Functionalized Carbon Nanotubes Research Articles

Synthesis, Characterization, and Impact of Different Carbon-Based Nanomaterials on Gram (Cicer arietinum) Plant Growth and Soil Properties

The ecology and general public health are badly impacted by the prolonged usage of chemical fertilizers. Applying carbon-based nanomaterials is one of the best options available for accelerating plant growth while reducing harm to the environment. The current study aims to assess the effects of graphene oxides (GO), functionalized carbon nanotubes (FCNTs), and carbon nanotubes (CNTs) on plant growth and soil nutrient content. To observe the impact on gram plant growth and soil parameters, we synthesized and applied GO, FCNTs, and CNTs at a rate of 100µg/mL (120 g per kg soil) in the corresponding pots. After 90 days of seed sowing, GO-treated crops showed a 41% increase in crop height compared to the control (no nanomaterials), but this increase was 33% and 40% in CNTs - and FCNTs-treated crops, respectively. When compared to the control, the GO-treated plants shown a twofold increase in root length; in contrast, the FCNTs and CNTs-treated plants showed increases of 60% and 25%, respectively. The highest increases in plant biomass, soil organic matter, total nitrogen, microbial biomass, and enzymatic activity were observed in plants treated with GO. A 52% increase in SDA was seen in the GO-treated soil as compared to the control; in the FCNTs and CNTs-treated soils, this increase was 32% and 19%, respectively. An organic material with a carbon base is a carbon-based nanomaterial, which has the ability to control the soil microenvironment and activate soil enzyme activity. The results verified that incorporating carbon-based nanomaterials, particularly GO, into the soil might enhance the growth of gram plants and the sustainability of the soil.

Zr-MOF composites with zipped and unzipped carbon nanotubes for high-performance electrochemical supercapacitors.

Metal-organic frameworks (MOFs) have gained considerable interest as crystalline porous materials with notable characteristics, such as high surface area and excellent electrochemical performance, particularly in supercapacitor applications. The combination of MOFs with various nanocarbon materials further enhances their performance. This study investigated the combination of zirconium-based MOFs (Zr-MOFs) with graphene oxide nanoribbons (GONRs), zipped carbon nanotubes, and functionalized carbon nanotubes (FCNTs) to fabricate composites with elevated electrical conductivity, adjustable surface area, chemical robustness, mechanical strength, and customizable attributes for specific applications. Zr-MOFs exhibit remarkable capacitance, making them promising electrode materials for supercapacitors. GONRs and FCNTs have recently emerged as focal materials owing to their unique properties, which make them promising materials for electrochemical energy storage devices. A thorough investigation of the supercapacitive behavior of GONRs, FCNTs, Zr-MOFs, Zr-MOFs/FCNTs, and Zr-MOFs/GONRs in 1 M H2SO4 using different evaluation systems (three- and two-electrode systems) revealed a significant enhancement in the capacitance of Zr-MOFs after the introduction of GONRs and FCNTs. Employing Zr-MOF/GONR and Zr-MOF/FCNT composites as positive electrodes and GONRs as negative electrodes in two-electrode measurements demonstrated remarkable cycling stability by retaining their specific capacitances (Cs) even after 10 000 consecutive charge/discharge cycles at a high current density of 10 A g-1. Moreover, they feature a broad potential window of 1.7 V in the three-electrode system. This extends to 2 V in the two-electrode system, achieving high Cs. This highlights the remarkable electrochemical performance of the Zr-MOF/GONR and Zr-MOF/FCNT composites, offering a compelling approach for energy storage applications.

Integrating manganese oxide nanoparticles with functionalized carbon nanotubes on carbon cloth to serve as a stable anode for high-capacity Li-ion cells

Globally, energy demands are massive, and environmental issues are rising against our sustainability. To maximize the use of renewable energy sources, development of efficient energy storage systems is mandatory. Lithium-ion batteries (LIBs) play an indispensable role in powering portable devices and electric vehicles, due to their high specific capacity and long cycle life. Manganese oxide (Mn3O4) is an environmentally friendly anode active material with high theoretical specific capacity of 936 mAh g−1 for applications in Li-ion cells.In the present work, Mn3O4-functionalized carbon nanotubes (FCNT) nanocomposite, coated on carbon cloth (CC) current collector and termed as Mn3O4-FCNT @CC, is used as the anode material. Li-ion coin cells based on this nanocomposite anode show discharge capacity of 1371mAhg−1 and charge capacity of 1141mAhg−1 at current density of 100 mA g−1 with initial Coulombic efficiency of 83%. After 70 cycles, the charge-discharge capacities of the cells are 953mAhg−1 and 958mAhg−1, respectively, with capacity retention of 91% at current rate of 100 mA g−1. These cells are found to deliver reversible charge capacity of 575mAhg−1 after 100 cycles at 1C (∼1 A g−1) and offer prospects of stable operation at high current rates.

Ocular drug delivery strategies using carbon nanotubes: A perspective

Ocular drug delivery has its own set of challenges due to the eyes’ complexity and barriers. Various nanocarriers have been developed to deliver drugs to the eye; however, this work focuses on carbon nanotubes (CNTs) as a nanocarrier. CNTs have unique properties that can address these challenges. The novelty of this work is to integrate CNTs with ocular drugs to improve solubility, transport across barriers and sustained release. The structure and properties of CNTs are discussed in the context of ophthalmic applications. Functionalization of CNTs to enhance biocompatibility and optimize drug delivery is also discussed with recent updates. Key applications include improving solubility, penetration through ocular barriers and controlled release. Future directions and emerging trends in nanotechnology for ocular drug delivery are also considered.

Thermal performance of bio‐nanofluid dihydrolevoglucosenone: Experimental and atomistic simulation investigations

AbstractThis work presents findings on using a bio‐nanofluid‐containing Cyrene as a potential bio‐organic thermal base fluid. The fluid thermal properties can be enhanced with 0.03 vol% carboxylic functionalized multiwalled carbon nanotube (MWCNT‐COOH) to boost its heat transfer capabilities. The study compares the findings with the commercially available heat transfer fluids, that is, Paratherm GLT and Therminol 55. Furthermore, the stability of the nanofluid was assessed using experiments and atomistic simulation. Additionally, thermophysical characteristics such as thermal conductivity, density, viscosity, and specific heat () were measured. The thermal conductivity at various weight percentages of nanoparticles was determined using the reverse non‐equilibrium molecular dynamics (NEMD) simulations and validated with experimental values. The microstructure of Cyrene on the surface of a single‐walled carbon nanotube (SWCNT) and SWCNT‐COOH was examined using density functional theory (DFT) calculations. Our study shows that the composition of CNTs and the nanofluid temperature significantly impact the thermal conductivity of pure Cyrene.

Carbon Nanotubes Decorated with Nickel or Copper as Anti-Wear and Extreme-Pressure Additives for Greases

To increase the anti-wear (AW) and anti-scuffing possibilities of commercially available lithium grease, this paper proposed enriching the original composition with functionalised carbon nanotubes (CNTs) at a concentration of 0.1% (w/w). The CNTs were modified by decorating them with nanoparticles of two metals with established tribological potential: copper and nickel. The AW and extreme-pressure properties were determined using the customised ISO-20623 test on a four-ball apparatus. The AW properties were determined using the standardised parameter MWSD (mean wear scar diameter) and the anti-scuffing properties using the last non-seizing load. The greases enriched with nanoadditives showed better AW properties compared to the reference grease at higher loads (1–1.2 kN). Particularly favourable results were observed for grease with the addition of Cu-decorated CNTs, for which the MWSD values were more than 50% lower than the reference. Optical microscopy, SEM and TEM microscopy with EDS analysis, and Raman spectroscopy were used to identify the wear mechanisms and characterise the role of nanoadditives in the lubrication process.

A dual-activation strategy for enhancing the energy storage performance of MoSe2/AFCNTs in symmetric supercapacitors

The MoSe2/AFCNTs composite obtained via one-step hydrothermal process demonstrates significant promise as supercapacitor electrode material. In this process, MoSe2 nanoflowers are decorated on the surface of activated functional carbon nanotubes (AFCNTs) which are functionalized through a dual-activation method involving acid and alkaline treatment. The resulting composite benefits from plentiful active sites and low charge-transfer resistance, which together contribute to its excellent energy storage and capacitive performance. The electrochemical performance of MoSe2/AFCNTs in a three-electrode system is impressive, with a specific capacitance of 335 F g−1 at a current density of 1 A g−1. This value is much higher than that of either individual MoSe2 or carbon nanotubes, highlighting the synergistic effect between the two components. When used in a symmetric supercapacitor device, MoSe2/AFCNTs delivers a maximum power density of 1.25 kW kg−1 and an energy density of 1.39 Wh kg−1. Additionally, this device can supply power for electric watch, demonstrating that the MoSe2/AFCNTs composite is a competitive supercapacitor electrode material in practical application.

Evaluation of a Non-Enzymatic Electrochemical Sensor Based on Co(OH)2-Functionalized Carbon Nanotubes for Glucose Detection.

This work reports on the assessment of a non-hydrolytic electrochemical sensor for glucose sensing that is developed using functionalized carbon nanotubes (fCNTs)/Co(OH)2. The morphology of the nanocomposite was investigated by scanning electron microscopy, which revealed that the CNTs interacted with Co(OH)2. This content formed a nanocomposite that improved the electrochemical characterizations of the electrode, including the electrochemical active surface area and capacitance, thus improving sensitivity to glucose. In the electrochemical characterization by cyclic voltammetry and chronoamperometry, the increase in catalytic activity by Co(OH)2 improved the stability and reproducibility of the glucose sensor without the use of enzymes, and its concentration range was between 50 and 700 μmol L-1. The sensor exhibited good linearity towards glucose with LOD value of 43.200 µmol L-1, which proved that the Co(OH)2-fCNTs composite is judicious for constructing cost effective and feasible sensor for glucose detection.

Development of Folic Acid Functionalized Carbon Nanotubes for Efficient Delivery of Curcumin and Quercetin Against Pathogenic Bacteria

Development of Folic Acid Functionalized Carbon Nanotubes for Efficient Delivery of Curcumin and Quercetin Against Pathogenic Bacteria

Removal of naphthenic acid by combined adsorption and advanced oxidation processes with green functionalized carbon nanotubes and peroxymonosulfate

Removal of naphthenic acid by combined adsorption and advanced oxidation processes with green functionalized carbon nanotubes and peroxymonosulfate

Investigating the effect of functionalized carbon nanotube with COOH group on the drug delivery process of doxorubicin in capillary networks around cancer tumors using molecular dynamics simulation

Investigating the effect of functionalized carbon nanotube with COOH group on the drug delivery process of doxorubicin in capillary networks around cancer tumors using molecular dynamics simulation

Facile Fabrication of Silicon Anodes Enhanced by Functionalized Carbon Nanotubes: Towards Affordable and High-Performance Lithium-Ion Batteries

While the adoption of electric vehicles (EVs) is inevitable, the growth of the market hasn't matched predictions. Despite technological advancements improving EV competitiveness against fossil fuels, affordability remains a hurdle. Lowering the cost of lithium-ion batteries (LIBs) below that of fossil fuels is crucial for furthering vehicle electrification. Achieving this entails optimizing and simplifying the manufacturing process, given the complexity and energy intensity of LIB fabrication, which results in high costs and greenhouse gas emissions.Recent LIB research has primarily focused on enhancing electrochemical performance, often involving complex procedures and costly materials. Silicon (Si) anodes, in particular, face challenges due to structural instability during Li alloying, requiring nanostructured particles, calcination processes, and expensive materials to improve performance. Despite Si's high theoretical capacity (~4000mAh g-1), these challenges have hindered its commercialization in LIBs. However, there's now a renewed effort among LIB manufacturers to develop high-energy-density batteries with Si anodes, prompting researchers to seek breakthrough methods to overcome Si anode weaknesses and high costs.Carbon nanotubes (CNTs) possess unique conductive properties due to their stable one-dimensional (1D) nanostructure, making them excellent for battery electrodes. While previously expensive and limited to laboratory use, advancements in technology and market growth have led to the construction of scale-up factories, reducing CNT prices. Multi-walled carbon nanotubes (MWNTs) are particularly now affordable compared to conventional carbon black conductive materials.Based on with this trend, we applied MWNTs to Si anodes using a simple fabrication method. Oxidized MWNTs were dispersed into an aqueous slurry without additional surfactants, enhancing electrode electrochemical behavior. MWNTs with surface oxygen groups self-arranged into interconnected network structures, forming a uniform coating on Si particles. These functionalized carbon nanotubes (FCNTs) only require a straightforward synthesis method and conventional slurry mixing process, making them ideal for large-scale production. With these advantages, FCNTs enabled superior full-cell performance with NCM cathodes.

Carbon Nanotube-Phenyl Modified g-C3N4: A Visible Light Driven Efficient Charge Transfer System for Photocatalytic Degradation of Rhodamine B.

In this study, we report the synthesis and characterization of a novel photocatalyst composite composed of functionalized carbon nanotubes (f-CNT) and phenyl-modified graphitic carbon nitride (PhCN). The incorporation of the phenyl group extends the absorption range into the visible spectrum compared to pure g-C3N4. Additionally, the formation of the heterostructure in the f-CNT/PhCN composite exhibits improved charge transfer efficiency, facilitating the separation and transfer of photogenerated electron-hole pairs and reducing recombination rates. The photocatalytic performance of this composite was evaluated by the degradation of Rhodamine B (RhB) under visible light irradiation. The f-CNT/PhCN composite exhibits remarkable efficiency in degrading RhB, achieving 60% degradation after 4 h, and 100% after 24 h under low-power white LED excitation. This represents a substantial improvement over the non-functionalized CNT/PhCN composite, which shows much lower performance. In contrast, pure PhCN demonstrates very little activity. Structural and optical properties were characterized using X-ray diffraction (XRD), transmission electron microscopy (TEM), Raman spectroscopy, and UV-Vis spectroscopy. Time-resolved photoluminescence measurements were used to study the behavior of photoexcited carriers, confirming that the composite improves charge transfer efficiency for photogenerated carriers by approximately 30%. The results indicate that the functionalization of CNTs significantly enhances the photocatalytic properties of the composite, making f-CNT/PhCN a promising candidate for environmental remediation applications, particularly in the degradation of organic pollutants in wastewater.

Dual driven asymmetric electrolyte with gradient distributed UPy-CNTs for high-performance lithium metal batteries

Asymmetric electrolytes with both anode and cathode compatibility are promising candidates for high-energy–density batteries and high-safety lithium metal batteries (LMBs). However, the asymmetric electrolyte is still hindered by the complex multi-layer coating process, resulting in multiple internal interfaces of the electrolyte and poor battery performance. Herein, a one-step constructed asymmetric electrolyte with gradient distributions of 2‐ureido‐4[1H]-pyrimidinone functionalized carbon nanotubes (UPy-CNTs) is prepared via the dual driving forces of solvent evaporation and fluoropolymer migration. On the one hand, during the solvent evaporation process, based on the competitive effect between evaporation of solvent and diffusion of dispersions, the gradient distribution of asymmetric electrolyte can be constructed by enhancing evaporation and inhibiting uniform diffusion. On the other hand, due to the abundant hydrogen bonds between UPy and F, the gradient distribution of UPy-CNTs can be further promoted when the fluoropolymer spontaneously migrates to the surface. The gradient distribution of UPy-CNTs not only greatly increases Young’s modulus of the asymmetric electrolyte on the Li metal side, but also can adjust the Li+ solvation structure to form a LiF-rich solid electrolyte interface (SEI), thereby inhibiting the generation and growth of lithium dendrites. Because of the ingenious structure of the asymmetric electrolyte, the ionic conductivity is 0.226 mS cm−1 and the Li+ transferences number is 0.79. Prominently, Li||Li symmetric batteries can stably cycle for 2500 h at 0.1 mA cm−2 and 0.1 mAh cm−2. In addition, Li||LFP batteries can maintain a high specific capacity of 146 mAh g−1 after 200 cycles at 0.5C.

Redox-mediated electrochemical separation of boron ions: Cell design, process optimization, adsorption isotherm, kinetics, and thermodynamics

Boron contamination of various water sources has been increasing in recent years and is receiving worldwide attention for its negative effects on the environment, wildlife, and humans; therefore, its removal is of utmost importance. Considering dwindling water sources and the possibility of the world population soon experiencing water scarcity, effective and innovative technologies must be developed to remove boron ions from water sources. The aim of the present study was to assess a sustainable separation process for the removal of boron ions using an electrochemical flow cell with symmetric redox-active polyvinyl ferrocene (PVF) functionalized carbon nanotube (CNT) electrodes using real-time measurements of the boron adsorption performance in continuous-flow mode while varying the flow rate, cell voltage, and boron concentration. A Box–Behnken experimental design (BBD) was used to improve boron adsorption. The adsorption isotherms, kinetics, and thermodynamics were investigated to further describe the adsorption process. The high R2 value, calculated using a linear and nonlinear procedure, demonstrated that the Langmuir isotherm and pseudo-first order models fit quite well. The maximum adsorption of 60.61 mg/g was observed. The thermodynamic results illustrated that the adsorption of boron ions onto the PVF/CNT electrodes was spontaneous and endothermic under continuous flow mode.

Adenosine-Derivative Functionalized Carbon Nanotubes Considered as Catalysts for Vanadium Flow Batteries

Adenosine-Derivative Functionalized Carbon Nanotubes Considered as Catalysts for Vanadium Flow Batteries

Incorporation of SnSe2/SnO2 heterostructures in carbon nanotubes for excellent lithium storage performance

As a new type of negative electrode material, tin-based material exhibits a high theoretical capacity. However, tin-based anode materials always undergo severe volume change upon alloying reaction during lithium insertion and extraction, which leads to the pulverization of the active materials and poor electrochemical performance, seriously hampering its practical application. In this work, oxygen-containing group functionalized carbon nanotubes (FCNTs) were facilely obtained, and the three-dimensional crosslinked SnSe2-SnO2@FCNTs multiphase materials were prepared by solvothermal and high-temperature heat treatment. The formation of Sn-O-C bonds from oxygen-containing functional groups of FCNTs combined with Sn can promote the electric connection and integrity of the composites. The implanted defects in FCNTs can not only be beneficial to anchoring SnO2 and SnSe2 nanoparticles, but also helpful to the penetration of Li+ ions into the electrodes from electrolyte. In addition, the large Fermi energy difference between SnSe2 and SnO2 nanoparticles results in the formation of a built-in electric field at the interface of the multiphase materials, accelerating the diffusion of ions. The smaller size of the multiphase materials leads to significant pseudocapacitive behavior, which facilitates the highly reversible surface/interface adsorption. Under the multiple effects of FCNTs, SnSe2, and SnO2, the SnSe2-SnO2@FCNTs multiphase materials exhibited excellent electrochemical performance. At a current density of 0.1 A·g−1, a discharge specific capacity of 898.0 mA h·g−1 was achieved. When the current density was increased to 2 A·g−1, it still exhibited a discharge specific capacity of 443.9 mA h·g−1. After a long charge/discharge cycling at 1 A·g−1 over 450 cycles, it still showed a specific capacity of ∼ 400 mA h·g−1. This work significantly demonstrated the enhanced Li-storage performance of SnSe2-SnO2 heterostructures incorporated in the functionalized multi-walled CNTs. This opens a new way to synthesize advanced tin-based materials as high-performance anodes for high-energy density lithium-ion batteries.

Functionalized Carbon Nanotubes: An Advanced Tool with Enhanced Biomedical Attributes

Background: The drug delivery system is revolutionized by nanoparticles, an essential component of nanotechnology, exhibiting an ultra-small size, large surface area to mass ratio, and high reactivity, different from bulk materials having the same composition. Various types of nanoparticles include liposomes, neosomes, micelles, carbon-based, etc. The most useful among them are carbon nanotubes because of their distinct optical, electrical, thermal, and mechanical properties and their architectures. Furthermore, the carbon nanotubes could either be single-walled or multiple-walled, based on the number of graphene sheets rolled. Like any other technique, these come with many limitations, including their tendency of hydrophobicity, insolubility, bundling together, low dispersibility, and, majorly toxicity. Objective: In this review, the main objective is to update the applications of functionalized carbon nanotubes as drug delivery systems in various therapies. Methods: Functionalization came into being to solve the mentioned disabilities. Functionalization could be covalent as well as non-covalent. As a result, functionalized carbon nanotubes have shown improvement in mentioned drawbacks. Conclusion: Now, the above-said functionalized carbon nanotubes have achieved bigger objectives with a better approach than conventional carbon nanotubes in the field of drug delivery systems.

Effects of Functionalized Carbon Nanotube on Cellular Homeostasis of Murine Hepatocytes

Nanotechnology in medicine represents a revolution offering significant advancements in the diagnosis, treatment, and prevention of diseases. This technology enables the development of devices and materials at the nanometer scale, allowing precise interactions with biological systems at the molecular and cellular levels. Among various nanomaterials, carbon nanotubes (CNTs) stand out due to their unique physical, chemical and mechanical properties. Due to their high strength, electrical and thermal conductivity and large surface area, CNTs have a wide range of applications. In healthcare they are explored for drug delivery and imaging diagnostics. CNTs can be functionalized to target drugs directly to diseased cells, minimizing side effects and enhancing treatment efficacy, additionally can be used in biosensors for early disease detection and in tissue engineering to cellular regeneration. The present study evaluated the effects of OCNT-TEPA, a multi-walled carbon nanotube functionalized, in murine hepatocytes AML-12. Cells were exposed to different concentrations of the sample for 12, 24, 48, and 72 hours. Cellular metabolism tests, cellular morphology by optical microscopy, synthesis of reactive oxygen species, changes in membrane potential and IL-6 cytokine secretion were performed. The results show that OCNT-TEPA altered the homeostasis of hepatocytes, as cellular metabolism decreased, cellular morphology was altered, the membrane experienced changes in its electrical potential, oxidative stress increased and inflammatory signaling molecules were synthesized. This alteration is dose-dependent, which may be harmful to hepatocytes at high concentrations but could be applied to the body at lower concentrations without causing harm.

Validation of experimental results for polyhedral oligomeric silsesquioxane, carbon nanotube and functionalized carbon nanotube/polymer nanocomposites through density functional theory study

The mechanical and thermal properties of polymer nanocomposites could be influenced by different parameters. Interfacial interaction between nanomaterial and polymer composite can effectively influence the properties of nanocomposite. In this paper, the interaction between carbon nanotube (CNT), functionalized carbon nanotube with Amin (CNT-Amin), and Polyhedral Oligomeric Silsesquioxane (POSS), absorbing on PA/EVA composite surface theoretically were investigated based on the density functional theory (DFT) calculations. The interaction energy of −36.64 kJ/mol between PA and CNT-Amin and −22.31 kJ/mol between EVA and CNT-Amin means that the absorption of CNT-Amin on PA and EVA monomer are stronger than CNT and POSS which could affect the mechanical and thermal properties of the nanocomposites. However, the interaction between the polymer composite and the nanomaterials was physisorption. Additionally, thermal and mechanical tests were conducted on nanocomposite samples. Thermal and mechanical results show that the DFT calculations are in good agreement with the experiment. DSC analysis shows that the melting temperature for PA in PA/EVA/CNT-Amin changed from 221.6 to 225.2 °C and crystallization temperature from 188.8 to 191.9 °C which illustrates that the CNT-Amin nanomaterial adsorbed to PA in PA/EVA composite. Finally, mechanical properties show that the modulus of PA/EVA/CNT-Amin nanocomposite changed from 307.4 to 327.2 MPa compared to neat PA/EVA composite emphasizing that the interaction between CNT-Amin nanomaterial and PA improves the strength of the nanocomposite and in addition, EVA adsorbs the CNT which affected the strain of the nanocomposite at break by 16 % which corresponds to the calculation result prediction.