Polyaniline Research Articles

Sodium alginate supramolecular nanofibers in synergy with surface crack engineering to prepare tough and highly sensitive hydrogels

Soft and wet hydrogels often struggle to achieve both toughness and high sensitivity simultaneously, limiting their usefulness in flexible devices. To tackle this challenge, we devised a strategy that combines supramolecular sodium alginate nanofibers, utilizing Zr4+ as physical crosslinkers, with surface crack engineering via the micro-phase separation of polyaniline, to create a physically and chemically dual crosslinked polyacrylamide (PAM)/sodium alginate (SA)/polyaniline (PANI) hydrogel with exceptional toughness and high sensitivity. Owing to the supramolecular sodium alginate nanofibers, the dual crosslinked hydrogel exhibited a tensile strength of 0.391 MPa, an elongation at break of 568.9 %, and a toughness of 1.020 MJ/m3. The in-situ polymerized polyaniline layer, confined within the dense network, introduced micro-cracks onto the hydrogel surface, resulting in a high gauge factor of 11.4 for the fabricated hydrogel. Furthermore, integrating this hydrogel into a triboelectric nanogenerator transformed it into self-powered sensors capable of detecting external forces and generating various signals without power supply. These findings suggest that the developed hydrogel held great potential in diverse fields, including human motion detection, human-machine interaction, and wearable electronic devices.

Comprehensive evaluation of interfacial interactions optimization for CF reinforced high-performance thermoplastic composites by electrochemical deposition of conjugated polymers

The mechanical properties of carbon fiber (CF) reinforced high-performance thermoplastic composites are significantly compromised due to inadequate interface bonding between CF and matrix. In this study, electrochemical polymerization techniques were employed to modify CFs with polypyrrole (PPy), poly-aniline (PANI), and poly-o-phenylenediamine (PoPd), to systematically investigate the impact of conjugated polymers on the interfacial properties of CF/copoly (phthalazinone ether sulfone ketone)s (PPESK) composites through a combination of experimental and molecular dynamics (MD) approaches. The findings revealed distinct differences among these conjugated polymers in terms of their effects on both IFSS and ILSS for CF/PPESK composites. Among all tested laminates, PoPd@CF-60s/PPESK exhibited the highest IFSS, ILSS and flexural strength values of 39.8 MPa, 75.6 MPa, and 1494 MPa, respectively, 94.1 %, 20.6 %, and 47.6 % higher than those of CF-desized/PPESK, without compromising CFs strength and thermal resistance of CF/PPESK composites. MD simulations combined with fracture morphology analysis confirmed that compatibility between conjugated polymers and matrix played a pivotal role in enhancing interface properties for CF/PPESK composites. Furthermore, the AFM outcomes demonstrated that the PoPd layer could serve as the modulus transition layer between the CF phase and the PPESK phase, which effectively enhancing the load transfer efficiency between the two phases under external forces. To summarize, this work presents a straightforward yet non-destructive approach that effectively enhances the interface strength within advanced CF reinforced high performance thermoplastic polymer composites (CFRHPTPs).

Highly stable Ag@Au nanowires micromesh as transparent conductive network for stretchable electrochromic modulator

The stretchable electrochromic modulator is one of the most promising energy-saving optoelectronic devices that can be integrated into smart portable and wearable electronics. A lot of focus has been on developing transparent conductive electrodes of stretchable electrochromic modulators, but they generally suffer from poor chemical stability, low photoelectric balance, and unsatisfactory deformability. To address this challenge, we first develop Ag@Au nanowires (NWs) micromesh-based stretchable transparent conductive electrodes (STCEs) using a self-assembled approach, which displays superior photoelectric performance (8.5 Ω sq-1 with a transmittance of 81.5 %), good chemical stability in harsh electrolyte environment (acidic and alkaline) as well as robust mechanical stability (bending, folding, stretching and twisting). As a demonstration, the grown WO3 on Ag@Au NWs-based STCEs can deliver good electrochromic stability even after bending over 1000 cycles and stretching to 50 %. Moreover, highly soft Zn//WO3 and polyaniline (PANI)//WO3 electrochromic modulators were assembled using flexible Ag@Au micromesh STCEs, which still retain uniform electrochromism in neutral and acidic electrolytes respectively. Definitionally, the strategy of in-situ grown Au shell on the surface of AgNWs micromesh provides an innovative solution to fabricate high-performance STCEs for the related portable smart wearable electronic devices.

Flexible zinc-ion hybrid supercapacitor based on Co2+-doped polyaniline/V2O5 electrode

With the rapid advancement of renewable energy sources and portable electronic devices, the demand for high-performance energy storage systems is growing, driving continuous progress in supercapacitor technology. Zinc-ion hybrid supercapacitors (ZIHS), known for their higher safety, cost-effectiveness, and environmental friendliness, have become a hot research topic. Vanadium pentoxide (V2O5) possesses flexible multivalence, low cost, low toxicity, wide voltage window, high capacitance, and high energy density. However, its poor electrical conductivity and low cycling stability hinder its electrochemical performance, thus limiting its application in ZIHS. Here, we propose a novel strategy of incorporating Co2+ ions and conductive polyaniline (PANI) with V2O5 (CoVO-PANI) as cathode materials for ZIHS. The synergistic effect between cobalt ions and polyaniline have led to an expansion of the interlayer spacing in CoVO-PANI, which reduce the binding energy of Zn2+ ion insertion, decrease the diffusion barrier of Zn2+ ion insertion, and enhanced the electronic conductivity of the material for electron transport. In result, the CoVO-PANI@CC//2 M ZnSO4//AC@CC can reach the areal capacitance of 847.3 mF cm−2 at 1 mA cm−2. Following 2000 times at 50 mA cm−2, the CoVO-PANI@CC//2 M ZnSO4//AC@CC maintains a retention rate of 81.37 %, and can achieve a Coulombic efficiency of 100 %. The assembled flexible ZIHS device exhibits excellent flexibility and stability, with an areal capacitance of 775.6 mF cm−2 at 1 mA cm−2. This work demonstrates the tremendous potential of CoVO-PANI@CC as a cathode material for ZIHS.

The Use of Low‐Quality Cotton‐Derived Cellulose Films as Templates for In Situ Conductive Polymer Synthesis as Promising Biomaterials in Biomedical Applications

AbstractHere, the use of cellulose films (CFs) produced from low‐quality cotton is reported as a template for in situ synthesis of well‐known conductive polymers, e.g., polyaniline (PANI) and polypyrrole (PPY) via oxidative polymerization. Three successive monomer loading/polymerization cycles of aniline (ANI) and pyrrole (PY) within CFs as PANI@CF or PPY@CF are carried out to increase the amount of conductive polymer content. The contact angle (CA) for three times ANI and PPY loaded and polymerized CFs as 3PANI@CF and 3PPY@CF are determined as 26.3±2.8 and 42.3±0.6 degrees, respectively. As the electrical conductivity is increased with increased number of conductive polymer synthesis within CF, the higher conductivity values, 3×10−4±8.1×10−5 S.cm−1 and 2.1×10−3±5.8×10−4 S.cm−1, respectively are measured for 3PANI@CF and 3PPY@CF composites. It is found that PANI@CF composites are hemolytic, whereas PPY@CF composites are not at 1 mg mL−1 concentrations. All PPY@CF composites exhibit better biocompatibility than PANI@CF composites on L929 fibroblast cells with more than 70±8% viability at 1 mg of CF‐based conductive polymer composites. Moreover, MIC and MBC values of 3PPY@CF composites for Escherichia coli (ATCC8739) and Staphylococcus aureus (ATCC6538) are determined as 2.5 and 5.0 mg.mL−1, whereas these values are estimated as 5 and 10 mg.mL−1 for Candida albicans (ATCC10231).

Electromagnetic interference shielding properties of PMMA modified-Co0.5Zn0.5Fe2O4 − polyaniline composites

Present work reports solution combustion synthesis (SCS) of Co0.5Zn0.5Fe2O4 spinel ferrite, its chemical modification with polymethylmethacrylate (PMMA), synthesis of polyaniline (PANI), and electromagnetic interference (EMI) shielding properties of their composites. Both as-prepared and PMMA-modified Co0.5Zn0.5Fe2O4 adopt cubic spinel structure as shown by X-ray diffraction studies. Field emission scanning electron microscopy images show the agglomerated and microporous nature of the ferrites. High resolution transmission electron microscopy image of as-prepared Co0.5Zn0.5Fe2O4 shows lattice fringes related to (311) plane of the spinel structure. X-ray photoelectron spectroscopy studies reveal the presence of Co2+, Zn2+, and Fe3+ in tetrahedral and octahedral coordinations in the ferrite. EMI shielding properties are evaluated for PMMA-modified Co0.5Zn0.5Fe2O4 and PANI composites in different weight ratios. Composites containing PMMA-modified ferrite and PANI with 50:50 and 10:90 weight ratios show the best performance among all the composites in 2−20 GHz frequency range. Optimized PMMA-modified Co0.5Zn0.5Fe2O4 and PANI composite with the ratio of 10:90 shows shielding effectiveness (SE) values of −16.6 to −24.2 dB in 2−20 GHz frequency region.Graphical

Surface Engineering of N‐Doped Carbon Derived from Polyaniline for Primary Zinc‐Air Batteries

AbstractZinc‐air batteries (ZABs) with metal‐free cathodes are considered environmentally friendly and cost‐effective. However, more active and durable catalysts are required for this purpose. Herein, polyaniline (PANI)‐derived carbon materials were obtained to boost the oxygen reduction reaction (ORR) and, consequently, the performance of a primary ZAB. The developed porous N‐doped carbon (NDC) materials were engineered by varying the polymerization time and calcination temperature (500–900 °C). SEM micrographs and BET surface areas showed that the polymerization of aniline under cold conditions (5 °C) at 6, 8, or 24 h did not have a significant effect on the morphology or surface area. The fibrous structure of PANI was engineered by temperature, resulting in a progressive increase in the surface area until a three‐dimensional porous structure was achieved at 900 °C with the highest area of 601.9 m2 g−1. The surface doping of nitrogen species shifted from PANI‐rich N species to enriched graphitic N from 12.69 % (500 °C) to 24.26 % at 900 °C. The NDC 900 °C presented a voltage of 1.4 V and power density of 56 mW cm−2 (only 7 mW cm−2 lower than that of Pt/C). The results demonstrate that this material is an excellent candidate for high‐performance primary ZABs.

Nanocomposites for Lithium‐Ion Battery Anodes Made of Silicon and Polyaniline Doped with Phytic Acid

The properties of lithium‐ion battery (LIB) anodes fabricated from nanoscale silicon Si and polyaniline (PANI) as a binder are reported. PANI is prepared by in situ polymerization of aniline in the presence of phytic acid, which serves both as dopant and as a gel‐forming agent. PANI pellets obtained by dry compression are used to investigate the morphology and to measure the resistivity of PANI and Si/PANI composites. The anodes are fabricated using the slurry technique. Their properties as a function of precursor ratio are studied in the half‐cell cells by charge–discharge characteristics, cyclic voltammetry, electrochemical impedance spectroscopy and cyclic lifetime. It is shown that stable cycling (>350 cycles at a current of 300 mA g−1) is inherent only to thin Si/PANI layers with composite loading <0.7 mg cm−2. The discharge capacity in this case is as high as 500–800 mAh g−1.

Design of a high-performance polyaniline coated niobium dicarbide MXene nanostructure based electro-membrane system for improved nanoplastic separation

This study explores the development of advanced electro-membrane filtration by incorporating Nb-based MXene (Nb2CTx) to enhance nanoplastic (NP) separation and fouling mitigation. The presence of NPs in water results in less effective filtration, hence increasing cost, highlighting the urgent need for advanced removal technologies. Nb2CTx was incorporated at varying loadings, revealing significant alterations in their morphological, structural, and physiochemical properties. The performance evaluation using NP-rich suspensions demonstrated that the membrane with 5 % Nb2CTx loading (MS5) achieved a NP removal efficiency of 97.4 % and a water flux of 90.5 L.m−2.h−1, which was significantly higher than the pristine sulfonated polyether sulfone (SPES) membrane (18.9 L.m−2.h−1 with 94 % removal efficiency). The membrane was developed for an electro-membrane system using a sacrificial anode. The sacrificial anode allowed for multiple complex process to occur simultaneously, including electrocoagulation and membrane filtration. Polyaniline (PANI) coating was added to further increase the conductivity to allow for a more energy efficient process. The study underscores the importance of Nb2CTx loading and PANI modification in improving the filtration efficiency and fouling resistance. Furthermore, applied electric field resulted in enhanced operational sustainability of SPES membranes, offering a novel approach for water treatment applications.

Phenylalanine: Amino Acid Metal Non-Enzymatic Electrochemical Voltammetric Sensors

This study presents a comparative analysis of non-enzymatic electrochemical voltammetric sensors, utilizing phenylalanine amino acid metal complexes (M: Ni, Zn, and Co) Polyaniline (PANI) nanocomposites (NCs). The PANI: Zn(Phala)2 NCs-based sensor detected dopamine (DA) with a sensitivity of 101.18 μAμM−1 cm−2. The limit of detection (LOD) for the PANI: Zn(Phala)2 NCs-based sensor was calculated as 0.391 μM. This exceptional sensitivity makes the PANI: Zn(Phala)2 NCs-based sensor highly promising for potential integration into biomedical test kits. To gain deeper insights into the structural properties of the PANI NCs, scanning electron microscopy (SEM), artificial-intelligence-based SEM, and Fourier transform infrared spectroscopy (FTIR) were employed for characterization. FTIR characterization provided insights into the functional groups of the NCs. The results of this comparative investigation a significant advancement in the field of PANI-based electrochemical sensors designed for DA sensing. The PANI: Zn(Phala)2 NCs-based sensor show great promise for a range of advanced sensing applications. The Z value of the PANI: Zn(Phala)2 NCs-based sensor is the lowest among the tested materials, indicating that the conductivity of the PANI: Zn(Phala)2 layer is higher than that of other active layers. Consequently, the PANI: Zn(Phala)2 NCs-based sensor achieved higher sensitivity in DA detection.

Multi-spectrum compatible electrochromic device combining microwave transmission with ultra-wide emissivity modulation

The potential of polyaniline (PANI)-based electrochromic devices (ECDs) to offer adaptive anti-surveillance stealth in the visible/infrared bands is considerable. However, the incompatibility between infrared and radar stealth renders it challenging to achieve compatibility between the two with PANI-based ECDs. In this work, an etched electrode with frequency-selective surface configurations is initially designed for selective transmission and reflection of microwaves. Subsequently, a stellate PANI is prepared on the electrode surface by introducing triphenylamine (TPA) modification into the long molecular chain of disordered PANI, and assembled into a multi-spectrum compatible ECD. The results demonstrate that the ECD can achieve efficient transmission between 10.2–13.9 GHz, with a transmission rate approaching 90 % at 11.92 GHz, and enables the visible characteristics to switch between jungle dark green and desert earthy yellow. Furthermore, thermal-infrared emissivity (ε) modulation is achieved in the atmospheric transmission windows of 3–5 μm and 8–14 μm, with maximum emissivity change (Δε) of 0.61 and 0.73, respectively. The ECD demonstrated the capacity to exceed the limitations of static camouflage associated with existing multi-spectrum stealth materials, and exhibited a high degree of adaptability in intelligent electromagnetic confrontation environments.

Communication—Tunable Lorentz-Type Negative Permittivity of PANI/Epoxy Resin Composites in the Frequency Range from 3 kHz to 1 MHz

Negative permittivity in percolation composites garnered significant interest due to its promising implications for practical applications. This study demonstrates that the percolation threshold of the polyaniline(PANI)/epoxy resin composite falls within the range of 40 wt% to 50 wt%. Beyond this percolation threshold, the composites exhibit a corresponding negative dielectric behavior. Notably, at a high PANI content level of 90 wt%, the permittivity exhibits characteristics akin to Lorentz resonance type behavior. This research presents an effective approach to exhibit tunable low-frequency negative permittivity through Lorentz resonance.

Charge Photogeneration and Transfer in Polyaniline/Titanium Dioxide Heterostructure

The photoinduction process in a p-n heterogeneous structure should be in correlation with the electronic properties of its semiconductor components. Based on that assumption, a double layer made of polyaniline (PANi) and titanium dioxide (TiO2) on glass substrate is used to investigate the charge photogenerated and transferred in the structure. The PANi layer is made by in situ polymerization of aniline in HCl acidic aqueous medium, while the TiO2 layer is made by thermolysis of TiCl3 dilute solution. It has been found that the PANi/TiO2 double layer is a composition of a PANi emeraldine salt layer (p-type semiconductor) covered by a TiO2 rutile layer (n-type conductor), creating a p-n heterogeneous structure. Upon exposure to the excitation light, the light sensitivity of the PANi layer in the PANi/TiO2 structure reveals a response mode distinct from those of the neat PANi layer. The conductance of the PANi layer in the coupling structure shows two modes of response: (1) a negative mode, i.e., a decrease in conductance in response to the excitation light of wavelength 369, 396 and 447 nm, and (2) a positive mode, namely an increase in conductance, as with the excitation light of wavelength 667 nm. On the other hand, the neat PANi layer simply shows a single positive response to excitation light. Those response modes account for a modulation of the PANi/TiO2 depletion region that in turn depends upon the photoexcited electrons and holes in the heterostructure. The diffusion of excess photogenerated electrons and holes over the heterojunction results in an expansion or reduction of depletion width that gives rise to an increase or decrease of the PANi layer conductance, i.e., a positive or negative response, respectively. In addition, the negative mode in response to the excitation light of wavelength 447 nm (~2.8 eV) is assumed to be an impact of the PANi in extending the photoinduction of the TiO2 component into the vision range at the blue region.

Protic Stabilization Engenders High Energy Density and Long Cycle Life in Polyaniline–Zinc Supercapacitors

The redox activities of polyaniline (PANI) are hindered by the instability of pernigraniline salt (PS) state which degrades into oligo‐aniline. In this work, the use of protic additives is examined to mitigate capacity fading and increase utilization of PANI in nonaqueous electrolytes. The protic additive propylene glycol, with its hydrogen‐bonding capabilities, stabilizes the PS PANI and promotes reversible redox reactions, facilitating high capacity and an extended cycle lifetime for applications in metal ion supercapacitors. The use of this protic nonaqueous electrolyte in a PANI–zinc device results in an energy density of 255 Wh kg−1 at a power density of 1.8 kW kg−1 and a robust cycle lifetime of 3,850 charge/discharge cycles. The PANI at a high current density of 6.5 mA cm−2 reaches a capacity of 257 mAh g−1, equivalent to 87% of the its theoretical capacity, showcasing the effectiveness of the protic additive in improving both capacity and cycle life in electrochemical supercapacitors.

Investigating the electrochemical properties of poly(vinylidene fluoride)/polyaniline blends doped with lithium-based salt

Conductive polymers have attracted much attention in various applications, owing to their excellent chemical, thermal, and oxidative stability. However, they have low dielectric constant, which limits their performance in electrochemical devices. To overcome this drawback, blending with other polymers helps improving their electrochemical properties. Herein, we investigate structural and electrochemical properties of poly (vinylidene fluoride) (PVDF)/polyaniline (PANI) blends doped with lithium-based salt. Results showed that the blends exhibit phase separation of PANI and PVDF, which is confirmed by the thermodynamic interaction parameter. We found that the interaction between the two polymers enhanced the ionic conductivity from 4.9 × 10−5 S cm−1 for neat PVDF to 5.3 × 10−4 S cm−1 for composition of 50:50 (PANI50), whereas the ionic conductivity was inversely proportional to the temperature. Moreover, by adding lithium salt to the blend, the thermal stability increased from 376.6 to 478.5 °C for PANI50. The ionic conductivity of the blends depends on the PVDF content, which affects the interaction between the two polymers.

Poly(aniline/aminophenol)-wrapped graphene nanoplates loaded with gabapentin inhibitor as a filler in poly(aniline/vinylalcohol/aminophenol)/acrylic coating to endow corrosion/wear durability by triple protection mechanism

A coating with excellent tribological behavior and corrosion durability was synthesized by chemical/electrochemical method from the composition of polyaniline (PANI), polyaminophenol (PAP), polyvinylalcohol (PVA), and reinforced with PANI/PAP/Gabapentin-functionalized Graphene nanoplates. Acrylic (AC) covered the composite coating as a top layer. According to the evaluations, G@PANI/PAP/GP-reinforced coating has 5 times more corrosion resistance than unreinforced one (on the 1st and 30th days). Not only has the corrosion resistance of PANI/PVA/PAP contained G@PANI/PAP/GP not decreased over time, but it has increased by ∼20 %. The defect density of passive film under (PANI/PVA/PAP)/Acrylic coating containing G@PANI/PAP/GP is 10 times less than that of the (PANI/PVA/PAP)/Acrylic coating. G@PANI/PAP/GP decreased the friction coefficient and wear rate of PANI composite coating over time by ∼47 % and 84 %. Furthermore, the simultaneous presence of graphene and gabapentin has increased the lubrication (Rsk = -0.24 µm) and adhesion (13 %) of the coating. It is how a polyaniline-based composite coating with three mechanisms of passivation, corrosion barrier, and inhibition protects the 304 SS over time.

Eco-Friendly Electrochemical Sensor for Accurate Soil Nitrate Detection using ZnOx/PANI Nanocomposite on Nickel Foam Electrode

This study presents an innovative approach to enhancing nitrate detection in soil, a critical macronutrient for agriculture. We developed a novel electrochemical sensor using a nanocomposite of Zinc Oxide (ZnOx) and Polyaniline (PANI) on a Nickel foam electrode. The nanocomposite was synthesized through cyclic voltammetry and characterized using Field Emission Scanning Electron Microscopy (FESEM), Energy Dispersive Spectroscopy (EDS), and X-ray Diffraction (XRD) to analyze its morphological, elemental, and crystalline properties. The sensor's performance was evaluated using square wave voltammetry, revealing a direct linear relationship between the peak current and nitrate concentration. The sensor demonstrated high sensitivity (4.53 µA/µM) and a low detection limit (0.40 µM), confirming its potential for precise and sensitive nitrate analysis in soil samples.

Unlocking high-efficiency charge storage: Co-assembled nanoparticles of lignin and polyaniline molecules

Redox-active lignin rich in phenolic hydroxyl groups is an ingenious charge storage material. However, its insulating nature limits the storage/release of electrons and requires the construction of electron transfer channels within it. Herein, nanoparticles (PANI/DKL-NPs) are prepared by co-assembly via π–π interactions between conducting polyaniline (PANI) and demethylated Kraft lignin (DKL) molecules for the first time, and rapid electron transfer inside DKL is achieved. The co-assembled PANI/DKL-NPs consist of interpenetrating structures of PANI and DKL at the molecular scale, and the content of PANI molecules interspersed within them is controllable. Meanwhile, the extensive and abundant mesoporous structure in nanoscale PANI/DKL-NPs facilitates ion transport and electron storage. Based on this favorable microstructure, the specific capacitance of PANI/DKL-NPs at 1 A·g−1 is as high as 532 F·g−1, which is 780 % and 90.68 % higher compared to DKL-NPs and PANI-NPs, respectively. Meanwhile, the rate performance of PANI/DKL-NPs is significantly enhanced than that of DKL-NPs (33.11 %) and comparable to that of PANI-NPs (more than 69 %). Furthermore, the symmetric supercapacitor (PANI/DKL-NPs//PANI/DKL-NPs) assembled from it achieves a high energy density of 27.49 Wh·kg−1 at 400 W·kg−1 power density, and superb flexibility and mechanical stability. Therefore, the co-assembly of DKL and PANI will effectively stimulate the energy storage potential of lignin, providing a practical pathway to promote the development of biopolymers in energy storage.

Synthesis and Characterization of Polyaniline / [BMIM][BF4] Polyionic Liquid by Interfacial Polymerization

Polyaniline (PANI) was prepared by polymerization via the chemical oxidation of aniline monomer with ammonium persulfate as the initiator. The interfacial polymerization method was used to prepare PANI/1-butyl-3-methylimidazolium tetrafluoroborate [BMIM][BF4] polyionic liquid (PIL). The obtained PANI/ [BMIM][BF4] PIL was investigated by the XRD, EDX, SEM, FTIR, and UV-Visible characterizations. X-ray diffractogram of PANI showed five prominent characteristic peaks at 27.1°, 24o, 21.8°, 19.8°, and 18.2°. This demonstrates the semi-crystalline character of the polyaniline produced through the interfacial polymerization process. Incorporation of [BMIM][BF4] into PANI reduced the crystalline phase and enhanced amorphicity. From the EDX pattern, several elements appeared in this test; oxygen had of the highest weight percentage of 54.2%. The SEM image showed a clear hierarchal porous structure with nano-sticks particles and forms a cross-linked framework between PANI and [BMIM][BF4]. From FTIR spectra of PIL, a prominent absorption peak at 3163.26 cm-1 was noted because of the N-H stretching vibrations present in the polymer. The UV-Vis spectra for PANI/[BMIM][BF4] polyionic liquid showed three peaks between 200 and 1060 nm. These bands result from π → π* and n → π* transitions, which are related to the excitement absorption of benzenoid and quinoid groups.

Multifunctional polymeric coating on stainless steel current collectors in aqueous energy storage devices

Herein, low cost stainless steel foils are employed as current collectors in aqueous Na-ion supercapacitors, while the foils are coated with following conducting polymers, namely, polyimide (PI), Schiff base polymer (SBP), polyanthraquinone sulfide (PAQS) and polyaniline (PANI). The foremost purpose of these polymeric coatings is the prevention of corrosion, and the resultant improvements in device performances. Notwithstanding, these polymeric coatings provide few additional benefits in device characteristics, and these are following: (i) enhancement of electrolyte stability window, (ii) contributing charge storage capacitance, (iii) conversion of 2D pristine substrate to 3D porous current collector. The four coating polymers are electrochemically characterized, and PI is selected for fabricating Na-ion supercapacitor cells. The PI-coating reduces the stainless steel’s corrosion rate ∼ 68 times, expands the electrolyte stability window ∼ 1.2 times, and delivers ∼ 2 times higher capacitance with respect to pristine current collector, whereas no appreciable interfacial resistances are observed. The supercapacitor cell with PI-functionality demonstrates ∼ 6.6 times improved capacitance than that of pristine cell at 25 mA/g current density, while > 95 and ∼ 90 % Faradaic efficiencies are noted for former and latter, respectively. The distinct enhancement of cell performances clearly demonstrates the effectiveness of multifunctional polymeric coating on corrosion-prone metallic current collectors.