Carbon Nanotubes Research Articles

Improving Electrochemical Performance of Ultrahigh-Loading Cathodes via the Addition of Multi-Walled Carbon Nanotubes

Improving Electrochemical Performance of Ultrahigh-Loading Cathodes via the Addition of Multi-Walled Carbon Nanotubes

An Investigation Into the Influence of Titania–Carbon Nanotube Nanophotocatalysts Into the Filtration Performance of Polyethersulfone‐Based Membranes

An Investigation Into the Influence of Titania–Carbon Nanotube Nanophotocatalysts Into the Filtration Performance of <scp>Polyethersulfone</scp>‐Based Membranes

Controlled Introduction of sp3 Quantum Defects in Fluorescent Carbon Nanotubes by Mechanochemistry

Controlled Introduction of sp3 Quantum Defects in Fluorescent Carbon Nanotubes by Mechanochemistry

Ultrasensitive non-enzymatic electrochemical detection of paraoxon-ethyl in fruit samples using 2D Ti3C2Tx/MWCNT-OH.

This study reports on the development of a highly sensitive non-enzymatic electrochemical sensor based on a two-dimensional Ti3C2Tx/MWCNT-OH nanocomposite for the detection of paraoxon-based pesticide. The synergistic effect between the Ti3C2Tx nanosheet and the functionalized multi-walled carbon nanotubes enhanced the sensor's conductivity and catalytic activity. The nanocomposite demonstrates superior electrochemical and electroanalytical performance compared to the pristine Ti3C2Tx and MWCNT-OH in detecting paraoxon-ethyl in fruit samples (green and red grapes), with a linear response range from 0.1 to 100 μM, a low limit of detection (LOD) of 10 nM, limit of quantitation (LOQ) of 70 nM, and sensitivity of 0.957 µA μM-1 cm-2 at pH 8. Furthermore, the sensors maintain excellent selectivity and effectiveness in detecting paraoxon-ethyl even in the presence of various interferents, including diazinon, carbaryl, Fe2+, NO2-, NO3-, ascorbic acid, and glucose. The facile fabrication and enhanced sensing capabilities of the Ti3C2Tx/MWCNT-OH nanocomposite position it as a reliable, cost-effective, and sustainable alternative to conventional detection systems for monitoring pesticide residues in agricultural products.

Exploring the Effect of Annealing on PLA/Carbon Nanotube Nanocomposites: In Search of Efficient PLA/MWCNT Nanocomposites for Electromagnetic Shielding.

In this research, poly(lactic acid) (PLA) nanocomposites with multi-walled carbon nanotubes (MWCNT) were produced by extrusion, injection, and compression molding, focusing on electromagnetic shielding. Various amounts of carbon nanotubes (MWCNTs) were tested in PLA matrix, specifically ranging from 1 to 4 parts per hundred resin (phr). The resulting nanocomposites were analyzed before and after undergoing annealing heat treatment. It was observed that as the MWCNT content increased, the melt flow index of PLA decreased. This reduction indicates that the nanotubes were effectively accommodated into the PLA chain. The PLA/MWCNT (2 phr) formulation presented the greatest balance of properties, with potential for electromagnetic shielding application. Scanning electron microscopy (SEM) demonstrated that incorporating 2 phr of carbon nanotubes in PLA promoted good distribution, favoring high electrical conductivity and electromagnetic shielding between 20-22 dB (8.2-18 GHz), corresponding to approximately 99% attenuation. Furthermore, its properties, such as elastic modulus (3156 MPa), tensile strength (65.1 MPa), hardness (77.8 Shore D), and heat deflection temperature (55.3 °C), increased compared to pure PLA. After annealing, the PLA/MWCNT (2 phr) nanocomposite underwent a molecular reordering, resulting in an increased crystalline fraction, as confirmed by X-ray diffraction (XRD). However, the electrical conductivity maintained the same order of magnitude, while the electromagnetic shielding varied from 19.7 to 20 dB. The results indicate that these nanocomposites are promising for electromagnetic shielding applications and can be manufactured in the molten state.

Lipocalin-2 Determination on Multiwalled Carbon Nanotube Integrated Circular Electrodes for Diagnosing Ulcerative Colitis.

Ulcerative colitis affects the inner lining of the large intestine, causing discomfort, pain, and digestion issues, and sometimes leading to life-threatening complications. With proper medication, symptoms and inflammation can be reduced, improving the condition. In this research, a multiwalled carbon nanotube (MWCN)-modified circular interdigitated electrode (circular-IDE) biosensor was developed to detect the ulcerative colitis biomarker lipocalin-2 and measured at 0-2V. A dual probing strategy with aptamer and antibody on gold nanoparticles was employed for the detection of lipocalin-2. Probe immobilization was optimized on MWCN-modified circular-IDE, and saturation of 800nM of aptamer on the GNP-antibody facilitated the identification of lipocalin-2 at concentrations as low as 1 pg/mL, with an R2 value of 0.9716 [y = 2.1058x - 2.7351]. Furthermore, lipocalin-2 spiking in serum increased the current responses in correlation with the concentrations of lipocalin-2, indicating selective identification without interference. In addition, nonimmune antibody and GNP-conjugated complementary aptamer did not increase the current responses, affirming the specific detection of lipocalin-2. This MWCN-modified circular-IDE biosensor, utilizing aptamer-antibody interactions, aids in identifying the condition of ulcerative colitis.

Performance and emissions of diesel engine combustion lubricated with Jatropha bio-lubricant and MWCNT additive

Vegetable oil-based lubricants, modified through transesterification and epoxidation, present a sustainable alternative to mineral lubricants for transport and industrial use. This study evaluates epoxidized jatropha oil (EJA) enhanced with multi-walled carbon nanotubes (MWCNT) as a bio-lubricant for compression ignition engines. MWCNT, dispersed in EJA using an ultrasonic probe sonicator with Triton X-100 as a surfactant, was tested at nanoparticle concentrations from 0.5 to 2 wt%. Engine performance and emission characteristics were assessed using SAE 20W40, EJA, and EJA-MWCNT in a four-stroke diesel engine. Results showed that EJA with 2 wt% MWCNT reduced friction power by 39.13% compared to SAE 20W40 and decreased brake specific energy consumption by 6.11%, while lowering emissions of hydrocarbons, carbon monoxide, and smoke. These findings highlight EJA-MWCNT as a promising lubricant for diesel engines, enhancing efficiency and reducing pollutants, making it a viable eco-friendly substitute for diminishing petroleum resources.

Hybrids of Deep HOMO Organic Cyanoacrylic Acid Dyes and Graphene Nanomaterials for Water Splitting Photoanodes.

Dye-sensitization is a promising strategy to improve the light absorption and photoactivity abilities of wide-bandgap semiconductors, like TiO2. For effective water-splitting photoanodes with no sacrificial agents, the electrochemical potential of the dye must exceed the thermodynamic threshold needed for the oxygen evolution reaction. This study investigates two promising organic cyanoacrylic dyes, designed to meet that criterion by means of theoretical calculations. Both yellow-colored dyes were synthesized and characterized by optical and photoelectrochemical techniques, demonstrating strong light absorption in the visible region, suitable experimental reduction potentials, and adsorption from the organic solvent onto mesoporous TiO2 layers. In addition, to promote immobilization in aqueous electrolytes, the dyes were hybridized with graphene oxide or multi-walled carbon nanotubes. Photoelectrochemical analysis of the dye-sensitized photoelectrodes demonstrated efficient charge transfer from the dyes to the TiO2 photoanode under simulated solar light. While the starting photocurrent notably surpassed the blank TiO2, a subsequent decay points to kinetic obstacles that still need to be overcome.

A Low-Cost Electrochemical Cell Sensor Based on MWCNT-COOH/α-Fe2O3 for Toxicity Detection of Drinking Water Disinfection Byproducts.

The disinfection of drinking water is essential for eliminating pathogens and preventing waterborne diseases. However, this process generates various disinfection byproducts (DBPs), which toxicological research indicates can have detrimental effects on living organisms. Moreover, the safety of these DBPs has not been sufficiently assessed, underscoring the need for a comprehensive evaluation of their toxic effects and associated health risks. Compared to traditional methods for studying the toxicity of pollutants, emerging electrochemical sensing technologies offer advantages such as simplicity, speed, and sensitivity, presenting an effective means for toxicity research on pollutants. However, challenges remain in this field, including the need to improve electrode sensitivity and reduce electrode costs. In this study, a pencil graphite electrode (PGE) was modified with carboxylated multi-walled carbon nanotubes (MWCNT-COOH) and nano-iron (III) oxide (α-Fe2O3) to fabricate a low-cost electrode with excellent electrocatalytic performance for cell-active substances. Subsequently, a novel cellular electrochemical sensor was constructed for the sensitive detection of the toxicity of three drinking water DBPs. The half inhibitory concentration (IC50) values of 2-chlorophenylacetonitrile (2-CPAN), 3-chlorophenylacetonitrile (3-CPAN), and 4-chlorophenylacetonitrile (4-CPAN) for HepG2 cells were 660.69, 831.76, and 812.83 µM, respectively. This study provides technical support and scientific evidence for the toxicity detection and safety assessment of emerging contaminants.

Open-atmosphere spinning of carbon nanotube fibers sans hydrogen flow by floating catalyst chemical vapor deposition: an insight into the mechanism

Open-atmosphere spinning of carbon nanotube fibers sans hydrogen flow by floating catalyst chemical vapor deposition: an insight into the mechanism

Extrusion foaming of semi-conductive poly (lactic acid)/carbon nanotube nanocomposites: Processing and foam microstructure correlations

Extrusion foaming of semi-conductive poly (lactic acid)/carbon nanotube nanocomposites: Processing and foam microstructure correlations

Ultrasensitive electrochemical detection of gallic acid in beverages based on nitrogen-doped multi-walled carbon nanotube networks embellished with cobalt 2-methylimidazole nanoparticles.

This work presents a convenient and easy-to-operate method for synthesizing the functionally integrated nanocomposite of nitrogen-doped multi walled carbon nanotube networks (N-CNTs) and cobalt 2-methylimidazole (ZIF-67) nanoparticles. The N-CNTs@ZIF-67 nanocomposite was utilized to design a novel electrochemical sensing platform for detecting gallic acid (GA). The N-CNTs@ZIF-67 modified glass carbon electrode (GCE) demonstrated high sensitivity for GA electrochemical detection (LOD: 10.17nM, detection concentration: 0.5-20μM). N-CNTs provided efficient electron transport channels for the GA electrochemical detection reaction, which improved the transfer rate of electrons/ions at the interface of sensing electrode/electrolyte. ZIF-67 nanoparticles with highly porous structure could adsorb GA molecules and promote the oxidation reaction. Besides that, N-CNTs provided more active sites on carbon nanotube networks by nitrogen-doping, which significantly enhanced the catalytic activity. The prepared N-CNTs@ZIF-67/GCE sensor exhibited favorable GA sensing detection performance, realizing an accurate analysis of GA in beverage samples (Recovery: 96.77-107.93%, RSD: 1.07-4.38%).

Optimized thermal oxidation strategy for amorphous carbon removal in wet-spun carbon nanotube fibers

Optimized thermal oxidation strategy for amorphous carbon removal in wet-spun carbon nanotube fibers

Comparative analysis on fatigue, creep, DMA, and flammability behavior of carbon nanotubes, onion peel extracted carbon quantum dots, and Kevlar fiber reinforced epoxy composite

Comparative analysis on fatigue, creep, DMA, and flammability behavior of carbon nanotubes, onion peel extracted carbon quantum dots, and Kevlar fiber reinforced epoxy composite

Temperature-Responsive Hybrid Composite with Zero Temperature Coefficient of Resistance for Wearable Thermotherapy Pads.

Carbon-based polymer composites are widely used in wearable devices due to their exceptional electrical conductivity and flexibility. However, their temperature-dependent resistance variations pose significant challenges to device safety and performance. A negative temperature coefficient (NTC) can lead to overcurrent risks, while a positive temperature coefficient (PTC) compromises accuracy. In this study, we present a novel hybrid composite combining carbon nanotubes (CNTs) with NTC properties and carbon black (CB) with PTC properties to achieve a near-zero temperature coefficient of resistance (TCR) at an optimal ratio. This innovation enhances the safety and reliability of carbon-based polymer composites for wearable heating applications. Furthermore, a thermochromic pigment layer is integrated into the hybrid composite, enabling visual temperature indication across three distinct zones. This bilayer structure not only addresses the TCR challenge but also provides real-time, user-friendly temperature monitoring. The resulting composite demonstrates consistent performance and high precision under diverse heating conditions, making it ideal for wearable thermotherapy pads. This study highlights a significant advancement in developing multifunctional, temperature-responsive materials, offering a promising solution for safer and more controllable wearable devices.

Loading ZIF‐67 onto carbon nanotubes in percolative nanocomposites towards improved dielectric performance

Loading <scp>ZIF</scp>‐67 onto carbon nanotubes in percolative nanocomposites towards improved dielectric performance

On carbon nanocones CNCm [n] and their face index

Over recent decades, there has been remarkable advancement in the field of nanomaterials, particularly with the emergence of carbon nanotubes, boron nanoclusters, boron nanowires, and boron nanotubes, among others. Among these nanomaterials, carbon-based variants are particularly noteworthy due to their exceptional specific geometric and electronic properties, which make them vital in the realm of nanotechnology. The face index of a graph is a significant metric in graph theory, providing essential insights into the structural characteristics of a graph. This index explains aspects of connectivity and planarity, thereby enabling researchers to analyze and comprehend the properties of graphs more effectively. In this study, we present calculations of the recently introduced face index for the graphical structure of carbon nanotubes CNCm [n] that anticipates to assist researchers and experimentalists in developing experiments/procedures aimed at elucidating the unknown physical and chemical properties of carbon nanocones.

Improvement of the Thermoelectric Properties in CNT/Bi2Te3 Composite Films Due to Evolution of the Depletion Layer and Point Defects under the Pulse Current Field.

A carbon nanotube (CNT) composite is an effective method to improve the thermoelectricity of materials. However, the depletion layer between the CNT and thermoelectric (TE) material always decreases the contribution of CNT to the conductivity of the TE material. It is important to eliminate the depletion layer for improving the TE properties. Pulsed-electric-field (PEF) treatment was used to eliminate the depletion layer based on the atomic short-range diffusion on the interface of CNT and Bi2Te3. When the pulse current density is 30 A·dm-2, the CNT composite Bi2Te3 film has high mobility, a high carrier concentration, and a high effective mass due to no depletion layer and a low density of point defects. Both the resistivity and Seebeck coefficient improve in the CNT composite Bi2Te3 films by PEF treatment of 30 A·dm-2. The power density is 1.36 W·m-2 when the hot side temperature is 373 K. The maximum ZT value of this film is 1.66 at 513 K. Thus, the PEF is an effective way to achieve TE property enhancement in the composite films.

The influence of the carbon nanofiller in the PDMS-based composites on the strain resistive effect

In this study flexible polymer nanocomposite material with different types of carbon nanotubes (CNTs) (single-walled CNT [SWCNT] or multi-walled CNT [MWCNT]) has been obtained for use in stretchable elements of flexible structures. The features of electrically conductive nanostructures and their distribution in the nanocomposite material have been studied using Raman spectrometer and scanning electron microscope, respectively. Setup for studying the functional characteristics of the nanocomposite material based on a testing machine has been developed. The setup ensures simultaneous measurement of the electrical resistance of the nanocomposite material under cyclic tension. The ultimate tensile strength of the polymer composite under 25% tension with different electrically conductive nanostructures has been determined. It has been exposed for a sample with MWCNT, the ultimate tensile strength is significantly lower. It has been revealed that the highest tensile strength had been achieved in composites at about 0.37 MPa. The strain sensitivity (gauge factor [GF]) of polydimethylsiloxane (PDMS)/MWCNT has higher GF value compared to PDMS/SWCNT. This shows a higher potential for using them as fillers for creating sensor systems based on nanocomposite conductive materials.

A novel 8T SRAM cell using PFC and PPC VS-CNTFET transistor

The 8T static random-access memory (SRAM) cell using carbon nanotube technology, positive feedback, and dynamic supply voltage scaling are presented in this work. Positive feedback strengthens the feedback loop and enhances the noise margin making SRAM cells less susceptible to disturbance and improving the stabilization of the cell by improving read and write timing response. Positive feedback control (PFC) adjusts the cell’s operating condition based on its current and external condition under varying conditions. The positive power supply controlled (PPC) technique in SRAM cell design improves the stability and leakage power consumption by adjusting the voltage level during the operation mode of the cell. The experiment with carbon nanotube field-effect transistor (CNTFET) offers higher drive current and lower power consumption compared to conventional silicon-based transistors. The performance of the 8T SRAM cell incorporating PFC and PPC transistor is investigated with Synopsys HSPICE using the Stanford CNFET model. The proposed SRAM cell architecture archives a 99.99% improvement in power consumption and delay product (PDP) compared to a conventional 6T SRAM cell. The static noise margin of 300 mV ensures better noise immunity and reliable retention of data. The mean value of power consumption is 43.19 nW showing a variance of 93.16 fW and a standard deviation (σ) of 305.2 nW and the mean value of delay is 14.71 ps showing a variance of 1.010 and a standard deviation (σ) of 10.05 ps. CNTFET 8T SRAM cell with the combination of positive feedback and dynamic feedback enhances the performance and efficiency of the memory cell under varying conditions.