Carbon Nanotubes Research Articles

Nanoscale water behavior and its impact on adsorption: A case study with CNTs and diclofenac.

Water is a fundamental component of life, playing a critical role in regulating metabolic processes and facilitating the dissolution and transport of essential molecules. However, emerging contaminants, such as pharmaceuticals, pose significant challenges to water quality and safety. Nanomaterial-based technologies emerge as a promising solution for removing those contaminants from water. Nevertheless, interfacial water plays a major role in the adsorption of chemical compounds in nanomaterials-as it plays in biological processes such as protein folding, enzyme activity, and drug delivery. To understand this role, in this study, we employ molecular dynamics simulations to explore the adsorption dynamics of potassium diclofenac on single-walled carbon nanotubes (SWCNTs) and double-walled carbon nanotubes (DWCNTs), considering both dry and wet conditions. Our findings reveal that the structuring of water molecules around CNTs creates hydration layers that significantly influence the accessibility of active sites and the interaction strength between contaminants and adsorbents. Our analysis indicates higher energy barriers for adsorption in DWCNTs compared to SWCNTs, which is attributed to stronger water-surface interactions. This research highlights the importance of understanding nanoscale water behavior for optimizing the design and functionality of nanomaterials for water purification. These findings can guide the development of more efficient and selective nanomaterials, enhancing contaminant removal and ensuring safer water resources while contributing to a deeper understanding of fundamental biological interactions.

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

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.

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.

Review of: "the carbon nanotubes that protect them from the environment interact, and for this reason, these CNTs nanotubes are called metal/carbon nanotubes"

Review of: "the carbon nanotubes that protect them from the environment interact, and for this reason, these CNTs nanotubes are called metal/carbon nanotubes"

MX/MWCNTs composite material aids new strategy for HBV-DNA electrochemical biosensor: achieving multi-level signal amplification and unlabeled detection

Hepatitis B virus DNA (HBV-DNA) serves as a crucial biomarker for the detection of the hepatitis B virus, with variations in its concentration in blood samples providing vital insights into patient infection and recovery status. We have developed an electrochemical biosensor tailored for HBV-DNA detection, exhibiting high sensitivity, specificity, and a broad detection range. The biosensor utilizes a composite material composed of MXene and multiwalled carbon nanotubes (MX/MWCNTs), prepared through a hand-shaking self-assembly technique, to modify the glassy carbon electrode (GCE) and serve as signal receivers. A meticulously designed padlock probe DNA specifically recognizes HBV-DNA and forms a double-stranded DNA structure, which is subsequently degraded by exonuclease III. The resulting sequence then hybridizes with a PolyT-primer to create template, triggering rolling circle amplification and releasing a substantial amount of pyrophosphate for the initial level of signal amplification. Subsequently, the pyrophosphate induces the release of methylene blue (MB) from MB@ZIF-90 composite, achieving a second level of signal amplification. The released MB is then adsorbed by the MX/MWNCNTs-modified GCE, which possesses cationic dye adsorption capabilities and a large specific surface area, generating a detection signal and completing the third level of amplification. This biosensor offers a detection range spanning from 1.0 pM to 1.0 × 106 pM, with a remarkable detection limit as low as 0.5 pM (3σ/S), and is capable of distinguishing base mismatches. Furthermore, it has demonstrated excellent specificity and recovery performance in serum testing. The performance of this biosensor demonstrates significant potential for clinical application, with the ultimate goal of improving the diagnosis and management of hepatitis B.Graphical

Molecular Strain Accelerates Electron Transfer for Enhanced Oxygen Reduction.

Fe-N-C materials are emerging catalysts for replacing precious platinum in the oxygen reduction reaction (ORR) for renewable energy conversion. However, their potential is hindered by sluggish ORR kinetics, leading to a high overpotential and impeding efficient energy conversion. Using iron phthalocyanine (FePc) as a model catalyst, we elucidate how the local strain can enhance the ORR performance of Fe-N-Cs. We use density functional theory to predict the reaction mechanism for the four-electron reduction of oxygen to water. Several key differences between the reaction mechanisms for curved and flat FePc suggest that molecular strain accelerates the reductive desorption of *OH by decreasing the energy barrier by ∼60 meV. Our theoretical predictions are substantiated by experimental validation; we find that strained FePc on single-walled carbon nanotubes attains a half-wave potential (E1/2) of 0.952 V versus the reversible hydrogen electrode and a Tafel slope of 35.7 mV dec-1, which is competitive with the best-reported Fe-N-C values. We also observe a 70 mV change in E1/2 and dramatically different Tafel slopes for the flat and curved configurations, which agree well with the calculated energies. When integrated into a zinc-air battery, our device affords a maximum power density of 350.6 mW cm-2 and a mass activity of 810 mAh gZn-1 at 10 mA cm-2. Our results indicate that molecular strain provides a compelling tool for modulating the ORR activities of Fe-N-C materials.

Preparation of Modified Composite Nanofiltration Membrane Synergistically Using Carboxylic Multi-walled Carbon Nanotube and β-cyclodextrin

Preparation of Modified Composite Nanofiltration Membrane Synergistically Using Carboxylic Multi-walled Carbon Nanotube and β-cyclodextrin

Understanding the Curvature Effect on the Structure and Bonding of MoCy Nanoparticles on Carbon Supports.

The interaction between molybdenum carbide (MoCy) nanoparticles and both flat and curved graphene surfaces, serving as models for carbon nanotubes, was investigated by means of density functional theory. A variety of MoCy nanoparticles with different sizes and stoichiometries have been used to explore different adsorption sites and modes across models with different curvature degrees. On flat graphene, off-stoichiometric MoCy featuring more low-coordinated Mo atoms exhibits stronger interaction and increased electron transfers from the carbide to the carbon substrate. This preferentially occurs through support C and Mo atoms leading to the formation of additional Mo-C bonds. Notably, the MoCy adsorption strength increases on concave surfaces and decreases on convex surfaces, showing a strong linear correlation with the surface curvature. This curvature-dependent behavior alters the charge state of the nanoparticles, making them more/less positively charged in concave/convex regions. The present results demonstrate that the interaction strength can be effectively tuned by manipulating the carbide stoichiometry, the substrate curvature, and the local concave/convex environments, providing valuable guidelines for the rational design of MoCy/C-based catalysts.

Investigating the impact of Multiwalled Carbon Nanotubes exposure on enzymatic activities and histopathological variations in Swiss albino mice

Present study was conducted to evaluate the detrimental impacts of exposure of Multi-walled Carbon Nanotubes (MWCNT-NP) on enzymatic activities and tissue structures in Swiss albino mice. The experimental groups of mice received MWCNT-NP for specific time period (seven or fourteen days). Two distinct doses of the MWCNT-NP solution were given orally: 0.45 µg and 0.90 µg, and the distilled water was given to the control group. Serum samples were extracted at 7 and 14 days after the experiment by centrifuging whole blood for 15 min at 3,000 rpm. An enzyme-linked immunosorbent test (ELISA) was used to measure many enzyme assays, such as Angiotensin Converting Enzymes (ACE), Alanine Aminotransferase (ALT), Aspartate Aminotransferase (AST), and Nicotinamide Adenine Dinucleotide Phosphate (NADPH) oxidase enzyme. Hematoxylin and Eosin (H&E) staining of tissue samples was done along with a histopathological examination. During a 14-day exposure, ACE, NADPH Oxidase, ALT, and AST enzyme levels were significantly higher in the exposed groups (0.45 µg and 0.90 µg) than in the control group (p < 0.05). Male mice exposed to MWCNT-NP showed substantial histological damage in the relevant organs as well as elevated enzyme activity levels. Present study showed a comprehensive and practical assessment of the toxicity associated with MWCNT-NP of different geometries and functionalization.

Study of the influence of carbon nanotubes, graphene, and hybrid buckypaper on the mechanical behavior of PAEK/carbon fiber composites

AbstractCarbon fiber‐reinforced thermoplastic composites are widely used in the aeronautical industry due to their high mechanical properties and low specific weight. Within the select group of thermoplastic matrices, poly (aryl ether ketone) (PAEK) stands out as a semicrystalline material with high glass transition and melting temperatures. This work aims to evaluate how buckypaper (BP) influences the mechanical properties of the composite PAEK/CF. For this, three types of BPs were made using vacuum filtration. The first one is with carbon nanotubes (CNT), the second is with graphene (GR), and the third is a mix of CNT and GR. The influence of BPs in mechanical behavior was performed by an interlaminar short beam test (ILSS), a compression shear test (CST), and an impulse excitation of vibration. Finally, the presence of BP reduced the mechanical properties of the material due to the low adhesion between matrix and BP. In the ILSS test, it was noted a reduction in interlaminar shear of 16% for CNT BP, 20% for GR BP and 28% for hybrid BP. In the CST, a reduction of 32% for CNT BP, 39% for GR BP and 13% for hybrid BP was observed. On the other hand, the composite with hybrid BP presents a greater increase in Young's Modulus, representing a gain of 13%.Highlights The vacuum filtration process used to produce BPs was determined. Morphology evaluation of BPs through scanning electron microscopy. Influence of BPs on the mechanical properties of composites. Effect of nanoparticles on the adhesion between matrix and BPs.

Advances in Drug Targeting, Drug Delivery, and Nanotechnology Applications: Therapeutic Significance in Cancer Treatment

In the 21st century, thanks to advances in biotechnology and developing pharmaceutical technology, significant progress is being made in effective drug design. Drug targeting aims to ensure that the drug acts only in the pathological area; it is defined as the ability to accumulate selectively and quantitatively in the target tissue or organ, regardless of the chemical structure of the active drug substance and the method of administration. With drug targeting, conventional, biotechnological and gene-derived drugs target the body’s organs, tissues, and cells that can be selectively transported to specific regions. These systems serve as drug carriers and regulate the timing of release. Despite having many advantageous features, these systems have limitations in thoroughly treating complex diseases such as cancer. Therefore, combining these systems with nanoparticle technologies is imperative to treat cancer at both local and systemic levels effectively. The nanocarrier-based drug delivery method involves encapsulating target-specific drug molecules into polymeric or vesicular systems. Various drug delivery systems (DDS) were investigated and discussed in this review article. The first part discussed active and passive delivery systems, hydrogels, thermoplastics, microdevices and transdermal-based drug delivery systems. The second part discussed drug carrier systems in nanobiotechnology (carbon nanotubes, nanoparticles, coated, pegylated, solid lipid nanoparticles and smart polymeric nanogels). In the third part, drug targeting advantages were discussed, and finally, market research of commercial drugs used in cancer nanotechnological approaches was included.

Applications of Nanomaterial Coatings in Solid-Phase Microextraction (SPME)

This review explores the advances in developing adsorbent materials for solid-phase microextraction (SPME), focusing on nanoparticles, nanocomposites, and nanoporous structures. Nanoparticles, including those of metals (e.g., gold, silver), metal oxides (e.g., TiO2, ZnO), and carbon-based materials (e.g., carbon nanotubes, graphene), offer enhanced surface area, improved extraction efficiency, and increased selectivity compared to traditional coatings. Nanocomposites, such as those combining metal oxides with polymers or carbon-based materials, exhibit synergistic properties, further improving extraction performance. Nanoporous materials, including metal–organic frameworks (MOFs) and ordered mesoporous carbons, provide high surface area and tunable pore structures, enabling selective adsorption of analytes. These advanced materials have been successfully applied to various analytes, including volatile organic compounds (VOCs), polycyclic aromatic hydrocarbons (PAHs), pesticides, and heavy metals, demonstrating improved sensitivity, selectivity, and reproducibility compared to conventional SPME fibers. The incorporation of nanomaterials has significantly expanded the scope and applicability of SPME, enabling the analysis of trace-level analytes in complex matrices. This review highlights the significant potential of nanomaterials in revolutionizing SPME technology, offering new possibilities for sensitive and selective analysis in environmental monitoring, food safety, and other critical applications.

Mixed-Dimensional Semiconductors-Based Ternary Circuits with Tunable Negative Transconductance Characteristics.

Multivalued logic (MVL) systems, in which data are processed with more than two logic values, are considered a viable solution for achieving superior processing efficiency with higher data density and less complicated system complexity without further scaling challenges. Such MVL systems have been conceptually realized by using negative transconductance (NTC) devices whose channels consist of van der Waals (vdW) heterojunctions of low-dimensional semiconductors; however, their circuit operations have not been quite ideal for driving multiple stages in real circuit applications due to reasons such as a reduced output swing and poorly defined logic states. Herein, we demonstrate ternary inverter circuits with near rail-to-rail swing and three distinct logic states by employing vdW p-n heterojunctions of single-walled carbon nanotubes (SWCNT) and MoS2 where the SWCNT layer completely covers the MoS2 layer. In particular, SWCNTs are inkjet printed to form heterojunctions with MoS2 grown by chemical vapor deposition (CVD), and both inkjet printing and CVD are fully scalable device fabrication methods for low-dimensional materials. In addition, the NTC characteristics of heterojunction field-effect transistors (H-FETs) are explained based on the electrical characteristics of individual SWCNT and MoS2 channels. By adjustment of the p-channel characteristics in H-FETs by exploiting the advantages of the inkjet printing technology, the widths of the NTC regions are easily adjusted accordingly. The extended NTC region enables stable middle logic state operations of low-dimensional semiconductors-based ternary inverters over a sufficiently wide input voltage range.

Revealing Crucial Influences of Boron Support on Regulating Geometric and Electronic Structures of 3D Catalyst for Hydrogen Evolution and Oxygen Reduction Reactions.

Building insights into the structure-performance relationship of catalysts has been emphasized recently. However, it remains a challenge due to catalysts' various and complex structures, especially the easily overlooked influence of the support material. Here, we reveal the crucial influences of boron introduction on synthesizing 3D carbon nanotube monoliths with embedded multistate Co metals, i.e., single atoms, clusters, and nanoparticles (Co-BNCNTs), by an interesting chemical blowing-assisted calcination method. The boron introduction can contribute to forming captivating boron-nitrogen pairs, shaping a 3D frame, and regulating electronic structure. The 3D Co-BNCNT monoliths present good catalytic performance for both the hydrogen evolution reaction (HER) at all pH values and the oxygen reduction reaction (ORR). The theoretical calculations indicate that the B incorporation in Co-NCNTs can optimize the free energy of adsorbed hydrogen and facilitate the O2 adsorption and the protonation of the O2* species. Furthermore, the Co-BNCNTs-based zinc-air battery provides great battery performance with a high power density and discharge-charge durability.

Mechanism and Characterization of Bicomponent-Filler-Reinforced Natural Rubber Latex Composites: Experiment and Molecular Dynamics (MD)

The incorporation of reinforcing fillers into natural rubber latex (NR) to achieve superior elasticity and mechanical properties has been widely applied across various fields. However, the tendency of reinforcing fillers to agglomerate within NR limits their potential applications. In this study, multi-walled carbon nanotube (MWCNT)–silica (SiO2)/NR composites were prepared using a solution blending method, aiming to enhance the performance of NR composites through the synergistic effects of dual-component fillers. The mechanical properties, dispersion behavior, and Payne effect of three types of composites—SiO2/NR (SNR), MWCNT/NR (MNR), and MWCNT-SiO2/NR (MSNR)—were investigated. In addition, the mean square displacement (MSD), fractional free volume (FFV), and binding energy of the three composites were simulated using molecular dynamics (MD) models. The results showed that the addition of a two-component filler increased the tensile strength, elongation at break, and Young’s modulus of NR composites by 56.4%, 72.41%, and 34.44%, respectively. The Payne effect of MSNR was reduced by 4.5% compared to MNR and SNR. In addition, the MD simulation results showed that the MSD and FFV of MSNR were reduced by 21% and 17.44%, respectively, and the binding energy was increased by 69 times, which was in agreement with the experimental results. The underlying mechanisms between the dual-component fillers were elucidated through dynamic mechanical analysis (DMA), a rubber process analyzer (RPA), and field emission scanning electron microscopy (SEM). This study provides an effective reference for broadening the application fields of NR.

Development of Thermoplastic Bi-Component Electrodes for Triboelectric Impact Detection in Smart Textile Applications

Smart textiles provide a significant technological advancement, but their development must balance traditional textile properties with electronic features. To address this challenge, this study introduces a flexible, electrically conductive composite material that can be fabricated using a continuous bi-component extrusion process, making it ideal for sensor electrodes. The primary aim was to create a composite for the filament’s core, combining multi-walled carbon nanotubes (MWCNTs), polypropylene (PP), and thermoplastic elastomer (TPE), optimised for conductivity and flexibility. This blend, suitable for bi-component extrusion processes, exemplifies the role of advanced materials in combining electrical conductivity, mechanical flexibility, and processability, which are essential for wearable technology. The composite optimisation balanced MWCNT (2.5, 5, 7.5, and 10 wt.%) and TPE (0, 25, and 50 wt.%) in a PP matrix. There was a significant decrease in electrical resistivity between 2.5 and 5 wt.% MWCNT, with electrical resistivity ranging from (7.64 ± 4.03)104 to (1.15 ± 0.10)10−1 Ω·m. Combining the composite with 25 wt.% TPE improved the flexibility, while with 50 wt.% TPE decreased tensile strength and hindered the masterbatch pelletising process. The final stage involved laminating the composite filament electrodes, with a 5 wt.% MWCNT/PP/(25 wt.% TPE) core and a TPE sheath, into a textile triboelectric impact detection sensor. This sensor, responding to contact and separation, produced an output voltage of approximately 5 V peak-to-peak per filament and 15 V peak-to-peak with five filaments under a 100 N force over 78.54 cm2. This preliminary study demonstrates an innovative approach to enhance the flexibility of conductive materials for smart textile applications, enabling the development of triboelectric sensor electrodes with potential applications in impact detection, fall monitoring, and motion tracking.

A mirror-image experiment: Sorting carbon nanotubes by L-DNA

A mirror-image experiment: Sorting carbon nanotubes by L-DNA

Computational investigation on ablation kinetics of graphene and carbon nanotube reinforced thermoset polymeric composites

Computational investigation on ablation kinetics of graphene and carbon nanotube reinforced thermoset polymeric composites

Molecular Determinants of Optical Modulation in ssDNA-Carbon Nanotube Biosensors.

Most traditional optical biosensors operate through molecular recognition, where ligand binding causes conformational changes that lead to optical perturbations in the emitting motif. Optical sensors developed from single-stranded DNA-functionalized single-walled carbon nanotubes (ssDNA-SWCNTs) have started to make useful contributions to biological research. However, the mechanisms underlying their function have remained poorly understood. In this study, we combine experimental and computational approaches to show that ligand binding alone is not sufficient for optical modulation in this class of synthetic biosensors. Instead, the optical response that occurs after ligand binding is highly dependent on the chemical properties of the ligands, resembling mechanisms seen in activity-based biosensors. Specifically, we show that in ssDNA-SWCNT catecholamine sensors, the optical response correlates positively with the electron density on the aryl motif, even among ligands with similar ligand binding affinities. Importantly, despite the strong correlations with electrochemical properties, we find that catechol oxidation itself is not necessary to drive the sensor optical response. We discuss how these findings could serve as a framework for tuning the performance of existing sensors and guiding the development of new biosensors of this class.