Dispersion Of Nanotubes Research Articles

A solar-powered electrocoagulation process with a novel CNT/silver nanowire coated basalt fabric cathode for effective oil/water separation: From fundamentals to application.

Electrocoagulation (EC) has proven its high efficiency and environmental sustainability for treating several types of wastewaters. However, the primary drawbacks of the conventional EC process are the suitable electrode materials and the relatively high cost due to the requirement for electric energy. To overcome these practical challenges, this study investigated effective oil/water separation by a solar-powered electrocoagulation (SPEC) process using a novel highly conductive basalt fabric (BF) cathode. The BF cathode was fabricated using a simple approach: dip-coating in carbon nanotubes (CNT) dispersion, followed by a bath exhaustion coating in a silver nanowires (AgNws) solution, and its successful preparation was confirmed through several advanced characterization techniques. The effect of the CNT-AgNws coating on the electrical conductivity of the BF-CNT/AgNws was investigated using the four-probe tester. The BF-CNT/AgNws cathode exhibited a high conductivity of 1.66×104S/m, which indicates its applicability in the SPEC system. Under the operating conditions of applied voltage (25V), SPEC time (30min), stirring rate (150rpm), and NaCl concentration (1g/L), the experiment's results showed a high COD removal of 90.2±0.03 %, a low energy consumption of 1.28±0.01 kWh/kgCOD, and electrode consumption of 0.35±0.06kg/m3. In addition, due to the use of solar-powered energy, the overall cost was reduced by eliminating the electricity fees. Moreover, the reusability test results proved that the BF cathode has potential reusability in successive SPEC experiments while maintaining its performance. In conclusion, the obtained findings are very encouraging in designing novel EC cathodes for effective oily wastewater treatment at an industrial scale.

Binary and Ternary Nanocomposite Membranes for Gas Separation Incorporating Finely Dispersed Carbon Nanotubes in a Polyether Block Amide Matrix

This work addressed the fine dispersion of Multiwalled Carbon Nanotubes (MWCNTs) in a polymer matrix to obtain Mixed Matrix Membranes (MMMs) suited for gas separation. Not-purified MWCNTs were effectively loaded within a polyether block amide (Pebax®2533) matrix, up to 24 wt%, using ultrasonication as well as a third component (polysorbate) in the dope solution. The obtained flexible thin films were investigated in terms of morphology, thermal properties, characterized by SEM, FT-IR, DSC, TGA, and gas permeation tests. The response to temperature variations of gas permeation through these nanocomposite specimens was also investigated in the temperature range of 25–55 °C. Defect-free samples were successfully obtained even at a significantly high loading of CNTs (up to 18 wt%), without a pre-treatment of the fillers. A remarkable enhancement of gas permeability upon the nanocarbons loading was reached, with a threshold value at a loading of ca. 7 wt%. The addition of polysorbates in the ternary MMMs further improves the dispersion of the filler, enhancing also the permselectivity of the membrane.

Thermally conductive polymer foams with sodium-dodecyl-benzenesulfonate-surface-modified graphene nanoplatelets and carbon nanotubes: supercritical CO2-induced foaming

Lightweight composite foams with high thermal conductivities are difficult to obtain owing to the trade-off between thermal conductivity and porosity. In this study, to improve the dispersion of graphene nanoplatelets (GNP) and multi-walled carbon nanotubes (MWNT) and the uniformity of pore size, sodium dodecyl benzenesulfonate (SDBS) can be used, which acts as a surface modification agent on GNP and MWNT and as a foam stabilizer on supercritical carbon dioxide (scCO2) foaming. The mixed morphology composite (MMC) network leads to improved thermal conductivity, which is not significantly reduced after scCO2 foaming. This may be attributed to the fact that the SDBS-assisted MMC networks of GNP and MWNT in polyamide 6 (PA6) are maintained after foaming with the homogeneous pores by scCO2 and the SDBS stabilizer. Thus, the density of the composite decreases to 1.249g/cm3 after foaming. The resulting high-heat-dissipation composites possess lightweight properties and high thermal conductivities, which are promising for application as battery pack components in next-generation automobiles.

Eco-Friendly Fabrication of NCM811 Cathodes with Alcohol-Based Dispersion of Single-Walled Carbon Nanotubes for Lithium-Ion Battery Application

Eco-Friendly Fabrication of NCM811 Cathodes with Alcohol-Based Dispersion of Single-Walled Carbon Nanotubes for Lithium-Ion Battery Application

Sustainable nanomaterials: the role of Cyrene in optimising carbon nanotubes dispersion and filtration efficiency

Sustainable nanomaterials: the role of Cyrene in optimising carbon nanotubes dispersion and filtration efficiency

Sequential Admicellar Polymerization of Polyindole and Poly(vinyl Acetate) for Increasing Electrical Conductivity and Water Dispersion of Multiwalled Carbon Nanotubes

Sequential Admicellar Polymerization of Polyindole and Poly(vinyl Acetate) for Increasing Electrical Conductivity and Water Dispersion of Multiwalled Carbon Nanotubes

Stretchable thermoplastic polyurethane/single-walled carbon nanotube masterbatch nanocomposites with enhanced electrical conductivity and thermal properties

A thermoplastic polyurethane (TPU)/single-walled carbon nanotube (SWCNT) nanocomposite was developed using a twin-screw extrusion process followed by injection molding. This study aimed to enhance the properties of TPU by incorporating a SWCNT masterbatch, with a polyol ester serving as the carrier resin. The electrical conductivity, rheological behavior, mechanical performance, and thermal properties of the TPU/SWCNT nanocomposites were systematically evaluated. The incorporation of the SWCNT masterbatch significantly improved the electrical conductivity of the TPU nanocomposites. With SWCNT loading levels below 0.6 wt%, the viscosity and processability of the nanocomposites were maintained. However, a noticeable decrease in viscosity was observed when the SWCNT content exceeded 0.6 wt%. The tensile and storage modulus of the nanocomposites increased, attributed to the stiffness and reinforcing effects of SWCNTs. Despite a slight reduction in tensile strength and elongation at break upon SWCNT addition, the tensile properties of the TPU/SWCNT nanocomposites at a loading of 0.4 wt% remained well-suited for strain sensor applications. The polyol ester in the SWCNT masterbatch facilitated the uniform dispersion of carbon nanotubes within the TPU matrix and enhanced the nucleation ability of SWCNTs, contributing to improved performance characteristics.

Nanotubes and Nanodiamonds in 3D printing: Enhancing Mechanical and Biological Properties of Nanocomposites through Advanced Formulation Technologies

Aim: With the aim to improve the thermal and mechanical characteristics of nanocomposites for cutting-edge engineering applications, this work looks at how nanotubes and nanodiamonds can be integrated into 3D printing processes. Background: The performance of 3D-printed products has been greatly enhanced by the addition of nanomaterials like carbon nanotubes (Carbon nanotubes) as well as nanodiamonds into polymer matrices. While nanodiamonds offer remarkable hardness and thermal stability, carbon nanotubes are widely recognized for their better electrical conductivity and bending strength. Their qualities make them the best options for raising the calibre of nanocomposites that are 3D printed. Objective: This paper looks at the effects of dispersion, functionalization, and synthesis of nanotubes and nanodiamonds on the mechanical and thermal properties of nanocomposites, taking into account the environmental impact, obstacles, and applications of these materials. Method: The techniques for adding nanotubes and nanodiamonds to 3D printing formulations were the main topic of a thorough literature study. A number of important factors were examined, including stability, toughness, elasticity, and tensile strength. The influence of uniform particle spread on overall composite performance as well as developments in dispersion technologies were reviewed in the paper. Results: The study found that the incorporation of nanotubes and nanodiamonds into 3D printing processes significantly improved the mechanical and biological properties of nanocomposites. These nanomaterials improved electrical conductivity and thermal stability, making them suitable for applications in electronics, aerospace, and biomedical fields. However, challenges such as high costs, ecological impacts, and long-term stability assessments remain. Conclusion: Although there is potential for next-generation materials with the incorporation of nanotubes along with nanodiamonds in 3D-printed nanocomposites, issues such as uniform nanoparticle dispersion still need to be resolved.

Enhancing Heat Transfer Efficiency Through Controlled Magnetic Flux in a Partially Heated Circular Cavity Using Multi-Walled Carbon Nanotube Nanofluid and an Internal Square Body

Applications including aircraft systems and electronics cooling depend on effective heat transfer. This study investigates magnetohydrodynamic (MHD) free convection and thermal radiation for heat transfer in a circular cavity filled with multi-walled carbon nanotube (MWCNT) nanofluid and containing a square obstruction. This study examines the impact of the internal geometry on heat transfer and fluid flow dynamics under three distinct boundary conditions, and it presents a comprehensive analysis based on a wide range of Hartmann (Ha) and Rayleigh (Ra) numbers. MWCNT nanofluid with high thermal conductivity was employed to enhance heat transfer efficiency, using a solid volume fraction (SVF) of 4% for MWCNTs and assuming Newtonian behavior for computational simplification. Magnetic properties were imparted to the nanofluid by assuming the dispersion of carbon nanotubes in a base fluid containing magnetic nanoparticles. Other walls were insulated, the bottom wall was heated, and a magnetic field (MF) with Ha ranging from 0 to 100 was applied. It was observed that raising Ra from 103 to 106 improved the Nusselt number (Nu) from 0.08 to 7.1 using the Galerkin finite element method. Ha increased from 0 to 100 and reduced Nu by 35%. Three boundary conditions for the square body showed that the heated conditions provided the largest Nu. By means of an increase in SVF from 0 to 0.04, the MWCNT nanofluid improved heat conductivity by 18%. Radiation effects with the radiation parameter Rd = 0.5 increased heat transmission by 22%. These results underline the importance of considering MHD and nanofluid characteristics in maximizing heat transfer for commercial purposes, and the approaches employed in this study contribute to a deeper understanding of the behavior of thermal systems under the influence of MHD and internal geometry.

PH-responsive re-dispersible dispersions of carbon black and single-walled carbon nanotubes in arabinogalactan solutions

pH-responsive re-dispersible dispersions of carbon black and single-walled carbon nanotubes in arabinogalactan solutions

Continuous Flow Chemistry and Bayesian Optimization for Polymer-Functionalized Carbon Nanotube-Based Chemiresistive Methane Sensors.

We report the preparation of poly(ionic) polymer-wrapped single-walled carbon nanotube dispersions for chemiresistive methane (CH4) sensors with improved humidity tolerance. Single-walled CNTs (SWCNTs) were noncovalently functionalized by poly(4-vinylpyridine) (P4VP) with varied amounts of a poly(ethylene glycol) (PEG) moiety bearing a Br and terminal azide group (Br-R1). The quaternization of P4VP with Br-R1 was performed using continuous flow chemistry and Bayesian optimization-guided reaction selection. Polymers (PyBrR1) with different degrees of functionalization were used to disperse SWCNTs and subsequently incorporated into sensors containing a platinum complex as an aerobic oxidative catalyst with a polyoxometalate (POM) redox mediator to facilitate room-temperature CH4 sensing. As the degree of quaternization in the PyBrR1-CNT composites increased, improvements in response magnitude were observed, with nominally 10% quaternized PyBrR1 giving the largest response. Incorporation of PEG improved sensor stability at relative humidities between 57-90% versus sensors fabricated from CNT dispersions with unfunctionalized P4VP. Devices fabricated with these dispersions outperformed those prepared in situ under dry conditions, and exhibited greater stability at elevated humidities. The influence of Keggin-type POM character was also evaluated to identify alternative POMs for enhanced sensor performance at high humidity. In an effort to identify areas for further improvement in algorithm performance for polymer functionalization, a kinetically informed machine learning model was explored as a route to predict reactivity of pyridine units and alkyl bromides under flow conditions.

Numerical simulation of rotating flow of CNT nanofluids with thermal radiation, ohmic heating, and autocatalytic chemical reactions

The dispersion of carbon nanotubes in conventional fluids provides a variety of applications, using their unique features to develop efficiency, performance, and functionality in many industrial and scientific processes. Some of the applications are energy conversion, fluid stirring, aligned nanocomposites, heat exchangers, electronics cooling, etc. Considering the aforementioned applications, this communication presents a comparative examination of the rotating flow of CNTs past a stretchable sheet with suction and velocity slip. This study is unique because it looks at the non-linear radiative, Darcy–Forchheimer, and rotational flow of CNTs past a stretchable sheet with considering ohmic heating and homogeneous/heterogeneous reactions. These type of issues have not been previously discussed. Suitable conversions are adopted to alter the governing nonlinear PDEs into nonlinear ODEs. The reduced ODEs are numerically reckoned by adopting the bvp4c scheme in MATLAB. The repercussions of flow factors on velocity, temperature, nanoparticle concentration, skin friction coefficients, and local Nusselt number are provided via tables and graphs. It is revealed that the primary velocity profile dwindles when augmenting the values of suction/injection, porosity, rotational, and magnetic field parameters. The temperature ratio and radiation parameters contribute to the thermal profile’s development. The magnetic field parameter and the Forchheimer number play a dual role in both directional skin friction coefficients. The larger values of radiation and temperature ratio parameters improve the heat transfer rate.

ОПЫТ ПРИМЕНЕНИЯ НАНОБЕТОНА В ПРОИЗВОДСТВЕ ТРЕХСЛОЙНЫХ СТЕНОВЫХ ПАНЕЛЕЙ В УСЛОВИЯХ КРАЙНЕГО СЕВЕРА

For the construction in the Far North, it is important to use high-strength building materials with high frost resistance, strength and low density. Such materials include nano concrete, which includes stabilized dispersions of carbon nano-tubes. The strength and relatively light weight of the reinforced concrete product based on nano concrete determines its high characteristics of the object, which leads to a reduction in transportation costs, labor intensity, installation of structural elements and reduces the cost of the construction object by 20%. A 6x6-meter garage has been proposed as an experimental building in the conditions of the Far North. For the construction, three-layer nano concrete wall panels were man-ufactured using mobile plant technology. The use of nano concrete made it possible to reduce the thickness of the concrete layer in the structural element on each side to 25 mm and reduce the weight of the product, as well as reduce the consumption of cement in the concrete mixture.

Obtaining carbon nanotubes dispersions in solutions of ethoxylated fatty alcohols for modifying gel systems

Obtaining carbon nanotubes dispersions in solutions of ethoxylated fatty alcohols for modifying gel systems

Closed-Form Solution for Scale-Dependent Frequencies of Shear Deformable Cellular Microplates Coated by Piezoelectric Polymeric Skins Consisting of FG Distributed CNTs

In this work, a rectangular cellular microplate is taken into consideration which is embedded between two functionally graded carbon nanotube-reinforced composite layers that have the piezoelectric ability. Different patterns for the carbon nanotube dispersion are considered. Moreover, an external electrical voltage is applied to them. The displacements are described based on a higher-order shear deformation theory which is called hyperbolic theory and the size influence is captured via the modified couple stress formulations. The governing motion equations are then derived using the variational technique and Hamilton’s principle. Then, for simply supported edge conditions, a closed-form solution is provided. Next, it turns to validate the results in simpler states, and after that, the effect of the most prominent parameters on the results is investigated. It is observed that by increasing the external applied voltage to the face sheets, the frequencies are reduced. Also, the natural frequencies have a tendency to decrease as the dimensionless material length scale parameter increases. This study’s outcomes may help design and manufacture micro-/nano-electro systems, sensors and actuators, small-scale devices, and other engineering structures.

Preparation and characteristics of CuS-CNTs modified PVDF-based flexible composite phase change films

It is indisputable that the impact of buildings on global energy demand. To address the issue of excessive energy consumption in buildings, this manuscript proposes the preparation of a flexible composite phase change films with excellent solar energy absorption conversion and thermal management capabilities. In this paper, composite phase change material was obtained by adsorbing paraffin into expanded graphite (EG) using vacuum adsorption method. The photothermal material copper sulfide‑carbon nanotubes (CuS-CNTs) was synthesized by hydrothermal reaction. The dispersion of EG and carbon nanotubes (CNTs) in polyvinylidene fluoride (PVDF) matrix was enhanced under the influence of polyvinylpyrrolidone (PVP). The flexible and bendable films were finally prepared by using the non-solvent-induced phase separation method. The latent heat of the film reaches 63.63 J/g, and the thermal conductivity of the film system approaches to 0.53 W/(m·K) through the adsorption of the high thermal conductivity enhanced phase EG and the intervention of CNTs. The photothermal conversion ability of CuS-CNTs improves the photothermal performance of the film, and the solar energy utilization reaches 46.2 % under simulated sunlight. The experimental results show that the prepared films can effectively convert solar energy into thermal energy and store it in the form of latent heat, and the films can release the energy in the form of heat again at low temperatures. Utilizing this property, the film can be applied to the field of building materials, which demonstrates great potential and prospect in reducing energy consumption and carbon emission in buildings. The prepared composite phase change film for photothermal conversion provides a new idea for modern building thermal management materials.

Long-Term Stable Dispersion of Multiwalled Carbon Nanotubes by Peroxydisulfate upon Ultrasonication Activation.

Poor dispersibility of carbon nanotubes greatly hinders their practical applications. Herein, a long-term stable dispersion of multiwalled carbon nanotubes (MWCNTs) in peroxydisulfate (PDS) is achieved. MWCNTs at 40mgL-1 are completely dispersed by PDS upon ultrasonication (US/PDS) within 64min and a stable dispersion is maintained at least 20 days. Mechanistically, US created defects on the nanomaterial and PDS-origin free radicals attacked these defects to introduce O-containing moieties (─OH and ─COOH). Interestingly, dispersion efficiency of MWCNTs by US/PDS initially at pH 7 and 3.8 is comparable, but lower than that initially at pH 12. Both •OH and SO4 •- are produced under alkaline condition, while SO4 •- is the dominant free radicals initially at pH 7 and 3.8 during the whole dispersion period. Stronger dispersion of MWCNTs initially at pH 12 resulted from greater amounts of O-containing moieties mainly in ─OH (46.32%) rather than ─COOH (24.19%) form. This differential more strongly promotes MWCNTs-water interaction via hydrogen bonding, thereby enhancing the dispersion. Notably, no significant mass loss of MWCNTs occurred during dispersion. Overall, the developed method achieves long-term stable dispersion of MWCNTs in a manner that can significantly extend their applications.

Carbon nanotube reinforced ionic liquid dual network conductive hydrogels: Leveraging the potential of biomacromolecule sodium alginate for flexible strain sensors

The rapid evolution of multifunctional wearable smart devices has significantly expanded their applications in human-computer interaction and motion health monitoring. Central to these devices are flexible sensors, which require high stretchability, durability, self-adhesion, and sensitivity. Biomacromolecules have attracted attention in sensor design for their biocompatibility, biodegradability, and unique mechanical properties. This study employs a “one-pot” method to integrate ionic liquids and multi-walled carbon nanotubes into a dual-network hydrogel framework, utilizing tannic acid, sodium alginate, acrylamide, and 2-acrylamido-2-methylpropane sulfonic acid. Tannic acid and sodium alginate, natural biomacromolecules, form a robust physical cross-linking network, while P(AM-AMPS) creates a chemical cross-linking network. Ionic liquids enhance carbon nanotube dispersion, resulting in a hybrid hydrogel with remarkable tensile strength (0.12 MPa), adhesive properties (0.039 MPa), and sensing performance (GF 0.12 for 40 %–100 % strain, GF 0.24 for 100 %–250 % strain). This hydrogel effectively monitors large joint movements (fingers, wrists, knees) and subtle biological activities like swallowing and vocalization. Integrating natural biomacromolecules into this composite hydrogel sensor not only enhances the functionality and biocompatibility of flexible wearable devices but also paves the way for innovations in biomedicine and bioelectronics.

Fe2O3-decorated multiwall carbon nanotube composites for boosted microwave absorption

Developing microwave absorption (MA) materials with a strong absorption ability over a wide bandwidth through a simple and environmentally friendly approach remains a tremendous challenge. Herein, we propose to use an Fe3+–tannic acid framework to assist the dispersion of multi-walled carbon nanotubes (MWCNTs) and successfully prepare MWCNTs/porous carbon/α-Fe2O3 composites through freeze-drying and subsequent heat treatment. The dielectric properties and MA performance can be regulated by the heat treatment temperature, which leads to tunable crystalline structure, composition, and graphitization degree of MWCNTs. Consequently, the MWCNTs/porous carbon/α-Fe2O3 composite heat-treated at 300 °C exhibits a high reflection loss (RL) of −58.9 dB and an effective absorption bandwidth (5.28 GHz) with a matched thickness of 2.26 mm at a filler proportion of only 5 wt%, and the related frequency bandwidth with RL below −10 dB reaches 14.3 GHz at a thickness of 2–5 mm. In conclusion, the balance between conduction and polarization loss endows the composite with excellent impedance matching and boosting MA performance. This study offers a guideline for fabricating excellent MA materials through a simple, environmentally friendly method.

Simulation-based analysis of impact of CNT dispersion on hydration of cement paste

Dispersion of carbon nanotubes (CNTs) is one of the key factors determining the mechanical properties of cement composites. This study analyzed impact of CNT dispersion on hydration of cement paste. An image analysis method based on optical microscopy images was proposed to quantitatively consider the CNT dispersion. To quantify CNT dispersion, this paper proposed PCNT, which is the percentage of a 1 μm2 space containing CNTs within entire water volume. To investigate CNT dispersion effect, the same amount of CNT was classified into six steps (S1, S5, S15, S30, S50, and S100) according to PCNT. The relationship between CNT dispersion and the hydration, porosity, and compressive strength of the cement paste was analyzed using a CEMHYD3D considered CNT effect. The optimal CNT dispersion for 0.1 wt% CNT reinforcement in a cement paste with water-to-cement ratio of 0.3 was found to be 15 % PCNT. The improvement in CNT dispersion resulted in acceleration of hydration of cement paste, improvement in compressive strength, and densified microstructure.