SWCNT Nanocomposites Research Articles

Synergistic Photocatalysis by α-MoO3 Nanostructures and SWCNT Nanocomposites for Efficient Cross-Linking and Oxidative Degradation of Polystyrene Nanoplastics.

Nanoplastics (NPs) generated from plastic debris weathering pose a significant threat to ecosystems. The ubiquity of plastics driven by their advantageous physical properties, necessitates the development of efficient degradation and removal methods. Polystyrene (PS), a common and hazardous aquatic NP is a long-chain hydrocarbon with alternating phenyl groups. This study investigates the photooxidative degradation of PS NPs under UV light irradiation using synthesized MoO3 nanoflakes, nanobelts, and MoO3/SWCNT nanocomposites. Raman spectroscopy, X-ray diffraction, atomic force microscopy, high-resolution transmission electron microscopy, energy dispersive X-ray, Brunauer-Emmett-Teller, and UV-vis spectroscopy were employed to characterize the photocatalyst. Field emission scanning electron microscopy was used to visualize morphological changes in the spherical PS NPs upon interaction with the photocatalysts. MoO3 nanoflakes acting as a photocatalyst under UV irradiation for 24 h achieved an impressive degradation efficiency exceeding 19%. This treatment significantly reduced the average diameter of PS NPs from 220 to 178 nm. Notably, even higher degradation efficiencies were observed with MoO3 nanobelts and nanocomposites as a complete change in the spherical morphology of PS NPs is observed. Fourier transform infrared spectroscopy elucidated the chemical transformations of PS during degradation. The observed changes in PS NPs structure due to photocatalytic oxidation at different time intervals indicate a promising approach.

A novel Ga2O3-doped ZnO decorated SWCNT nanocomposite based amperometric sensor for efficient detection of dopamine in real samples

Our current research focuses on developing an efficient electrochemical Dopamine sensor for diagnosing neurological disorders related to abnormal Dopamine levels. We utilized a Ga2O3-doped ZnO decorated SWCNT (Ga2O3·ZnO@SWCNT) nanocomposite to modify a glassy carbon electrode. The structure and morphology of the Ga2O3·ZnO@SWCNT nanocomposite was examined utilizing a variety of approaches to ensure of their appropriateness as the sensing nanomaterial. The sensor effectively detects Dopamine within a wide range (1.0–2056 μM) in neutral phosphate buffer solution, exhibiting high sensitivity (0.2536 μAμM−1cm−2) and a practical detection limit (0.052 μM). It accurately quantifies Dopamine in human blood serum and commercial dopamine injection samples, displaying excellent reproducibility, repeatability, and stability. This proposed Dopamine sensor proves to be a reliable tool for Dopamine determination.

Piezoelectric Energy Harvesting Using Flexible Self-Poled Electroactive Nanofabrics Based on PVDF/ZnO-Decorated SWCNT Nanocomposites

Piezoelectric Energy Harvesting Using Flexible Self-Poled Electroactive Nanofabrics Based on PVDF/ZnO-Decorated SWCNT Nanocomposites

Investigation of the Effects of Multi-Wall and Single-Wall Carbon Nanotubes Concentration on the Properties of ABS Nanocomposites

The effects of two types of carbon nanotubes, namely multiwall (MWCNT) and single-wall (SWCNT) carbon nanotube, on the thermal and mechanical properties of acrylonitrile-butadiene-styrene (ABS) nanocomposites, have been investigated. ABS filled-CNT nanocomposites with various filler loadings of 5–10 wt% were properly produced by a solvent-free process in blend compounding at 190 °C. Compression moulded plates and extruded filaments were obtained at 190 °C and 230 °C, respectively. Melt flow index (MFI), shore hardness, Vicat temperature, differential scanning calorimeter (DSC) and thermogravimetric analysis (TGA) were performed to characterize and compared the different CNT nanocomposites. ABS/SWCNT composite filaments showed higher tensile properties (i.e., stiffness and strength), than ABS/MWCNT. The electrical resistivity of ABS/SWCNT and ABS/MWCNT filaments decreased to 0.19 Ω.cm and 0.65 Ω.cm for nanocomposites with 10 wt% of nanofillers; a power law was presented to describe the electrical resistivity of composites as a function of the CNTs content. A final comparative parameter regarding melt flow, stiffness and conductivity was also evaluated for understanding the combined effects of the nanofillers. SWCNT nanocomposites exhibited better overall cumulative results than MWCNT nanocomposites.

Role of interface bonding on the elastic properties of epoxy-based nanocomposites with carbon nanotubes using multiscale analysis

The interface bonding between filler and matrix governs the elastic properties of the overall polymer/nanotube nanocomposites and is generally difficult to model. In this work, a cohesive law based on the Lennard-Jones potential was established to describe the van der Waals interactions at the nanotube-polymer interface. The elastic properties of epoxy (RTM6-2)/SWCNT nanocomposites were evaluated through 3D multiscale finite element model of the representative volume element (RVE) of the nanocomposites with imperfect polymer-matrix interface and nanotube-nanotube interactions based on van der Waals force. We evaluated the effect of interface debonding on the elastic properties of the nanocomposites for different values of SWCNT loading and aspect ratio, and compared the results with the case of perfect bonding between polymer and matrix. Results show that the presence of the interface generates significantly lower elastic properties than in the case of perfect bonding due to the decohesion effect, which reduces the load transfer between matrix and filler, such as in real nanocomposite systems.

Effect of SWCNT Filler on Mechanical Properties and Electrical Conductivity of PVA/CS/GA/SWCNT Nanocomposite Thin Film

This study aims to investigate the effect of SWCNT nanofiller on mechanical properties and electrical conductivity of PVA/CS/GA nanocomposite film. Polyvinyl alcohol (PVA) and chitosan (CS) are used as polymer matrix that crosslinked by glutaraldehyde (GA). Nanofiller SWCNT was inserted in a polymer composite matrix at different composition. The thin films were characterized using FTIR (Fourier Transform Infrared Spectroscopy), XRD (X-ray diffraction), SEM (Scanning Electron Microscopy), TG/DTA (Thermal Gravimetric/Differential Thermal Analysis), sheet resistance, and tensile strength measurements. The results revealed that the addition of SWCNT notably increased the electrical conductivity of composite film from 1.2 x 10‒4 S.cm‒1 to 9 x10‒3 S cm‒1 as well as tensile strength and elongation 43 MPa to 62 MPa, 68% to 84%, respectively. The cross-sectional SEM images indicated that the conductive thin films have a layered structure where the insertion of SWCNT did not change their morphological structure significantly. Additionally, SWCNT improved the thermal stability of PVA/CS/GA nanocomposites thin film. These finding can be promising for the development of optoelectronic devices i.e. photovoltaic, emitting diodes, etc.

Fabrication of organo-modified carbon nanotube with excellent heat resistance and preparation of its polymer-based nanocomposite by simple melt compounding

Crystalline polymer/single-walled carbon nanotube (SWCNT) nanocomposites were prepared using organo-modified SWCNTs with surface modification by long-chain phosphonic acid derivatives having bidentate bonds, resulting in excellent heat resistance properties. Surface modification with a long-chain phosphonate is non-desorbing, has a high desorption suppression temperature and can improve miscibility with matrix polymers by changing the other end of the functional group in various ways. In addition, since organo-SWCNTs showed amphiphilic properties when introducing a modified chain after hydrophilization, their structure and morphology could be characterized by the method of organized molecular films. The utilization of phosphonic acid derivatives containing fluorocarbon chains endowed SWCNTs with remarkable cohesive properties in phase-separable crystalline fluoropolymers to achieve polymer-based nanocomposite formation. Fluorinated SWCNTs could be easily introduced into fluoropolymers via a simple melt-compounding method. The crystalline fluoropolymer/fluorocarbon-modified SWCNT nanocomposite showed clear improvement in crystallization temperature compared with the matrix polymer. Simultaneously with the improvement in the crystallization temperature, it was confirmed that the crystallite size was increased, the lamella was thickened, the mechanical properties were improved, and the pyrolysis temperature was increased. These enhancements of the physical properties seem to be the result of the interaction between the modified-chain end and the polymer ends, and it was predicted that heterogeneous nucleation was induced by the nucleation effect.

Synthesis and electrical properties of conductive polyaniline/ SWCNT nanocomposites

The synthesis of conducting polyaniline (PANI) nanocomposites containing various concentrations of functionalized single-walled carbon nanotubes (f-SWCNT) were synthesized by in situ polymerization of aniline monomer. The morphological and electrical properties of pure PANI and PANI/SWCNT nanocomposites were examined by using Fourier transform- infrared spectroscopy (FTIR), and Atomic Force Microscopy (AFM) respectively. The FTIR shows the aniline monomers were polymerized on the surface of SWCNTs, depending on the -* electron interaction between aniline monomers and SWCNTs. AFM analysis showed increasing in the roughness with increasing SWCNT content. The AC, DC electrical conductivities of pure PANI and PANI/SWCNT nanocomposite have been measured in frequency range (50Hz - 600KHz) and in the temperature range from (30 to 160K). The results show the electrical conductivity of the nanocomposite is higher than pure PANI.

TEM Nano-Moiré Pattern Analysis of a Copper/Single Walled Carbon Nanotube Nanocomposite Synthesized by Laser Surface Implanting

In our previous studies, we have developed a wet process to synthesize a copper-single walled carbon nanotube (Cu–SWCNT) metal nanocomposite with excellent mechanical properties. The nanostructure of this Cu–SWCNT composite was confirmed independently by energy-dispersive X-ray spectroscopy mapping, spectroscopy measurements, and Transmission Electron Microscope (TEM) images with discernable SWCNT clusters in nano sizes. However, TEM images with discernable nano-sized SWCNT clusters are rare. In this paper, we present analysis of indirect TEM image patterns, such as moiré fringes, to infer the existence of SWCNT clusters within the copper matrix. Moiré fringes or patterns in the TEM images of a Cu–SWCNT nanocomposite could be generated due to the overlapping of more than one thin crystals with similar periodic arrangements of atoms, promoted by SWCNT clusters. However, the presence of moiré patterns is not a sufficient or a necessary condition for the existence of SWCNT clusters. It was found that based on the overlapping angle of two periodic arrangements, it is feasible to distinguish the moiré fringes induced by SWCNT clusters from those by other factors, such as dislocations. The ability to identify SWCNTs within the copper matrix based on indirect TEM moiré patterns helps to widen the usability of TEM images.

ZnO:CNT assisted charge transport in PTB7:PCBM blend organic solar cell

Enhanced photocurrents were observed by employing zinc oxide doped single wall carbon nanotube (ZnO:SWCNT) in the photoactive medium of thin film organic solar cells (TFOSC). The investigations were conducted based on either poly [[4,8-bis [(2-ethyhexyl)oxy] benzo(1,2-b:4,5-b’)dithiophene-2,6-diyl][3-uoro-2-[(2 ethylhexyl)carbonyl]thieno [3,4-b]thiophenediyl]] (PTB7) blended with [6,6]-phenyl-C61-butyric acid methyl ester (PCBM),PTB7:PCBM or poly (3hexylthiophene) (P3HT): [6,6]-phenyl-C61-butyric acid methyl ester, P3HT:PCBM blend active layers containing ZnO:SWCNT nanocomposite at various concentrations. The best performances of the devices were found to be dependent on both the concentration of ZnO:CNT and the nature of the host medium. A substantial improvements in power conversion efficiencies (PCE) were observed as high as 68% and 31% for PTB7:PCBM and P3HT:PCBM blend with ZnO:CNT, respectively. Further device improvement were noted by employing co-solvent and solvent additive in the processing of TFOSC. The optical, electrical and morphological properties of photoactive films are discussed based on the experimental results along with the associated effect on device performances.

All-aromatic SWCNT-Polyetherimide nanocomposites for thermal energy harvesting applications

The thermoelectric properties of amorphous and semi-crystalline high-performance polyetherimide–SWCNT nanocomposites are reported for the first time. Nanocomposites based on a non-linear polyetherimide (PEI) model system, labeled aBPDA-P3, with 0.6, 4.4 and 10 vol% SWCNTs remained amorphous after the addition of SWCNTs. In contrast, SWCNTs induced crystallization in a linear PEI model system labeled as ODPA-P3. The (thermo)mechanical properties were fully characterized using thermogravimetric analysis (TGA), differential scanning calorimetry (DSC) and dynamic mechanical analysis (DMTA). The electrical conductivity was studied by four-probe measurements and showed higher values for the ODPA-P3 films reaching 20 S/m at 10 vol% of SWCNTs. The thermoelectric performance revealed by Seebeck coefficient (S) measurements showed values of 40 and 55 μV/K for the 0.6 and 4.4 vol% ODPA-P3 SWCNT nanocomposites, while 16 and 47 μV/K for aBPDA-P3 amorphous films. This enhancement has been attributed to SWCNT–induced crystallization in ODPA-P3 matrix. The PEI-SWCNT nanocomposites are ideal candidates as organic flexible films and coatings for large area thermal energy harvesting, where high temperature gradients exist. Potential applications can be envisaged in the aerospace, automotive and micro-electronics sectors.

Synthesis of Hedgehoglike F-TiO2(B)/CNT Nanocomposites for Sonophotocatalytic and Photocatalytic Degradation of Malachite Green (MG) under Visible Light: Kinetic Study.

The present study describes the preparation of hedgehoglike F-doped titanium dioxide bronze (F-TiO2(B)) and its nanocomposites containing single-walled and multiwalled carbon nanotubes (SWCNTs, MWCNTs) by using combined ball milling-hydrothermal processes. Then, sonophotocatalytic and photocatalytic degradation of malachite green (MG) dye from aqueous solution using prepared materials was performed. The results show that F-TiO2(B)/SWCNT displays a good sonophotocatalytic and photocatalytic performance among other products under visible light. In addition, they indicated that the efficiency of malachite green degradation is more than 95% and 91% for sonophotocatalytic and photocatalytic methods, respectively. Also, they demonstrate that the photocatalytic efficiency of catalysts increases in the presence of ultrasound and the sonophotocatalysis process followed a second-order kinetics. The catalysts have been characterized by transmission electron microscopy (TEM), field emission scanning electron microscopy (FESEM), X-ray diffraction analysis (XRD), Fourier transform infrared spectroscopy (FTIR), UV-vis diffuse reflectance spectroscopy, and energy-dispersive X-ray spectroscopy (EDX). The analyzed data confirmed the presence of CNTs and fluorine (F) as dopant in all nanocomposites. The presented hybrid method reduced the band gap from 3.02 eV for F-TiO2(B) to 2.7 eV for F-TiO2(B)/SWCNT nanocomposite.

Laser synthesis of a copper–single-walled carbon nanotube nanocomposite via molecular-level mixing and non-equilibrium solidification

A copper–single-walled carbon nanotube (Cu–SWCNT) metal nanocomposite could be an ideal material if it can substantially improve the strength of copper while preserving the metal’s excellent thermal and electrical properties. However, synthesis of such a nanocomposite is highly challenging, because copper and SWCNTs do not form intermetallic compounds and are insoluble; as a result, there are serious issues regarding wettability and fine dispersion of SWCNTs within the copper matrix. In this paper we present a novel wet process, called the laser surface implantation process (LSI), to synthesize Cu–SWCNT nanocomposites by mixing SWCNTs into molten copper. The LSI process includes drilling several microholes on a copper substrate, filling the microholes with SWCNTs suspended in solution, and melting the copper substrate to create a micro-well of molten copper. The molten copper advances radially outward to engulf the microholes with pre-deposited SWCNTs to form the Cu–SWCNT implant upon solidification. Rapid and non-equilibrium solidification is achieved due to copper’s excellent heat conductivity, so that SWCNTs are locked in position within the copper matrix without agglomerating into large clusters. This wet process is very different from the typical dry processes used in powder metallurgy. Very high hardness improvement, up to 527% over pure copper, was achieved, confirmed by micro-indentation tests, with only a 0.23% SWCNT volume fraction. The nanostructure of the nanocomposite was characterized by TEM imaging, energy-dispersive x-ray spectroscopy mapping and spectroscopy measurements. The SWCNTs were found to be finely dispersed within the copper matrix with cluster sizes in the range of nanometers, achieving the goal of molecular-level mixing.

Dosimetry characteristics of HDPE–SWCNT nanocomposite for real time application

In this experimental work, different dosimetric characteristics of high density polyethylene-single wall carbon nanotube nanocomposite were investigated. The nanocomposite samples were prepared with different nanotube contents of 0.22, 0.25, and 0.39 weight percentages which were before, exactly in, and after percolation region of the nanocomposite, respectively. The samples were exposed to 60Co gamma radiation source over the dose rate of 65–214mGy/min, while the applied bias was 100V. A linear response achieved for the sample contained 0.25 nanotube wt% verified that the percolation threshold is the optimum point for dosimetric purposes. The current–voltage characteristics curve measured for 0.25 CNT wt% nanocomposite showed that the behavior of this sample was bias polarity independent. Also, the results showed that the response of this nanocomposite was energy-independent. The maximum discrepancy of photocurrent due to angular variation within 0–90° with respect to beam incidence and the reproducibility of the response were measured as 5.4% and 0.8%, respectively. The stability study showed that this material may be suitable for protection dose level control. Therefore, this kind of nanocomposite requiring calibration can be used as a real-time dosimeter.

Interfacial control of PVDF-TrFE/SWCNT nanocomposites using P3HT-PMMA block copolymer for ultra-low percolation threshold

Poly(vinylidenefluoride-co-trifluoroethylene) (PVDF-TrFE)/SWCNT nanocomposites with ultra-low percolation threshold were prepared by interfacial control using a block copolymer comapatibilizer. For this, a well-defined block copolymer of poly(3-hexylthiophene) (P3HT) and poly(methyl methacrylate) (PMMA) (P3HT-b-PMMA) was synthesized by combination of GRIM and ATRP (Mn = 24 K, Mw/Mn = 1.25), where the P3HT block segment wrapped the SWCNTs by π–π interaction and the resulting PMMA block segment dangled from the SWCNTs, which gave de-bundled SWCNTs without any aggregations for over 5 months in most common organic solvents for PMMA. The block copolymer coated SWCNT (TMCNT) was then mixed with PVDF-TrFE to prepare PVDF-TrFE/SWCNT nanocomposites (PVT-TMCNT), which enabled excellent dispersion of SWCNT in a PVDF-TrFE matrix without aggregation due to the miscibility of the PMMA on TMCNT and PVDF-TrFE. Obtained PVT-TMCNT showed large enhancements of the electrical conductivity and the dielectric constant with ultra-low percolation threshold (fc = 0.07 wt.%) due to excellent interfacial control by the block copolymer comapatibilizer between SWCNT and PVDF-TrFE. Improved ferroelectric properties of PVT-TMCNT were also observed by an increase of field-induced polarization response, which was almost over 10-times higher than for neat PVDF-TrFE.

Polymer Chain Conformations in CNT/PS Nanocomposites from Small Angle Neutron Scattering

Chain conformations dictate many of the important physical properties of polymers including their dynamics. Using small angle neutron scattering, we probed chain conformations, specifically the radius of gyration (Rg), in both SWCNT/polystyrene (rSWCNT/Rg ∼ 0.4) and MWCNT/polystyrene (rMWCNT/Rg ∼ 1) nanocomposites. We fit the scattering data using a model that includes an ideal Gaussian chain to describe the polymer conformation and a rod network to describe the carbon nanotube (CNT) network. The scattering contribution from the rod network increases with the CNT concentration in both SWCNT and MWCNT nanocomposites, and the contribution is higher for SWCNT nanocomposites due to the smaller mesh size and higher mesh density. When the SWCNT and MWCNT concentrations are below 2 wt %, there is no significant change in Rg. Above 2 wt %, Rg in the MWCNT nanocomposites decreases slightly, while Rg in the SWCNT nanocomposites increases monotonically as a function of CNT concentration, showing a ∼30% increase at 1...

Effect of strain hardening on the elastic properties and normalized velocity of hybrid UHMWPE–nylon 6–SWCNT nanocomposites fiber

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Development of dehydrogenase-based bioanode using poly(phenosafranin)-functionalized SWCNT nanocomposites and its application to ethanol biosensor

Development of dehydrogenase-based bioanode using poly(phenosafranin)-functionalized SWCNT nanocomposites and its application to ethanol biosensor

Characterization of ferritin core on redox reactions as a nanocomposite for electron transfer

The kinetics of the change in mass related to the release from and deposition onto the cavities of a ferritin in the SWCNT nanocomposite by electrochemical redox reactions, and the effects of the SWCNT on the kinetics of the variation in mass of the ferritin nanocomposite were characterized using an electrochemical quartz crystal microbalance. The change in mass of reconstituted ferritin in the SWCNT nanocomposite shows reversible variation and stability of the ferritin/SWCNT nanocomposite on redox reactions was confirmed by using a coreless apoferritin and a Fe 2+ chelating agent. The ferritin/SWCNT nanocomposite is a good candidate for applications based on electron transfer, such as biosensor, biobatteries and electrodes for biofuel cell.

Nanocomposites of Electrospun Poly[(D,L‐lactic)‐co‐(glycolic acid)] and Plasma‐Functionalized Single‐Walled Carbon Nanotubes for Biomedical Applications

AbstractThe conductance of amine‐functionalized SWCNTs (a‐SWCNTs), obtained by inductively coupled N2/H2 plasma treatment of commercially available carboxyl‐functionalized SWCNTs (c‐SWCNTs), was decreased compared to that of the c‐SWCNTs. As a result, the diameter and surface energy of electrospun PLGA/a‐SWCNT nanocomposites decreased and increased, respectively, compared to those of electrospun PLGA/c‐SWCNT nanocomposites. The results also showed that the a‐SWCNTs were well dispersed in the nanocomposites, improved adhesion of SWCNTs to the surrounding polymer matrix and thereby enhanced the tensile modulus of electrospun PLGA/c‐SWCNT and PLGA/a‐SWCNT nanocomposites by 127 and 226%, respectively, compared to that of electrospun PLGA membranes.magnified image