Multi-walled Carbon Nanotubes Hybrid Research Articles

Electronic Textiles Based on Highly Conducting Poly(vinyl alcohol)/Carbon Nanotube/Silver Nanobelt Hybrid Fibers.

Highly stable conducting fibers have attracted significant attention in electronic textile (e-textile) applications. Here, we fabricate highly conducting poly(vinyl alcohol) (PVA) nanocomposite fibers with high thermal and chemical stability based on silver nanobelt (AgNB)/multiwalled carbon nanotube (MWCNT) hybrid materials as conducting fillers. At 20 vol % AgNB/MWCNT, the electrical conductivity of the fiber dramatically increased (∼533 times) from 3 up to 1600 S/cm after thermal treatment at 300 °C for 5 min. Moreover, PVA/AgNB/MWCNT fiber resists the harsh conditions of good solvents for PVA as well as high temperatures over the melting point of PVA, whereas pure PVA fiber is unstable in these environments. The significantly enhanced electrical conductivity and chemical stability can be realized through the post-thermal curing process, which is attributed to the coalescence between adjacent AgNBs and additional intensive cross-linking of PVA. These remarkable characteristics make our conducting fibers suitable for applications in e-textiles such as water leakage detectors and wearable heaters. In particular, heating behavior of e-textiles by Joule heating can accelerate the desorption of physically trapped moisture from the fiber surface, resulting in the fully reversible operation of water leakage monitoring. This smart e-textile sensor based on highly stable and conductive composite fibers will pave the way for diverse e-textile applications.

Doping and Surface Modification Enhance the Applicability of Nanostructured Fullerene–MWCNT Hybrid Draped LiNi0.1Mg0.1Co0.8O2 as High Efficient Cathode Material for Lithium-Ion Batteries

Development of high performance cathode materials, layer-structured ternary LiNixCoyM1−x−yO2 cathode materials have attracted much attention owing to their larger capacity and higher energy density. Persistent efforts have been devoted to tackling certain issues like low electronic conductivity and poor structural stability. Dual strategy of Mg doping and surface modification of the cathode material was adopted to improve the performance of the battery. Fullerene–Multi-Walled Carbon Nanotube (MWCNT) hybrid draped LiNi0.1Mg0.1Co0.8O2 nanocomposite was synthesized by a simple chemical route. The fullerene–MWCNT hybrid modifies the surface of pristine LiNi0.1Mg0.1Co0.8O2 thereby improves the electrochemical performance and maintains the structural stability of the cathode material. Pristine LiNi0.1Mg0.1Co0.8O2 and LiNi0.1Mg0.1Co0.8O2/fullerene–MWCNT nanocomposite were studied using various advanced characterization techniques such as X-ray diffraction (XRD), Micro-Raman spectroscopy, Field Emission Scanning Electron Microscopy (FESEM), X-ray Photoelectron Spectroscopy (XPS), and High-Resolution Transmission Electron Microscopy (HRTEM). It is found that LiNi0.1Mg0.1Co0.8O2 particles retain their structural integrity after being enveloped with a fullerene–MWCNT hybrid. The electrochemical performance was investigated with cyclic voltammetry (CV), galvanostatic charge–discharge (GCD) test and electrochemical impedance spectroscopy (EIS). As prepared LiNi0.1Mg0.1Co0.8O2, when deployed in the form of LiNi0.1Mg0.1Co0.8O2/fullerene–MWCNT composite exhibits a high specific capacity of 208 mAh g−1. Fullerene–MWCNT hybrid draped LiNi0.1Mg0.1Co0.8O2 nanocomposite provides an effective Li+ and electron channel that significantly increased the Li-ion diffusion coefficient and reduced the charge transfer resistance. Besides,the lithium diffusion coefficient increased from 5.13 × 10–13 (Li/LiNi0.1Mg0.1Co0.8O2) to 8.313 × 10–13 cm2 s−1 due to the improved kinetics of Li insertion/extraction process in Li/LiNi0.1Mg0.1Co0.8O2 + fullerene–MWCNT cell.

Natural rubber nanocomposites: effect of carbon black/multi-walled carbon nanotubes hybrid fillers on the mechanical properties and thermal conductivity

ABSTRACT This work presents the effect of carbon black (CB)/multiwall carbon nanotubes (MWCNT) hybrid filler system on the mechanical properties and thermal conductivity of natural rubber (NR) based nanocomposites. A 30 phr (parts per hundred of rubber) of CB nanocomposite was used as a reference for which various amounts (0.5, 1, 2 and 5 phr) of MWCNT were incorporated as a CB replacement. Scanning electron microscopy (SEM) was used to investigate the state of dispersion of the CB/MWCNT fillers inside the NR matrix, while dynamic mechanical analysis (DMA) was performed to characterize their storage and loss moduli, Payne effect and loss factor (tan δ). The scorch time (t10) and optimum curing time (t90) gradually increased with increasing MWCNT content due to the shape difference between CB and MWCNT, as well as the adsorption of curatives onto the MWCNT. Finally, due to the intrinsic properties of MWCNT and its synergy with CB, substantial improvements in thermal conductivity and mechanical properties were achieved by the substitution of 5 phr CB with MWCNT. For example, a thermal conductivity of 0.602 W/m.K was achieved, which corresponds to a 80% increase compared to the reference sample. Furthermore, a 72% and 54% increase of the modulus at 100% and 300% strain (M100 and M300) was respectively achieved, while the elongation at break decreased by only 20%.

High Sensitivity Humidity Detection Based on Functional GO/MWCNTs Hybrid Nano-Materials Coated Titled Fiber Bragg Grating.

A high performance humidity sensor using tilted fiber Bragg grating (TFBG) and functional graphene oxide (GO)/multi-walled carbon nanotubes (MWCNTs) hybrid nano-materials was proposed. The humidity-sensitive material with three-dimensional (3D) structure was synthesized by the MWCNTs and GOs. Comparing with traditional two dimensional (2D) GOs film, water molecules could be absorbed effectively due to the larger ripples and more holes in GO/MWCNTs layers. The water molecule will fill the entire space in the 3D structure instead of air, which further enhances the absorption efficiency of the hybrid nanomaterial. TFBG as a compact and robust surrounding complex dielectric constant sensing platform was utilized. The mode coupling coefficient or the amplitude of TFBG cladding mode will vary sharply with the imaginary part of permittivity of the hybrid nanomaterial, realizing the high performance RH sensing. In the experiments, we successfully demonstrated that this 3D structural nanomaterial composed by the MWCNTs and GOs has significant advantages for expanding the range of humidity detection (range from 30% to 90%) and enhancing the detection sensitivity (0.377 dB/% RH is twice more than humidity sensor with 2D GO film). The TFBG-based RH sensor also exhibits good repeatability and stability. Our proposed humidity sensor has potential application in environmental and healthy monitoring fields.

Rational design and fabrication of lightweight porous polyimide composites containing polyaniline modified graphene oxide and multiwalled carbon nanotube hybrid fillers for heat-resistant electromagnetic interference shielding

In this paper, porous polyimide composites (PPIC) for electromagnetic interference (EMI) shielding were rationally designed and fabricated by using polyimide (PI) matrix, polyaniline modified graphene oxide (PANI-g-GO) and multiwalled carbon nanotube (MWCNT) as hybrid fillers through innovatively combining in-situ polymerization process and thermally assisted non-solvent induced phase separation (TNIPS) method. The polyimide matrix and porous structure endow the composites with good heat resistance and lightweight, and hybrid fillers can form effective conductive networks in the PI matrix, which results in the enhancement of EMI shielding performance. The porous polyimide composite with a hybrid filler content of 12 wt% (PPIC12) exhibited a low density of 0.56 g/cm3, high T10 of 554.81 °C, excellent EMI shielding effectiveness up to 28.2 dB at a thickness of 2 mm. Therefore, the novel porous polyimide composites are promising polymer-based EMI shielding materials with lightweight and good heat resistance.

Numerically simulated behavior of radiative Fe3O4 and multi-walled carbon nanotube hybrid nanoparticle flow in presence of Lorentz force

Numerically simulated behavior of radiative Fe3O4 and multi-walled carbon nanotube hybrid nanoparticle flow in presence of Lorentz force

Effect of Nanofiller Content on Dynamic Mechanical and Thermal Properties of Multi-Walled Carbon Nanotube and Montmorillonite Nanoclay Filler Hybrid Shape Memory Epoxy Composites.

The aim of the present study has been to evaluate the effect of hybridization of montmorillonite (MMT) and multi-walled carbon nanotubes (MWCNT) on the thermal and viscoelastic properties of shape memory epoxy polymer (SMEP) nanocomposites. In this study, ultra-sonication was utilized to disperse 1%, 3%, and 5% MMT in combination with 0.5%, 1%, and 1.5% MWCNT into the epoxy system. The fabricated SMEP hybrid nanocomposites were characterized via differential scanning calorimetry, dynamic mechanical analysis, and thermogravimetric analysis. The storage modulus (E’), loss modulus (E”), tan δ, decomposition temperature, and decomposition rate, varied upon the addition of the fillers. Tan δ indicated a reduction of glass transition temperature (Tg) for all the hybrid SMEP nanocomposites. 3% MMT/1% MWCNT displayed best overall performance compared to other hybrid filler concentrations and indicated a better mechanical property compared to neat SMEP. These findings open a way to develop novel high-performance composites for various potential applications, such as morphing structures and actuators, as well as biomedical devices.

An Ultrasensitive New Coccine Detection Sensor Based on Molecularly Imprinted Electrode Using Pod-Like Cerium Molybdate and Multi-Walled Carbon Nanotubes Hybrids

An Ultrasensitive New Coccine Detection Sensor Based on Molecularly Imprinted Electrode Using Pod-Like Cerium Molybdate and Multi-Walled Carbon Nanotubes Hybrids

Carbon Nanotubes/Graphene Oxide Composite Applications in Fiber RH Sensor

We propose a high-sensitivity optical fiber relative humidity (RH) sensor based on multiwalled carbon nanotubes (MWCNTs)/graphene oxide (GO) composite, which functions as the humidity-sensitive film. The optical component of this demonstrated sensor is a single-mode fiber-solid core fiber-single-mode fiber-based multimode interference structure. For the composite sensitive film, GO is used as a dispersant for two types of MWCNTs with different lengths. Subsequently, GO-dispersed MWCNT hybrid films are formed on fiber surfaces by the dip-coating method. Herein, the hydroxylated MWCNTs can function as supporting structures to avoid the formation of layer-by-layer stacked GO, and this destacking humidity-sensitive film is beneficial to enhance water molecules' absorptive capacity. To clarify the principle, the interaction between composite humidity-sensitive film and water molecules is investigated. The experimental results reveal that the interference fringe shows a redshift with the increase in RH. When RH changing from 40% to 90%, the sensor probe with long-range MWCNT-based film has higher sensitivity than that with short-range MWCNT-based film, which demonstrates the effect of the supporting action of MWCNTs. Besides, a larger specific surface area and pore size of long-range GO-MWCNTs benefit sensitivity enhancement. In addition, this proposed sensor has good repeatability, stability, and a large linear measurement range (40% RH-90% RH).

Mass-produced metallic multiwalled carbon nanotube hybrids exhibiting high N-type thermoelectric performances

Finding a stable n-type flexible thermoelectric (TE) material with a high power factor and mass production is a challenge for wearable TE devices.

Synergistic Effect of MWCNT and Carbon Fiber Hybrid Fillers on Electrical and Mechanical Properties of Alkali-Activated Slag Composites

Herein, we investigated the synergistic effect of multi-walled carbon nanotube (MWCNT) and carbon fiber (CF) hybrid fillers on electrical and mechanical characteristics of alkali-activated slag (AAS) composites. Many studies on AAS composites have been conducted in the past; however, not much progress has been made regarding characteristics of AAS composites with hybrid conductive fillers. The specimens with different mix proportions were fabricated in the present study, and numerous material characteristics, including flowability, electrical resistivity, and compressive strength of AAS composites were measured. In addition, the synergistic effects were investigated through scanning electron microscopy and thermogravimetric analysis. It was found that the 0.5 wt.% of MWCNTs and CFs lead the effects of the bridging and reducing crack propagation, thereby improving its electrical and mechanical performances. The filler exceeding a percolation point improved the electrical performance of the AAS composites; however, it interfered with the hydration process during the curing period, and caused a decrease in compressive strength of AAS composites.

Wear Behavior of Chemically Bonded Ceramic Coatings Reinforced by MWCNTs–ZnO Hybrid Material

Zinc oxide (ZnO) decorated multi-walled carbon nanotubes (MWCNTs) hybrid material was prepared to improve the tribological performance of chemically bonded ceramic coatings. TEM results reveal that ZnO has been successfully fabricated on the surface of MWCNTs. The tribological performance of the ceramic coatings with MWCNTs–ZnO hybrid material was investigated using a ball-on-disc method. The results show that the friction coefficient and wear rate of the ceramic coatings decrease with the increase of MWCNTs–ZnO hybrid material. The ceramic coatings with MWCNTs-ZnO hybrid material shows a smooth worn surface with less cracks and delamination. In addition, the worn surface of the counterpart ball shows a smaller worn area and a smooth surface. The excellent wear resistance of the ceramic coatings is attributed to the good bonding strength between MWCNTs–ZnO hybrid material and ceramic matrix.

Influence of montmorillonite/carbon nanotube hybrid nanofillers on the properties of poly(lactic acid)

Multi-walled carbon nanotube (MWCNT) and montmorillonite (Mt) are used as reinforcing fillers in polymers. Achieving homogeneous distribution of the reinforcing nanoparticles without agglomerates in polymeric matrices continues to be an important topic in materials science. In this study, hybrid Mt/MWCNT nanofiller was prepared after determining the most stable composition with the help of dynamic light scattering (DLS). The hybrid Mt/MWCNT was characterized via X-ray diffraction (XRD) and Fourier-transform infrared (FTIR) spectroscopy. The Mt/MWCNT hybrid fillers were incorporated in poly(lactic acid) (PLA) at concentrations of 0.5, 1 and 2 wt%, by a two-step procedure of solution and melt mixing, and their physicochemical, thermal, mechanical and morphological properties were evaluated. The physicochemical studies suggested strong hybrid-polymer interaction. The structural analyzes confirmed synergy between nanoclay and carbon nanotubes in achieving homogeneous dispersion of Mt/MWCNT nanoparticles in the PLA matrix. The thermal characterizations depicted that the Mt./MWCNT hybrid nanofillers synergistically restricted the PLA segment motions and promoted the crystallization of the polymer matrix. The mechanical properties of PLA/Mt/MWCNT nanocomposites were improved, confirming the reinforcing effect of the Mt/MWCNT hybrid on PLA matrix.

Synergistic effect of carbon nanotubes and nano-hydroxyapatite on mechanical properties of polyetheretherketone based hybrid nanocomposites

Hybrid nanocomposites utilize the benefits of properties of different fillers to enhance its desired properties. Polyetheretherketone (PEEK) based hybrid nanocomposites have immense potential applications in aerospace, automobile, high-temperature electrical applications, and medical and health care. The present work is an attempt to improve the elastic modulus, hardness, fracture resistance, and storage modulus simultaneously by reinforcing the PEEK matrix with multiwall carbon nanotubes (MWCNTs) filler and 30 wt.% nano hydroxyapatite (nHA)-MWCNT hybrid filler. The nanocomposites having 0,1,3,5 and 7 wt.% of MWCNTs were fabricated by the Ball Mixing and Compression Molding Method. Customized Die Heater setup was used to ensure uniform heating and cooling during compression molding. The morphology was examined by Field Emission Scanning Electron Microscopy (FESEM) and Energy-Dispersive X-ray Spectroscopy (EDS) and uniform distribution of nano-fillers was observed. The nanoindentation method was adopted to investigate the Static Mechanical Analysis (SMA) and Dynamic Mechanical Analysis (DMA) at varying frequencies of loading, of nanocomposites. At 5 wt.% of MWCNTs, the enhancements in elastic modulus, hardness, fracture resistance, and storage modulus were observed to be 80%, 36%, 32%, and 58% respectively in case of PEEK/(0–7%)MWCNT nanocomposite and 104%, 76%, 16%, and 80% respectively in case of PEEK/30%nHA-(0–7%)MWCNT hybrid nanocomposite. The decrements in loss factor indicated the improvement in elastic behavior of nanocomposites with increasing wt.% of MWCNTs. The elastic modulus of PEEK/30%nHA-5%MWCNT hybrid nanocomposite was observed to be 7.67 GPa, which falls within the range of elastic modulus of the human cortical bone. The results revealed that 5 wt.% of MWCNTs is optimum filler composition for improving the mechanical properties.

Effect of carbon nanotubes reinforcement on mechanical properties of aramid/epoxy hybrid composites

Abstract Present investigation focuses on the inquiry of effect of incorporation of multi walled carbon nanotubes (MWCNTs) into plain weave aramid fabric reinforced epoxy (AE) composites on its physical and mechanical properties. The MWCNTs were dispersed into the epoxy system at 0.15%, 0.3% and 0.5% by weight. For homogeneous dispersion and better interfacial adhesion, the filler was subjected to ultra-sonication in the epoxy medium. Uniform impregnation of resin mixture into fiber mat and improved fabrication was ensured by subjecting the stacked laminate with uniform pressure of 1 MPa. The laminate coupons according to ASTM standards were subjected to mechanical tests like hardness, tensile, flexural, and impact. Modification of epoxy matrix with MWCNTs could increase the interfacial adhesion between aramid fiber and epoxy matrix. Obtained results indicated that the addition of 0.3 wt% MWCNTs into the AE composite considerably improved the mechanical properties. Finally, it was concluded that MWCNTs hybrid AE composites will provide alternative constructional materials respect to conventional materials.

Mechanical, thermal and morphological properties of thermoplastic polyurethane composite reinforced by multi-walled carbon nanotube and titanium dioxide hybrid fillers

A suitable material for wind turbine blades has promoted great interest in carbon-based thermoplastic polyurethane (TPU) composites as they are flexible, lightweight, and mechanically robust. However, these carbon-based fillers deteriorate the thermal and mechanical properties in the long run due to the high agglomeration of the nanoparticles. In addition to that, these fillers also increase the production cost because of the chemical treatment conducted on the fillers. Therefore, a new approach is essential for maintaining the mechanical and thermal properties without using expensive chemical treatment in a low-cost platform. In this work, we present low agglomeration with even distribution of reinforcing fillers in the TPU matrix and robust mechanical and thermal properties by incorporating TiO2 in the carbon-based TPU matrix (TiO2/MWCNT/TPU), without inclusion of costly chemical treatments. TiO2 improves morphology due to the low valency of Ti2+, which may decrease the particle size and thus, reduces agglomeration. Moreover, the enhanced morphology assists in sustaining the rigidity of its molecular structure at high temperatures. The composite also reveals excellent mechanical properties of high tensile stress (4.46 MPa), more extended elongation at break (49%), and high Young's Modulus (9.17 MPa). The thermal analysis using DMA and TGA revealed that the sample TiO2/MWCNT/TPU is a good heat insulator and has a high glass transition temperature compared to the neat TPU indicating its ability to sustain rigidity at high temperatures overall, this composite can perform in elevated weather conditions.

Exploring mechanical performance of hybrid MWCNT and GNMP reinforced cementitious composites

Nano-engineered cement composites using a hybrid of multiwalled carbon nanotubes (MWCNTs) and graphite nano-micro particles (GNMPs) integrates the superior mechanical performance of MWCNTs and the better dispersibility and shielding capability of GNMPs. Combinations of MWCNTs and GNMPs at total of 0.08% over cement weight were ultrasonically dispersed in aqueous solution to make the cement mortar. The results show that incorporation of graphite platelets can synergistically improve the dispersion and compatibility of MWCNTs with surrounding cementitious matrix. Furthermore, the incorporation of 2-dimenstional GNMPs provided better resistance against water absorption and external sulphate attack. We assert that by limiting the hybridization of MWCNTs and GNMPs to a ratio of 1:0.125 (C1G0.125), a cementitious composite with enhanced mechanical performance can be developed. Young’s modulus, flexural strength and flexural toughness was improved by 87%, 61%, and 51% respectively. Furthermore, the findings of this study provide the new insights on the design of hybrid nano reinforced cement composites with improved mechanical properties for various applications.

Photocatalytic performance improvement by utilizing GO_MWCNTs hybrid solution on sand/ZnO/TiO2-based photocatalysts to degrade methylene blue dye.

In this work, sand/zinc oxide (ZnO)/titanium dioxide (TiO2)-based photocatalysts were hybridized with graphene oxide (GO) and GO_multi-walled carbon nanotubes (MWCNTs) hybrid solution. The novel hybrid was then used in photocatalysis to degrade dye contamination. The nanocomposite photocatalyst was initially fabricated by growing ZnO nanorods (NRs) via sol-gel immersion followed by synthesizing TiO2 NRs for different times (5 and 20 h) using a hydrothermal method on sand as a substrate. Prior to the hybridization, the initial GO was synthesized using electrochemical exfoliation and further mixed with 1 wt% MWCNTs to form GO_MWCNTs hybrid solution. The synthesized GO and GO_MWCNTs hybrid solution were then incorporated onto sand/ZnO/TiO2 nanocomposite-based photocatalysts through immersion. Various sand/ZnO/TiO2-based photocatalysts were then tested for methylene blue (MB) dye degradation within 3 days. On the basis of UV-Vis measurement, the highest MB degradation was achieved by using sand/ZnO NRs/TiO2 NRs (5 h)/GO_MWCNTs (92.60%). The high surface area and high electrical conductivity of GO_MWCNTs prolonged the lifetime of electron/hole separation and thus enhanced the photocatalytic performance.

Rapid synthesis of a hybrid of rGO/AuNPs/MWCNTs for sensitive sensing of 4-aminophenol and acetaminophen simultaneously.

In this work, a hybrid of multiwalled carbon nanotubes, nanogold, and reduced graphene (rGO/AuNPs/MWCNTs) was synthesized rapidly with an easy method, and then combined with chitosan (CS), which was fixed on a glassy carbon electrode (GCE) to construct a new kind of electrochemical sensor to simultaneously determine 4-aminophenol (4-AP) and acetaminophen (AC). When detecting 4-AP and AC simultaneously, the linear range is 0.12~12μM for acetaminophen and 0.05~25μM for 4-aminophenol; the detection limit is 42nM for acetaminophen and 2.95nM for 4-aminophenol. Compared with previously related reports, the proposed sensor has an excellent electrocatalytic performance for the redox of 4-AP and AC, which can effectively determine 4-AP and AC simultaneously in actual samples and has potential application prospect. Graphical abstract.

Electromagnetic Shielding Effectiveness and Conductivity of PTFE/Ag/MWCNT Conductive Fabrics Using the Screen Printing Method

The management of the electromagnetic interference (EMI) of thin, light, and inexpensive materials is important for consumer electronics and human health. This paper describes the development of conductive films that contain a silver (Ag) flake powder and multiwall carbon nanotube (MWCNT) hybrid grid on a polytetrafluoroethylene (PTFE) film for applications that require electromagnetic shielding (EMS) and a conductive film. The Ag and MWCNT hybrid grid was constructed with a wire diameter and spacing of 0.5 mm. The results indicated that the proposed conductive films with 0.4 wt% MWCNTs had higher electromagnetic shielding effectiveness (EMSE) and electrical conductivity than those with other MWCNT loading amounts. The results also showed that the film with 0.4 wt% MWCNT loading had a high 62.4 dB EMSE in the 1800 MHz frequency and 1.81 × 104 S/cm electrical conductivity. This combination improved stretchability, with 10% elongation at a 29% resistivity change rate. Conductive films with Ag/MWCNT electronic printing or lamination technologies could be used for EMI shielding and electrically conductive applications.