particles with a cone angle three times smaller. We conclude that the cone angle and the growth rate are directly related, and propose a mechanism to explain that large difference between the two etchants [ABSTRACT FROM AUTHOR]

Carbon is one of the most abundant elements on Earth. In addition to the well-known crystallographic modifications such as graphite and diamond, other allotropic carbon modifications such as graphene-based nanomaterials and carbon nanotubes have recently come to the fore. These carbon nanomaterials can be designed to help deliver or target drugs more efficiently and to innovate therapeutic approaches, especially for cancer treatment, but also for the development of new diagnostic agents for malignancies and are expected to help combine molecular imaging for diagnosis with therapies. This paper summarizes the latest designed drug delivery nanosystems based on graphene, graphene quantum dots, graphene oxide, reduced graphene oxide and carbon nanotubes, mainly for anticancer therapy. [ABSTRACT FROM AUTHOR]

In this perspective paper, we critically analyse the state-of-the-art of arc discharge technique of carbon nanoparticle synthesis. We discuss improving controllability of the arc discharge synthesis of carbon nanotubes, synthesis of graphene as well as general understanding of the synthesis process. Fundamental issues related to relationship between plasma parameters and carbon nanostructure characteristics are considered. Effects of electrical and magnetic fields applied during single-wall carbon nanotube synthesis in arc plasma are explored. Finally our personal opinion on what future trends will be in arc discharge synthesis is offered. [ABSTRACT FROM AUTHOR]

This review paper presents historical perspectives, recent advances and future directions in the multidisciplinary research field of plasma nanoscience. The current status and future challenges are presented using a three-dimensional framework. The first and the largest dimension covers the most important classes of nanoscale objects (nanostructures, nanofeatures and nanoassemblies/nanoarchitectures) and materials systems, namely carbon nanotubes, nanofibres, graphene, graphene nanoribbons, graphene nanoflakes, nanodiamond and related carbon-based nanostructures; metal, silicon and other inorganic nanoparticles and nanostructures; soft organic nanomaterials; nano-biomaterials; biological objects and nanoscale plasma etching. In the second dimension, we discuss the most common types of plasmas and plasma reactors used in nanoscale plasma synthesis and processing. These include low-temperature non-equilibrium plasmas at low and high pressures, thermal plasmas, high-pressure microplasmas, plasmas in liquids and plasma-liquid interactions, high-energy-density plasmas, and ionized physical vapour deposition as well as some other plasma-enhanced nanofabrication techniques. In the third dimension, we outline some of the 'Grand Science Challenges' and 'Grand Socio-economic Challenges' to which significant contributions from plasma nanoscience-related research can be expected in the near future. The urgent need for a stronger focus on practical, outcome-oriented research to tackle the grand challenges is emphasized and concisely formulated as from controlled complexity to practical simplicity in solving grand challenges. [ABSTRACT FROM AUTHOR]