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In this study, the shear strength and thermal properties of the adhesively bonded joints were investigated of adhesives reinforced with nanoparticles using carbon fiber-reinforced composite materials. The diglycidyl ether bisphenol A (DGEBA) was used as the epoxy resin. Single lap joint tests of 1% wt. Multi-walled carbon nanotubes (MWCNT) and 3, 5, and 7% wt. silicon dioxide (SiO2) nanoparticle-reinforced mixed adhesives were performed according to ASTM D5868 standards. The shear strengths of the mixed adhesives obtained by mixing at different ratios were compared with the epoxy resin. Upon conducting an analysis of the shear strengths of nanomaterials, results indicate that the incorporation of 1CNT + 3SiO2 in the nanomaterials showed the greatest improvement, with a 46% increase in shear strength. 1CNT + 5SiO2, 1CNT, and 1CNT + 7SiO2 showed increases of 32%, 14%, and 5%, respectively. The results of a tensile test indicate that pure epoxy exhibited a tensile strength of 5953 N, 1CNT, and 3SiO2, while the epoxy composite demonstrated a significantly higher tensile strength of 8738 N, along with an elongation of 0.72 mm. In addition, the morphology of fractured surfaces was examined by scanning electron microscopy (SEM). To investigate damage mechanisms, such as bridging, crack blunting, and branching of nanoparticles were observed. Characterization of epoxy resin and mixed MWCNT + SiO2 nanoparticles reinforced adhesives were also performed using Fourier infrared spectroscopy (FTIR), thermogravimetric analysis (TGA), and differential thermal analysis (DTA). Nanoparticles are settled between polymer chains, improving polymer chains' motion and thermal properties. [ABSTRACT FROM AUTHOR]

With the advancement of nanotechnology, various types of nanomaterials have been integrated into electrochemical immunoelectrodes to enhance their performance. Among these, MXene stands out as a promising candidate due to its high electron transfer capacity and abundant surface chemical groups. However, the improvement in electrode performance is often hindered by the self-restacking and agglomeration of MXene. To address this issue, multi-walled carbon nanotubes (MWCNTs) were selected to form composites with MXene. Subsequently, a label-free immunosensor, BSA/Ab/AuNPs/MXene-MWCNTs-Nafion/ITO, was fabricated for specific detection of carcinoembryonic antigen (CEA), a widely used tumor marker. The results demonstrated that the incorporation of MWCNTs can effectively prevent the self-stacking of MXene. Moreover, the composites enhanced the loading of gold nanoparticles (AuNPs) to connect the antibodies, thereby improving electronic transmission signals and sensitivity. The sensor exhibited excellent analytical performance towards CEA with a wide linear range (0.050 to 200 ng mL−1) and a low limit of detection of 0.015 ng mL−1 (S/N = 3). The possibility of it being applied in clinical trials was verified by using ELISA and differential pulse voltammetry (DPV) assays to detect CEA in serum samples. The recoveries ranged from 95.34 to 102.09% with relative standard deviations (RSDs) below 5.00%. Furthermore, the sensor displayed satisfactory selectivity, repeatability, and stability. We hope the findings highlight promising prospects for advanced immunosensor development and alternative strategies in cancer diagnosis. [ABSTRACT FROM AUTHOR]

This study developed carboxylated multi-walled carbon nanotubes (MWCNTs-COOH) as sorbents to extract flavonoids from grapefruit peel. The impact of solution pH and desorption conditions on extraction efficiency was investigated. In addition, Fourier transforms infrared spectroscopy, thermogravimetry, UVvisible spectroscopy, and scanning electron microscopy were used to characterize the carbon nanotubes. After five cycles, the desorption percentage of flavonoids was 82.7 %. HPLC analysis indicated that naringin was the dominant flavonoid in the grapefruit extracts, followed by rutin and quercetin. Insights into the adsorption mechanism of naringin to the MWCNT-COOH were obtained using the Freundlich isotherm equation to model the results. The carbon nanotubes developed in this study offer a cost-effective and straightforward method of extracting valueadded functional ingredients from food waste, thereby improving the sustainability and economic viability of the food supply. [ABSTRACT FROM AUTHOR]

Our study aimed to evaluate the efficiency of solar power systems by developing dye-sensitized solar cells (DSSCs) with an electrolyte of carbon nanotubes (CNTs) dispersed in poly (methyl methacrylate) (PMMA). Photovoltaic and impedance spectral studies showed that a polymer electrolyte with 3% carbon nanotubes resulted in an efficiency of solar power conversion of 7.40% and a photovoltaic current per unit cross-sectional area of 17.13 mA/cm2 in DSSCs. The optimal distribution of CNT fillers decreased the charge recombination of the titanium dioxide-dye-CNT-PMMA electrolyte surface. The X-ray diffraction spectrum showed characteristic peaks of PMMA and CNT at 28.6° and 63.0°, respectively, obtained in pure form and composites with dispersed carbon nanotubes. The peak intensity increased with the addition of CNTs in the polymer. A Fourier transform infrared spectroscopy investigation revealed the bonding within the CO and CH of PMMA and CNT to the polymer composite. The dielectric constant increased from 2.9 to 4.4, and the dielectric loss increased from 0.10 to 0.90 at 1 MHz for the dispersion of 6% CNT in PMMA. Scanning electron microscopy analysis showed that the internal particle structure and porosity had changed due to the presence of the CNTs in the PMMA. The dispersion of CNTs into the PMMA increased the maximum voltage of the polymer electrolytes. A breakdown voltage of 7.4 kV was attained with 6% CNTs in the polymer. [ABSTRACT FROM AUTHOR]

This study evaluated the effect of multi‐walled carbon nanotubes (MWCNT) addition on the thermomechanical, and electrical responses of unidirectional flax fibers/Elium acrylic modified carbon nanotubes‐based composite. The manufacturing process of these laminated composites involved infusing the nanofillers onto the fibers, ensuring good dispersion of MWCNT within the matrix. Regardless of the rate of incorporated nanotubes, this study revealed a significant deterioration of the mechanical properties in tension and viscoelastic properties of the Elium acrylic resin‐based nanocomposite. The electrical conductivity significantly increased for all nanocomposites and laminated composites. In contrast to the nanocomposite, the unidirectional flax fibers/MWCNT/Elium acrylic composite exhibited a considerable improvement in mechanical properties. An increase in Young's modulus and stress at break of about 27% and 23% respectively, was achieved for the material loaded with 2 wt% of MWCNT. The presence of MWCNT reduces the saturation weight by 5% for the unidirectional composite filled with an amount of 1.5 wt% in MWCNT. Highlights: Improving the electrical properties of nanocomposites and unidirectional fibers (UD) composites.Improving the mechanical properties of Elium/flax/multi‐walled carbon nanotubes (MWCNT) composites.Influence of MWCNTs on the water absorption of UD composites.Influence of MWCNT on the glass transition temperature of nanocomposites.Inhibiting polymerization of MWCNT with Elium. [ABSTRACT FROM AUTHOR]

In this work, a novel approach is taken to enhance the thermal conductivity and mechanical properties of composites by developing highly efficient thermally conductive PVDF‐based composites. This is developed by incorporating tetra‐pod zinc oxide whiskers (T‐ZnOw) in conjunction with multiwalled carbon nanotubes (MWCNT) to form binary hybrid fillers within a polyvinylidene fluoride (PVDF) matrix. Polydopamine (PDA), characterized by physical adsorption, is selected for surface coating on T‐ZnOw since T‐ZnOw is easy to self‐agglomerate and difficult to modify by physical and chemical methods. The coating aims to improve the dispersibility of T‐ZnOw and reduce the interfacial thermal resistance with the substrate. MWCNT is oxidized to improve its dispersion ability while strengthening the interaction with the matrix, due to the absence of interaction between MWCNTs and polymer matrix and poor dispersibility with the matrix. The dispersity of PDA@T‐ZnOw and o‐MWCNT is improved, and the three‐dimensional hybrid network structure can be better constructed to improve the thermal conductivity of the composite membrane. At a filler content of 25 wt%, the thermal conductivity reaches 0.302 W m−1 K−1 for T‐ZnOw–MWCNT–PVDF and 0.222 W m−1 K−1 for PDA@T‐ZnOw–o‐MWCNT–PVDF. [ABSTRACT FROM AUTHOR]

Polyvinylpyrrolidone (PVP) was used as a dispersant and combined with ultrasonic technology to disperse multi walled carbon nanotubes(MWCNTs). A water-based dispersion of MWCNTs was prepared, and it was used as a doping phase to prepare fly ash concrete. The influence of multi walled carbon nanotube content on the mechanical and durability properties of fly ash concrete was studied through TEM, XRD, SEM, FT-1R, mechanical performance testing and rapid freeze-thaw experiments. The results indicated that PVP combined with ultrasonic technology could effectively disperse MWCNTs, and the addition of MWCNTs to fly ash concrete could accelerate the cement hydration reaction and increase the generation of hydration products such as C-S-H and Ca(OH)2. Moderate doping of MWCNTs could refine the internal pore structure of cement, reduce the number of cracks and large-sized pores, and transform the failure mode of fly ash concrete from brittle fracture to ductile fracture. The peak load and deformation of the MWCNTs-0.3 % specimen reached their maximum values, which were 41.6 kN and 2.92 mm, respectively. The compressive strength and flexural strength reached their maximum values, which were 60.5 and 11.2 MPa, respectively. After 100 rapid freeze-thaw cycles, the mass loss rate of the MWCNTs-0.3 % sample was the lowest value of 0.271 %, and the maximum relative dynamic elastic modulus was 84.34%, indicating a significant improvement in frost resistance. [ABSTRACT FROM AUTHOR]

Wheat sharp eyespot is a prevalent soil-borne disease that causes substantial economic losses in agriculture. Metconazole, a new triazole broad-spectrum fungicide, has demonstrated effective control of soil-borne diseases. Multi-walled carbon nanotubes (MWCNTs) are an innovative adsorbent material known for their large surface area and high absorptive capacity. This study identifies MWCNTs as the optimal adsorption material for metconazole, achieving an adsorption rate of 85.27% under optimal conditions (stirring time of 30 min and feeding ratio of 6:1). The optimized formula consists of 1.5% dispersant sodium wood, 1% emulsifier BY-112, 2% AEO-15, 3% glycol, 3% filmogen, and 4% red dyes. A 0.5% MWCNT–metconazole suspension concentrate for seed coating (FSC) significantly enhances the inhibitory effect of metconazole on wheat growth and promotes root development. At the tillering stage, a coating ratio of 1:100 shows a marked impact on wheat growth, and MWCNTs can improve the control effect of metconazole to Rhizoctonia cerealis. This work offers a novel approach for applying metconazole in a wheat suspension concentrate for seed coating. [ABSTRACT FROM AUTHOR]

An innovative supramolecular architecture is reported for bienzymatic glucose biosensing based on the use of a nanohybrid made of multi-walled carbon nanotubes (MWCNTs) non-covalently functionalized with a Schiff base modified with two phenylboronic acid residues (SB-dBA) as platform for the site-specific immobilization of the glycoproteins glucose oxidase (GOx) and horseradish peroxidase (HRP). The analytical signal was obtained from amperometric experiments at − 0.050 V in the presence of 5.0 × 10−4 M hydroquinone as redox mediator. The concentration of GOx and HRP and the interaction time between the enzymes and the nanohybrid MWCNT–SB-dBA deposited at glassy carbon electrodes (GCEs) were optimized through a central composite design (CCD)/response surface methodology (RSM). The optimal concentrations of GOx and HRP were 3.0 mg mL−1 and 1.50 mg mL−1, respectively, while the optimum interaction time was 3.0 min. The bienzymatic biosensor presented a sensitivity of (24 ± 2) × 102 µA dL mg−1 ((44 ± 4) × 102 µA M−1), a linear range between 0.06 mg dL−1 and 21.6 mg dL−1 (3.1 µM–1.2 mM) (R2 = 0.9991), and detection and quantification limits of 0.02 mg dL−1 (1.0 µM) and 0.06 mg dL−1 (3.1 µM), respectively. The reproducibility for five sensors prepared with the same MWCNT–SB-dBA nanohybrid was 6.3%, while the reproducibility for sensors prepared with five different nanohybrids and five electrodes each was 7.9%. The GCE/MWCNT–SB-dBA/GOx-HRP was successfully used for the quantification of glucose in artificial human urine and commercial human serum samples. [ABSTRACT FROM AUTHOR]

This study presents a comprehensive evaluation of catalytic ozonation as an effective strategy for indigo dye bleaching, particularly examining the performance of four carbon-based catalysts, activated carbon (AC), multi-walled carbon nanotubes (MWCNT), graphitic carbon nitride (g-C3N4), and thermally etched nanosheets (C3N4-TE). The study investigates the efficiency of catalytic ozonation in degrading Potassium indigotrisulfonate (ITS) dye within the constraints of short contact times, aiming to simulate real-world industrial wastewater treatment conditions. The results reveal that all catalysts demonstrated remarkable decolorization efficiency, with over 99% of indigo dye removed within just 120 s of mixing time. Besides, the study delves into the mechanisms underlying catalytic ozonation reactions, elucidating the intricate interactions between the catalysts, ozone, and indigo dye molecules with the processes being influenced by factors such as PZC, pKa, and pH. Furthermore, experiments were conducted to analyze the adsorption characteristics of indigo dye on the surfaces of the materials and its impact on the catalytic ozonation process. MWCNT demonstrated the highest adsorption efficiency, effectively removing 43.4% of the indigo dye color over 60 s. Although the efficiency achieved with C3N4-TE was 21.4%, which is approximately half of that achieved with MWCNT and less than half of that with AC, it is noteworthy given the significantly lower surface area of C3N4-TE. [ABSTRACT FROM AUTHOR]

Redox-active porous organic polymers (POPs) demonstrate significant potential in supercapacitors. However, their intrinsic low electrical conductivity and stacking tendencies often lead to low utilization rates of redox-active sites within their structural units. Herein, polyimide POPs (donated as PMTA) are synthesized in situ on multi-walled carbon nanotubes (MWCNTs) from tetramino-benzoquinone (TABQ) and 1,4,5,8-naphthalene tetracarboxylic dianhydride (PMDA) monomers. The strong π–π stacking interactions drive the PMTA POPs and the MWCNTs together to form a PMTA/MWCNT composite. With the assistance of MWCNTs, the stacking issue and low conductivity of PMTA POPs are well addressed, leading to the obvious activation and enhanced utilization of the redox-active groups in the PMTA POPs. PMTA/MWCNT then achieves a high capacitance of 375.2 F g−1 at 1 A g−1 as compared to the pristine PMTA POPs (5.7 F g−1) and excellent cycling stability of 89.7% after 8000 cycles at 5 A g−1. Cyclic voltammetry (CV) and in situ Fourier-Transform Infrared (FT-IR) results reveal that the electrode reactions involve the reversible structural evolution of carbonyl groups, which are activated to provide rich pseudocapacitance. Asymmetric supercapacitors (ASCs) assembled with PMTA/MWCNTs and activated carbon (AC) offer a high energy density of 15.4 Wh kg−1 at 980.4 W kg−1 and maintain a capacitance retention of 125% after 10,000 cycles at 5 A g−1, indicating their good potential for practical applications. [ABSTRACT FROM AUTHOR]

In this study, the atmospheric plasma (APP) surface modification technology was used to modify the surface of additive materials and mix them into the commercial thermal interface material (base-TIM). This technology allows for the preparation of a hybrid additives thermal interface material (HA-TIM) to improve the heat conduction performance of the base-TIM. The additives selected for HA-TIM include aluminum nitride (AlN), multi-walled carbon nanotubes (MWCNTs), and graphene flakes (GNFs) with different proportions. Additives with different sizes, shapes, and high thermal conductivity were expected to achieve a synergistic effect to produce an HA-TIM with high heat dissipation performance. After the preparation of the HA-TIM with different configuration ratios was completed, heat dissipation performance experiments would be carried out under different heating power and ambient temperature to determine the optimal configuration ratio of the HA-TIM. The results show that the HA-TIM prepared by adding 1 wt% GNFs and 1 wt% MWCNTs to the base-TIM has the best heat conduction performance. In the optimum configuration of the HA-TIM at the heating power of 50 W, 100 W, and 150 W, the heater surface temperature under the ambient temperature of 25 °C is 1.0 °C, 3.0 °C, and 4.2 °C lower than those of base-TIM, and the heater surface temperature under the ambient temperature of 30 °C is 1.1 °C, 3.2 °C, and 6.3 °C lower than those of base-TIM, respectively. Furthermore, the results show that HA-TIM has a better heat dissipation performance under high ambient temperature and heating power. [ABSTRACT FROM AUTHOR]

Effective solid-phase extractants (SPE) based on multi-walled carbon nanotubes (CNT) of various structures modified with an organic reagent, 2-mercaptobenzothiazole, were developed. Using scanning and transmission electron microscopy, the morphological and structural features of SPE samples and their elemental composition were determined. It was shown that the specific surface area of the modified CNT is approximately two times lower compared to the original CNT. It was revealed that the modified materials are CNT coils coated with a uniform organic shell 10−15 nm thick. The sorption capacity of the original nanotubes in 1.0 M HCl and of their modified forms (in 0.1−3.0 M HCl) at room temperature and at 80°C was determined. It was found out that in strongly acidic media, SPE based on G-183 CNT and 2-mercaptobenzothiazole, effectively sorbs Pt, Pd and Au at room temperature, and Ru and Rh at the temperature of 80°C. A possibility of the selective extraction of platinum group metals and gold with this sorbent in the presence of macroquantities of Al, Fe, Cu, Ca and Mg was assessed. [ABSTRACT FROM AUTHOR]

Flexible strain sensors need to obtain a stable signal as the target undergoes random and repeated deformation. Therefore, excellent mechanical properties, adhesion properties, and electrical conductivity are essential. In this study, a stretchable, self-adhesive, and conductive ionic hydrogel was designed and synthesized. Zwitterionic hydrogels were synthesized by micellar copolymerization of hydrophobic monomer methacrylate stearic acid (C18) with hydrophilic monomers [2-(methacryloyloxy)ethyl]dimethyl-(3-sulfopropyl) ammonium hydroxide (SBMA) in the presence of sodium dodecyl sulfate (SDS) surfactant. Compared with traditional chemical cross-linked hydrogels, the elongation at break is increased by 934%. The multi-walled carbon nanotubes (MWCNTs) modified with tannic acid (TA) have good dispersibility and stability, which can be added to the hydrogel as a functional filler to enhance the tensile and conductive properties of the sensor. The hydrogel flexible sensor prepared under the synergistic action of various mechanisms has good mechanical properties, bonding properties, and conductive properties. In addition, due to the inherent antibacterial properties of the raw material, the hydrogel has a bactericidal ratio of up to 99% against E. coli and S. aureus under the premise of good biocompatibility in vitro, which has great potential in the field of monitoring human movement and healthcare. [ABSTRACT FROM AUTHOR]

Ternary nanocomposites of reduced graphene oxide/multi-walled carbon nanotubes/cobalt oxide nanoparticles (rGO/MWCNT/Co3O4) were synthesized employing a facile hydrolysis method with subsequent heat treatment. The good electrical conductivity and remarkable carrier mobility of rGO and MWCNTs make them a suitable matrix for hybrid supercapacitors, and their composites with metal oxides exhibit enhanced electrochemical properties due to the advantages of the synergistic contribution and the integration of different dimensionalities. The binary counterparts of Co3O4 with GO or MWCNTs were also produced using the same technique to gain additional insight into the characteristics of the individual components. The structural and morphological properties of the composites were analyzed using various analytical techniques. The electrochemical behaviors of the prepared composites were investigated using cyclic voltammetry (CV), galvanostatic charge–discharge (GCD), and electrochemical impedance spectroscopy (EIS) in 1 M H2SO4. A platinum electrode modified with the rGO/MWCNT/Co3O4 composite displayed a remarkable specific capacitance of 922 F g−1 at a current density of 1 A g−1 composite with a negligible capacitance drop after 2000 cycles. The symmetric supercapacitor fabricated using the rGO/MWCNT/Co3O4 composite showed an energy density of 32.2 Wh Kg−1 at 1 A g−1, and the corresponding power density was 2000 W Kg−1. The supercapacitor fabricated using the composite displayed 83% capacitance retention after 2000 cycles at 3 A g−1 composite. [ABSTRACT FROM AUTHOR]

Inflammation is associated with an increased risk of developing various cancers in both animals and humans, primarily solid tumors but also myeloproliferative neoplasms (MPNs), myelodysplastic syndromes (MDS), and acute myeloid leukemia (AML). Multi-walled carbon nanotubes (MWCNTs), a type of carbon nanotubes (CNTs) increasingly used in medical research and other fields, are leading to a rising human exposure. Our study demonstrated that exposing mice to MWCNTs accelerated the progression of spontaneous MOL4070LTR virus-induced leukemia. Additionally, similar exposures elevated pro-inflammatory cytokines such as interleukin (IL)-1β, IL-6, and tumor necrosis factor (TNF)-α and induced reactive oxygen species (ROS) in a murine macrophage cell line. These effects were significantly reduced in immunodeficient mice and when mice were treated with methoxypolyethylene glycol amine (PEG)-modified MWCNTs. These findings underscore the necessity of evaluating the safety of MWCNTs, particularly for those with hematologic cancers. [ABSTRACT FROM AUTHOR]

The concentration level of urinary 8-hydroxy-2′-deoxyguanosine (8-OHdG), an oxidative stress biomarker for various diseases especially cancer, has been attracted as a pathway suitable for diagnostic purposes. Determination of urinary 8-OHdG is challenging due to its low level within a complex matrix. In this study, a new approach of solid/liquid phase microextraction technique prior to high-performance liquid chromatography diode-array detection (HPLC-DAD) analysis was developed for the determination of trace levels of 8-OHdG in urine samples. The solid/liquid phase microextraction device was constructed by reinforcement of multi-walled carbon nanotubes into the pores of a short segment 2.5 cm of hollow fiber microtube with two ends heat sealed. Based on the optimized procedure, the selected analyte was extracted from an acidic sample solution (10 mL adjusted at pH = 5) into the five extraction devices. After the extraction period (30 min), the 8-OHdG was eluted from the extraction device using methanol (350 µL) under ultrasonication for 5 min. The analytical performance of the method in synthetic urine samples showed good linearity (R 2 > 0.999) with the limits of detection of 0.85 ng mL−1, and extraction recovery > 92.36%. The developed microextraction technique exhibited a confident sensitivity, feasible operation, and simplicity in comparison with other published methods and was valid to determinate trace 8-OHdG in urine cancer patients' samples by using a cheap and commonly available HPLC-DAD instrument. [ABSTRACT FROM AUTHOR]

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AbstractA flexible formaldehyde sensor with high sensitivity was successfully fabricated by integrating palladium (Pd) nanoparticles, polyvinylpyrrolidone (PVP), multi-walled carbon nanotubes (MWCNTs) and nanocellulose (NC) into composite films. The flexible composite films were fabricated via vacuum filtration. The morphology, structure, composition, crystallinity, and functional group of as-fabricated sensing materials were characterized by scanning electron microscopy, transmission electron microscopy, electron probe microanalyzer, Raman spectroscopy, and Fourier transform infrared spectrometer. Pd nanoparticles-PVP-MWCNTs-NC (Pd-PVP-MWCNTs-NC) composite films exhibited an 11-fold increase in formaldehyde sensitivity compared to MWCNTs-NC composite films. The excellent sensing performances of Pd-PVP-MWCNTs-NC sensors were attributed to the combination of Pd nanoparticles and PVP. The enhanced sensitivity is attributed to the synergistic effect of the high electron transfer from formaldehyde molecule to Pd nanoparticles and swelling of PVP due to sorption of formaldehyde molecule. Pd-PVP-MWCNTs-NC sensors still maintained good response under bending angle up to 30° and 300 bending cycles. The results demonstrate that the Pd-PVP-MWCNTs-NC composite films are highly promising in terms of sensitivity and flexibility for sub-ppm level formaldehyde detection at room temperature. [ABSTRACT FROM AUTHOR]

In order to explore the micro‐pore structure improvement mechanism of multi‐walled carbon nanotubes (MWCNT) on the frost resistance of concrete, five kinds of MWCNT concrete with different contents were prepared and the frost resistance test and mercury intrusion test were carried out. The results show that when the content of MWCNT is 0.1 wt%, the mass loss rate and compressive strength loss rate of concrete after freezing and thawing are 15.97% and 23.85% lower than that of ordinary concrete, respectively, indicating that this content is best amount to improve the frost resistance of concrete in this study. Moreover, 0.1 wt% MWCNT can significantly optimize the internal pore structure of concrete, and the average pore diameter growth rate and harmful pore ratio are 30.1% and 64.45%, respectively, after 200 freeze–thaw cycles. The proportion of more harmful pores has the greatest influence on compressive strength and relative elastic modulus, and the gray correlation degree is more than 0.8. Finally, the mathematical models of compressive strength‐pore parameters and relative dynamic elastic modulus‐pore parameters of MWCNT concrete after freeze–thaw cycle are established considering pore structure parameters and pore size distribution. [ABSTRACT FROM AUTHOR]

This study uses a modified electrode made of Molecularly Imprinted Polymers (MIPs) and Multi-Walled Carbon Nanotubes (MWCNTs) to provide a unique method for the extraction and electrochemical detection of cyanidin in berry fruits. The special pairing of MIPs with MWCNTs improves the sensors' sensitivity and selectivity, allowing for accurate cyanidin detection and quantification. The electropolymerization procedure was used to create the electrode, and TEM, XRD, and Raman studies were used to confirm its structure. Using Differential Pulse Voltammetry (DPV), the electrochemical response of the MIP/MWCNTs/GCE sensor was investigated. With a detection limit of 0.14 mg/mL, the sensor showed a linear range of 0.5 mg/mL to 242 mg/mL, demonstrating good sensitivity and adaptability. Real samples (berry fruits, human urine, and tap water) were used to further validate the sensor's performance, and the results revealed a strong correlation with the UPLC technique. The DPV approach showed excellent accuracy and suitability with low relative standard deviation values (less than 4.66%) and adequate recovery values (97.00–99.50%). Excellent selectivity, repeatability, and stability characterize the suggested MIP/MWCNTs/GCE sensor, which makes it a viable instrument for real-world uses in the food and environmental industries. This work advances the field by offering a more selective and sensitive way to identify cyanidin in berry fruits. [ABSTRACT FROM AUTHOR]

This study demonstrated a unique method for quantifying β-glucan in edible mushrooms by immobilizing glucose oxidase (GOx) and β-glucanase (βg) on Multi-Walled Carbon Nanotubes (MWCNTs) modified glassy carbon electrode (GCE)-Nafion composite. Utilizing the special qualities of MWCNTs and Nafion, the electrochemical sensor's performance was improved. A sensitive and precise measurement of β-glucan was made possible by the sensor's design, which made use of βg and GOx. βg-GOx/MWCNTs/Nafion/GCE were evaluated for their efficacy in determining β-glucan. The findings indicated that the βg-GOx/MWCNTs/Nafion/GCE reacted only to β-glucan determination and not to other substances that could interfere. Peak current changed in a manner that was exactly proportional to β-glucan concentration in the 1–181 µg/mL range; this suggests a sensitivity of 2.14808 µA/µg mL− 1 and a detection limit of 0.7 ng/mL. By comparing seven identical biosensors made under the same circumstances, the suggested biosensor's homogeneity was assessed. The biosensor's repeatability was verified with a 4.40% relative standard deviation (RSD). Using edible mushroom samples, the βg-GOx/MWCNTs/Nafion/GCE was utilized and verified as a β-glucan sensor. Relative standard deviations of less than 4.88% and excellent recoveries ranging from 97.00 to 99.70% were obtained from the amperometric study. This confirmed that the results of βg-GOx/MWCNTs/Nafion/GCE for determining β-glucan concentration in edible mushroom samples were adequate and validated. The results of this study have the potential to greatly improve our knowledge of polysaccharides and how to use them in food science and agriculture. [ABSTRACT FROM AUTHOR]

This study presents the results of a comprehensive investigation into the fabrication of single-walled carbon nanotubes (SWCNTs) employing chemical vapor deposition (CVD) technique, with nickel nanoparticles serving as crucial catalysts. These nanoparticles are synthesized via the reduction of oxide precursors using hydrogen and are strategically incorporated with ethanol vapor as the primary carbon source. The effectiveness and reproducibility of this synthesis method are thoroughly validated using advanced analytical techniques. Particularly noteworthy is the demonstrated ability to conduct the process at relatively low temperatures, not exceeding 500°C, which is of significant importance. Such precise control over synthesis conditions not only augurs well for the scalability of SWCNT production but also carries substantial implications for the advancement of nanomaterial synthesis methodologies.

There is a rising interest in nanocomposites with unanticipated features that are different from traditional materials to fulfill the demands of these applications. Cobalt oxide (Co3O4) nanoparticles, and cobalt oxide with multi-walled carbon nanotubes (Co3O4/ MWCNTs) as nanocomposites were created. In this study, cobalt oxide nanoparticles (Co3O4 NPs) were synthesized via co-precipitation method chemical using CoCl2 salt as a source of cobalt nanoparticles and sodium hydroxide solution as a factor agent at room temperature. The cobalt hydroxide (Co(OH)2) precipitate was obtained, then it calcinated the cobalt hydroxide precipitate at 600°C to obtain the cobalt oxides nanoparticles (Co3O4 NPs). Also, MWCNTs were prepared by a locally manufactured reactor at 423 k. Binary composites were prepared by solution method using cobalt oxide nanoparticles dispersion over MWCNTs surfaces. The structural, morphological, and spectral properties were confirmed and investigated by using FE-SEM, Raman spectroscopy, and (XRD), respectively. The surface area and pore size obtained by BET and BJH showed that the binary nanocomposites (Co3O4/MWCNTs) have a higher surface area than their pristine cobalt oxide and multi-walled carbon nanotubes nanoparticles. The adsorption processes of nanocomposites have attracted significant care from the scientific public because of their distinctive possessions and aptitude to reduce and adsorb Cu+2 and Ni+2 as heavy metals from water pollution. As a result, Co3O4 and its nanocomposite with MWCNTs were used to remove copper and nickel ions from the dilute aqueous solution.

This study focuses on the analysis of peristaltic transport of a hybrid nanofluid comprising deionized water as a base fluid and the multi-walled carbon nanotubes (MWCNTs) and copper oxide (CuO) as nanoparticles within a sinusoidal wavy porous duct, taking into consideration the influence of heat generation or absorption. The inaugural literature piece addresses the utilization of hybrid nanofluid in the context of peristaltic flow within ducts. To simplify the analysis, we have converted the non-dimensional equations into a two-dimensional (2D) coordinate system using the assumptions of a very long wavelength (δ < 1) and low Reynolds number (Re). The non-dimensional equations governing the behavior of the hybrid nanofluid are then solved numerically using the finite volume method. Numerical solutions for temperature and the 2D peristaltic flow are obtained with the assistance of the Mathematics software MATLAB. These solutions are subsequently represented graphically using MATLAB software. The graphical results highlight several key findings for important parameters. First, it is observed that the pressure rise, temperature profile, and pressure gradient in the hybrid nanofluid (CuMWCNTs/H2O) flow increases as heat generation increases. Furthermore, an increase in the nanoparticle volume fraction of both nanoparticles leads to a decrease in the pressure rise and pressure gradient in the hybrid nanofluid flow. Additionally, the widening of the channel reduces the pressure gradient and pressure rise in the CuMWCNTs/H2O hybrid nanofluid. The analysis also includes the visualization of streamlines for peristaltic transport. These streamlines reveal that an increase in amplitude results in larger bolus sizes, while heightened heat generation has the opposite effect, decreasing bolus sizes. The results of this investigation can be found in various cooling devices as flows in the ducts are very frequently utilized for the cooling process of engines. A further topic is common in applications related to microfluidics, heat exchangers, and biomedical devices where peristaltic pumping is employed. Our results are in 100% agreement with the existing literature in special cases. [ABSTRACT FROM AUTHOR]

A novel electrochemical sensor was fabricated for the rapid and sensitive detection of chloramphenicol (CAP). The experiments combined molecular imprinting technology with electrochemical workstation, using multi-walled carbon nanotubes (MWCNTs) and gold-platinum nanoparticles to double sensitize the electrode, which was used to enhance the electron transfer rate on the surface of the glassy carbon electrode (GCE) and enhance the current response value of the electrochemical sensor, thus reducing the detection limit. Characterization was carried out using scanning electron microscopy and electrochemical methods. Study the adsorption performance of molecularly imprinted modified electrodes through adsorption kinetics experiments and isothermal adsorption experiments, and analyze their selectivity. Detect chloramphenicol in actual samples of chicken, fish, and milk using modified electrodes and analyze their detection effectiveness. Results showed that, the modification effect of the electrode could be clearly seen from the cyclic voltammetry (CV) and electrochemical impedance spectroscopy (EIS), and the enhancement of the electron conduction rate on the electrode surface by MWCNTs and gold-platinum nanoparticles (Au-PtNPs) was obvious. The adsorption properties of the molecularly imprinted modified electrodes were studied by adsorption kinetic tests and isothermal adsorption tests to determine the adsorption properties and analyze their selectivity. The experiments showed good selectivity for its structural analogues, and the analyticity of the sensor was evaluated, and the sensor showed good linearity between CAP concentrations of 0.66 and 56.66 µg/L with R2>0.99 and a detection limit of 0.45 nmol/L (0.146 µg/L). The recoveries of CAP were 83.72%~103.43% with the relative standard deviations (RSDs) of 2.61%~6.03% in the assays of actual samples of chicken, fish and milk, respectively, which met the requirements of GB/T 27404-2008 for quantitative analysis and detection (the measured components were

A nanocomposite of chitosan and poly acrylic acid grafting multi-walled carbon nanotubes p(CS-co-AA)/MWCNTs was produced using free radical polymerization to study its efficiency in eliminating the antibiotic ofloxacin (OFL) from aqueous solutions. The synthesized nanocomposite material has undergone characterization using FTIR, XRD, FESEM, TEM, EDX, and Zeta potential techniques. The adsorption of OFL on the p(CS-co-AA)/MWCNTs has been evaluated using three established Langmuir, Freundlich, and Temkin isotherm models. The isotherm constant (KF) of 0.218 and the separation factor (R2) of 0.956 indicate strong and desirable adsorption of OFL on p(CS-co-AA)/MWCNTs with a concentration of 100 mg/L at a temperature of 293K and an acidic medium with a pH of 7.0. The primary cause of the reduction in OFL adsorption and dehydrogenation is the increase in pH level. The Van't Hoff equation indicates that the OFL adsorption process exhibits fast kinetics, as seen by a negative thermodynamic parameter ΔH of -0.012 kJ/mol. The pseudo-second-order kinetic model (R2= 1.00) confirms this observation. The results indicate that the synthesized nanocomposite can effectively remove OFL from polluted aqueous solutions.

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Cadmium (Cd) and zinc (Zn) in seawater enter the human body through the food chain. Combined toxicity tests indicated that high concentrations of Cd(II) and low concentrations of Zn(II) had a synergistic effect on humans. Thus, there is an urgent need to prepare a sensor for rapid and simultaneous detection of Cd(II) and Zn(II) in seawater. Herein, a reduced graphene oxide/carboxylated multi-walled carbon nanotube (rGO/MWCNT-COOH)-modified glassy carbon electrode was prepared in the experiments using the dropping method. The synthesis of various materials achieved the purpose of expanding the surface area, and scanning electron microscopy was used to observe the structure of the composite membrane. Moreover, the large number of functional groups on the surface of the composite membrane can also increase the adsorption of ions. For the determination of trace cadmium (II) and zinc (II) in seawater, the method used was differential pulse voltammetry (DPV). The results show that the peak current, which was obtained in the range of 5–400 μg/L for Cd(II) and Zn(II), has a linear relationship with concentration, corresponding to the detection limits of 0.8 μg/L for Cd(II) and 0.98 μg/L for Zn(II). The modified electrode was used to determine the Cd(II) and Zn(II) content in the coastal seawater of the Maowei Sea, and the recovery rate was between 95.8 and 98.2% for Cd(II) and 96.7~99.4% for Zn(II), which provided a novel approach of detection to define trace Cd(II) and Zn(II) in seawater. [ABSTRACT FROM AUTHOR]

The 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. [ABSTRACT FROM AUTHOR]

Producing hydrogen by electrolyzing water has received increased attention. Nevertheless, a major challenge remains in the search for high performance hydrogen evolution reaction (HER) electrocatalysts. In this work, multi-walled carbon nanotubes (MWCNTs) capped by TpPa covalent organic framework (TpPa-COF) react with cobalt nitrate hexahydrate (Co(NO 3) 2 ·6H 2 O) to form a novel ternary one-body complex (MWCNTs@TpPa-COF@Co/CoO). Wherein, TpPa-COF is constructed from 2,4,6-Triformylphloroglucinol (Tp) and p -phenylenediamine (Pa) as structural units. This COF is relatively inexpensive, provides more coordination sites for metal loading, and is particularly stable in acidic and basic media. The results show that the composite material has high electrocatalytic HER activity in a potassium hydroxide (KOH) condition with an overpotential value of 28.8 mV and a Tafel slope of 69.07 mV dec−1 at a current density of 10 mA cm−2. Meanwhile, the MWCNTs@TpPa-COF@Co/CoO showed excellent stability after 2000 cycles in alkaline media. The characterization demonstrated that the material provided low resistance during the charge transfer process, which resulted in improved electrochemical performance. In addition, the COF loaded with cobalt nanoparticles provided more active sites for the reaction. Thus, the synthesized MWCNTs@TpPa-COF@Co/CoO emerges turns out to be a Pt-free, stable and efficient HER electrocatalyst, holding significant promise for practical applications. • MWCNTs@TpPa-COF@Co/CoO electrocatalyst with high HER performance has been prepared. • The accessible active sites on MWCNTs and COF contribute to the electrocatalytic HER performance. • The best electrocatalyst exhibited an ultra-low overpotential of 28.8 mV@10 m A/cm2. • The composite shows remarkable long-term stability after 24 h and 2000 CV cycles. [ABSTRACT FROM AUTHOR]

This study presents the results of a comprehensive investigation into the fabrication of single-walled carbon nanotubes (SWCNTs) employing chemical vapor deposition (CVD) technique, with nickel nanoparticles serving as crucial catalysts. These nanoparticles are synthesized via the reduction of oxide precursors using hydrogen and are strategically incorporated with ethanol vapor as the primary carbon source. The effectiveness and reproducibility of this synthesis method are thoroughly validated using advanced analytical techniques. Particularly noteworthy is the demonstrated ability to conduct the process at relatively low temperatures, not exceeding 500°C, which is of significant importance. Such precise control over synthesis conditions not only augurs well for the scalability of SWCNT production but also carries substantial implications for the advancement of nanomaterial synthesis methodologies. [ABSTRACT FROM AUTHOR]

The paper presents the results of studying the effect of the addition of multi-walled carbon nanotubes (MWCNTs) on the physical and mechanical properties of aluminum alloys AK9 and AK12 obtained by using a stir casting and suspension casting technologies. When conducting experiments on stir casting MWCNTs, limitations were revealed, such as the difficulty of their uniform distribution in the melt, as well as a decrease in efficiency when increasing the thickness of the cast piece and/or performing sand-mold casting. A comparative analysis of the samples was carried out, which showed that the use of multi-walled carbon nanotubes (0.1 wt. %) as micro-additives leads to an increase in the tensile strength of the composite by at least 15% provided their uniform distribution. However, at increased casting thickness, samples obtained by using a suspension casting technology demonstrate higher mechanical properties. In addition, the suspension casting technology enables an increased productivity without equipping the furnace with a stirring device. [ABSTRACT FROM AUTHOR]

Silicone elastomers are continuously gaining importance in a variety of industrial applications, including strain gauges, electrical heaters, electromagnetic interference, and electrostatic discharge protection coatings. But these materials have certain drawbacks such as high cost, poor resistance to solvents, low tear strength, limited high-temperature resistance, difficulty in bonding and limited abrasion resistance. Therefore, unique nanocomposites of organosilicon elastomers with metals have been prepared using MWCNTs. The prepared nanocomposites demonstrated nano-diameter structures (15–60 nm) with micron-sized fibrous structures (12–60 μm). Aluminum elongated inclusions (60 µm in size) and bronze spherical inclusions (12–30 µm) were observed in the nanocomposites. The composites containing MWCNTs, Co-Mo/Al2O3-MgO catalyst and bronze (3 wt. %) had the maximum thermal and electrical conductivity. The prepared nanocomposites were used to make the heaters. The heating of the heaters was carried out by applying a voltage of 12–24 V. The Highest temperature achieved was more than 50 °C in all the heaters. By supplying 12–24 V electricity to the heaters in the ventilation and heat recirculation system, the interior of a minibus or living space can be heated. The developed electric heater has another important economic application in temperature-controlled materials. [ABSTRACT FROM AUTHOR]

Catalysts of the hydrogen peroxide cathodic synthesis are obtained from multiwalled carbon nanotubes pre-oxidized with nitric acid, follow by hydrogen reduction in the 300–500°C temperature range. Evaluation of physico-chemical properties of the catalysts showed the synthesis method used to be able controlling changes in the surface oxygen groups' composition without any change in the multiwalled carbon nanotubes' structure and morphology. Investigation of catalytic activity in the cathodic process for hydrogen peroxide production demonstrated the sample prepared by hydrogen reduction at 300°C with oxygen content of 5.2 at % (according to XPS data) to have the highest efficiency. The sample produced the hydrogen peroxide with the rate of 0.34 mol/(g h) and Faradaic efficiency of 78%. Increase in the reduction temperature above 300°C resulted in a decrease in the rate of Н2О2 accumulation without severe changes in Faradaic efficiency. [ABSTRACT FROM AUTHOR]

The promotion of different properties of polymers has become a substantial worldwide objective for different counterparts in industry and academia. In this work, different loadings of multi walled carbon nanotubes (MWCNTs) were employed to reinforce acrylonitrile butadiene styrene (ABS) to prepare polymer nanocomposites. The employed loadings by solution blending approach were (0.1, 0.5, 1.0, and 5.0) wt. %. FTIR and XRD were utilized to investigate the chemical interaction and crystal structure; respectively. The morphological investigation performed by scanning electron microscopy (SEM) showed the nature of the neat polymer, the dimensions and orientations of the nanotubes, and the good dispersion of the nanotubes within the polymer for the loadings up to 1.0 wt. %. As a result of this good dispersion, thermal properties represented by thermal degradation temperature (Td) and glass transition temperature (Tg) were improved. Furthermore, Young's modulus and tensile strength for the nanocomposite of 1.0 wt. % were enhanced by 87% and 46%, respectively as compared to the neat polymer. [ABSTRACT FROM AUTHOR]

This work is focused on the thermophysical and tribological study of eight nanolubricant compositions based on a polyalphaolefin (PAO 20) and two different nanoadditives: multi-walled carbon nanotubes (MWCNTs) and hexagonal boron nitride (h-BN). Regarding the thermophysical properties, density and dynamic viscosity of the base oil and the nanolubricants were measured in the range of 278.15–373.15 K, as well as their viscosity index, with the aim of evaluating the variation of these properties with the addition of the nanoadditives. On the other hand, their lubricant properties, such as contact angle, coefficient of friction, and wear surface, were determined to analyze the influence of the nanoadditives on the tribological performance of the base oil. The results showed that MWCNTs and h-BN nanoadditives improved the wear area by 29% and 37%, respectively, at a 0.05 wt% concentration. The density and dynamic viscosity increased compared with the base oil as the nanoadditive concentration increased. The addition of MWCNTs and h-BN nanoparticles enhanced the tribological properties of PAO 20 base oil. [ABSTRACT FROM AUTHOR]

Biocatalytic engineering was carried out by varying monotonically the binary CNTs-silica composition and, accordingly, the physicochemical characteristics of adsorbents developed for immobilization of recombinant T. lanuginosus lipase (r Pichia /lip). The adsorbents based on composite carbon-silica materials (CCSMs) were produced by impregnating finely dispersed multi-walled carbon nanotubes with silica hydrosol followed by calcination in argon at 350°C; the mass ratio of the hydrophobic and the hydrophilic components varied over a wide range. Biocatalysts (BCs) for green low-temperature synthesis of various esters in a non-aqueous medium of organic solvents were prepared by adsorption of r Pichia /lip with subsequent drying under ambient conditions. The characteristics of the CCSMs and BCs were characterized by thermogravimetry, nitrogen porosimetry and electron microscopy. The catalytic properties of BCs, such as enzymatic activity, substrate conversion and specificity, as well we their operational stability depending on the chemical composition of CCSMs were extensively studied in the esterification of saturated monocarboxylic acids (C 4 , C 7 , C 18) and primary aliphatic alcohols (C 2 , C 4 , C 16) in hexane at 20°C. It was found that the esterifying activity manyfold decreased with increasing the silica content primarily due to a decrease in adsorption ability of CCSMs toward r Pichia /lip. The substrate specificity and operational stability of the lipase-active BCs did not greatly depend on the composition of CCSMs. Biocatalysts retained more than half of their initial esterifying activity after 10 reaction cycles. • Recombinant lipase r Pichia /lip was adsorbed on carbon-silica composite materials. • The binary composition of MWCNTs-silica materials affected the properties of the biocatalysts. • Modulation of esterifying activity, substrate specificity and operational stability were studied. • At high silica content, a multifold decrease in activity was due to decrease in lipase adsorption. • The optimal MWCNTs content in the developed composite adsorbents exceeded 90 wt%. [ABSTRACT FROM AUTHOR]

In the current study, synthesis and use of a novel adsorbent (composite in nature) are presented for treatment of one of the most commonly found pharmaceutical compound, viz, diclofenac sodium (DCF) in waste water. Synthesis of the composite adsorbent was done by hydrothermal method metal organic framework (MOF) based on Zr metal and multi-walled carbon nanotube (MWCNT). The composite adsorbent is termed as UiO-66/MWCNT. The confirmation of successful synthesis of the adsorbent is done with the help of sophisticated characterization techniques like FTIR, XRD, zeta potential analyser, and SEM. The synthesized composite adsorbent is found to have good adsorption capacity for DCF. The experiments related to the process of adsorption were done in batch mode and the significance of various operating parameters affecting the specific uptake of DCF. Maximum adsorption is observed at 3 pH (acidic condition) when the initial concentration of DCF and adsorbent dose was 30 mg/L and 100 mg/L, respectively. The Langmuir isotherm model best describes the process of adsorption with a maximum adsorption capacity of 256.41 mg/g. Experimental results obtained through the studies conducted related to the kinetics displayed that the process followed pseudo-second order model, and intraparticle studies suggested that diffusion through pores controls the rate. Thermodynamic studies suggest that the adsorption of DCF on UiO-66/MWCNT was completely spontaneous with ΔH = −22.089 kJ/mol. The possible mechanism for the adsorptive removal of DCF through UiO-66/MWCNT as found from this study is electrostatic interaction. [ABSTRACT FROM AUTHOR]

In this work, new nanoadsorbents consisting of polymer‐modified multi‐walled carbon nanotubes (MWCNTs) were used to remove toxic ionic dyes, of methylene blue (MB) and methyl orange (MO), effectively from aqueous solutions. The MWCNTs were coated with polymer brushes of poly(potassium 3‐sulfopropyl methacrylate) (PKSPMA) and poly(2‐methacryloyloxyethyltrimethylammonium chloride) (PMETAC) via surface‐initiated atom transfer‐radical polymerization. The PKSPMA@MWCNTs and PMETAC@MWCNTs delivered removal efficiencies of ~80% at pH 7. Maximum adsorption capacity (qmax) reached 411.62 mg/g for MB using PKSPMA@MWCNTs and 224.60 mg/g for MO using PMETAC@MWCNTs, showcasing the effectiveness of these novel nanoadsorbents. The experimental results were analyzed using adsorption isotherm models (Langmuir, Freundlich, and Temkin) and kinetic models (pseudo‐first‐order, pseudo‐second‐order, and intraparticle diffusion). The Freundlich model provided an excellent fit for MB adsorption on both adsorbents, whereas the Temkin model best described MO adsorption on PKSPMA@MWCNTs and the Langmuir model on PMETAC@MWCNTs. The fitting results showed that the pseudo‐second‐order kinetic model was the most accurate fit for MB and MO adsorption on both nanoadsorbents, suggesting that the removal mechanism was chemisorption. In conclusion, PKSPMA@MWCNTs and PMETAC@MWCNTs demonstrate significant potential as effective adsorbents for dye removal from water, providing a promising approach for water treatment and environmental remediation. [ABSTRACT FROM AUTHOR]

Disposable sensors are inexpensive, user-friendly sensing tools designed for rapid single-point measurements of a target. Disposable sensors have become more and more essential as diagnostic tools due to the growing demand for quick, easy-to-access, and reliable information related to the target. Dopamine (DA), a prevalent catecholamine neurotransmitter in the human brain, is associated with central nervous system activities and directly promotes neuronal communication. For the sensitive and selective estimation of DA, an enzyme-free amperometric sensor based on polyaniline-doped multi-walled carbon nanotubes (PANI-MWCNTs) drop-coated disposable screen-printed carbon electrodes (SPCEs) was fabricated. This PANI-MWCNTs-2/SPCE sensor boasts exceptional accuracy and sensitivity when working directly with ex vivo mouse brain homogenates. The sensor exhibited a detection limit of 0.05 μM (S/N = 3), and a wide linear range from 1.0 to 200 μM. The sensor's high selectivity to DA amidst other endogenous interferents was recognized. Since the constructed sensor is enzyme-free yet biocompatible, it exhibited high stability in DA detection using ex vivo mouse brain homogenates extracted from both Parkinson's disease and control mice models. This research thus presents new insights into understanding DA release dynamics at the tissue level in both of these models. [ABSTRACT FROM AUTHOR]

This study employs potassium ferrate (K2FeO4) for the oxidation treatment of multi‐walled carbon nanotubes (MWNTs) under neutral and acidic conditions. A wet flash evaporation process is utilized to prepare natural rubber/MWNTs/carbon black composites, enhancing the performance of rubber composites. The increased oxidation level of MWNTs enhances their hydrophilicity, increases the quantity of oxygen‐containing hydroxyl groups on the surface, promotes dispersion within the natural rubber matrix, and ultimately improves the performance of the rubber products. The effective dispersion of MWNTs reduces electron transport resistance, forming a favorable electron transport channel in natural rubber. Experimental results indicate that K2FeO4 achieves the highest oxidation degree and optimal performance in an acidic environment. Compared to untreated MWNTs rubber composites, the oxidized MWNTs rubber composites exhibit a 34.9% reduction in the Payne effect, a 15.7% decrease in wear, a 12.7% reduction in rolling resistance, and a two‐order‐of‐magnitude increase in conductivity. This study provides a novel approach for preparing water‐dispersible MWNTs and high‐performance rubber composites, holding potential applications in premium rubber products and conductive rubber fields. Highlights: The wet flash refining process improved the dispersion of MWNTs.K2FeO4 oxidation of MWNTs was enhanced under acidic conditions.Oxidized MWNTs combined with CB to form a CB‐MWNTs‐CB filler network.Oxidized MWNTs and CB increased the "ball‐chain" arrangement in NR. [ABSTRACT FROM AUTHOR]

Plastics offer many advantages and are widely used in various fields. Nevertheless, most plastics derived from petroleum are slow to degrade due to their stable polymer structure, posing serious threats to organisms and ecosystems. Thus, developing environmentally friendly and biodegradable plastics is imperative. In this study, biodegradable cellulose/multi-walled carbon nanotube (MCNT) hybrid gels and films with improved ultraviolet-shielding properties were successfully prepared using cotton textile waste as a resource. It was proven that MCNTs can be dispersed evenly in cellulose without any chemical or physical pretreatment. It was found that the contents of MCNTs had obvious effects on the structures and properties of hybrid films. Particularly, the averaged transmittance of cellulose/MCNT composite films in the range of 320–400 nm (T320–400) and 290–320 nm (T290–320) can be as low as 19.91% and 16.09%, when the content of MCNTs was 4.0%, much lower than those of pure cellulose films (T320–400: 84.12% and T290–320: 80.03%). Meanwhile, the water contact angles of the cellulose/MCNT films were increased by increasing the content of MCNTs. Most importantly, the mechanical performance of cellulose/MCNT films could be controlled by the additives of glycerol and MCNTs. The tensile strength of the cellulose/MCNT films was able to reach as high as 20.58 MPa, while the elongation at break was about 31.35%. To summarize, transparent cellulose/MCNT composites with enhanced ultraviolet-shielding properties can be manufactured successfully from low-cost cotton textile waste, which is beneficial not only in terms of environmental protection, but also the utilization of natural resources. [ABSTRACT FROM AUTHOR]

Three different types of Zr-based MOFs derived from benzene dicarboxylic acid (BDC) and naphthalene dicarboxylic acid as organic linkers (ZrBDC, 2,6-ZrNDC, and 1,4-ZrNDC) were synthesized. They were characterized using X-ray diffraction analysis (XRD), X-ray photoelectron spectroscopy (XPS), Fourier-transform IR spectroscopy (FT-IR), and Transmission electron microscopy (TEM). Their hydrophilic/hydrophobic nature was investigated via contact angle measurements; ZrBDC MOF was hydrophilic and the other two (ZrNDC) MOFs were hydrophobic. The three MOFs were combined with MWCNTs as electrode modifiers for the determination of a hydrophobic analyte, flibanserin (FLB), as a proof-of-concept analyte. Under the optimized experimental conditions, a significant enhancement in the oxidation peak current of FLB was observed when utilizing 2,6-ZrNDC and 1,4-ZrNDC, being the highest when using 1,4-ZrNDC. Furthermore, a thorough investigation of the complex oxidation pathway of FLB was performed by carrying out simultaneous spectroelectrochemical measurements. Based on the obtained results, it was verified that the piperazine moiety of FLB is the primary site for electrochemical oxidation. The fabricated sensor based on 1,4-ZrNDC/MW/CPE showed an oxidation peak of FLB at 0.8 V vs Ag/AgCl. Moreover, it showed excellent linearity for the determination of FLB in the range 0.05 to 0.80 μmol L−1 with a correlation coefficient (r) = 0.9973 and limit of detection of 3.0 nmol L−1. The applicability of the developed approach was demonstrated by determination of FLB in pharmaceutical tablets and human urine samples with acceptable repeatability (% RSD values were below 1.9% and 2.1%, respectively) and reasonable recovery values (ranged between 97 and 103% for pharmaceutical tablets and between 96 and 102% for human urine samples). The outcomes of the suggested methodology can be utilized for the determination of other hydrophobic compounds of pharmaceutical or biological interest with the aim of achieving low detection limits of these compounds in various matrices. [ABSTRACT FROM AUTHOR]

Application of titanium dioxide nanomaterial having different crystal forms has been extensively studied in various fields. However, as a drilling fluid additive it is still an unexplored area. Changing the composition of TiO2 morphology, leads to substantial improvements in the environmental and energy sector. These enhancements are based on the chemical and physical interaction of the crystal structure. In the current work, the carbon supported anatase TiO2 particles are used as a drilling fluid additive to improve the efficiency of water-based mud systems. For the first time, the effect of the crystal system is considered on the drilling fluid performance. Three carbon supported particles in the form of MWCNT/TiO2, GO/TiO2 and activated carbon/TiO2 are used in drilling fluid. Each particle was added in the mud system with concentration ranging from (0.35 g, 0.875 g, 1.75 g, 2.625 g, 3.5 g,) respectively. The rheology, filtration, stability, and shale inhibition characteristics of the samples was performed. Improvement in electrochemical characteristics of the mud system was recorded after the incorporation of carbonaceous TiO2 particles. Moreover, the gelation and filtration characteristics of the muds were also enhanced after the synergy of carbonaceous material with TiO2. This interaction leads to better cutting suspension and provides smooth and compacted mud cake. In addition, all the mud samples interacted with Ranikot formation to observe its stability behavior. Substantial improvement in hydrophobic nature of the shale sample was recorded after interacting with the carbon supported TiO2 nanoparticles. These carbon supported particles are extremely potential in plugging the nano-pores of Ranikot shale and are responsible for maintaining the shale integrity. [ABSTRACT FROM AUTHOR]

Abstract The work proposes the use of multi-walled carbon nanotubes in various concentrations treated in nitric acid (f-MWCNT) as a filler for urea-formaldehyde resin to produce birch plywood with improved physical-mechanical, water-resistant and thermal properties. The MWCNTs were characterized using transmission electron microscopy, IR and Raman spectroscopy, and the zeta potential was determined. The thermal stability of plywood on the UFR/f-MWCNT adhesive composition was assessed and a higher thermal stability of plywood was revealed when a nanofiller was added to the resin. The modulus of rupture increased by 62.7% and the modulus of elasticity by 113% with the addition of 1.5% f-MWCNT. A decrease in water absorption was established by 43%. A steady decrease in the emission of free formaldehyde from plywood was determined. The possibility of intermolecular interaction between the functional groups of f-MWCNT and urea-formaldehyde resins has been established.

A microbial fuel cell (MFC) is a device that converts chemical energy into electrical energy through the catalytic processes of microorganisms. In this study, flexible and porous WO3/CNTs-Graphite-PVC film was fabricated through uniform adding of Zn powder into matrix of carbon nanotubes-graphite- Polyvinyl Chloride) PVC (film followed by selective dissolving of Zn from the film structure in acidic solution and finally electrodeposition of WO3 (Tungsten trioxide) into previously porous CNTs-Graphite-PVC film. Surface morphology studies showed that the flexible film has rough and porous structure and carbon nanotubes are uniformly present as electron conduction channels within the composite film. Studies also showed that porous WO3/MWCNTs-Graphite-PVC film as a bioanode in MFC at resistance of 1000 ohms and current density of 900 mA/m2 has a power density of 324 mW/m2. The method presented in this research can be used as a suitable method for preparing of suitable electrocatalysts based on commercial graphite powder in microbial fuel cells.