Carbon Nanotube Nanocomposites Research Articles

Enhancement of dielectric and electro-optical characteristics of liquid crystalline material 4'-octyl-4-cyano-biphenyl with dispersed functionalized and nonfunctionalized multiwalled carbon nanotubes.

For recent applications, liquid crystal-carbon nanotube based nanocomposite systems have been proven to be highly attractive. In this paper, we give a thorough analysis of a nanocomposite system made of both functionalized and nonfunctionalized multiwalled carbon nanotubes that are disseminated in a 4'-octyl-4-cyano-biphenyl liquid crystal medium. Thermodynamic study reveals a decrease in the nanocomposites' transition temperatures. In contrast to nonfunctionalized multiwalled carbon nanotube dispersed systems, the enthalpy of functionalized multiwalled carbon nanotube dispersed systems has increased. In comparison to the pure sample, the dispersed nanocomposites have a smaller optical band gap. A rise in the longitudinal component of permittivity and, consequently, the dielectric anisotropy of the dispersed nanocomposites has been observed by dielectric studies. When compared to the pure sample, the conductivity of both dispersed nanocomposite materials has increased by two orders of magnitude. For the system with dispersed functionalized multiwalled carbon nanotubes, the threshold voltage, splay elastic constant, and rotational viscosity all decreased. For the dispersed nanocomposite of nonfunctionalized multiwalled carbon nanotubes, the value of the threshold voltage is somewhat decreased but the rotational viscosity and splay elastic constant both are enhanced. These findings show the applicability of the liquid crystal nanocomposites for display and electro-optical systems with appropriate tuning of the parameters.

Nanoantibiotic effect of carbon-based nanocomposites: epicentric on graphene, carbon nanotubes and fullerene composites: a review.

Carbon in many different forms especially, Graphene, Carbon nanotubes (CNTs), and Fullerene is emerging as an important material in the areas of the biomedical field for various applications. This review comprehensively describes the nano antibiotic effect of carbon-based nanocomposites: epicenter on graphene, carbon nanotubes, and fullerene Composites. It summarises the studies conducted to evaluate their antimicrobial applications as they can disrupt the cell membrane of bacteria resulting in cell death. The initial section gives a glimpse of both "Gram"-positive and negative bacteria, which have been affected by Graphene, CNTs, and Fullerene-based nanocomposites. These bacteria include Staphylococcus Aureus, Bacillus Thuringiensis, Enterococcus faecalis, Enterococcus faecium, Bacillus subtilis, Escherichia coli, Klebseilla pneumoniae, Pseudomonas aeroginosa, Pseudomonas syringae , Shigella flexneri,Candida Albicans, Mucor. Another section is dedicated to the insight of Graphene, and its types such as Graphene Oxide (GO), Reduced graphene oxide (rGO), Graphene Nanoplatelets (GNPs), Graphene Nanoribbons (GNRs), and Graphene Quantum Dots (GQDs). Insight into CNT, including both the types SWCNT and MWCNT, studied, followed by understanding fullerene is also reported. Another section is dedicated to the antibacterial mechanism of Graphene, CNT, and Fullerene-based nanocomposites. Further, an additional section is dedicated to a comprehensive review of the antibacterial characteristics of Graphene, CNT, and nanocomposites based on fullerene. Future perspectives and recommendations have also been highlighted in the last section.

PPy/SWCNTs-Modified Microelectrode Array for Learning and Memory Model Construction through Electrical Stimulation and Detection of In Vitro Hippocampal Neuronal Network.

The learning and memory functions of the brain remain unclear, which are in urgent need for the detection of both a single cell signal with high spatiotemporal resolution and network activities with high throughput. Here, an in vitro microelectrode array (MEA) was fabricated and further modified with polypyrrole/carboxylated single-walled carbon nanotubes (PPy/SWCNTs) nanocomposites as the interface between biological and electronic systems. The deposition of the nanocomposites significantly improved the performance of microelectrodes including low impedance (60.3 ± 28.8 k Ω), small phase delay (-32.8 ± 4.4°), and good biocompatibility. Then the modified MEA was used to apply learning training and test on hippocampal neuronal network cultured for 21 days through electrical stimulation, and multichannel electrophysiological signals were recorded simultaneously. During the process of learning training, the stimulus/response ratio of the hippocampal learning population gradually increased and the response time gradually decreased. After training, the mean spikes in burst, number of bursts, and mean burst duration increased by 53%, 191%, and 52%, respectively, and the correlation of neurons in the network was significantly enhanced from 0.45 ± 0.002 to 0.78 ± 0.002. In addition, the neuronal network basically retained these characteristics for at least 5 h. These results indicated that we have successfully constructed a learning and memory model of hippocampal neurons on the in vitro MEA, contributing to understanding learning and memory based on synaptic plasticity. The proposed PPy/SWCNTs-modified in vitro MEA will provide a promising platform for the exploration of learning and memory mechanism and their applications in vitro.

Corrosion, mechanical and microstructural properties of aluminum 7075—carbon nanotube nanocomposites for robots in corrosive environments

Corrosion, mechanical and microstructural properties of aluminum 7075—carbon nanotube nanocomposites for robots in corrosive environments

Nanocomposite of copper oxide nanoparticles and multi-walled carbon nanotubes as a solid contact of a copper-sensitive ion-selective electrode: intermediate layer or membrane component–comparative studies

In this paper, ion-selective electrodes sensitive to copper(II) ions are presented, in which new composite, synthesized from copper(II) oxide nanoparticles (CuONPs) and multi-walled carbon nanotubes (MWCNTs), was used as a solid contact. For comparison, electrodes obtained using separate components of the nanocomposite, i.e., CuONPs and MWCNTs, as well as unmodified electrodes, were also studied. The tested nanomaterials have been applied in two ways: as an intermediate layer placed between the ion-sensitive membrane and the internal electrode, and as an additional component of the ion-selective membrane mixture. To investigate the influence of the electrode’s structure modification, the selected analytical parameters obtained by potentiometric measurements (slope, linearity range, detection limit, potential stability, and reversibility) and electrochemical impedance spectroscopy measurements (membrane resistance and charge transfer resistance as well as double layer capacitance) were determined and compared. It was found that the use of all nanomaterials improves the properties of the electrodes, with the effect being the strongest for electrodes modified with the CuO-MWCNTs nanocomposite. The nanocomposite-based electrodes, both those with an intermediate layer and those with a nanocomposite-modified membrane, showed a Nernstian slope of the characteristic, a wider working range and a lower detection limit compared to unmodified electrodes. Moreover, application of all nanomaterials, especially nanocomposite resulted in improvement of both, stability and reversibility of the sensor potential. Modification of the electrodes did not make them sensitive to changing external measurement conditions (lighting, presence of gasses, redox potential). The electrode with the best parameters (based on nanocomposite) was successfully used to determine the Cu2+ ions content in tap water and mineral water, obtaining satisfactory results.

Novel electrochemical sensing platform basing on di-functional stimuli-responsive imprinted polymers for simultaneous extraction and determination of metronidazole

A novel magnetic-controlled electrochemical sensor has been fabricated by combined photo-responsive surface molecular imprinted polymers (P-SMIPs) and electrochemical sensor. In particular, the P-SMIPs were obtained by living radical polymerization of photo-responsive functional monomer onto the magnetic Fe3O4 modified multi-walled carbon nanotubes nanocomposites. The magnetic glassy carbon electrode was introduced to make the anchoring and removal of P-SMIPs onto the magnetic-controlled glassy carbon electrode easy to manipulate. Driven by UV/vis light, the platform performs releasing and absorption of metronidazole basing on conformational variations of the photo-responsive monomer at the receptor sites part in the P-SMIPs. This process can be tested by the photo-responsive variations of metronidazole electrochemical signal. As the consequence, extracting of P-SMIPs sensor can be conveniently triggered by the controllable UV light intervention measure, leading to effectively improve in both analytes mass transfer rate to the receiving media and extraction efficiency. The experimental result indicated that the excellent recoveries of metronidazole were varied between 77.9% and 89.9% with RSDs ≤4.87% in the biological samples. Therefore, the P-SMIPs sensor shows satisfactory potential in reusable extractions that can be recycled several times with no significant loss of activity, and this utilization strategy can be extended to other analytes, achieving manifold applications of pharmaceutical and environmental.

Microstructural Characterization of Al/CNTs Nanocomposites after Cold Rolling.

The deformation behaviour of aluminium reinforced by carbon nanotubes (Al/CNTs) nanocomposites during cold rolling was investigated in this work. Deformation processes after production by conventional powder metallurgy routes may be an efficient approach to improve the microstructure and mechanical properties by decreasing the porosity. Metal matrix nanocomposites have enormous potential to produce advanced components, mainly in the mobility industry, with powder metallurgy being one of the most reported production processes. For this reason, it is increasingly important to study the deformation behaviour of nanocomposites. In this context, nanocomposites were produced via powder metallurgy. Advanced characterization techniques carried out the microstructural characterization of the as-received powders and produced nanocomposites. The microstructural characterization of the as-received powders and produced nanocomposites was carried out through optical microscopy (OM), and scanning and transmission electron microscopy (SEM and TEM), complemented by electron backscattered diffraction (EBSD). The powder metallurgy route followed by cold rolling is reliable for Al/CNTs nanocomposites. The microstructural characterization shows that the nanocomposites exhibit a different crystallographic orientation than the Al matrix. CNTs in the matrix influence grain rotation during sintering and deformation. Mechanical characterization revealed that during deformation, there is an initial decrease in the hardness and tensile strength for the Al/CNTs and Al matrix. The initial decrease was attributed to the Bauschinger effect being more significant for the nanocomposites. The difference in the mechanical properties of the nanocomposites and Al matrix was attributed to distinct texture evolution during cold rolling.

Regulating surfactant strategy to synthesize Co@NCNT nanocomposites with conductive networks towards excellent electromagnetic wave absorption

In this paper, Prussian blue analogues (PBAs) with different morphologies have been synthesized in a co-precipitation process with Na3C6H5O7·2H2O and polyvinyl pyrrolidone (PVP) as surfactant, and then the electromagnetic wave absorption (EMWA) properties of their derivatives obtained via a pyrolysis reaction were investigated. To explore the best suitable pyrolysis temperature, PBA precursor synthesized via the addition of Na3C6H5O7·2H2O was annealed at four different temperatures (550/650/750/850 °C) to obtain the cobalt encapsulated in nitrogen-doped carbon nanotube (Co@NCNT) nanocomposites. Our results show that when the pyrolysis temperature is 650 °C, the Co@NCNT shows a minimum reflection loss (RLmin) of - 43.95 dB at the thickness of 2.05 mm, and the effective absorption bandwidth reaches 5.695 GHz, spanning the X and Ku bands. The excellent EMWA property is ascribed to the synergistic effect of dielectric and magnetic loss.

Silver Nanoparticle/Carbon Nanotube Hybrid Nanocomposites: One-Step Green Synthesis, Properties, and Applications.

Hybrid nanocomposites of silver nanoparticles and multiwalled carbon nanotubes (AgNPs/MWCNTs) were successfully synthesized by a green one-step method without using any organic solvent. The synthesis and attachment of AgNPs onto the surface of MWCNTs were performed simultaneously by chemical reduction. In addition to their synthesis, the sintering of AgNPs/MWCNTs can be carried out at room temperature. The proposed fabrication process is rapid, cost efficient, and ecofriendly compared with multistep conventional approaches. The prepared AgNPs/MWCNTs were characterized using transmission electron microscopy (TEM) and X-ray photoelectron spectroscopy (XPS). The transmittance and electrical properties of the transparent conductive films (TCF_Ag/CNT) fabricated using the prepared AgNPs/MWCNTs were characterized. The results showed that the TCF_Ag/CNT film has excellent properties, such as high flexible strength, good high transparency, and high conductivity, and could therefore be an effective substitute for conventional indium tin oxide (ITO) films with poor flexibility.

Retraction Note to: Synthesis of Carbon Nanotube and Zinc Oxide (CNT–ZnO) Nanocomposite

Retraction Note to: Synthesis of Carbon Nanotube and Zinc Oxide (CNT–ZnO) Nanocomposite

Unusual nonlinear switching in branched carbon nanotube nanocomposites

In this experimental study, we investigate the nonlinear dynamic response of nanocomposite beams composed of polybutylene terephthalate (PBT) and branched carbon nanotubes (bCNTs). By varying the weight fraction of bCNTs, we obtain frequency response curves for cantilever specimens under harmonic base excitations, measuring the tip displacement via 3D scanning laser vibrometry. Our findings reveal a surprising nonlinear softening trend in the steady-state response of the cantilevers, which gets switched into hardening for higher bCNT weight fractions and increasing oscillation amplitudes. The interaction of bCNTs with the thermoplastic hosting matrix results in stick-slip hysteresis, causing a softening nonlinearity that counteracts the geometric hardening associated with the nonlinear curvature of the first mode of the cantilever. However, when the weight fraction of bCNTs is greater than 1%, the bridging of the branched CNTs leads to the formation of a strong network that contributes to the hardening response at higher oscillation amplitudes. This mechanical behavior is detected by the trend of the nonlinear harmonic spectra and the equivalent damping ratio estimated using the half-power bandwidth method. To predict the observed unusual experimental behavior, we use a nonlinear mathematical model of the nanocomposite cantilever samples derived from a 3D mesoscale hysteretic model of the PBT/bCNT material. Our results suggest that the presence of bCNTs in a thermoplastic matrix is the main driver of the highly tunable nonlinear stiffness and damping capacity of the material. The reported experimental and modeling results provide valuable insights into the nonlinear dynamic behavior of PBT/bCNT nanocomposites and have potential applications in the design of advanced materials with tailored mechanical properties.

Optimization of PDMS -MWCNT nanocomposites for strong Ku-band absorption by integrating microwave simulations and genetic algorithm

This study combines genetic algorithm (GA) and microwave simulations to optimize the thickness of polymer nanocomposite layers for microwave absorption. The solution processed polydimethylsiloxane (PDMS)-multi wall carbon nanotube (MWCNT) nanocomposites are studied in the Ku-band (12.4–18 GHz). The most promising reflection loss (RL) characteristics (minimum RL value or RLmin, and RL ≤ -10 dB bandwidth) were found for bi-layered PDMS-MWCNT nanocomposites with MWCNT composition of 3 vol% and 1.5 vol% at an optimal thicknesses of 1 mm and 1 mm (overall thickness 2 mm), respectively. The simulated data match well with experimental data viz., the recorded RLmin value was −28.5 dB with an excellent RL ≤ −10 dB bandwidth of 4.5 GHz, indicating suitability for real time Ku-band applications. On the other hand, an appreciable RL value of −44.5 dB was found for single layer (3 vol% MWCNT) with a 2.5 GHz absorption bandwidth at a thickness of 6.4 mm. The error analysis of the simulated and experimental data was also carried out and it was found to be in the acceptable region (≤3 dB).

Effect of fabrication method on the physical properties of carbon-nanotube/silicone-rubber nanocomposite in high-voltage insulators

Effects of fog condensation and fine dust on the high-voltage insulator surface are harmful. The insulator housing material (silicone rubber) must be changed in order to allow a controlled leakage current to flow on the surface and causes Joule heating effect. Accordingly, surface temperature of the insulator is increased and fog condensation on the insulator surface is prevented. For this purpose, silicone rubber - multiwalled carbon nanotubes (MWCNT) nanocomposites (SRCNT) were prepared using two different processes: a solution-blending (SB) method and a dry-state of melt-blending (MB) method. Field Emission Scanning Electron Microscopy (FESEM) images indicated that the MWCNT dispersion in silicone rubber matrix of SRCNT samples produced by SB method is much better than that of MB method. Fourier Transform Infrared (FTIR) spectroscopy determined the possibility of a greater reduction in hydrophobicity properties in the sample prepared by the SB method compared to the sample made by the MB method, and the contact angle measurements confirmed this expectation. Furthermore, in a same MWCNT concentration, the electrical conductivity of SRCNT samples prepared by SB method are greater than those produced by MB method. Results showed that MB is a high efficient method for producing the SRCNT in a large amount.

Carbon nanotube (CNT) reinforced cementitious composites using carboxymethyl cellulose (CMC) treatment for enhanced dispersion, mechanical, and piezoresistive properties

Controlling CNT dispersion has been the key challenge for CNT nanocomposites. This study investigated the dispersion, mechanical and piezoresistive properties of CNT reinforced cementitious composites using carboxymethyl cellulose (CMC) treatment by comparing with three other existing mixing methods, including direct mixing, surface treatments using octenyl succinic anhydride (OSA) modified tapioca starch as a polymeric additive, and sodium dodecylbenzene sulfonate (NaDDBS) as a surfactant. The experimental results first indicated that the CMC treatment was categorized as a noncovalent functionalization and showed effectiveness in improving CNT dispersion, compressive strength, modulus of elasticity, Poisson ratio, and piezoresistive sensitivity of CNT reinforced cementitious composites.

Single-crystalline MoO3/functionalized multiwalled carbon nanotube nanocomposites for sensing phenothiazine in biological samples

The increasing use of pharmaceutical medications has significantly negative repercussions on the environment and human health. Here, a hydrothermal technique was employed to generate a single-crystalline molybdenum trioxide (MoO3)/functionalized multi-walled carbon nanotubes (MoO3/f-MWCNTs) nanocomposite that was then used as a novel electrode material for the electrochemical detection of phenothiazine (PTZ). The encapsulation of hydrothermal synthesized MoO3 nanorods on f-MWCNTs was achieved by the sonochemical method. Extensive characterization of the MoO3/f-MWCNTs nanocomposite is reported by means of spectroscopic and microscopic techniques. The electrode modified with the MoO3/f-MWCNTs nanocomposite displays superior electrocatalytic activity and lower oxidation overpotential (0.492 V vs.Ag/AgCl) to PTZ compared to benchmarking electrodes modified with MoO3 and f-MWCNTs, respectively. Electrodes performance is evaluated by means of differential pulse voltammetry that reveals a low detection limit (7 nM), more comprehensive linear response range (up to 226 µM), and superior sensitivity (2.04 µA µM−1 cm−2). The MoO3/f-MWCNTs nanocomposite electrode can also detect PTZ in the presence of several biological compounds and metal ions in various aqueous environments demonstrating the sensing practicality.

Bio-based polyamide nanocomposites of nanoclay, carbon nanotubes and graphene: a review

Bio-based polyamide nanocomposites of nanoclay, carbon nanotubes and graphene: a review

Simultaneous Electrochemical Analysis of Uric Acid and Xanthine in Human Saliva and Serum Samples Using a 3D Reduced Graphene Oxide Nanocomposite-Modified Electrode

Accurate and effective diagnosis and individualized management of gout can be potentially achieved by detecting uric acid (UA) and xanthine (XT) simultaneously using an easy-to-use method. Herein, we report simultaneous detection of UA and XT using a 3-dimensional (3D) macroporous gold nanoparticle-incorporated reduced graphene oxide–carbon nanotube nanocomposite (GNP/rGO-CNT). The GNP/rGO-CNT was simply prepared on a glassy carbon electrode (GCE) by one-step electrochemical deposition/co-reduction. It displayed highly sensitive and selective responses to UA and XT, showing excellent stability and good reproducibility in neutral pH. It was demonstrated that 3D GNP/rGO-CNT on GCE could detect UA and XT in human saliva and blood serum simultaneously. This GNP/rGO-CNT for simultaneous detection of UA and XT in human body fluids can be utilized for monitoring drug adherence for gout treatment, together with gout diagnosis.

Facile Synthesis of a Nickel-Based Dopamine MOF/Multiwalled Carbon Nanotubes Nanocomposite as an Efficient Electrocatalyst for the Oxygen Evolution Reaction

For manufacturing hydrogen energy via water splitting is the most important consequence for the revolution of a power disaster, and a vigorous and inexpensive electrocatalyst is the most challenging task. Herein, we report a unique MOF derived nanocomposite as an electrocatalyst (Ni-DA-MWCNTs-a) fabricated through the hydrothermal method, with ultrahigh functionality for the catalytic OER. The Ni-DA-MWCNTs-a synthesized electrocatalyst displays extremely porous morphology and is characterized by a number of different techniques. The fabricated nanocomposite demonstrates an extremely low overpotential of 267 mV, with a minimum Tafel slope of 61 mV dec–1, considering the three-electron transfer process. Furthermore, the resultant nanocomposite displays the outstanding stability of 20 h and is confirmed by chronoamperometry. Hence, this work also exposed the valuable visions for the development of an inexpensive, effective, and useful electrocatalyst with an extremely small overpotential and good long-lasting durability for OER performance by utilizing 3D-MWCNTs resulting in a major alternative material derived from noble metals.

Metallization of 3D-Printed UV Photopolymer Structures by the Incorporation of Pd-Decorated Carbon Nanotubes

Pd-decorated carbon nanotube (CNT) nanocomposites were added to a UV photopolymer resin to be used as the ink in the printing of three-dimensional (3D) structures. The nanocomposites were prepared with a UV-induced reduction method, in which Pd nanoparticles with a size ranging from 10 to 150 nm were produced and decorated on CNTs. The printed 3D structures from the resin containing 1.0 wt % Pd-decorated CNTs exhibited much improved mechanical properties, achieving a 40% enhancement in fracture strength and a 40% increase in microhardness over the 3D structures printed from the bare resin. In the presence of Pd-decorated CNTs as catalyst seeds, further deposition of defect-free, nearly conformal Ni–P layer on the 3D-printed structures at a high deposition rate can be realized. The cross-cut adhesion testing revealed a significantly enhanced adhesion between the deposited Ni–P layer and the 3D-printed structures. The metallized 3D-printed structures displayed superior electrical conductivity, showing an electrical resistance down to 0.11 Ω as 1.0 wt % Pd-decorated CNTs were incorporated. The findings from this work highlight the merits of employing Pd-decorated CNTs as both mechanical property enhancer and catalyst seeds in the advanced manufacturing of 3D-printed structures.

Structural conductive carbon nanotube nanocomposites for stretchable electronics

Carbon nanotube (CNT) nanocomposites have been widely used for electronic devices because of their high conductivity and ease of processing. However, these nanocomposites have limited functionality because of their rigid intrinsic mechanical properties. In this study, we fabricated a stretchable serpentine structure using a CNT nanocomposite with a carboxymethyl cellulose binder. For a flexible mold, a polydimethylsiloxane (PDMS) was cast by the stretchable serpentine structure fabricated by a 3D printer. The CNT nanocomposite slurry was squeegeed into the serpentine-patterned PDMS mold. Fourier-transform infra-red spectroscopy and scanning electron microscopy were used to analyze the material properties of the nanocomposites with 15–45 wt% CNTs. We analyzed the serpentine grid structure using current-voltage curves, strain resistance values, and the Joule heating effect. Next, we developed the structural CNT nanocomposite electrode (SCNE) that was insulated by PDMS, and induced a skin-warming effect by Joule heating. Furthermore, light emitting diodes (LEDs) were implanted in series into a T-shaped linear SCNE, which had greater stretchability. The nine LEDs embedded in the SCNE were successfully operated by applying 20 V during the bending of the structure. Finally, the serpentine-shaped linear SCNEs with serially-implanted LEDs were programmed to light the LEDs in unison with the beat of a song.