Chemical Oxidative Polymerization Of Aniline Research Articles

Adsorption of hexavalent chromium from wastewater using polyaniline-coated microcrystalline cellulose nanocomposites.

In this study, the effectiveness of microcrystalline cellulose (MCC) as an adsorbent for the removal of hexavalent chromium, Cr(vi), from synthetic wastewater was enhanced through functionalization with polyaniline (PANI). Scanning electron microscopy (SEM) showed that MCC was an effective scaffold for in situ chemical oxidative polymerization of aniline. Fourier transform infrared spectroscopy (FTIR) spectroscopy and X-ray diffraction confirmed successful PANI synthesis. The MCC/PANI nanocomposites exhibited relatively high specific surface areas, compared to that of the MCC (2.05 m2 g-1). Batch adsorption studies showed that the optimal conditions for the removal of Cr(vi) from wastewater using the MCC/PANI-69 wt% nanocomposite were an initial Cr(vi) concentration of 100 mg L-1, an adsorbent dosage of 4 g L-1 and a Cr(vi) solution pH of 7. The MCC/PANI-69 wt% required only 30 min to reach equilibrium and the equilibrium removal efficiency was 95%. FTIR spectroscopy and energy dispersive X-ray spectrometry results suggest that the Cr(vi) removal mechanism by the MCC/PANI-69 wt% nanocomposite at pH 7 was through electrostatic attraction of Cr(vi) species by PANI, reduction of Cr(vi) into Cr(iii) and precipitation of Cr(iii) on the nanocomposite surface. The kinetics for the removal of the Cr(vi) by the MCC/PANI-69 wt% nanocomposite were adequately described by the pseudo second order (PSO) kinetics model, whereas the Langmuir isotherm adequately described the equilibrium data. The MCC/PANI-69 wt% nanocomposite had a significantly improved maximum adsorption capacity of 35.97 mg g-1, at pH 7, in comparison to that of the MCC (3.92 mg g-1 at pH 1). The study demonstrated that, whereas most of the reported adsorbents for Cr(vi) are only effective at low pH values, the MCC/PANI nanocomposite synthesized in this study was effective at pH 7.

Effect of carbon allotropes and thickness variation on the EMI shielding properties of PANI/NFO@CNTs and PANI/NFO@RGO ternary composite systems.

The innovative design of thin, multiphase flexible composite systems with good mechanical properties, low density and improved EMI shielding properties at low filler content has become a key area of research. In this work, we report the low temperature synthesis of three-dimensional ternary composites (PANI/NFO@CNTs and PANI/NFO@RGO) by oxidative chemical polymerization of aniline in the presence of two different binary composites, viz. NFO@CNTs and NFO@RGO. Enhanced impedance matching is achieved by varying the ratio of the carbon allotropes (CNTs and RGO) to the ferrite component. The synthesis of NFO, PANI/NFO@CNTs and PANI/NFO@RGO is validated by XRD and FTIR spectroscopy. Field emission scanning electron microscopy (FE-SEM) confirmed the synthesis of core-shell structures of PANI/NFO@CNTs and PANI/NFO@RGO, where the binary composites (NFO@CNTs and NFO@RGO) serve as a core onto which a tubular PANI layer was coated. Shielding effectiveness of 22.36 dB (99.41% attenuation) is exhibited by the ternary composite PANI/NFO@CNTs (8 : 1), while for PANI/NFO@RGO (20 : 1) a total shielding effectiveness of 31 dB equivalent to 99.92% attenuation was observed at a thickness of 2 mm. The ternary composite PANI/NFO@RGO (20 : 1) 4 mm showed a maximum SET of 43 dB corresponding to 99.996% attenuation of incident EM waves. The enhanced EMI shielding properties of the synthesized ternary composite systems are accredited to good impedance matching, effective dielectric and magnetic loss mechanisms and good conductivity, which facilitate multiple reflections and scattering of incident radiation.

PANI/Ferrous Oxide Based Hybrid Material for Ammonia Sensing Applications

AbstractIn the present study, polyaniline (PANI) and ferrous oxide (α‐Fe2O3) are amalgamated for ammonia sensing purpose. The hybrid nanocomposite is prepared by a single step in situ chemical oxidative polymerization of aniline in presence of hydrothermally prepared α‐Fe2O3 nanoparticles. The structural and compositional analyses of the hybrid material are fully executed by FTIR, PXRD, and SEM techniques. A naive, exceedingly selective, quickly restorable, and ambient temperature functioning ammonia detecting device is established by using PANI/α‐Fe2O3. The investigation results indicate that the PANI/α‐Fe2O3 hybrid nanocomposite exhibits selective sensing ability towards ammonia vapors. The PANI/α‐Fe2O3 displays excellent response for 5 ppm and maximum response for 100 ppm of ammonia. The response time of the PANI/α‐Fe2O3 sensor is found to be quick with reasonably short recovery time. Due to excellent reusability, good environmental stability, and highly economical synthesis the PANI/α‐Fe2O3 delivers a capable, simple, and efficient sensor system for ammonia detection at ambient temperature.

POLYANILINE, HALLOYSITE NANOTUBES AND THEIR NANOCOMPOSITE AS ADSORBENTS FOR ORGANIC DYES

This work is devoted to the study of the adsorption efficiency of methylene blue and methyl orange dyes by polyaniline base (PANI), halloysite nanotubes (HNTs), and their nanocomposite (HNTs/PANI). PANI and the nanocomposite were prepared by the chemical oxidative polymerization of aniline in the absence and presence of HNTs followed by subsequent dedoping by ammonia solution. The morphology and thermal stability of the adsorbents were explored. In particular, the TEM method showed that the nanocomposite consisted of practically non-agglomerated nanoparticles with a “core-shell” morphology. Particles of pure polymer are quite agglomerated and form massive aggregates. The kinetics of decreasing the concentration of dyes in solutions upon their contact with adsorbent powders was studied by the method of electron spectroscopy. The HNTs/PANI nanocomposite was found to absorb both dyes with slightly higher efficiency than the PANI base probably due to more developed surface of the former. Processing of the obtained results of adsorption of both dyes on the studied adsorbents according to different kinetic models (pseudo-first and pseudo-second order and intraparticle diffusion) showed that in all cases this process is best described by the pseudo-second order model, which indicates the chemical nature of adsorption. The calculated adsorption capacity of the adsorbents under study appeared be quite close to the experimental one. These materials can be used as effective adsorbents for cleaning wastewaters from organic dyes.

Investigation of Structural, Dielectric and Optical Properties of Polyaniline-Magnesium Ferrite Composites.

A study on the influence of magnesium ferrite nanoparticles on the optical and dielectric attributes of Polyaniline has been conducted. Magnesium nano Ferrite powder is synthesized by the self-propagating solution combustion method. Polyaniline-Magnesium nano ferrite composites are synthesized by chemical oxidative polymerization of aniline with the addition of Magnesium nanoparticles. The samples are characterized with XRD and UV-Vis spectrometer, in the wavelength range of 200-800 nm and studied for optical properties. Dielectric properties are studied in the frequency range of 50 Hz to 5 MHz. X-ray diffraction reveals single phase formation of Magnesium ferrite, whereas Polyaniline shows an amorphous nature. In the XRD of the composites, we see the crystalline peaks of ferrite becoming more intense with the addition of ferrite and whereas the peak of Polyaniline diminishes. The crystallite size is quantified with the Debye-Scherrer formula, and it increases as the content of ferrite in the composites increases. The micro-strain decreases in the composites as the percentage of ferrite enhances in the composites. In the UV-Vis absorption spectra of composites, the peaks of Polyaniline shift to higher wavelength and there is also an absorption band in the spectra of composites corresponding to that of Magnesium ferrite particles. Both direct and indirect band gaps are calculated with the Tauc plot, and both the optical band gap decrease as the percentage of ferrite increases in the composite. The dielectric loss and dielectric constant both decrease with frequency in all the samples, and the dielectric response are in good agreement with Maxwell-Wagner model. Ferrite-polymer composites with both conducting and magnetic properties are considered useful for electromagnetic shielding and microwave absorption.

Peculiar Properties of Template-Assisted Aniline Polymerization in a Buffer Solution Using Laccase and a Laccase-Mediator System as Compared with Chemical Polymerization.

The conventional chemical polymerization of aniline has been described in multiple publications, while enzymatic polymerization has been poorly explored. A comparative study of the template-assisted enzymatic and chemical polymerization of aniline in a buffer solution of sodium dodecylbenzenesulfonate micelles was performed for the first time. The high-redox potential laccase from the fungus Trametes hirsuta was used as a catalyst and air oxygen served as an oxidant. Potentiometric and spectral methods have shown that oligomeric/polymeric products of the enzymatic polymerization of aniline are synthesized in the conducting emeraldine salt form immediately after the reaction is initiated by the enzyme. The use of the laccase-mediator system enabled a higher rate of enzymatic polymerization and a higher yield of final products. Potassium octocyanomolybdate (IV) served as a redox mediator. The products of the enzymatic polymerization of aniline were studied by the ATR-FTIR, MALDI-TOF and atomic force microscopy methods. The chemical oxidative polymerization of aniline under the same conditions resulted in forming a non-conducting dark brown product.

Fast response and recovery polyaniline montmorillonite reduce graphene oxide polymer nanocomposite material for detection of hydrogen cyanide gas

In the present work, we have developed a polymer based gas sensor. The polymer nanocomposites are synthesized by the chemical oxidative polymerization of aniline with ammonium persulfate and sulfuric acid. The fabricated sensor is able to achieve a sensing response of 4.56% for PANI/MMT-rGO at 2 ppm of hydrogen cyanide (HCN) gas. The sensitivity of the sensors PANI/MMT and PANI/MMT-rGO are 0.89 ppm−1 and 1.1174 ppm−1 respectively. The increase in the sensitivity of the sensor may be due to an increase in the surface area provided by MMT and rGO which provided more binding sites for the HCN gas. The sensing response of the sensor increases as the concentration of the gas exposed increases but saturates after 10 ppm. The sensor recovers automatically. The sensor is stable and can work for 8 months.

Polyaniline/Manganese-Cobalt ferrite nanocomposite as an efficient material for crystal violet dye degradation under sunlight irradiation

In the present work, the polyaniline (PANI) and Mn0.25Co0.75Fe2O4 (MCF) nanocomposites with varying weight percentage of MCF (0, 10, 20, 50, 100) were synthesized for the degradation of the crystal violet dye under solar radiation. The PANI/MCF nanocomposites were synthesized via in-situ chemical oxidative polymerization of aniline. The XRD and FTIR spectra confirmed the formation of pure phase for all the samples. The crystallite size for MCF and PANI/MCF have been found in the range of 20–30 nm. FTIR spectra showed all the prominent peaks of MCF and PANI. PANI/MCF nanocomposite with 10 and 20 wt% of MCF showed maximum degradation efficiency. The degradation efficiency for PANI/MCF nanocomposites with 10 and 20 wt% are 77% and 89%, respectively in 75 min of reaction time. It is attributed to the formation of heterogeneous photocatalysts having lower values of optical band gap. The degradation rate constant for PANI/MCF nanocomposites with 10 and 20 wt% of MCF is maximum with values 0.5 and 0.7 min−1, respectively.

Polypyrrole-Ag/AgCl Nanocomposite-Enabled Exhaled Breath-Acetone Monitoring Non-Invasive Biosensor for Diabetes Diagnostics

The state-of-the-art diabetes diagnosis is concerned with developing non-invasive nano-enabled exhaled breath-acetone detection strategies. This communication details the potential of polypyrrole(PPy)– Silver/silver chloride (Ag/AgCl) ternary nanocomposites (NCs) for monitoring low-trace of acetone in human breath for diabetes diagnosis. The PPy–Ag/AgCl NCs were synthesized through in situ chemical oxidative polymerization of aniline by silver nitrate in the presence of hydrochloric acid. The morphological analysis revealed the existence of spherical Ag/AgCl nanoparticles (diameter ∼50 nm) embedded in PPy matrix of nano fibrillar morphology (diameter ∼20 nm). The structural investigations confirm the co-existence of PPy, Ag and AgCl nanoparticles in the ternary nanocomposite. The NC exhibited manifold superior sensing performance towards low trace (as low as ∼1 ppm) of breath-acetone with excellent sensitivity (∼20%), prompt response (∼20 s), fast recovery (∼100s), linear detecting range, and high repeatability at room temperature compared to pristine PPy. It is attributed to synergistic effects in ternary NC due to physicochemical merits of all precursors. Moreover, it showed high stability and selectivity towards acetone in the presence of prominent interfering VOCs and varying humidity. It opens a new window for non-invasive, economic, energy-efficient and point-of-care sensors for diagnosing diabetes in humans and, revolutionizing clinical diagnostics and personal healthcare.

Polyaniline Hybrids with Biological Tissue, and Biological Polymers as Physiological—Electroactive Materials

A sprout/polyaniline was synthesized via the chemical oxidative polymerization of aniline in the presence of natural sprout, based on a concept of cyborg plant composite. The composite consisted of both polyaniline and plants. The chemical structure was confirmed by infrared absorption spectroscopy measurements. Optical microscopy observation revealed that polyaniline was deposited into the micro-tissue of the sprout to form the conductive polymer bio-composite. Micro-optical fiber functions for the composite were visually confirmed. Furthermore, the sprout/polyaniline based organic diode exhibited an avalanche breakdown phenomenon. Next, a fucoidan/polyaniline composite as a physiological active material/conducting polymer composite was prepared. This composite showed good film-forming ability, electrochromism, and a micro-porous surface. This paper reports the preparation of conducting polymer composites with a combination of bio-tissue and bio-substance for the creation of bio-based electrically active organized architecture.

Black phosphorous-based human-machine communication interface

Assistive technology involving auditory feedback is generally utilized by those who are visually impaired or have speech and language difficulties. Therefore, here we concentrate on an auditory human-machine interface that uses audio as a platform for conveying information between visually or speech-disabled users and society. We develop a piezoresistive tactile sensor based on a black phosphorous and polyaniline (BP@PANI) composite by the facile chemical oxidative polymerization of aniline on cotton fabric. Taking advantage of BP’s puckered honeycomb lattice structure and superior electrical properties as well as the vast wavy fabric surface, this BP@PANI-based tactile sensor exhibits excellent sensitivity, low-pressure sensitivity, reasonable response time, and good cycle stability. For a real-world application, a prototype device employs six BP@PANI tactile sensors that correspond to braille characters and can convert pressed text into audio on reading or typing to assist visually or speech-disabled persons. Overall, this research offers promising insight into the material candidates and strategies for the development of auditory feedback devices based on layered and 2D materials for human-machine interfaces.

Surfactant incorporated polyaniline/Co3O4/rGO ternary hybrid composite symmetric supercapacitors for efficient energy storage applications

Development of surfactant incorporated high-performance ternary hybrid composite via one-pot chemical oxidative polymerization of aniline with metal hydroxide and surfactant (sodiumlaurylsulfate, SLS) wrapped graphene oxide as symmetric supercapacitor (SSC) electrode is reported. The composite materials are characterized well and unveiled an exceptional specific capacitance of 1982 F g−1 at a scan rate of 10 mV s−1. Furthermore, the fabricated symmetric supercapacitor displayed excellent specific capacitance of 662 F g−1, with a specific energy of 29.4 Wh kg−1 at 1 A g−1. The enhanced electrochemical performance of the developed system is attributed to its good surface-to-volume ratio achieved by the incorporation of the surfactant and the homogeneous morphology of the composite in favor of the strong pseudocapacitance of doped PANI. The synergy between the faradaic and nonfaradaic counterparts maintained a capacitance retention of 80.2 % for the fabricated SSC after 5000 CD cycles and a coulumbic efficiency of 98.9 %. The results demonstrate that the surfactant incorporated hybrid composite is an ideal candidate for supercapacitor applications.

Synthesis and Characterization of a Polyaniline-Polyvinyl Alcohol (PANI-PVA) Composite As Anion-Exchange Membrane

Different polyaniline-polyanilylalcohol composites with different concentrations of constituent polymers and degrees of cross-linking were synthesized by chemical oxidative polymerization of aniline in an acidic medium. The electrochemical properties of the PANI/PVA composites were evaluated by electrochemical impedance spectroscopy (EIS), cell diffusion and sorption experiments. The following resistivity, permselectivity, permeability, ion exchange capacity, and chemical stability properties, were obtained and were used to estimate the diffusion coefficients across the membrane for Na+, Cl- and OH- ions. The PANI/PVA composites exhibited high conductivities, especially for higher PANI compositions, given the electrical properties of PANI. Also, although the degree of crosslinking provides higher resistance, it reduces the electrical properties of the membrane, also decreasing the mobility of ions passing through the membrane. Based on the results, potential applications of PANI/PVA in alkaline fuel cells and reverse electrodialysis technology are discussed. PANI base blends and composites have been widely reported due to their low cost and easy preparation through chemical and electrochemical routes. The properties and performance of the composite materials were compared with commercial and custom-made membranes.

Wearable Conductive Polymer Matrix Composites for Breath Monitoring with Ammonia Detection

Conductive polymers, such as polyaniline (PANI), Polythiophene (PTh), polypyrrole (PPy), etc., are widely used for gas sensors due to their excellent electrical conductivity and low cost to manufacture [1]. In particular, PANI has attracted more attention due to its ease of synthesis, high environmental stability, and high reactivity with ammonia gas. In addition, the selection of acid-base dopant during the preparation process of polyaniline can adjust carrier concentrations for the change in electrical conduction or resistance to improve sensing properties. There have been many reports on the fabrication of flexible gas sensors using PANI [2-4]. Bandgar et al. [5] synthesized a low-temperature flexible polyaniline gas sensor by in-situ chemical oxidation polymerization of aniline on a polyethylene terephthalate (PET) substrate, showing 99% reproducibility, rapid response and recovery. Still, the response value was only 26% in 100 ppm ammonia atmosphere. Qi et al. [6] prepared a gas sensor by in-situ polymerization of aniline on non-woven fabric. The high air permeability of the fabric effectively improved the performance of the polyaniline-based gas sensor. Due to the outbreak of the COVID-19 pandemic, the use of face masks in public has become essential to reduce the spread of the virus. Some reports claim that the increased carbon dioxide in the mask over time may cause medical issues related to the respiratory system. Therefore, monitoring breathing air quality can help detect the wearer's vital conditions.In this study, we used a disposable mask as a flexible substrate to prepare polypropylene/carbon nanotube/polyaniline composite film through a layer-by-layer method. The polypropylene/carbon nanotube composite films were prepared by applying the carbon nanotube aqueous solution with surfactants evenly on the surface of a mask filter layer by a drop-coating method. Then, the in-situ polyaniline polymerization was performed on the surface of the polypropylene/carbon nanotube composite film through ammonium sulfate. The polypropylene/carbon nanotube /polyaniline composite film exhibits high sensitivity, fast sensing response/recovery time, room temperature operation, reliable flexibility, and cycle stability. The synthesized and wearable masks have demonstrated real-time detection respiratory rate and other breathing conditions such as CO2 and humidity. The ammonia gas sensing can also be used as a potential biomarker for health screening. The design and integration of multiple gas sensing materials in masks will help wearers better understand their own body conditions.

Comparative study of CdS&TiO2 based polyaniline/polyvinyl alcohol nanocomposites as electrode for supercapacitors

The researchers used the oxidative chemical polymerization of aniline to prepare the polyaniline/polyvinyl alcohol (PANI/PVA) blend and its nanocomposites loaded with cadmium sulfide and Titanium dioxide nanoparticles (CdS-NPs & TiO2-NPs) were synthesized by aniline oxidative chemical polymerization. CdS and TiO2 were incorporated into the prepared nanocomposite to reinforce the mechanical and electrical energy storage performance. XRD revealed the presence of CdS NPs & TiO2 NPs in the polymer matrix; meanwhile, SEM confirms they are well dispersion in the polymer matrix and are dispersed well on the superficies of the synthesized nanocomposites. The presence of characteristic peaks in the Fourier transforms infrared proved the compatibility of the investigated nanocomposite. This study demonstrates how stable the synthesized samples are, with residual material for TiO2/PANI/PVA exceeding 60% even at 800 °C and for CdS/PANI/PVA exceeding 33% at 800 °C. The capacitance of CdS/PVA/PANI nanocomposites (492.29 F.g−1) at 1 A.g−1. The CdS/PVA/PANI and TiO2/PVA/PANI nanocomposites possesses the maximum Es of 2343.65 Wh.kg−1 and 373.17 Wh.kg−1. The CdS/PVA/PANI nanocomposites had the highest energy storage and power density among these binary hybrids. A broadband dielectric spectroscopy was used to examine the electrical and dielectric properties of the prepared samples over a broad range of frequencies and at four selected temperatures. The growth in dc caused by the rise in temperature from 25 to 150 °C (from 10−12 to 10−7 S cm−1) was around five decades as well as the second nanocomposite, TiO2/PANI/PVA, has slightly higher conductivity. The study shows that the blend behaves similarly to its two nanocomposites in the activation plot. However, the blend has higher dc-conductivity by about four orders of magnitude, and an electrode polarization is developed accompanied by apparently colossal ε′ values. This makes it very promising for applications in many fields of advanced microelectronics.

MnO2 integrated emeraldine polyaniline (PANI- MnO2) nanocomposites with inflated opto-electricaltraitsas ETLs for OLED applications

Herein, we report a preparation method of a new hybrid nanocomposite based on polyaniline nanofibers and manganese dioxidenanorods (PANI-MnO2) via in-situ chemical oxidative polymerization of aniline with the addition of varying MnO2 content by using ammonium peroxydisulphide (APS) as an oxidant. The synthesized PANI-MnO2 nanocomposites were characterized using X-ray Diffraction (XRD) and Field Emission Scanning Electron Microscope (FESEM), which confirmed their formation. FESEM images revealed that PANI nanofibers coated the MnO2 nanorods. Fourier Transform Infrared Spectroscopy (FTIR) was employed to investigate the interaction between PANI and MnO2 nanoparticles. Optical properties of PANI-MnO2 nanocomposites were examined by UV–Vis. Spectroscopy and the reduced band gap was observed about 1.76 eV for the optimized PMN2 nanocomposite. Blue, violet and green bands were observed in the photoluminescence spectrum for PANI-MnO2 nanocomposites. The color purity of 39% was obtained from CIE software in the light blue region. The conductivity of PMN2 was enhanced by 21% from pristine PANI. Also,the dielectric constant increases with temperature due to better implantation of dipoles of the conjugated polymer PANI in the direction of the electric field These resultsinferred that optimized PMN2 appeared to be a potential candidate as an effective electron transport layer for efficient OLED devices for lighting and display purposes.

Fabrication of electrospun polyetherimide/polyaniline self-supporting microfiber membranes as electrodes for flexible supercapacitors via in-situ polymerization

The intrinsic properties and structural construction of active materials are crucial to improving the performance of electrodes. Herein, flexible and hydrophilic polyetherimide/polyaniline (PEI/PANI) conductive microfiber membranes with unique core-shell architecture were prepared via electrospinning followed by in-situ chemical oxidation polymerization of aniline doped with 2-acrylamido-2-methyl-1-propanesulfonic acid, and used to boost the properties through the combined action of the pseudocapacitive PANI and abundant porous PEI membranes. For achieving excellent PEI/PANI microfiber membranes as free-standing electrodes, the polymerization time was controlled to refrain from exceed PANI particles agglomeration and maintain the unique three-dimensional porous network structure. Optimized PEI/PANI microfiber membranes with the polymerization time of 7 h presented the best electrochemical properties with high specific capacitance of 249.5 F g−1 at 1 A g−1 and low charge-transfer resistance of 8.316 Ω. Ascribing to the combined effect between the unique pore structure of PEI microfiber membranes and pseudocapacitance of PANI, the flexible supercapacitor based on PEI/PANI-7 demonstrated exceptional capacitance (175.1 F g−1 at 1 A g−1), high energy density (43.4 Wh kg−1) and power density (34.0 kW kg−1), and outstanding flexibility while preserving the cyclic stability. Therefore, this free-standing PEI/PANI microfiber membranes could be deemed as a prospective electrode contender for flexible supercapacitor applications.

Grape‐clustered polyaniline grafted with carbon nanotube woven film as a flexible electrode material for supercapacitors

AbstractThe continuously reinforced carbon nanotube woven film (CNWF) prepared via the floating catalytic chemical vapor deposition (FCCVD) was modified by mixed acid and vinyltrimethoxysilane (VTMS) respectively to obtain carbon nanotube woven film (CNWF@VTMS) grafted with CH2CH group. A series of novel self‐supporting composite electrode materials (CNWF@VTMS/PANI) for supercapacitors were then prepared by in‐situ chemical oxidative polymerization of aniline in the presence of the CNWF@VTMS film substrate as a conductive network framework. The results showed that CNWF@VTMS/PANI14 flexible electrode with grape‐clustered structure exhibited the highest specific capacitance of 531.3 F/g and the highest energy density of 26.5 Wh/kg at the current density of 1 A/g. It could maintain 75.1% of the initial value at a high current density of 10 A/g. The excellent electrochemical cycle and the structural stability have been confirmed on the condition of the higher capacitance retention of 96.6% after 2000 times of galvanostatic charge/discharge, and the almost unchanged electrochemical performances after 300 times of bending and twisting. Meanwhile, the stronger interfacial bonding between CNWF and PANI endowed a higher tensile strength of 129.2 MPa. In this article, CNWF@VTMS/PANI14 composite electrode could be a potential application in the field of deformable supercapacitors.

Nickel Oxide-Incorporated Polyaniline Nanocomposites as an Efficient Electrode Material for Supercapacitor Application

This work reports the facile, controlled, and low-cost synthesis of a nickel oxide and polyaniline (PANI) nanocomposites-based electrode material for supercapacitor application. PANI-NiO nanocomposites with varying concentrations of NiO were synthesized via in-situ chemical oxidative polymerization of aniline. The XRD and FTIR support the interaction of PANI with NiO and the successful formation of the PANI-NiO-x nanocomposite. The SEM analysis showed that the NiO and PANI were mixed homogenously, in which the NiO nanomaterial was incorporated in porous PANI globular nanostructures. The multiple phases of the nanocomposite electrode material enhance the overall performance of the energy-storage behavior of the supercapacitor that was tested in 1 M H2SO4 using cyclic voltammetry (CV), galvanostatic charge-discharge (GCD), and electrochemical impedance spectroscopy (EIS). Among the different nanocomposites, PANI-NiO-3 exhibit the specific capacitance of a 623 F g−1 at 1 A g−1 current density. Furthermore, the PANI-NiO-3 electrode retained 89.4% of its initial capacitance after 5000 cycles of GCD at a 20 A g−1 current density, indicating its significant cyclic stability. Such results suggest that PANI-NiO nanocomposite could be proposed as an appropriate electrode material for supercapacitor applications.

Hierarchical construction of reduced graphene oxide-polyaniline-NiMoS4 phases to enhance the asymmetric supercapacitor capacity

The ternary reduced graphene oxide (rGO)/polyaniline (PANI)@NiMoS4 composite with the three-dimensional hierarchical structure was constructed by the in-situ chemical oxidation polymerization of aniline on GO surface, followed by the hydrothermal treatment. The grafted PANI cannot only provide the additional Faradaic redox reaction, but also support the rGO and NiMoS4, alleviating the self-stacking phenomenon for many ion transfer channels. The optimized rGO/PANI@NiMoS4 exhibits the high specific capacity of 194 mAh/g at 0.75 A/g. Meanwhile, the corresponding rGO/PANI@NiMoS4//AC asymmetric supercapacitor also exhibits the high energy density of 30.75 Wh/kg at 1500 W/kg, and good cycle stability with capacity retention of 93 % after 6000 cycles. These satisfactorily electrochemical performances of rGO/PANI@NiMoS4 composites reveal the potential supercapacitor application. This work provides an efficient way to increase the capacity of NiMoS4 related electrode materials.