Functionalized Carbon Nanotubes Research Articles

Analysis of the adhesion mechanism of functionalized carbon nanotubes by molecular dynamics simulation.

Although a lot of research has been carried out on the adhesion mechanism of gecko bristles, the research on materials inspired by gecko bristles is still limited to the design of geometric structure and the optimization of preparation process, and the adhesion mechanism of materials is still unclear. In this paper, the molecular structure of the end of the bristle-like material is focused on, and the interaction between functional group modified carbon nanotubes and the interface is analyzed by molecular dynamics simulation. Thus, the influence of different polar functional groups on the interfacial force between carbon nanotubes and silica is revealed, and the adhesion enhancement mechanism of polar groups on the interface between carbon nanotubes and silica is further verified.

Mathematical Modeling of Diffraction and Parametric Instability Thresholds for Magnetic Nanostructures Based on Magnetically Functionalized Carbon Nanotube Arrays

Mathematical Modeling of Diffraction and Parametric Instability Thresholds for Magnetic Nanostructures Based on Magnetically Functionalized Carbon Nanotube Arrays

Mathematical Modeling of Resonance Interaction of the Microwave and Terahertz Electromagnetic Radiation with 3D Arrays of Magnetically Functionalized Carbon Nanotubes

Mathematical Modeling of Resonance Interaction of the Microwave and Terahertz Electromagnetic Radiation with 3D Arrays of Magnetically Functionalized Carbon Nanotubes

Single‐Anion Conductive Solid‐State Electrolytes with Hierarchical Ionic Highways for Flexible Zinc‐Air Battery

Flexible zinc‐air batteries are leading power sources for next‐generation smart wearable electronics. However, flexible zinc‐air batteries suffer from the highly‐corrosive safety risk and limited lifespan due to the absence of reliable solid‐state electrolytes (SSEs). Herein, a single‐anion conductive SSE with high‐safety is constructed by incorporating a highly amorphous dual‐cation ionomer into a robust hybrid matrix of functional carbon nanotubes and polyacrylamide polymer. The as‐fabricated SSE obtains dual‐penetrating ionomer‐polymer networks and hierarchical ionic highways, which contribute to mechanical robustness with 1200% stretchability, decent water uptake and retention, and superhigh ion conductivity of 245 mS·cm‐1 and good Zn anode reversibility. Remarkably, the flexible solid‐state zinc‐air batteries delivers a high specific capacity of 764 mAh·g‐1 and peak power density of 152 mW·cm‐2 as well as sustains excellent cycling stability for 1050 cycles (350 hours. This work offers a new paradigm of OH‐ conductors and broadens the definition and scope of OH‐ conductors.

Single-Anion Conductive Solid-State Electrolytes with Hierarchical Ionic Highways for Flexible Zinc-Air Battery.

Flexible zinc-air batteries are leading power sources for next-generation smart wearable electronics. However, flexible zinc-air batteries suffer from the highly-corrosive safety risk and limited lifespan due to the absence of reliable solid-state electrolytes (SSEs). Herein, a single-anion conductive SSE with high-safety is constructed by incorporating a highly amorphous dual-cation ionomer into a robust hybrid matrix of functional carbon nanotubes and polyacrylamide polymer. The as-fabricated SSE obtains dual-penetrating ionomer-polymer networks and hierarchical ionic highways, which contribute to mechanical robustness with 1200% stretchability, decent water uptake and retention, and superhigh ion conductivity of 245 mS·cm-1 and good Zn anode reversibility. Remarkably, the flexible solid-state zinc-air batteries delivers a high specific capacity of 764 mAh·g-1 and peak power density of 152 mW·cm-2 as well as sustains excellent cycling stability for 1050 cycles (350 hours. This work offers a new paradigm of OH- conductors and broadens the definition and scope of OH- conductors.

Fabrication of Strontium Molybdate with Functionalized Carbon Nanotubes for Electrochemical Determination of Antipyretic Drug-Acetaminophen.

In recent years, there has been a significant interest in the advancement of electrochemical sensing platforms to detect antipyretic drugs with high sensitivity and selectivity. The electrochemical determination of acetaminophen (PCT) was studied with strontium molybdate with a functionalized carbon nanotube (SrMoO4@f-CNF) nanocomposite. The SrMoO4@f-CNF nanocomposite was produced by a facial hydrothermal followed by sonochemical treatment, resulting in a significant enhancement in the PCT determination. The sonochemical process was applied to incorporate SrMoO4 nanoparticles over f-CNF, enabling a network-like structure. Moreover, the produced SrMoO4@f-CNF composite structural, morphological, and spectroscopic properties were confirmed with XRD, TEM, and XPS characterizations. The synergistic effect between SrMoO4 and f-CNF contributes to the lowering of the charge transfer resistance (Rct=85 Ω·cm2), a redox potential of Epc=0.15 V and Epa=0.30 V (vs. Ag/AgCl), and a significant limit of detection (1.2 nM) with a wide response range of 0.01-28.48 µM towards the PCT determination. The proposed SrMoO4@f-CNF sensor was studied with differential pulse voltammetry (DPV) and cyclic voltammetry (CV) techniques and demonstrated remarkable electrochemical properties with a good recovery range in real-sample analysis.

Characterization of Mixed Amine Functionalized Carbon Nanotube from Nigerian Sub Bituminous Coal

Characterization of Mixed Amine Functionalized Carbon Nanotube from Nigerian Sub Bituminous Coal

Steering bidirectional polysulfide conversion in virtue of interface microenvironment of Ni/porous carbon Mott-Schottky heterojunctions

Originating from the notorious shuttle effect and intrinsically sluggish redox kinetics of polysulfides (especially under the conditions of high sulfur loadings and low electrolytes), the low capacity and sulfur utilization efficiency, unsatisfactory rate performance, and unremarkable cycle performance severely hinder the practical commercialization of lithium-sulfur batteries (LSBs). Furnishing rapid electron transfer and mass diffusion in virtue of interface modulation and nanostructure design is an effective strategy to enhance the activity of catalysts. Herein, a Mott-Schottky heterojunction composed of porous carbon (PC)-supported nickel (Ni) nanoparticles was fabricated on a functionalized carbon nanotube sponge (Ni/PC/FCNTS) via adjusting the geometric structure such as the particle size, aggregation state and pore volume (based on the different solvothermal reaction temperature of the Ni-MOF precursor and the high-temperature pyrolysis process). Transmission electron microscope (TEM) and X-ray photoelectron spectroscopy (XPS) demonstrated the charge redistribution and a self-generated built-in electric field accelerated electron transfer at the heterogeneous interface between Ni and PC. Meanwhile, the high pore volume of Ni/PC/FCNTS-170 provided a reaction space for rapid ion diffusion and sulfur redox process. Benefiting from the synergistic effect, the derived S@Ni/PC/FCNTS-170 cells manifested excellent rate performance with a capacity of 784.2 mAh g-1 at 2 C and a high areal capacity of 8.09 mAh cm-2 with a high sulfur loading of 17.6 mg cm-2 and low electrolyte/sulfur of 11.3 µL mg-1.

Sensitive surface plasmon resonance biosensor by optimized carboxylate functionalized carbon nanotubes/chitosan for amlodipine detecting

The adoption of biophotonic sensing technologies holds significant promise for application in health care and biomedical industries in all aspects of human life. Then, this piece of writing employs the powerful effective medium theory and FDTD simulation to anticipate the most favorable state and plasmonic attributes of a magnificent nanocomposite, comprising carboxylate functionalized carbon nanotubes and chitosan (CS). Furthermore, it thoroughly explores the exhibited surface plasmon resonance behaviors of this composite versus the quantity of CS variation. Subsequently, enlightening simulations are conducted on the nanocomposite with a delicate layer and a modified golden structure integrating as a composite. The intricate simulations eventually unveil an optimal combination to pave the way for crafting an exceptional specific biosensor that far surpasses its counterpart as a mere Au thin layer in terms of excellence. The proposed biosensor demonstrated linear behavior across a wide range from 0.01 μM to 150 μM and achieved a detection limit of 10 nM, with a sensitivity of 134◦RIU−1.

Mechanical improvement of carbon fiber/epoxy composites by sizing functionalized carbon nanotubes on fibers

AbstractA sizing agent mainly consisting of polyethersulfone and acidified multi‐walled carbon nanotubes (MWCNT) was developed for surface modification of carbon fibers (CF) to enhance the interfacial bond and to form carbon fiber‐carbon nanotube (CF‐MWCNT) multiscale reinforcements. To prepare the modified carbon fiber/epoxy resin composites (CFRP), a vacuum molding technique was used in this study. The effects of the MWCNT‐containing sizing agent on the morphology and chemical structure of the CF surface were observed by scanning electron microscopy and Fourier transform infrared spectroscopy. The influence of MWCNT length and content on the mechanical properties of CFRP were also studied. The experimental results showed that the strength of the CFRP decreased with the increase of MWCNT length, and the MWCNT with a content of 0.05 wt% had a good reinforced effect on the CFRP. After the sizing treatment, the interlaminar shear strength (ILSS) of the CFRP is increased. These enhancements are attributed to the improved mechanical bonding and chemical bonding between CF and resin matrix. The MWCNT provides nanosized rough surface to CF and these acidified MWCNTs attached to the surface of CF with polar oxygen‐containing functional groups improve the compatibility with reinforcement and resin matrix.Highlights Carbon fiber was modified by a sizing agent mainly consisting of polyethersulfone and acidified carbon nanotube (CNT). CNTs enhance the interfacial chemical bonding and mechanical bonding. The CNT length affects the mechanical properties of the carbon fiber/epoxy resin composites (CFRP). The modified carbon fiber has enhanced the mechanical properties of the CFRP.

Ruthenium nanoparticles supported on functionalized carbon nanotubes as high-efficiency catalysts for ammonia borane hydrolysis

Developing high-activity catalysts for the hydrolysis of ammonia borane (NH3BH3; AB) is a crucial and urgent task, which is presently considered an effective strategy for hydrogen generation in the applications of portable proton exchange membrane fuel cells (PEMFCs). In this study, carbon nanotubes (CNTs) were modified by self-growth of metal-organic frameworks (MOFs) on their surfaces. As self-sacrificial templates, the carbonization of cobalt and nitrogen containing MOFs led to the modification of CNT. Subsequently, cobalt was transformed into cobalt phosphide (Co2P) via phosphatization to form Co2P/N co-decorated CNTs (NCP-CNTs). Ru/NCP-CNT catalysts were obtained by loading ruthenium nanoparticles (NPs) using a chemical reduction method and their catalytic performance for H2 production via the hydrolysis of AB was systematically investigated. Ru/NCP-CNTs exhibited excellent catalytic activity, with an initial high turnover frequency (TOF) of 193.9 molH2·molRu−1·min−1 and a low activation energy of 32.4 kJ·mol−1. The incorporation of Ru NPs and their excellent synergistic effect with the NCP-CNT supports can explain the improved performance. This work provides an updated approach for fabricating low-cost and high-efficiency catalysts for the hydrolysis of AB.

Effect of functionalization on the adsorption performance of carbon nanotube as a drug delivery system for imatinib: molecular simulation study

In this study, efficiency of functionalized carbon nanotube as a potential delivery system for imatinib anti-cancer drug was investigated. Accordingly, carboxyl and hydroxyl functionalized carbon nanotube were inspected as a notable candidate for the carriage of this drug in aqueous media. For this purpose, possible interactions of imatinib with pure and functionalized carbon nanotube were considered in aqueous media. The compounds were optimized in gas phase using density functional calculations. Solvation free energies and association free energies of the optimized structures were then studied by Monte Carlo simulation and perturbation method in water environment. Outcomes of quantum mechanical calculations presented that pure and functionalized carbon nanotubes can act as imatinib drug adsorbents in gas phase. However, results of association free energy calculations in aqueous solution indicated that only carboxyl and hydroxyl functionalized carbon nanotubes could interact with imatinib. Monte Carlo simulation results revealed that electrostatic interactions play a vital role in the intermolecular interaction energies after binding of drug and nanotube in aqueous solution. Computed solvation free energies in water showed that the interactions with functionalized carbon nanotubes significantly enhance the solubility of imatinib, which could improve its in vivo bioavailability.

Real-time, ultra-sensitive and label-free detection of OTA based on DNA aptamer functionalized carbon nanotube field-effect transistor

Ochratoxin A (OTA), widely recognized as a mycotoxin contaminant across various food products, poses significant health risks attributed to its nephrohepatotoxic and carcinogenic effects. Consequently, detecting OTA is crucial for ensuring food safety and preventing mycotoxicosis. In our study, we employed a carbon nanotube field-effect transistor (CNT FET) functionalized with DNA aptamers for targeted OTA detection. The sensor achieved a remarkably low detection threshold of 0.2 femtomolars (fM) in phosphate-buffered saline (PBS), enabling real-time detection of OTA over a broad concentration spectrum spanning from 8 fM to 80 pM. This research confirmed the sensor’s superior selectivity by effectively distinguishing OTA from non-target fungal toxins and showcased its rapid analysis capabilities across diverse complex matrices. Utilizing homogenized liquids from ten representative food samples for analysis, the sensor delivered real-time responses within 100 s, accurately identifying varying OTA concentrations down to 80 fM. In conclusion, this biosensor provides a label-free, highly sensitive, and rapid detection method for OTA, introducing novel solutions for effective mycotoxin surveillance in food safety. This biosensor also paves the way for the creation of a multiplex platform for concurrent monitoring of multiple fungal toxins.

Vibration energy harvesting in an FG-CNTRC circular microplate with a surface-bonded piezoelectric layer

Piezoelectric energy harvesting using circular microplate has great potential to power microelectromechanical systems (MEMS). This paper studies vibrational energy harvesting by creating a model of a thin-walled circular microplate with a base layer of functional gradient carbon nanotube reinforced composites (FG-CNTRC) and a piezoelectric surface layer. Using the extended modified couple stress theory and the rule of mixture, the size effect and the effective Young's and shear moduli of the carbon nanotube reinforced composite (CNTRC) plate are established. Then, the governing equations are derived through the Lagrange's equations, and the analytical solutions of the relevant physical quantities are obtained. The specific examples are used to investigate the influence of length scale, carbon nanotube distribution, excitation frequency, and the ratio of the upper and lower plate radii on displacement, voltage, and power.

Synergistic effect of gold nanoparticles decorated functionalized carbon nanotubes nanohybrids on the thermal, dielectric, and sensing properties of polyaniline ternary nanocomposites

AbstractThe synthesis of gold nanoparticles reinforced functionalized single‐walled/multi‐walled carbon nanotubes nanohybrid based polyaniline nanocomposites were carried out using in situ polymerization. The chemical interaction and nanostructured morphology of the synthesized nanocomposites are studied using ultraviolet–visible spectroscopy, Fourier transform infrared spectroscopy, Raman spectroscopy, x‐ray diffraction analysis, x‐ray photoelectron spectroscopy, and field emission scanning electron microscopy. Thermal stability of synthesized PANI/Au@f‐SWNTs is boosted by a magnitude of 30°C as compared with the pristine PANI matrix, which is attributed to a strong barrier effect because of the development of tortuous path that resulted from a uniform distribution of Au@f‐CNTs throughout the PANI matrix. For PANI/Au@f‐SWNTs, the AC conductivity and dielectric permittivity are improved by a value of 83.58 S/cm and 1.35 × 10−5 as well as the dielectric loss is reduced by a factor of 0.11 in comparison with the pure PANI matrix at an applied frequency of 106 Hz. PANI/Au@f‐SWNTs and PANI/Au@f‐MWNTs ternary nanocomposites exhibited excellent selectivity toward the hazardous Cr(VI) heavy metal ions in an aqueous medium with a limit of detection of 0.74 and 0.89 μM with a binding constant of 1.028 × 105 and 3.46 × 104 M−1, respectively, that can be selective and sensitive for the detection of Cr(VI) metal ions in water at trace level.

Why Carbon Nanotubes Improve Aqueous Nanofluid Thermal Conductivity: A Qualitative Model Critical Review

Media thermal conductivity is important in various heat-transfer processes. Many conventional fluid conductors suffered low conductivity and environmental issues. Therefore, research was active in finding out alternative systems, mostly relying on aqueous liquids that are low-cost and ecofriendly. After the emergence of carbon nanotubes (CNTs), with their many special structural, electrical and thermal properties, they have been examined for many applications, including heat-transfer processes. Adding CNTs to water yields CNT aqueous nanofluids that have been widely investigated as heat-transfer media. The literature shows that CNT addition improves water thermal conductivity and other water properties, such as viscosity, surface tension, freezing point and boiling point. The literature also shows that nanofluid thermal conductivity improvement is affected by CNT type and concentration, in addition to other factors such as surfactant addition. All these subjects were widely described in literature, focusing on experimental, modelling and theoretical accounts. Despite the wide literature, there exist inconsistencies and discrepancies between reports that need to be justified. In addition to technical papers, many reviews were published on various aspects of the subject including experimental results and mathematical modeling. However, the very basic question here is as follows: Why does adding CNT to water affect its thermal conductivity? In spite of the wide published literature, this issue was not targeted in a simple qualitative approach. This review provides a clear understanding of how CNTs improve thermal conductivity of aqueous nanofluids. A qualitative model is presented to explain mechanisms behind improvement as presented in the literature. CNT type effects are discussed with other factors such as aspect ratio, Reynold number, dispersion quality, composition, temperature and additives. CNT functionalization is described. Relations to estimate nanofluid thermal conductivity are discussed. The model will help specialists to tailor CNT aqueous nanofluid characteristics as desired by varying types and concentrations of CNT and surfactant, and other factors.

Enhanced degradation and removal of ciprofloxacin and ofloxacin through advanced oxidation and adsorption processes using environmentally friendly modified carbon nanotubes.

This study explores the utilization of adsorption and advanced oxidation processes for the degradation of ofloxacin (OFL) and ciprofloxacin (CIP) using a green functionalized carbon nanotube (MWCNT-OH/COOH-E) as adsorbent and catalyst material. The stability and catalytic activity of the solid material were proved by FT-IR and TG/DTG, which also helped to elucidate the reaction mechanisms. In adsorption kinetic studies, both antibiotics showed similar behavior, with an equilibrium at 30min and 60% removal. The adsorption kinetic data of both antibiotics were well described by the pseudo-first-order (PFO) model. Different advanced oxidation processes (AOPs) were used, and the photolytic degradation was not satisfactory, whereas heterogeneous photocatalysis showed high degradation (⁓ 70%), both processes with 30min of reaction. Nevertheless, ozonation and catalytic ozonation have resulted in the highest efficiencies, 90%, and 70%, respectively, after 30-min reaction. For AOP data modeling, the first-order model better described CIP and OFL in photocatalytic and ozonation process. Intermediates were detected by MS-MS analysis, such as P313, P330, and P277 for ciprofloxacin and P391 and P332 for ofloxacin. The toxicity test demonstrated that a lower acute toxicity was observed for the photocatalysis method samples, with only 3.1 and 1.5 TU for CIP and OFL, respectively, thus being a promising method for its degradation, due to its lower risk of inducing the proliferation of bacterial resistance in an aquatic environment. Ultimately, the analysis of MWCNT reusability showed good performance for 2 cycles and regeneration of MWCNT with ozone confirmed its effectiveness up to 3 cycles.

Effect of functionalized carbon nanotube on cement mortar: From experiment to DFT research

In this paper, functionalized nanotube-reinforced cementitious composites were prepared, and the mechanical property test results showed that the 28d flexural strength of the composite was increased by 41.58% at a hydroxylated carbon nanotube mass fraction of 0.08[Formula: see text]wt.% compared to the original cement mortar. Carboxylated carbon nanotubes with a mass fraction of 0.02%, on the other hand, increased the 28d compressive strength by 99.12%. Probing the effect of the presence of functional groups on carbon nanotubes on the CNT/C–S–H interface by first principles. The results showed that the shear strengths (11.392[Formula: see text]MPa and 14.130[Formula: see text]MPa) of hydroxylated carbon nanotubes and plain carbon nanotubes at the interface with cementitious (CNT-OH/CSH and CNT/CSH) were lower than the shear strengths (21.584[Formula: see text]MPa) of carboxylated carbon nanotubes at the interface with cementitious (CNT-COOH/CSH). The adsorption of functional groups on carbon nanotubes changes the electron distribution on the surface of carbon nanotubes. The introduction of carboxyl groups exacerbates the charge transfer between carbon nanotubes and cementitious groups and promotes the generation of solid chemical bonds. This is the reason that carboxylated nanotubes added as reinforcement to cement mortar give better strength to the composite than hydroxylated nanotubes.

Promoting Effect of Ball Milling on the Functionalization and Catalytic Performance of Carbon Nanotubes in Glycerol Etherification.

A facile and eco-friendly approach using in situ-generated 4-benzenediazonium sulfonate (BDS) was applied to prepare highly functionalized carbon nanotubes (CNTs). The effectiveness of this functionalization was additionally enhanced by a green and short-time ball milling process applied beforehand. The obtained BDS-modified CNTs presented significant activity in glycerol etherification, producing tert-butyl glycerol ethers, which are considered promising fuel additives. Excellent results of ~56% glycerol conversion and ~10% yield of higher-substituted tert-butyl glycerol ethers were obtained within just 1 h of reaction at 120 °C using a low catalyst loading of only 2.5 wt.%. Furthermore, the sulfonated CNTs were reusable over several reaction cycles, with only a minor decrease in activity. Additionally, the sample activity could be restored by a simple regeneration approach. Finally, a clear correlation was found between the content of -SO3H groups on the surface of CNTs and the catalytic performances of these materials in glycerol etherification. Improved interaction between functionalized ball-milled CNTs and the reactants was also suggested to positively affect the activity of these catalysts in the tested process.

Modulus-tunable multifunctional hydrogel ink with nanofillers for 3D-Printed soft electronics

Seamless integration and conformal contact of soft electronics with tissue surfaces have emerged as major challenges in realizing accurate monitoring of biological signals. However, the mechanical mismatch between the electronics and biological tissues impedes the conformal interfacing between them. Attempts have been made to utilize soft hydrogels as the bioelectronic materials to realize tissue-comfortable bioelectronics. However, hydrogels have several limitations in terms of their electrical and mechanical properties. In this study, we present the development of a 3D-printable modulus-tunable hydrogel with multiple functionalities. The hydrogel has a cross-linked double network, which greatly improves its mechanical properties. Functional fillers such as XLG or functionalized carbon nanotubes (fCNT) can be incorporated into the hydrogel to provide tunable mechanics (Young's modulus of 10–300 kPa) and electrical conductivity (electrical conductivity of ∼20 S/m). The developed hydrogel exhibits stretchability (∼1000% strain), self-healing ability (within 5 min), toughness (400–731 kJ/m3) viscoelasticity, tissue conformability, and biocompatibility. Upon examining the rheological properties in the modulated region, hydrogels can be 3D printed to customize the shape and design of the bioelectronics. These hydrogels can be fabricated into ring-shaped strain sensors for wearable sensor applications.