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Lithium nickel–cobalt–aluminum oxide (NCA) is a promising cathode material for lithium-ion batteries due to its high energy density of more than 274 mAh/g. However, thermal runaway inhibits its practical applications. Lithium ferromanganese phosphate (LFMP), due to its olivine structure, can effectively stabilize the surface stability of NCA and reduce the exothermic reactions that occur during thermal runaway. LFMP can also inhibit cathode expansion and contraction during charging and discharging. To improve the conductivity of an NCM–LFMP composite electrode, three different conductive additives, namely carbon black, carbon nanotubes (CNTs), and graphene, were introduced into the electrode. Finally, battery safety tests were conducted on 1.1 Ah pouch cells fabricated in the present study. The energy density of the NCA–LFMP 1.1 Ah lithium-ion pouch cells with only 0.16% CNT content reached 224.8 Wh/kg. The CNT–NCA–LFMP pouch cell was also the safest among the cells tested. These results provide a strategy for designing high-energy-density and safe pouch cells for energy storage device applications. [ABSTRACT FROM AUTHOR]

Nanotechnology is an emerging technology and it brings a tremendous change to human life and economy. When the size of a material is reduced to the nanoscale, its properties may change significantly and becomes a new substance. A fullerene is a molecule of carbon in the shape of a hollow sphere, ellipsoid, tube, and many other geometrical structures. For example, buckyballs are spherical fullerenes and carbon nanotubes are cylindrical fullerenes. Fullerenes have been under intensive investigation for their expanding applications in electronics, energy, medicine, and many other research fields. Nanostructure analysis is very important for understanding the formation of different materials and their properties. In this study, a virtual laboratory is developed for learning fullerene production and its nanostructure analysis. The learners can use the arc discharge equipment to produce fullerenes and then use the transmission electron microscope (TEM) to observe the nanostructures of different fullerene samples. The high interactivity and 3D visual effects of the virtual laboratory enable the learners to become familiar with the geometrical structures and properties of fullerenes. A teaching experiment has been conducted and the results show that the virtual laboratory can improve their learning motivation and effectiveness. [ABSTRACT FROM AUTHOR]

Abstract: Anisotropic electrical conduction measurements have been carried out for thin films of vertically-aligned single-walled carbon nanotubes (VA-SWCNTs) grown by an alcohol catalytic CVD process. Combined with controlled synthesis and structure characterization by optical spectroscopy, the influence of the aligned structure on the electrical conduction has been identified. The out-of-plane conductivity of the films was measured to be about 0.56S/mm, independently of the film thickness. On the other hand, the in-plane conductivity was found to be more than an order of magnitude smaller, which gives rise to highly anisotropic electrical conduction, reflecting the high degree of alignment in the VA-SWCNT films. The in-plane conductivity decreases with increasing film thickness, in contrast to the film of random SWCNT networks, which exhibit thickness-independent in-plane resistance. The thickness-dependent in-plane conductivity can be expounded by a growth model of vertically aligned SWCNT films in which a thin layer of nanotube networks form on top of films at the initial stage of the growth. Such electrical anisotropy of VA-SWCNT films can be useful in miniaturized sensing devices. [ABSTRACT FROM AUTHOR]

To alleviate the discomfort caused by the blood sampling process, a noninvasive saliva glucose sensor is investigated in this study. Owing to the low glucose concentration in the body fluid, the fabricated sensor is requested to possess high sensitivity. Herein, a chemical polymerization method is used to deposit polypyrrole (PPy) on a fluorine-doped tin oxide (FTO) conductive glass substrate followed by modification with acid treated carbon nanotubes (acid-CNTs) via the drop-casting method in order to fabricate acid-CNTs/PPy/FTO electrodes. In addition, the sensing device uses glucose oxidase as an enzyme to catalyze the redox reaction and improve the electrode selectivity. The electron transfer resistance decreases with layer-by-layer CNTs modification, and the acid-treatment time of CNTs significantly affects the sensing performance. The acid-CNTs/PPy/FTO electrodes exhibit excellent sensing performance with a high sensitivity of 95.26 μA/mMcm2 and a broad linear range of 10–700 μM with a R2 of 0.9958. Moreover, the acid-CNTs/PPy/FTO electrodes show high selectivity to glucose along with excellent stability. Furthermore, the sensing capability of the acid-CNTs/PPy/FTO electrode is tested using artificial saliva, that further confirms high potential of acid-CNTs/PPy/FTO electrodes in the noninvasive diagnosis of diabetes. [Display omitted] • Acid-CNTs/PPy/FTO electrodes are fabricated for noninvasive saliva glucose sensor. • The acid-treatment time of CNTs significantly affects the sensing performance. • The high sensitivity of 95.26 μA/mMcm2 (10–700 μM) with a R2 of 0.9958 is achieved. • The electrodes show excellent stability and high selectivity towards glucose. [ABSTRACT FROM AUTHOR]

Melamine sponges coated with reduced graphene oxide/carbon nanotube (rGO–CNT sponges) through a dip-coating method were fabricated that provide a large electrical conductive surface for Escherichia coli growth and electron transfer in microbial fuel cell. Four rGO–CNT sponges with different thicknesses and arrangements were tested as an anode in this study. The thinnest one (with a thickness of 1.5 mm) exhibited the best performance, providing a maximum current density of 335 A m −3 and a remarkably durable life time of 20 days at 37 °C. Analyses of bacterial colonisation on the rGO–CNT sponges using FE-SEM and the bacterial metabolic activity using the β-galactosidase assay indicates that the rGO–CNT sponges provide excellent biocompatibility for E. coli proliferation and could help to maintain high bacterial metabolic activity, presumably due to the high mass transfer rate of the porous scaffold. In this regard, the rGO–CNT sponges showed higher durability and performed better electrochemical properties than traditional carbon-based and metal-based anodes. [ABSTRACT FROM AUTHOR]

[Display omitted] • An efficient GOx/Nf-CNT/SPE electrochemical saliva glucose sensor is developed. • The ratio of Nafion and CNT is optimized for high glucose sensitivity. • The effect of plasma treatment on morphology and glucose sensing is studied. • A high sensitivity of 99.13 µA/mMcm2 in the range of 20–700 µM glucose is achieved. Due to unhealthy lifestyles, the population of diabetics is rapidly increasing, therefore, the demand of glucose meter is also increasing. However, not all the people could overcome the fear of jabbing a needle during blood glucose tests. In this regard, we report a non-invasive glucose sensing electrode composed of conductive and bio-compatible Nafion-carbon nanotubes (Nf-CNT) nanocomposite and glucose oxidase (GOx), which are sequentially coated on screen-printed electrode (SPE). The Nf-CNT nanocomposite is prepared through ultrasonication followed by drop casting it onto the SPE. Subsequently, Nf-CNT/SPEs are subjected to plasma treatment followed by drop-casting of GOx to fabricate GOx/Nf-CNT/SPE electrodes. The plasma treatment alters the hydrophobic nature of Nf-CNT/SPE, which not only exposes the surface of Nf-CNT layer, but also enables it for uniform coating of GOx. The results confirm that the mixing ratio of Nafion and CNT as well as plasma treatment time significantly affects sensing performance. The GOx/Nf-CNT/SPE subjected to 1 min of plasma treatment prior to the coating of GOx shows the best performance with a sensitivity of 99.13 μA/mMcm2 and a linear range of 20–700 μM. Moreover, the GOx/Nf-CNT/SPE electrodes are also tested under artificial saliva, which shows their high potential in the diagnosis of diabetes. [ABSTRACT FROM AUTHOR]

[Display omitted] • FTO-CNTs/PEI/GOx electrochemical saliva glucose sensor is developed. • CNT forest favors the stable immobilization of GOx in considerable quantities. • Electrochemical glucose detection in artificial saliva samples is achieved. • The high sensitivity of 63.38 µA/mMcm2 (70–700 µM glucose) is achieved. With the aim of improving the life quality for diabetics, we develop a novel electrode for the noninvasive glucose sensor which can determine the glucose levels in saliva. In this work, carbon nanotubes (CNTs) are directly grown on a fluorine-doped tin oxide (FTO) coated glass substrate through chemical vapor deposition, followed by the immobilization of glucose oxidase (GOx) via electrostatic force with the aid of polyethylenimine (PEI). The results confirm that the CNT forest can substantially enhance the charge transferability, and considerable quantities of GOx can be stably immobilized on the rough surface of the electrode because of the networked structure of the CNT forest. With a fast electron transfer rate and short electron transfer distance, both the current difference of the oxygen consumption and enzyme reduction reaction are detected for glucose sensor using the cyclic voltammetry method. The FTO-CNTs/PEI/GOx electrode exhibits the high sensitivity of 63.38 µA/mMcm2 with a wide linear range of 70–700 µM glucose. Furthermore, the FTO-CNTs/PEI/GOx electrode shows good stability as well as high selectivity towards glucose. Finally, the glucose sensing performance of the FTO-CNTs/PEI/GOx electrode is investigated in artificial saliva, which exhibits great sensitivity even under high-viscosity conditions such as artificial saliva, thus, reveals excellent potential for use in practical applications. [ABSTRACT FROM AUTHOR]

Abstract: The influences of carbon nanomaterials on bacteria were investigated using three types of dispersed and functionalized carbon nanomaterials (F-CNMs), viz. functionalized carbon nanopowder (F-CNP), functionalized single-walled carbon nanotubes (F-SWCNTs), and functionalized multi-walled carbon nanotubes (F-MWCNTs). F-CNMs with different aspect ratios were used to study the influence of material configuration on the viability of Escherichia coli (E. coli). Although these materials were functionalized to improve their dispersibility, the original morphologies and chemical properties of the materials were maintained. Traditional bacteria quantitative plating analysis was conducted, and the results of which revealed that the F-CNP and the F-SWCNTs showed a less significant effect on the viability of E. coli, while the F-MWCNTs obviously inhibited cell viability. A Fourier transform infrared spectroscopy and a scanning electron microscopy were used to verify the functionalization of the F-CNMs and to examine the interaction of F-CNMs with E. coli, respectively; in addition, we adopted chemiluminescence assays to measure the concentration of adenosine triphosphate (ATP) released from the damaged cells. The results showed that the ATP of the F-MWCNTs sample is two-fold higher than that of the control, indicating direct piercing of E. coli by F-MWCNTs leads to bacteria death. Furthermore, F-SWCNTs were concluded to have less influence on the viability of E. coli because ultra-long F-SWCNTs used in this study performed less rigidity to pierce the cells. [Copyright &y& Elsevier]

• The devices are composed of polyethylenimine-polyethylene glycol/carbon nanotubes. • The bilayer-structure devices provide 3.25% sensitivity under 5 vol% CO 2. • The responses with 15, 8, and 6 vol% CO 2 are 4.95, 3.95 and 3.52%, respectively. • The devices show excellent stability and reversibility under multiple cycle tests. This work aims to fabricate polyethylenimine (PEI)-polyethylene glycol (PEG)/multi-walled carbon nanotubes (MWCNTs) bilayer-structure devices for CO 2 gas sensors. The devices are composed of two layers; the first layer is made of MWCNTs, which act as the electron transport layer, whereas the second layer is made of PEI-PEG blender which can functionalize MWCNTs and acts as the CO 2 adsorption material. Both layers are sequentially spray-coated on the screen-printed carbon electrodes. After functionalization, the resistance of the device is increased due to the functionalization effect by the PEI-PEG blender. Using air as background gas, the bilayer-structure devices provide 3.25% sensitivity under 5 vol% CO 2. Moreover, the devices show excellent stability and reversibility under multiple cycle tests for 400 min. [ABSTRACT FROM AUTHOR]