Multi-walled Carbon Nanotubes Hybrid Research Articles

Enhancing thermo-physical properties of hybrid nanoparticle-infused medium temperature organic phase change materials using graphene nanoplatelets and multiwall carbon nanotubes

Phase change materials (PCMs) have emerged as an intriguing option for the storage of thermal energy because of their remarkable capacity to store latent heat. However, the practical application of these materials is hindered by their low thermal conductivity and limited photo-absorbance. For this investigation, graphene nanoplatelets (GNP) and multiwall carbon nanotubes (MWCNT) hybrid nanoparticles were disseminated in RT-54HC organic PCMs at different weight fractions. The nanoparticles were incorporated into the base PCMs using a melt blending technique. Based on the findings, one combination of GNP to MWCNT in a 0.25:0.75 ratio has shown the highest thermal conductivity, with an increase of 40% (0.28 Wm−1 K−1) compared to other hybrid combinations. This breakthrough could potentially open new avenues in the field of thermal energy storage. The chemical stability of the hybrid nanoparticle dispersed composites was assessed through FTIR analysis. In addition, the composites exhibited excellent thermal stability, maintaining their structural integrity even at temperatures as high as 300 ℃. The melting temperature of the composites also showed minimal variation. Based on the evaluation of latent heat enthalpy, the organic PCM known as base RT-54HC demonstrated a heat storage capacity of 230 J/g. However, the composites exhibited a slight decrease in latent heat with increasing nanoparticle weight fraction. In addition, the composite with added hybrid nanoparticles demonstrated an increase in optical absorbance, accompanied by a decrease in transmissibility. Therefore, the hybrid nano-enhanced composites have demonstrated enhanced thermo-physical properties, making them not only suitable but also highly promising for use in applications with mid-range melting temperatures.Graphical

Electrochemical determination of 4-nitrophenol using functionalized graphene oxide/functionalized multi-walled carbon nanotubes hybrid material modified glassy carbon electrode

Herein, a novel carboxylated multi-walled carbon nanotubes-carboxylated graphene oxide coated glassy carbon electrode (f-MWCNTs/f-GO/GCE) was prepared for electrochemical determination of 4-nitropehenol (4-NP). The sensor was characterized using fourier transform infrared spectroscopy (FTIR), field emission scanning electron microscopy (FE-SEM), raman spectroscopy, and powder x-ray diffraction (XRD). Electrochmical experiments were performed using cyclic voltammetry (CV), electrochemical impedance spectroscopy (EIS), and amperometry. The resulting f-MWCNTs/f-GO/GCE could be performed for quick, sensitive, and selective determination of 4-NP in the presence of other electroactive compounds. 4-NP was electrochemically detected depending on the reduction of 4-NP at −0.65 V potential using amperometric method. Under the optimum condutions, the sensor showed excellent response to the determination of 4-NP with three linear detection ranges from 0.018 to 700 µM. The sensor exhibited extremely low limit of detection (5.4 nM). Also, the fabricated sensor was used for detection of 4-NP in different water samples.

Bi2MoO6/MWCNTs-COOH/GCE electrochemical probe for ultrasensitively and selectively detecting antibiotic norfloxacin

Antibiotics have emerged as a class of contaminants of concern globally, raising widespread worry and unease, primarily because of their inappropriately use and endless migration in food chains. Electrochemical ultrasensitive and selective determination of norfloxacin (NOR) using bismuth-based bimetallic salt bismuth molybdate (Bi2MoO6) and carboxylated multi-walled carbon nanotube (MWCNTs-COOH) hybrid electrode as sensing platforms is presented hereby. The electrocatalytic ability of the electrodes was verified to be enhanced by the synergy effect of both Bi2MoO6 and MWCNTs-COOH using cyclic voltammetry and electrochemical impedance spectroscopy. Linear scan voltammetry was applied to detect NOR. The oxidation peak current was linearly correlated with NOR concentration of 0.03–10 μM and the low limit detection of the optimized method was 6.7 nM (S/N = 3). In addition, it was verified that Bi2MoO6/MWCNTs-COOH/GCE probe had good stability, reproducibility, repeatability and selectivity. The spiked recovery method for NOR in milk and lake water samples showed recoveries of 94.8 – 96.9% and 90.2 – 98.3%, respectively, which can be used to determine NOR in real samples with high sensitivity. The preparation of Bi2MoO6/MWCNTs-COOH/GCE provides a new prototype for probing NOR detection at nanomolar concentration and safeguarding antibiotic contamination in environmental and food chains.

Nb2Fe14B/MWCNTs hybrids with Rambutan-like structure for efficient microwave absorption

To avoid the potential danger of electromagnetic waves from electronic devices, there’s an urgent demand to develop high-performance microwave absorbers. In this work, we presented Nb2Fe14B and multi-wall carbon nanotubes (MWCNTs) hybrid particles with a rambutan structure synthesized by chemical vapor deposition. Mixed the hybrid particles and paraffin with different contents, the composites could have an excellent absorption performance because of the synergistic effects of MWCNT and Nb2Fe14B. The best reflection loss (RL) of the composite with 20.wt% content and 4.5 mm thickness could reach − 47.4 dB at 4.7 GHz. The composite with 25.wt% content and 2 mm thickness also had a RL of –40.7 dB at 12.5 GHz.

PVDF Hybrid Nanocomposites with Graphene and Carbon Nanotubes and Their Thermoresistive and Joule Heating Properties.

In recent years, conductive polymer nanocomposites have gained significant attention due to their promising thermoresistive and Joule heating properties across a range of versatile applications, such as heating elements, smart materials, and thermistors. This paper presents an investigation of semi-crystalline polyvinylidene fluoride (PVDF) nanocomposites with 6 wt.% carbon-based nanofillers, namely graphene nanoplatelets (GNPs), multi-walled carbon nanotubes (MWCNTs), and a combination of GNPs and MWCNTs (hybrid). The influence of the mono- and hybrid fillers on the crystalline structure was analyzed by X-ray diffraction (XRD) and differential scanning calorimetry (DSC). It was found that the nanocomposites had increased amorphous fraction compared to the neat PVDF. Furthermore, nanocomposites enhanced the β phase of the PVDF by up to 12% mainly due to the presence of MWCNTs. The resistive properties of the nanocompositions were weakly affected by the temperature in the analyzed temperature range of 25-100 °C; nevertheless, the hybrid filler composites were proven to be more sensitive than the monofiller ones. The Joule heating effect was observed when 8 and 10 V were applied, and the compositions reached a self-regulating effect at around 100-150 s. In general, the inclusion in PVDF of nanofillers such as GNPs and MWCNTs, and especially their hybrid combinations, may be successfully used for tuning the self-regulated Joule heating properties of the nanocomposites.

Numerical treatment for radiative hybrid nanofluid flow over a stretching sheet

Artificial neural networks (ANNs) have brought a huge transformation to the machine learning regime by furnishing unparalleled abilities for modeling intricate phenomena and coping with a variety of challenges. In the oneiric field of ANNs, the essential approach for training ANNs is backpropagation. However, optimization is crucial when handling the complex fluid flow phenomenon through backpropagation. The current article implements the Levenberg Marquardt Technique with ANN backpropagation (LMT-BP-ANN) to investigate the radiative flow of a hybrid nanofluid (RHNF) addressing a Cattaneo-Christov flux system past a stretching sheet (SS). Fe2O3 with single-walled carbon nanotubes (SWCNT) and multi-walled carbon nanotubes (MWCNT) hybrid nanofluid is considered. The base fluid is ethylene glycol. Physical parameters of nanofluidic system, including the magnetic parameter M, the solid volume fractions φ1 and φ2, the velocity slip parameter λ, the relaxation time parameter Ω, the Biot number ϒ, and the thermal radiation parameter Gr are evaluated through appropriate variations that effectively accomplish the dynamics of the fluid model. These are utilized to create the dataset for LMT-BP-ANNs using the renowned deterministic Adam's numerical technique in Mathematica software. In MATLAB software, 70 % of data is kept for preparing, 15 % for checking, and 15 % for validating the neural network. The performance plot, regression graphs, and error histograms are constructed to demonstrate the suggested LMT-BP neural network scheme's high efficiency, efficacy, and exactness. When ANN performs, a mean squared error (MSE) of order 10−11 is observed. The observed R squared value is 1. As the magnetic parameter estimate grows, the fluid velocity declines, although the thermal profile shows increasing behavior. As the velocity slip parameter increases, the velocity of the fluid drops. Key findings of this study are anticipated to have a noteworthy bearing on sectors that require local refrigeration and heating by contravention.

Effects of PVA fibers and multi-walled carbon nanotubes reinforcement on uniaxial compression fatigue properties of Engineered geopolymer composites

As a new type of green and environmentally friendly cementing material, engineered geopolymer composites (EGC) have broad application prospects. In this study, uniaxial compression fatigue tests were conducted to investigate the fatigue properties of geopolymer material. A total of 137 samples were tested to investigate the effects of carbon nanotubes content, polyvinyl alcohol (PVA) fibers volume content, and maximum stress level on the fatigue life and deformation of geopolymers. The results showed that the fatigue life of geopolymers obeys Weibull distribution, and PVA fibers and multi-walled carbon nanotubes (MWCNTs) achieved multiscale enhancement of the fatigue life by up to 16.34 times. The total strain accumulation, residual strain, and fatigue stiffness of the geopolymers under fatigue loading exhibited a three-stage evolution rule, with stability within the secondary creep branch. In the process of EGC production, the innovative adoption of optimized MWCNTs surface modification and dispersion strategies improved the uniformity of MWCNTs distribution in the matrix. Scanning electron microscopy (SEM) confirmed the hybridization of MWCNTs and PVA fibers at the microscopic level, which can achieve multi-scale enhancement of geopolymers. This study successfully optimized the content of MWCNTs and PVA fibers, further expanding the application range of composite materials.

Multifunctionality of MWCNT and TiC hybrid filler silicone composite for energy harvesting and strain sensing

AbstractThe flexible silicone elastomer‐conductive composite was developed with enhanced energy harvesting and strain sensing. A hybrid nanofiller system with multi‐walled carbon nanotubes (MWCNTs) and titanium (IV) carbide (TiC) was used as reinforcing agents for the elastomer. The 4 MWCNT +5 TiC composite has 1.34 MPa tensile strength, 136.85% higher than unfilled silicone rubber (SR) matrix. The unfilled sample has a 1.558 MPa compressive modulus, while 4 MWCNT +5 TiC has 3.87 MPa. The machine and finger presses were utilized to test the energy harvesting of the composite. With greater cyclic stability, the 4 MWCNT +5 TiC sample performed exceptionally well in the machine press in the output voltage range of around 120 mV. Among the thumb presses, 2 MWCNT +5 TiC yielded the best results, with a voltage of about 100 mV. The 3 MWCNT +5 TiC sample produced 9044% more energy than the single filler 3 phr MWCNT sample from our previous work. Higher MWCNT content enhanced composite stiffness, making finger pressing harder and decreasing energy output. The strain sensing test on the 4 MWCNT +5 TiC composite showed high gauge factors (GF = 7.532 and 23.944) and good linearity (R2 = 0.909 and 0.939) over a strain range of Δε = 0%–14% and 14%–22%. Silicone composites' mechanical, energy harvesting, and strain sensing performance improved greatly with the MWCNT and TiC hybrid fillers. These composites could be used in self‐powered wearable electronics, machine or structural deformation monitoring, and human motion sensing.Highlights A stretchable device was developed with improved energy harvesting and strain sensing. Rubber composites were fabricated from MWCNTs, TiC hybrid fillers, and SR matrix. The energy harvesting was 9044% higher for hybrid filler compared to MWCNT as the only filler. Robust strain sensing properties with a gauge factor of 23.9, linearity of 0.91, and relaxation time of 0.1 s. The final composites are useful for self‐powered wearable electronics, health monitoring, and human motion sensing.

Studies on (polytrimethylene terephthalate)/graphene oxide/f-MWCNT hybrid nanocomposites

Natural resource-driven approaches to bioengineering plastics are being developed to compete in the automobiles, power, and other sectors. Polytrimethylene terephthalate (PTT) is a particular of them, and it was chosen for the current investigation to build an advanced nanocomposite material. Using a twin-screw micro compounder, injection moulded PTT/Graphene-Oxide (GO)/Carboxyl functionalized Multiwall Carbon nanotube (f-MWCNT) hybrid nanocomposites were prepared. The impact of GO and f-MWCNT reinforcement on the composite’s thermal and mechanical characteristics of hybrid nanocomposites was examined. GO was synthesized from the graphite powder by modified Hummer’s method and MWCNTs were functionalized using the concentrated sulfuric acid (H2SO4) and nitric acid (HNO3) with a volume ratio of 3:1 in an ultrasonic bath at room temperature. In all formulations, the investigation was done at a constant filler amount of 2 wt%. To understand the chemical interaction between PTT and nanofiller, Raman spectroscopy was used and to examine the state of dispersion, scanning electron microscopy (SEM) was systematically analysed. In comparison to pristine PTT, the water absorption, tensile strength, flexural strength and impact strength of hybrid nanocomposites were improved marginally. It was also observed that GO has more prominent in increasing the mechanical properties of the hybrid and f-MWCNT in thermal properties. The 3-D geometrical bridge between GO (2-D) and f-MWCNT (1-D) made the hybrid more dispersible and effective for different applications.

Synergistic Effect of CNT-TiO2 Catalyst and 3D Electrode Architecture for Electrochemical Performance in Lithium-Sulfur Batteries

Lithium-sulfur batteries (LSBs) are a potential electrochemical storage system for the future with high capacity (1675 mAh g−1) and energy density (∼2600 Wh kg−1). The poor conductivity of sulfur, polysulfide shuttle effect, and volume expansion of the sulfur cathode are the main hurdles to their commercialization. To mitigate these issues, this work represents a rational composite of hybrid multiwalled carbon nanotubes (MWCNT) -TiO2 high surface area carbon-sulfur composite (CTHS) onto a 3D carbon fiber (CF) based free-standing electrode (CTHS@CF) architecture. TiO2 can effectively anchor the polysulfides by chemical bonding and improve cyclability. MWCNTs and CFs are the effective electron transport materials that accelerate the redox kinetics of polysulfides. The electrochemistry of CTHS@CF reveals an excellent discharge capacity of 910 mAh g−1 (1st cycle) at 100 mA g−1 compared to the conventional aluminum-coated (CTHS@Al) of 532 mAh g−1. The CTHS@CF (at 300 mA g−1) displays 514 mAh g−1 (initial discharge) capacity with 83% capacity retention up to 100 cycles, whereas CTHS@Al shows 394 mAh g−1 with 44% capacity retention. Combining 3D electrode architecture with the metal oxide (TiO2) plays a vital role in the electrochemistry of LSBs by improving the stability of the battery’s cycle life and overall energy density.

Effect of nano hybrid additives on low velocity impact responses of aramid composite plates: example of CNT and ZrO2

Aramid reinforced composites are advanced materials that are widely used in many industrial applications thanks to their combination of high strength and lightness. Nano additives are of great importance for improving the mechanical properties of aramid reinforced composites and reducing costs. In this paper, multi-walled Carbon Nanotube (CNT) and Zirconia (ZrO2) nano hybrid additives were used to determine the effect on the mechanical characterization of aramid composite plates. Therefore, low velocity impact responses of aramid fiber reinforced composites were investigated by adding ZrO2 and CNT nano hybrid additives to the Polives 701 polymer vinylester resin matrix. Low velocity impact tests were carried out at 10 J and 15 J. As a result of the experiments, the effects of nano hybrid additives on the impact absorption properties of aramid composite plates were determined. By determining the maximum force, displacement and time values, the effect of CNT and ZrO2 nano hybrid additives on the impact resistance of the composite plates was analyzed. In addition, it contributed to the development of composite materials used in industrial applications by providing information on increasing the performance of composite materials by using nano additives. As a result of this study, it was determined that the strength of the composite material increased proportionally when the CNT additive was used, and the material became embrittled when the ZrO2 additive was used.

Two‐dimensional Ti3C2Tx (MXene)‐multiwalled carbon nanotubes reinforced ethyl methyl acrylate/ethylene octene copolymer binary blend hybrid nanocomposites with enhanced thermal and dielectric properties

AbstractPolymer composites with high dielectric constant and minimal dielectric losses have wide ranging prospects for advanced applications in the flexible electronics and electrical industry. In this study, we used the advantages of carbonaceous hybrid nanofillers to develop a flexible dielectric material. Herein, a set of hybrid nanocomposites were successfully fabricated by incorporating the Ti3C2Tx (MXene) and MWCNTs (multi‐walled carbon nanotubes) hybrid mixture as the conductive moiety into the poly(ethylene‐co‐methyl acrylate) (EMA)/ethylene‐octene co‐polymer (EOC) binary blend as the matrices using solution mixing technique followed by compression molding. As prepared, EMA/EOC/Ti3C2Tx/MWCNTs hybrid composites have been characterized by FTIR (Fourier transform infrared) spectroscopy, XRD (X‐ray diffraction), TGA (thermogravimetric analysis), FESEM (field emission scanning electron microscopy), and DSC (differential scanning calorimetry). We studied the effects of Ti3C2Tx and MWCNTs contents in the hybrid composites on the thermal, dielectric, and electrical properties. Among all the 15 wt% hybrid mixture containing 2 wt% MWCNTs loaded composite has the highest dielectric constant (ℇr = 122.21) and the lowest dissipation loss (tan δ = 0.030) at 100 Hz. The present studies recommend the EMA/EOC/Ti3C2Tx/MWCNTs hybrid composites can be used in smart and flexible electronic storage material.Highlights EMA‐EOC blend composites with hybrid Ti3C2Tx/MWCNTs were processed. 2.5 wt% MWCNTs loaded hybrid composite shows excellent thermal stability. Composite with 2 wt% MWCNTs has ℇ' = 122.21 and tanδ = 0.03 at 100 Hz. 2.5 wt% MWCNTs composite has electrical conductivity of 3.26 × 10−8 Ω−1 m−1. This composite can be used in smart and flexible electronic storage material.

Flexible pressure sensor with wide pressure range based on 3D microporous PDMS/MWCNTs for human motion detection

Introducing microstructure in the flexible pressure sensors is an effective strategy to enhance the performance of the sensor. Herein, we fabricated a flexible pressure sensor with three-dimensional (3D) miroporous based on a hybrid of polydimethylsiloxane (PDMS) and multiwalled carbon nanotubes (MWCNTs). The 3D microporous was produced by a facile and low-cost process using NH4HCO3 as a sacrificial template, the NH4HCO3 particles were decomposed to gas and left microporous in the hybrid of PDMS and MWCNTs. The microporous structure inside the sensor allowed for a wide pressure range (∼140 kPa). The sensor could detect large motions of finger, wrist, elbow, knee, and even small motion such as facial expression. In addition, a 3 × 3 tactile sensor array was successfully applied in the pressure distribution of fingers to grasp a cup. The results demonstrate that the sensor is promising application in wearable electronics and human-machine interfaces for pressure sensing.

Experimental investigations of particle sizes effects on exergy and entropy characteristics of AL2O3 - MWCNT hybrid nanofluid along the transitional flow regime

Experimental investigation on particle size effect on entropy and exergy characteristics of AL2O3 - MWCNT hybrid nanofluid in transitional flow Regime was carried out with four different particle sizes (i.e., for Aluminum oxide (AL2O3), 20 nm, and 5 nm used while Multiwalled Carbon Nanotubes (MWCNT) <7 nm and 30–50 nm particles). 0.3 vol concentrations of three hybrid nanofluids with different particle size combinations (i.e., Al2O3(20 nm) – MWCNT(20–30 nm), Al2O3(20 nm) – MWCNT(<7 nm), and then Al2O3(5 nm) – MWCNT(<7 nm)) are prepared using a two-step method, at a percentage weight composition (PWC) of 60:40. Results shows that Nanofluid with Al2O3 (20 nm) and MWCNT (<7 nm) have shown the best performance. It has an exergy efficiency of 54.12% at turbulent Reynold number of 4500, while in the transitional flow regime, it records an exergy efficiency of 47.85%. Frictional entropy and thermal entropy in the transitional regime were reduced with hybrid nanofluid of Al2O3 (20 nm) and MWCNT (<7 nm) by 6.78% and 13.53%, respectively, as compared to Al2O3 (5)- MWCNT (<7) nanofluid. Both thermal and frictional entropy effects were better minimized in the turbulent regime than in the lamina and transitional regime, as they were reduced by 16.66 and 24.7%, respectively. The study also recommends that for further investigations, more samples need to be taken to reach a clearer conclusion the effect of particle size, and since this is a hybrid nanofluid the samples should be of different sizes from both nanoparticles.

Flexo and screen printing of graphene/ multiwall carbon nanotube hybrid

In this work, we present the development of conductive graphene waterbased inks suitable for printing of several themes on different kinds of papers based on flexography and screen printing techniques. The inks were prepared by a hydrophilic graphene/carbon nanotube hybrid and suitable mixtures of resins. The as-prepared conductive inks were stable, highly conductive and their printing quality was comparable with that of conventional commercial inks. Especially, for flexography, the relationship between printing quality and the ink-carrying volume of the cells of the anilox roll and the pre-inking was investigated.

Mechanism of heat transfer in Falkner–Skan flow of buoyancy-driven dissipative hybrid nanofluid over a vertical permeable wedge with varying wall temperature

Heat transport issues of wedge-shaped flow on hybrid nanofluids are of special significance by reason of their importance in manufacturing uses including heat exchangers solar panels, electronic equipment cooling, drying processes, and air heaters. Consequently, the current investigation investigates the behavior of dissipative Single-walled Carbone nanotubes (SWCNT) — Multi-walled Carbon nanotubes (MWCNT) hybrid nanofluid in the buoyant flow towards a radiative vertical permeable wedge subjected to variable wall temperature considering heat source/sink. By selecting appropriate similarity conversions, the resultant flow regulating nonlinear boundary layer PDEs are subsequently transformed into coupled nonlinear ODEs. After that, the boundary layer Boussinesq approximations are numerically resolved. The significant outcome of the current investigation is the heat transport which is higher for linear radiation, volume fraction, and uniform heat source parameters. The momentum is controlled with wedge angle and volume fraction of nanotube particles. The momentum boundary layer is upsurged with mixed convection parameters for an assisting flow. Changes to the Nusselt number and fluid flow rate are measured for flow-controlling parameters. Furthermore, the results are compared and effectively validated with previously reported literature results.

Mixed phase nanoarchitectonics of NiS@SnS@Ni3Sn2S2 as a tetrafunctional catalyst for dye-sensitized solar cells, supercapacitors, and water splitting applications

The development of low-cost, high-efficiency multifunctional electrocatalysts is an ongoing concern, and it is critical for future energy-related devices. Mixed-phase NiS@SnS@Ni3Sn2S2 nanostructures are synthesized by facile microwave approach and are used as an electrocatalyst for the reduction of tri-iodide to iodide (I3−/I−) in dye-sensitized solar cells (DSSCs), asymmetric supercapacitors, and overall water-splitting applications. Further, the performances have been improved by adding multi-walled carbon nanotubes (MWCNT). For assessing the crystalline structure, phase, size, shape, porosity, and composition, several analytical tools are employed. The electrochemical outcomes show that NiS@SnS@Ni3Sn2S2/MWCNT counter electrode assisted DSSC cell delivered the highest efficiency of 6.0 % and found to be an efficient electrode for supercapacitors, evidencing a large specific capacitance (766 F g−1 at 1 A g−1), an outstanding energy density of 85.2 W h kg−1 at an ultra-high-power density of 3600 W kg−1 and cycling stability (94 % after 10,000 cycles at 15 A g−1). Furthermore, the optimized NiS@SnS@Ni3Sn2S2/MWCNT catalyst demonstrates better oxygen and hydrogen evolution reaction. The combination of different phases and shapes in the catalysts can provide a synergistic effect as well as good surface active sites along with a carrier transfer path, resulting in efficient I3− reduction, higher specific capacitance and energy density, superior cycling stability, and low over-potential, thus making NiS@SnS@Ni3Sn2S2/MWCNT hybrid as an efficient tetrafunctional electrocatalyst for energy gadgets.

Highly fire safe and flexible nanoarchitectures with tunable interface towards excellent electromagnetic interference shielding

To meet the demand for practical applications, it is imperative to develop flexible electromagnetic interference (EMI) shielding materials with fire safety. In this work, highly fire safe and flexible thermoplastic polyurethane (TPU)-based EMI shielding nanocomposites were prepared via melt blending polyphenyl phosphate ester amide (PPPEA) with MXene/carboxylic multiwalled carbon nanotubes hybrid (MC), air-assisted thermocompression and layer-by-layer stacking. Combining PPPEA with MC led to peak of heat release rate, total heat release and total smoke release of TPU nanocomposite containing 5.0 wt% PPPEA and 2.0 wt% MC decreased by 39.0%, 24.5% and 23.8%, respectively. Furthermore, the hierarchical TPU/5PA/2.0MC/carbon fiber cloth (CF) nanocomposite showed a prominent averaged EMI shielding effectiveness (SE) of 35.5 dB and a high normal SE value of 29.6 dB/mm, which were superior to most previously reported results. Catalytic carbonization of PPPEA and multiply reflected and scattered effect of MC together with continuous conductive network of CF were responsible for the improvement of these performances.

Co-electrodeposited poly (3, 4-ethylenedioxythiophene) (PEDOT)-multiwall carbon nanotubes (MWCNT) hybrid electrodes based solid-state supercapacitors using ionic liquid gel electrolyte for energy storage with pulsed power capabilities

Electrochemical and energy storage properties of poly(styrene sulfonate) doped poly (3, 4-ethylenedioxythiophene) (PEDOT:PSS) conducting polymer hybridized with the multiwall carbon nanotubes (MWCNT) are studied as solid-state supercapacitor with anion-doped ionic liquid (IL) gel electrolyte. The PEDOT: PSS-MWCNT composite electrodes were formed by co-electrodeposition using sequential 4 mA cm−2 current density with 10 ms current pulses in an aqueous medium with highly dispersed MWCNTs using Na-dodecyl sulfate (SDS) surfactant, PSS dopant (10–20 %) and EDOT monomer. Raman spectral study confirms with ≤10%PSS, the MWCNTs are moored into PEDOT chains via covalent bonding with carbons at α and β-position as PEDOT grows over flexible graphite substrate. Specific capacitance of 138 F g−1 discerned from cyclic voltammetry in IL-gel electrolyte is higher than reported in liquid electrolytes and chemically polymerized electrodes. Electrical double layer (EDL) capacitance analysis shows high 71.2 mF cm−2 contribution originated from MWCNTs with 10 % PSS, and slightly lower 48.8 mF cm−2 with 20 % PSS. The performance optimized PEDOT: PSS (10 %)- MWCNT (1 mg) based supercapacitors show large (43 %) access to the electroactive nanoporous surface regions contributing to capacitive charge and 57 % electrode has access to charge storage via diffusion limited Faradaic process. Nyquist plots analyzed for Warburg coefficient show minimal charge transfer resistance unimpacted by ionic diffusion. From the frequency response of the real and imaginary impedances pulsed power is assessed as 6.33 kW kg−1 at energy density 3.43 Wh kg−1. Charge-discharge behavior of optimized supercapacitor over 0.05–2.0 A g−1 current densities is triangular, highly symmetrical. Ragone plot shows high energy density of 7.7 Wh kg−1 at specific power 5.3 kW kg−1 plateauing out to 4.4 Wh kg−1 at higher specific power of 11.5 kW kg−1. Charge-discharge cycle analysis shows merely 20 % loss of specific capacitance by ∼500 cycles largely stabilizing for over 2000 cycles while the Coulomb efficiency remaining invariant at 95 %.

Polyimide/Carboxylated Multi-walled Carbon Nanotube Hybrid Aerogel Fibers for Fabric Sensors: Implications for Information Acquisition and Joule Heating in Harsh Environments

Polymeric hybrid sensors have garnered great interest in health monitoring, human–computer interaction, and soft robotics for their lightweight, flexibility, and feasible fabrication process. However, polymeric hybrid sensors suitable for harsh environments remain a considerable challenge, limiting further application. Herein, polyimide (PI)/carboxylated multi-walled carbon nanotube (c-MWCNT) hybrid aerogel fibers with a micro-porous structure were fabricated via wet-spinning and chemical thermal imidization. The fabricated PI/c-MWCNT hybrid aerogel fibers’ conductivity and the change of current in response to the bending degree were tested, in which the relative current change achieved 4.78% with a bending degree of 150°. The fibers possessed a density of 0.41 ± 0.06 g/cm3, a conductivity of 17.8 ± 2.9 μS/m, and a tensile strength of 13.0 ± 1.1 MPa. In addition, they exhibited excellent heat/cold durability, whose decomposition temperature, cold resistance, and service life were 367 °C, −196 °C, and 300 cycles, respectively. Furthermore, the fabric sensor woven with PI/c-MWCNT hybrid aerogel fibers demonstrated two sensitivity stages of stage 1 (S1) = 6.04 and stage 2 (S2) = 0.55 under various pressures. Besides, it could be heated to 62 °C at a voltage of 30 V in 90 s with a changing resistance. The above properties demonstrate that the as-prepared fabric sensor exhibited great application potential for information acquisition and joule heating in harsh environments.