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In the present study, composites of Polyaniline and some fruit peels were synthesized in various conditions and used for lead removal from aqueous solutions. Adsorption tests were conducted in batch mode using the most efficient adsorbent, and the effects of medium pH, initial lead concentration, contact time, adsorbent dosage, and adsorption isotherms were investigated. The results showed that all composites were more efficient in lead removal compared to the fruit peels alone. The highest removal percentage was related to the composite of banana peel and Polyaniline that synthesized in the aqueous solution in the presence of 2 g·L−1 Poly ethylene glycol. This composite showed 95.96% lead adsorption at pH=6, the contact time of 90 min, the initial lead concentration of 25 mg·L−1, and an adsorbent concentration of 8 g·L−1. Adsorption isotherm study showed that adsorption of lead by synthesized composite could be fitted by both Langmuir and Freundlich models, but the Langmuir model was more fitted than Freundlich. Besides, some characteristics of the composites, such as chemical composition (XRD analysis), structure, and morphology (SEM analysis) and functional groups (FTIR analysis), were studied.

Clay mineral obtained from Tuticorin in Tamilnadu, India (Indian Clay- IC) was purified and used to synthesise polyaniline-Indian clay nanocomposites (Pani-IC NCP) by polymerising aniline with the clay by chemical oxidation method using potassium perdisulphate as oxidant and by varying the aniline to clay ratio. The formation of composite in nanoscale was confirmed by XRD and TEM analysis. The in situ intercalative polymerization of monomer within the clays was ascertained by FTIR, UV–visible, XRD, SEM and TEM studies. The analyses of UV visible and FTIR spectroscopy demonstrated that aniline has been polymerized to Pani in its conducting emeraldine form. The conformation adopted by Pani Chains in the clay interlayer depended on the molar ratio of aniline to clay. SEM analysis showed the variation in morphology from granular agglomerate to layered flaky structure as the clay concentration was increased. Thermal stability of the nanocomposites was studied using TGA/DTA and DSC studies and it was found that they showed better thermal stability than their pristine polymers indicating the enhanced barrier property of the nanoclay. XRD showed that the clay host used accommodates higher amount of emeraldine salt than MMT. The Cyclic voltammetry studies of the synthesized nanocomposites showed the one with 0.5 g clay showed better electrochemical response. It exhibited good adherent behaviour on electrode surface at pH 1.0 with two oxidation peaks at 463 and 672 mV and two reduction peaks at 360 and 126 mV. By varying the atmosphere it was found that the nanocomposite modified electrode exhibited oxygen reducing capacity than their Bentonite counterpart. Chronoamperometric and Chronocoulometric studies were also carried out at inert as well as oxidising atmosphere which confirmed the above fact. EIS studies of the modified electrodes showed double layer capacitance value of 5.95 × 10−8 Fcm−2 with the bode phase angle of 70°.

Transition metal dichalcogenides (TMDCs) are two dimensional nanomaterials made up of a monolayer of transition metal atoms sandwiched (X-M-X) between two layers of chalcogen atoms in a hexagonal lattice. Molybdenum di sulfide (MoS2) have attracted much attention among the TMDCs family and is a suitable electrode material for supercapacitors. It has remarkable physical and chemical properties such as large surface area, sheet like structure, superior capability and lower rates of cyclic induced degradation. However, MoS2 suffers from lower electronic conductivity that limits its energy storage. Hence the conducting polymer, polyaniline is doped with the MoS2 to overcome the deficiencies and to enhance the electrochemical performance. A novel microwave assisted method is implemented to synthesize MoS2/PANI nanocomposites for the strategy of supercapacitors. The microwave assisted processing of MoS2/PANI nanocomposites provides several advantages than the conventional heating method such as tuning the physiochemical properties as reduction of impurity, mono dispersivity in the morphology that results in enhancing the electrochemical performance. The phase purity, homogeneity, and functional groups present in the MoS2/PANI nanocomposites are synthesized and characterized by X-ray diffraction (XRD), Field Emission Scanning Electron microscope (FESEM), High Resolution Transmission Electron Microscope (HR-TEM), Fourier Transform infrared spectroscopy (FT-IR), UV–Visible (UV–Vis) absorption spectroscopy and Raman spectroscopy. The optimized MoS2 /PANI nanosheets exhibits a high specific capacitance of 348 F/g at 0.5 A/g and MoS2/PANI nanocomposites retains 89.21% of its initial specific capacitance even after 2000 cycles. Hence the strategy of microwave assisted synthesis of MoS2/PANI nanocomposites improve the electrochemical performance of two dimensional MoS2 based electrode materials for energy storage.

Nano composites of conducting polyaniline with ZnS nanoparticles (PANI/ZnS) have been synthesized by in-situ polymerization of aniline monomer using ammonium persulphate as oxidizing agent. The formation of PANI/ZnS composites was assessed by UV–Vis spectroscopy, Transmission Electron Microscopy (TEM), Fourier Transform Infra-Red Spectroscope (FTIR), Atomic Force Microscope (AFM), Scanning Electron Microscope (SEM) and X ray diffraction analysis (XRD). FTIR and UV studies provided the information of functional group and optical behavior respectively SEM studies shows the well dispersion of ZnS Nanoparticles in the polyaniline matrix. Size determination identified and confirmed by TEM analysis.

Polyanilines doped with different concentrations of oxalic acid have been synthesized by oxidative chemical polymerization using potassium perdisulfate as oxidizing agent. The effect of dopant on the kinetics of polymerization has been studied by UV–VIS spectroscopy. The presence of oxalic acid in the polymer has been studied by FTIR, and morphology by SEM and TEM. The thermal stability of the polymer was investigated by TGA and degree of crystallinity of polyaniline was studied by XRD. The electrochemical behaviour has been studied by cyclic voltammetry (CV) and the phenomenon of charge transport and capacitance was examined by Electrochemical Impedance Spectroscopy (EIS). The morphological study shows the particles to be of nanosize and EIS studies show that these samples have significant double layer capacitance (Cdl) and can be used as capacitors.

Zinc oxide nanoparticles were synthesized through wet chemical method. Polyaniline was synthesized by oxidative polymerization of aniline using potassium perdisulphate as oxidizing agent. Polyaniline -Zinc oxide nanocomposites were prepared by five different percentages of zinc oxide nanoparticles mixed with synthesized polyaniline. The prepared metal oxide, polymer and Nano composites were characterized by UV–Vis, FT-IR, AFM and electrochemical studies. The FT-IR spectral studies indicated the presence of metal oxide and polymer in Nano composites. From the FT-IR spectra of Nano composites, the peak around 464 cm−1 indicated the bonding between Zn and O, the peak around 1573 cm−1 and 1503 cm−1 due to stretching vibrations of the quinonoid and benzenoid rings of polyaniline respectively. The surface morphology was characterized by AFM. The UV–Vis spectrum of polyaniline was observed five absorption bands around 230 nm, 258 nm, 299 nm, 457 nm and 632 nm. Among these five bands, the absorption band around 299 nm is assigned to the π–π* transition of the phenyl ring and another band at 632 nm is assigned to the polaron n–π* transition. The UV–vis spectral absorption intensity of Nano composites was increased as increasing of zinc oxide incorporation in polyaniline. Cyclic Voltammetric studies exhibit good sensitivity response at pH 1.0. Chronoamperometric and Chronocoulometric studies were also carried out for polymer–metal oxide nanocomposites. The present study especially aims to investigate PAni-ZnO Nano composites in order to obtain a new noble material which can be utilized for solar cell applications.

The major challenge in the field of antibacterial agents is to overcome the low-permeability of bacteria cell membranes that protects the cells against diverse drugs. In this work, water-soluble polyaniline (PANI)-poly (p-styrenesulfonic acid) (PSS) (PANI:PSS) is found to spontaneously penetrate bacteria cellular membranes in a non-disruptive way, leaving no evidence of membrane poration/disturbance or cell death, thus avoiding side effects caused by cationic ammonia groups in traditional ammonia-containing antibacterial agents. For aqueous synthesis, which is important for biocompatibility, the polymer is synthesized via an enzyme-mimetic route relying on the catalysis of a nanozyme. Owing to its fluorescent properties, the localization of as-prepared PANI:PSS is determined by the confocal microscope, and the results confirm its rapid entry into bacteria. Under 808 nm near-infrared (NIR) irradiation, the internalized PANI:PSS generates local hyperthermia and destroys bacteria highly efficiently from inside the cells due to its excellent photothermal effects. Staphylococcus aureus (S. aureus), Methicillin-resistantStaphylococcus aureus (MRSA) and Escherichia coli (E. coli) could be effectively eliminated as well as the corresponding bacterial biofilms. Results of in vivo antibacterial experiments demonstrate excellent antibacterial activities of the water-soluble PANI:PSS without side effects. Therefore, the prepared water-soluble polymer in this study has great potential in the treatment of various bacterial infections., Graphical abstract Image 1, Highlights • Water-soluble, amphiphilic PANI:PSS can penetrate the membrane without overt membrane disruption/poration. • PANI:PSS is superior to traditional cationic antibacterial agents. • PANI:PSS can generate local hyperthermia from inside the bacteria. • PANI:PSS can eliminate bacteria as well as their biofilms.

The metal ions or conductive macromolecules intercalated hydrated vanadium oxides for aqueous Zn-ion batteries (AZIBs) have received increasing attention in recent years. The strategy for the preparation of the intercalated hydrated vanadium oxides has been achieved great advances but is still a huge challenge. In this contribution, we develop an interface-intercalation method to synthesize the polyaniline-intercalated hydrated vanadium pentoxide (V2O5·nH2O), denoted as PANI-VOH, as the cathode materials for AZIBs. The prepared PANI-VOH exhibits a 3D sponge-like morphology and the surface area of 190 m2·g−1. The interlayer spacing of VOH is expanded to be 14.1 A, which provides a lot of channels for the rapidly reversible (de)intercalation of Zn2+ ions. The coin-typed Zn//PANI-VOH battery shows the specific discharge capacity of 363 mAh·g−1 at 0.1 A·g−1 and stable cycling performance. Furthermore, the specific capacity remains 131 mAh·g−1 after 2000 cycles at 5 A·g−1, and the energy density is calculated to be 275 Wh·kg−1 at 78 W·kg−1 on the mass of PANI-VOH. The achieved values are comparable to or even much higher than that of the most state-of-the-art V-based cathode materials for AZIBs. The PANI intercalation can shorten the pathways and facilitate the transports for the migration of ions and electrons. Our finding guides a novel strategy for the intercalation of PANI into the layered materials to adjust their interlayer spacing, which exhibits super ions migration efficiency, as the cathode materials for AZIBs and even other multivalent ions batteries.

Metal-organic framework (MOF)-based electrode materials have become a hot subject for supercapaitors. Herein, Ni-MOFs grown on Co nanoparticles modified carbon nanofibers (CNFs) (C-Co@MOF) are prepared via a facile process. Interestingly, the presence of Co nanoparticles in CNFs not only boosts the hybridization of CNF and MOFs, but also releases Co ions to participate in the growth of MOF, leading to a favorable electrochemical behavior. In detail, the specific capacitance of C-Co@MOF reaches 1201.6 F g−1 that exceeds those of C-M@MOFs (M = Ni, V, Mo, Mn, Fe, Cu and Zn) and CNF@MOF. More importantly, an asymmetric solid-state supercapacitor is assembled using C-Co@MOF and nitrogen-doped carbon nanotubes derived from polyaniline as positive and negative electrode materials, respectively, representing a high energy density of 37.0 Wh kg−1 and outstanding durability. This work highlights the superiority of electrospun CNFs modified by metal nanoparticles for the growth of MOF, showing great potential for electrochemical energy storage and conversion applications.

A novel conductive nanohydrogel hybrid support was prepared by in situ polymerization of polyaniline nanorods on an electrospun cationic hydrogel of poly(ε-caprolactone) and a cationic phosphine oxide macromolecule. Subsequently, the cellulase enzyme was immobilized on the hybrid support. Field-emission scanning electron microscopy and Brunauer-Emmett-Teller analyses confirmed a mesoporous, rod-like structure with a slit-like pore geometry for the immobilized support and exhibiting a high immobilization capacity and reduced diffusion resistance of the substrate. For comparison, the catalytic activity, storage stability, and reusability of the immobilized and free enzymes were evaluated. The results showed that the immobilized enzymes have higher thermal stability without changes in the optimal pH (5.5) and temperature (55 °C) for enzyme activity. A high immobilization efficiency (96%) was observed for the immobilized cellulose catalysts after optimization of parameters such as the pH, temperature, incubation time, and protein concentration. The immobilized enzyme retained almost 90% of its original activity after 4 weeks of storage and 73% of its original activity after the ninth reuse cycle. These results strongly suggest that the prepared hybrid support has the potential to be used as a support for protein immobilization.

Nanostructured porous polyaniline (PANI) has been synthesized and coated simultaneously on a highly flexible and conductive carbon cloth (CC) substrate using a simple in-situ chemical oxidative polymerization technique. PANI coated CC (PANI−CC) based flexible electrodes were further used for the fabrication of flexible supercapacitor devices. For the comparison purpose, pure PANI has also been synthesized and tested for its electrochemical performance. The energy storage capacity of PANI and PANI–CC composite was investigated using electrochemical techniques like CV, GCD, and EIS in a potential range from 0 to 0.8 V in 1 M H2SO4 electrolyte. PANI−CC flexible electrodes exhibited the highest specific capacitance of 691 F/g; whereas, pure PANI could only achieve 575 F/g of specific capacitance at 1 A/g. Composite also exhibited outstanding cyclic stability by recollecting 94 % of its initial capacitance after 2000 GCD cycles. For actual implementation, a flexible supercapacitor device has been fabricated using stainless steel sheets and PANI−CC flexile electrodes. The energy storage performance of the PANI−CC flexible supercapacitor device was tested at several bending angles, which resulted in 72 % of capacitance retention at a maximum bending angle of 140° compared to the capacitance obtained at an angle 0° (flat state). PANI−CC exhibited improved electrochemical performance than pure PANI due to the synergistic effect between PANI and CC. Here, CC helped in enhancing the conductivity and stability; whereas, PANI boosted the capacitance owing to its excellent porosity and fast pseudocapacitive charge storage response.

The gadolinium substituted cobalt ferrite (CoFe1.9Gd0.1O4) nanoparticles and CoFe1.9Gd0.1O4/Polyaniline (PANI) microwave absorber were synthesized by sol-gel auto combustion technique using lemon juice and in-situ polymerization method respectively. X-ray patterns confirmed the formation of single phase cubic structure. The crystallite size of the synthesized CoFe1.9Gd0.1O4 nanoparticles are within the range of 15–68 nm. The saturation magnetization of CoFe1.9Gd0.1O4 ferrite/Polyaniline (PANI) composite was reduced due to nonmagnetic PANI. The reflection loss for microwave absorbing properties of CoFe1.9Gd0.1O4 ferrite nanoparticles and CoFe1.9Gd0.1O4/PANI nanocomposite were investigated and minimum value of reflection loss was found to be −16.85 dB at 13.52 GHz for nanoparticles of thickness 2.5 mm and −25.59 dB at 11.92 GHz for CoFe1.9Gd0.1O4/PANI nanocomposite of thickness 2.0 mm) respectively. The prepared samples have low density, high surface resistivity and enhanced attenuation constant. The nanocomposite exhibits excellent absorption performance over a broad band range in the radar band.

In recent years, synergistic chemo-photothermal therapy has revealed promising potential in treatments against various kinds of cancer. However, the development of superb photothermal agents with high drug loading capacity is still highly required. In this work, a hollow mesoporous polyaniline nanoparticle (HPANI NP) has been developed for encapsulating chemotherapeutic drug doxorubicin (DOX) with an remarkable drug loading content as high as 37.5%. Additional PEG modification endowed the drug-loaded HPANI NPs with improved water-dispersibility and bioavailability. Such PEG-HPANI-DOX NPs exhibited strong NIR absorbance and robust photothermal conversion capacity, exhibiting highly efficient synergistic cancer treatment. More interestingly, the responsively released DOX molecules could emit strong red fluorescence, which could be employed to monitor the cellular endocytosis and drug release profile of PEG-HPANI-DOX NPs. Finally, the as-fabricated NPs showed good biocompatibility and low toxicity, serving as a promising nanoagent for highly efficient drug delivery and cancer combination therapy.

An attempt has been made to combine interfacial polymerization with a fast mixing technique without the use of surfactant. Effects of mixing speed, reaction time, temperature, oxidant-to-monomer molar ratio and nitric-to-monomer molar ratio were tested for electrical conductivity and polyaniline nanofiber size. The findings demonstrate that the diameter of polyaniline nanofiber can be reduced by optimising the synthesising parameter, thereby increasing the electrical conductivity of polyaniline nanofiber. Infrared spectroscopy has shown increased amplitude of the main absorption peak of polyaniline nanofiber during the conversion of aniline to conductive polyaniline nanofiber. The crystalline nature of polyaniline nanofiber has been discovered by the X-ray diffraction spectra. Hall effects experiments have shown that the electrical conductivity of polyaniline nanofiber has improved from 5.2 to 17.5 Scm−1 with an increase in homogenizer speed. The morphological properties of polyaniline nanofiber through electron microscopy scanning have confirmed the decreasing size of polyaniline nanofiber from 50-60 nm to 20–30 nm by increasing the homogenizer speed to 30,000 rpm. These findings demonstrate that higher homogenization speed can split the solution to smaller molecules during polymerization contributing to the creation of smaller nanofiber sizes.

Hypothesis Hydrogel-based sensors have attracted considerable attention due to potential opportunities in human health monitoring when both mechanical flexibility and sensing ability are required. Therefore, the integration of excellent mechanical properties, electrical conductivity and self-healing properties into hydrogels may improve the application range and durability of hydrogel-based sensors. Experiments A novel composite hydrogel composed of polyaniline (PANI), polyacrylic acid (PAA) and 2,2,6,6-tetramethylpiperidin-1-yl)oxyl (TEMPO)-oxidized cellulose nanofibrils (TOCNFs) was designed. The viscoelastic, mechanical, conductive, self-healing and sensing properties of hydrogels were studied. Findings The TOCNF/PANI/PAA hydrogel exhibits a fracture strain of 982%, tensile strength of 74.98 kPa and electrical conductivity of 3.95 S m−1, as well as good mechanical and electrical self-healing properties within 6 h at ambient temperature without applying any stimuli. Furthermore, owing to the high sensitivity of the TOCNF/PANI/PAA-0.6 hydrogel-based strain sensor (gauge factor, GF = 8.0), the sensor can accurately and rapidly detect large-scale motion and subtle localized activity. The proposed composite hydrogel is as a promising material for use as soft wearable sensors for health monitoring and smart robotics applications.

Herein, we report a successful synthesis of supramolecularly assembled polyaniline/silver oxide/graphene oxide composite (PANI/Ag2O/GO) for enhanced NO2 gas sensing application. The PANI/Ag2O/GO composite was synthesized by facile stirring followed by an ultrasonication process. The prepared material was characterized by different techniques such as x-ray diffraction, field emission scanning electron microscopy (FESEM), transmission electron microscopy (TEM), Fourier transform infrared (FTIR) spectroscopy and Raman-scattering spectroscopy. The detailed analysis revealed that the average crystallite sizes of PANI/Ag2O and PANI/Ag2O/GO composites were found to be 37.37 nm and 41.55 nm, respectively. FESEM and TEM analysis showed coral-like rough-surfaced and extensively agglomerated morphology for PANI and ultrathin flexible sheet-like morphology for GO. Ag2O nanoparticles with diameters 20–30 nm were well incorporated in the GO sheets and PANI matrix in the case of PANI/Ag2O/GO composites. The synthesized materials were used to make resistive sensor devices that had a high response to NO2 gas. The fabricated sensors were examined at various temperatures to obtain the optimal sensing temperature. The fabricated NO2 gas sensor device based on PANI/Ag2O/GO composite exhibited a highest sensitivity of 5.85 for 25 ppm at an optimized temperature (100 °C) as compared to the pure PANI (2.5) and PANI/Ag2O composite (3.25). Further, the fabricated sensor device based on PANI/Ag2O/GO composite was also examined at different NO2 gas concentrations.

Antibiotic residues from animal wastes enter underground and surface water streams, posing high risks to public health. Novel technologies capable of removing the residues from the matrix of concern such as animal waste should be developed. This research investigates the development of nanofiber absorbent for removing tetracycline (TC) antibiotic residues from liquid streams of dairy manure produced in a typical dairy farm. Hierarchically structured nanofibrous adsorbent was developed through growing a uniform polyaniline (PAni) nanodots on poly (vinyl alcohol-co-ethylene) (EVOH) nanofiber membrane (NFM). Moreover, Cu2+ ions were chelated on the developed EVOH/PAni-Cl NFM to improve TC adsorption efficiency and selectivity. The TC adsorption capacities of EVOH/PAni-Cl-Cu2+ and EVOH/PAni-Cl) NFM were 1100 mg g−1 and 600 mg g−1 within 120 min., respectively. The NFMs adsorption efficiency was investigated using dairy wastewater. Initial TC concentrations in dairy wastewater sample varied between 20 and 50 ppm. The EVOH/PAni-Cl-Cu2+ NFM showed TC removal of 86% from dairy manure samples at 25 ppm initial TC concentration within 60 min. during batch mode treatment. Results showed that the dynamic binding efficiency of 450 mg g−1 can be achieved at an initial TC concentration of 50 ppm. Furthermore, the NFM displayed efficient chemical and physical stability even after 8 cycles of reusing without significant changes in its performance or hazardous Cu2+ leaching.

Water pollution by synthetic dyes and other organic contaminants is a serious issue of the present days for both mankind and scientists. From the past few years, much attention has been given to the graphene oxide nanocomposites due to their greater ability to adsorb and degrade the industrial pollutants and greater suitability to the environment. In the present research, polymeric graphene oxide (GO) nanocomposites such as GO/polyaniline (PAN), GO/polypyrrole (PPy) and GO/polystyrene (PS) were utilized as promising adsorbents for removal of actacid orange RL (AO-RL) dye. Characterization of synthesized nanocomposites was done by Fourier transform infrared spectroscopy and scanning electron microscopy techniques. Higher adsorption rates were achieved at pH values 2, 6 and 3 for all three nanocomposite GO/PAN, GO/PPy, and GO/PSty. Maximum removal 39.54, 44.76 and 21.43 mg/g were achieved, respectively when optimum adsorbent dose of 0.01 g was used at 35 °C. The maximum adsorption of 39.65, 43.99, and 21.10 mg/g for all three nanocomposites were obtained at the equilibrium contact time of 60 min. For GO/PAN and GO/PPy the maximum adsorption rates were attained when 150 mg/L of initial dye concentration was used and for GO/PSty nanocomposite the maximum removal 54.34 mg/g was obtained when 100 mg/L of initial dye concentration was used. Obtained results showed that removal of AO-RL dye was best fit by the pseudo 2nd order kinetic model and Langmuir adsorption isotherm with R2 values 0.99, 0.997, and 0.986, respectively. Negative values of enthalpy variation: −40.95,-62.95 and −55.52 kJ/mol, respectively, show the spontaneity and exothermic nature of the reaction. So, results indicated that the synthesized polymeric GO nanocomposites have a good perspective for the treatment of wastewater.

The major requirement of a solar light-activated photocatalyst is the effective utilization of the light-induced electron-hole pair and exciton lifetime. Herein, the reduced graphene oxide and polyaniline assisted carbon doped porous ZnO (c-ZnO) heterojunction nanocomposites (RPZ nanocomposites) were designed for enhanced photocatalytic degradation of the commercially available pharmaceutical antibiotic drug amoxicillin and clavulanate potassium (ACP) and methylene blue (MB) dye using natural sunlight. The surface morphology, phase purity, and bonding environment of the prepared RPZ heterojunction nanocomposite were analyzed using scanning electron microscopy, X-ray diffraction, and soft X-ray absorption spectroscopy, respectively. In comparison with pure ZnO, a doping and composite formation reduced the bandgap energy from 3.34 to 2.80 eV, calculated using the Tauc plot. From photocatalytic degradation studies, the as-prepared RPZ heterojunction nanocomposite efficiently degraded 95% and 47% of MB dye and ACP in 100 min under natural sunlight with the reaction rates of 0.0296 and 0.0055 min−1, respectively. The removal efficiency of the photocatalyst was obtained to be 95% and 46.14% for MB dye and ACP, respectively.

In this study, facile preparation using a new solvent – lactic acid and physical properties of PAni-Cs films are observed. The main goal of the study is to easily synthesize PAni-Cs films using lactic acid as solvent through the solvent casting method and investigate if producing PAni-Cs with lactic acid will enhance its properties. The presence of PAni-Cs was confirmed by observing its structure using Fourier transform infrared (FTIR) spectroscopy. The wettability of the films showed that films produced with lactic acid are less hydrophobic than those produced with acetic acid. Consequently, the computed surface energies revealed PAni-Cs films produced using lactic acid were higher. Water uptake of the films showed deviations when PAni and the solvents (lactic acid and acetic acid) were introduced. Furthermore, films produced with lactic acid were observed to be more flexible. These characterizations revealed that PAni-Cs produced with lactic acid are comparable to the properties of those produced with acetic acid showing that lactic acid helps in the improvement of PAni-Cs surface properties.

Carbon nanofiber-based supercapacitors have broad prospects in powering wearable electronics owing to their high specific capacity, fast charge/discharge process, along with long-cycling life. Herein, a poly(acrylonitrile-co-β-methylhydrogen itaconate) copolymer was prepared and used to synthesize flexible hollow carbon nanofibers (HCNFs) via an electrospinning method without breaking after multiple bending. Subsequently, the inner and outer surfaces of HCNFs were evenly covered with ordered needle-like polyaniline (PANI) through in-situ polymerization methods to obtain three-dimensional flexible HCNFs/PANI composites, which exhibited a high capacity 1196.7 F/g at 1 A/g and good cycling stability (90.1% retention at 5 A/g after 3000 cycles). The symmetrical supercapacitor based on the HCNFs/PANI composites also delivered an outstanding electrochemical performance with high energy/power density (60.28 Wh/kg at 1000 W/kg) and superior cycling durability (90% capacitance retention after at 5 A/g 3000 cycles), which confirmed that the HCNFs/PANI composites had a wide application potential in flexible energy storage devices.

Aqueous aluminum ion batteries (AIBs) are attractive alternatives for post-lithium energy storage systems. However, the short lifespan seriously limits the development of AIBs, arising from the formation of a passivation layer on the Al electrode surface as well as the strong electrostatic interaction between bulky Al3+ ions and host materials. Herein, we developed a hybrid electrolyte based on aluminum trifluoromethanesulphonate (Al(TOF)3) and H3PO4 which can effectively alleviate the passivation and exhibit superior stability. A full aqueous AIB based on this electrolyte and polyaniline (PANI) cathode exhibits a record-breaking lifespan of 3850 cycles and superior rate capability. Mechanism study suggests that Al3+ ions are bonded to both the H2PO4− and TOF− to form complex ions Al(H2PO4−)x(TOF−)y+(H2O)n, which can mitigate the strong charge densities of trivalent Al3+ and contribute to fast reaction kinetics. Besides, the ex-situ study reveals that PANI cathode experiences a co-intercalation/deintercalation process of Al(H2PO4−)x(TOF−)y+(H2O)n, TOF−, and H+ during the charging/discharging process with high reversibility and stability. As a proof of concept, an electrochromic Al//PANI battery is fabricated, which combines both electrochromism and energy storage and delivers a higher coloration efficiency of 84 cm2 C−1 at a wavelength of 630 nm. This work presents an effective and facile strategy to developing long-life aqueous Al//PANI batteries and may promote the application of AIBs with electrochromic function.

Herein, [As2IIIAsVMo8VIV4IVO40]2[CuICu2II(pz)4]2·9H2O/polyaniline/reduced graphene oxide (pz = pyrazine, abbreviated to As3Mo8V4/PANi/rGO) composite is first assembled, characterized and systematically explored for its supercapacitor performance. As3Mo8V4/PANi/rGO composite shows a exceptional specific capacitance (2351 F g−1 at 1 A g−1) and outstanding cyclic stability (96.9% after 5000 cycles). The symmetric supercapacitor exhibits high specific capacitance of 1295 F g−1 at 1 A g−1 and excellent energy density of 88.1 Wh kg-1 at power density of 349.6 W kg-1, while maintaining a notable capacitance retention of 85.7% after 5000 cycles at 2 A g-1. The above results confirm the potential application of As3Mo8V4/PANi/rGO composite in energy storage devices.

EOR is a semi-reaction of direct ethanol fuel cells (DEFCs), and determines the performance of the DEFCs. Therefore, it is very important for EOR to rationally design an electrocatalyst with excellent activity, stability and CO-resistance. Based on this, we report the synthesis of MOF based composite catalysts by a facile method, which is formed by combining polyaniline hydrogel (PANH) with MOF 1 and carbon cloth (CC). At the same time, the structures of the composites were characterized by XRD, SEM and XPS. Under the optimum conditions, the j value for EOR is 107 mA cm−2 under alkaline conditions at 0.6 V, which indicates that composite 2 has excellent catalytic activity for EOR, and is superior to that of the previously reported nickel-based catalysts for EOR. The Tafel slope and the exchange current density of composite 2 are 88.9 mV dec−1 and 1.95 × 10−5 A cm−2 respectively. In addition, the j value of composite 2 was 65% of the original value after 1000 CV cycles. However, when the electrolyte was changed into the original one (1 M KOH + 1 M EtOH), the j value returned to 74% of the original value. Based on the excellent electrocatalytic performance, good stability and anti-CO poisoning, composite 2 is expected to be an economic, efficient and CO poisoning resistant electrocatalyst for EOR.

Ferrites are an important group of magnetic materials which are used as absorbers. The incorporation of ferrite and conducting polymer achieves great enhancement in microwave absorption properties. The nanocomposites of hexagonal ferrites embedded by conducting polymers such as polypyrrole, polyaniline and polythiophene (PTH) have been paid much attention. In the present study, strontium hexagonal ferrite doped by Zr and Zn with the final formula of SrFe12-x(ZrZn)0.5xO19 considering x = 0.9 and embedded by PTH was produced to achieve a nanocomposite with the highest microwave absorbing ability. In this study, after synthesis of SrFe12O19(ZrZn)0.5xO19 and PTH, the nanocomposite was prepared by in situ polymerization. Wrapping the ferrite particles and PTH chains could form nanocomposite properly, and therefore acceptable interactions were observable between SrFe12-x(ZrZn)0.5xO19ferrite particles and PTH polymer chains in the composites. Assessing the X-ray diffraction (XRD) patterns of SrFe12-x(ZrZn)0.5xO19, PTH, and PTH/SrFe12-x(ZrZn)0.5xO19 nanocomposite indicated that the PTH characteristic peak shifts slightly and its peak intensity reduces, which may be attribute to the coating of PTH polymer chains onto SrFe12-x(ZrZn)0.5xO19 particles. We revealed also lower magnetic properties in the obtained nanocomposite. The morphological assessment also suggested that PTH could effectively coat the SrFe12-x(ZrZn)0.5xO19 particles. The synergistic effect of SrFe12-x(ZrZn)0.5xO19 particle plus PTH leads to microwave absorption percentage higher than 95% by PTH/SrFe12-x(ZrZn)0.5xO19 nanocomposite. Overall, nanocomposite creating by coupling interaction between SrFe12-x(ZrZn)0.5xO19 particles (x = 0.9) and PTH can effectively lead to achieve the highest rate of absorption of electromagnetic waves.

Raman spectroscopy is widely applied in wood science because of its features of being nondestructive, rapidity, and high resolution. However, Raman scattering is weak, and the Raman signal is easily disturbed by autofluorescence arising from endogenous fluorescent molecules in biological tissue. In this work, a sensitive lignin detection platform was fabricated by a composite with a polyaniline (PANI) nanofiber and toluidine blue (TB) under the excitation of visible light. In this platform, TB acts as a specific marker for lignin, and a PANI nanofiber was used as a reinforcing reagent to improve the Raman intensity of TB. When wood slice is impregnated with TB/PANI, the lignin in wood can be precisely labeled with the TB, and the Raman intensity of TB had a threefold increase at 532 nm excitation. This TB/PANI detection platform is expected to make a significant contribution in qualitative and quantitative analysis of lignin to avoid autofluorescence in various lignin-based biosciences.

In this study, chitosan-polyaniline nanocomposite film was prepared in combination with different concentrations of polyaniline at various synthesis times. Surface morphology, antioxidant properties, water solubility, water vapor permeability (WVP), color properties and light transparency properties of the films were investigated. The size, shape and morphology of the synthesized particles were examined with scanning electron microscopy (SEM) technique. The results indicated that the synthesized polyaniline particles were spherical and in the range of 45–70 nm. The results obtained from the study of the effect of polyaniline on the physical properties of the chitosan film showed that increasing polyaniline concentration and synthesis time causes a decrease in the rate of the water solubility and water vapor permeability. This is an important factor in expanding its use in food packaging. The results of the colorimetric studies showed that the polyaniline sharply changed the surface color of the film. Polyaniline also increased antioxidant properties of composite film. Investigating the light transmission and transparency of the films showed that the polyaniline reduced the transparency and transmission of light, which could be used to package products that are susceptible to oxidation in the light.

Features of creation of porous nanostructured oxides of transition materials on an example of niobium are considered. It has been experimentally shown that variation in anodizing modes makes it possible to obtain non-porous and porous amorphous anodic oxide films (AOF) and films of the crystalline type. It is determined that the process of AOF formation on niobium, as well as its structure and properties depend on such parameters as the type of electrolyte, anodizing voltage, activator concentration, the duration of the process. It is confirmed that the presence of an activator in the electrolyte is a necessary and decisive factor in the process of forming a nanostructured anode oxide layer. To obtain a nanostructured surface of niobium oxide, a necessary condition is the introduction of fluoride into the electrolyte, but also an important task is to determine the type of compound with which F– ions are introduced into the electrolyte. It has been experimentally determined that the optimal solution for the rapid growth of porous crystalline oxide is a solution consisting of a background electrolyte in the form of 1M H2SO4 with the addition of a fluoride ion activator in the form of 0.5M NaF. The increase in the activator accelerates the formation of the crystal structure on the surface of niobium. It is shown that higher voltage and longer anodizing time leads to an increase in the size of microcones and their number on the surface of niobium. Optimal for the formation of porous crystalline oxide is a voltage of 60 V in the electrolyte 1M H2SO4 + 0.5M NaF for 2 hours.

Polyaniline (PANI) is one of the most important conducting polymer and has been widely used in various fields for its tunable electrical conductivity. In this manuscript, conductive polyaniline/ramie fabrics were developed by in situ polymerization and characterized. The effect of aniline content, polyetherimide (PEI) pretreatment, padding and the color depth (K/S value) on electrical resistivity was analyzed. The result showed that electrical conductivity was increased with the increase of aniline (ANI) contents. PEI pretreatment and padding method improved the conductivity of the fabric significantly. The result of K/S value was reversely consistent with the conductivity. Both scanning electron microscope (SEM) and Fourier transform infrared spectroscopy (FTIR) analysis confirmed that polyaniline particles were successfully deposited on the surface of the ramie fabrics. Thermal degradation (TG) measurement showed that polyaniline (PANI) polymerization decreased the onset decomposition temperature. Mechanical measurement showed that pretreatment process reduced the tensile strength of conductive ramie fabrics by 30%. K/S value in full range showed that the color of PANI/ramie fabric was sensible to pH value. Contact angle (CA) measurement disclosed the conductive PANI/ramie fabric was hydrophobic and this hydrophobicity was stable to the change of pH value. The obtained PANI/ramie fabrics can be used as potential conductive multifunctional textiles.

Good conductivity is the key to ensuring high electrochemical performance, and the uniformity of the active material directly affects the electrical conductivity. This paper proposes a novel modified stepwise in situ polymerization method to prepare composite materials, and then uses the K/S value method to characterize the uniformity of polyaniline distribution. Specifically, the study presents a papermaking wet-lay technique to prepare a carbon fiber paper substrate (CP) that is light-weight, flexible, and foldable while also having low internal resistance and high porosity. The γ-MnO2 is wrapped with PANI to form a core–shell structure, and a modified stepwise in situ polymerization method is adopted to deposit the core–shell structure uniformly on the CP substrate by physical adsorption. This process yields a flexible electrode material for supercapacitors, called γ-MnO2-PANI-CP electrode. Results show that the γ-MnO2-PANI-CP electrode has a high specific capacitance of 642.5 F g−1 at a current density of 1 A g−1, and also has a high energy density of 114.2 Wh kg−1 at a power density of 798.6 W kg−1. In addition, the electrode retains 81.3% of the initial capacitance after 5000 cycles, demonstrating high cycling performance.

In this study, polythiophene/Al2O3 (PTh/Al2O3) and polyaniline/Al2O3 (PAn/Al2O3) nanocomposites in the presence of poly(vinyl alcohol) (PVA) as the surfactant were synthesized via in situ chemical oxidative polymerization method in aqueous medium. The synthesized nanocomposites were characterized by scanning electron microscopy (SEM), Fourier transform infrared (FTIR) spectroscopy and X-ray diffraction (XRD). Results indicated that the Al2O3 and poly(vinyl alcohol) influenced the properties of synthesized nanocomposites. The aim of this research was to investigate the sorption characteristics of polythiophene and polyaniline nanocomposites for the removal of heavy metal cations including Pb(II), Zn(II) and Cd(II) from aqueous solution. The factors that affected the adsorption equilibrium as well as the removal efficiency of the nanoadsorbents, i.e., contact time, metal ion concentration, pH and adsorption conditions were investigated in detail. From the kinetic results, it was concluded that the pseudo-second-order kinetic model was found to be the best at describing the adsorption process for Pb(II), Zn(II) and Cd(II) on PTh-PVA/Al2O3 and PAn-PVA/Al2O3. In addition, thermodynamic analysis suggests the endothermic and spontaneous nature of the present adsorption process with increased entropy on PTh-PVA/Al2O3 and PAn-PVA/Al2O3. The results suggest polythiophene, polyaniline and their nanocomposites have great potential to be used as efficient absorbent for the removal of heavy metal ions from water. Highlights Synthesis of polythiophene nanocomposites containing Al2O3.; Products were investigated in terms of morphology.; Batch adsorption experiment was performed for the removal of heavy metal ions.; pH played vital role in the removal process.; The factors that affected the adsorption equilibrium as well as the removal efficiency, i.e., contact time, metal ion concentration, pH and adsorption conditions were investigated.

Metal oxide nanoparticles and their composites with conducting polymers, specifically Polyaniline (PANI) were utilized for fabricating nanoscale supercapacitor (SC) electrode materials. In the present study, we have synthesized pristine Pr2O3, NiO, Co3O4 nanoparticles, binary PANI-Pr2O3, PANI-NiO, PANI-Co3O4, ternary Pr2O3–NiO–Co3O4, and quaternary PANI-Pr2O3–NiO–Co3O4 spherical core-shell nanocomposite using co-precipitation and ultra-sonication methods. The grown samples were characterized with different analytical techniques. The XRD pattern revealed that the as-synthesized products were crystalline with Pr2O3 hexagonal phase, NiO cubic phase, and Co3O4 cubic phase in pure and nanocomposites. The Williamson-Hall, Scherrer, and size-strain plot methods were employed to study the crystalline development and contribution of micro-strain. FTIR pattern exhibited the metal-oxygen and PANI bond vibrations. FE-SEM images shown the spherical core-shell shape morphology of quaternary nanocomposite. EDX evident the presence of praseodymium, cobalt, and nickel in synthesized samples. UV–vis spectroscopy confirmed the absorption in the visible region. The IV graphs showed a higher conductivity of quaternary nanocomposite. The cyclic voltammetry results revealed that the quaternary nanocomposite has a higher specific capacitance 500 Fg-1 as compared to binary nanocomposites 134 F g−1 (PANI-Pr2O3), 143 F g−1 (PANI-Co3O4), 256 F g−1 (PANI-NiO), and PANI (90.8 F g−1) at a scan rate of 5 m Vs−1. The GCD results also showed that the quaternary nanocomposite has a higher specific capacitance of 905 F g−1 at current density 1 A g−1 with maximum energy density and power density of 87.99 kWhkg-1 and 2.6 k W kg−1, respectively. The EIS curve also confirmed that the quaternary nanocomposite has a lower polarization resistance (Rp) and solution resistance (Rs). The higher capacitance of quaternary nanocomposite can facilitate ion transfer, and the formation of its core-shell structure flourish to enhance surface-dependent electrochemical properties. Furthermore, this study gives a novel research idea to manufacture electrode materials for supercapacitors.

Efficacious regulation of the geometric and electronic structures of carbon nanomaterials via the introduction of defects and their synergy is essential to achieving good electrochemical performance. However, the guidelines for designing hybrid materials with advantageous structures and the fundamental understanding of their electrocatalytic mechanisms remain unclear. Herein, superfine Pt and PtCu nanoparticles supported by novel S,N-co-doped multi-walled CNT (MWCNTs) were prepared through the innovative pyrolysis of a poly(3,4-ethylenedioxythiophene)/polyaniline copolymer as a source of S and N. The uniform wrapping of the copolymer around the MWCNTs provides a high density of evenly distributed defects on the surface after the pyrolysis treatment, facilitating the uniform distribution of ultrafine Pt and PtCu nanoparticles. Remarkably, the Pt1Cu2/SN-MWCNTs show an obviously larger electroactive surface area and higher mass activity, stability, and CO poisoning resistance in methanol oxidation compared to Pt/SN-MWCNTs, Pt/S-MWCNTs, Pt/N-MWCNTs, and commercial Pt/C. Density functional theory studies confirm that the co-doping of S and N considerably deforms the CNTs and polarizes the adjacent C atoms. Consequently, both the adsorption of Pt1Cu2 onto the SN-MWCNTs and the subsequent adsorption of methanol are enhanced; in addition, the catalytic activity of Pt1Cu2/SN-MWCNTs for methanol oxidation is thermodynamically and kinetically more favorable than that of its CNT and N-CNT counterparts. This work provides a novel method to fabricate high-performance fuel cell electrocatalysts with highly dispersed and stable Pt-based nanoparticles on a carbon substrate.

Palygorskite was coated with a thin layer of carbon by using a hydrothermal process with glucose, in order to form palygorskite/carbon (Pal/C) composites, which were then used as a template to load polyaniline through in-situ polymerization, thus obtaining dispersed spherical shell-shaped palygorskite/carbon/polyaniline (Pal/C/PANI) ternary composites. The Pal/C/PANI composites exhibit promising electromagnetic absorption performances, which can be optimized by adjusting the content of Pal/C. In this case, palygorskite acts as a skeleton and dispersion agent, which effectively prevents the agglomeration of carbon and polyaniline. Due to the improved impedance matching and increased dielectric loss, the Pal/C/PANI composites display an optimal reflection loss of −74 dB at 6.24 GHz, with a maximum effective absorption bandwidth of 4.96 GHz. Such composites could be candidates as high performance microwave absorbers.

Hybrid electrode materials composed of metal-organic framework (MOF)-derived oxides and conducting polymers have abundant potential for energy applications. The energy storage and conversion phenomena of such materials are due to their high porosity, long stability, good conductivity, low charge transport resistance, and fast charge-discharge rate. Herein, CuxO-C/PANI is synthesized by the in situ polymerization of aniline on multilayered mesoporous CuxO-C from Cu-MOF. Such an integrated hybrid can provide a potential route for electron transfer and improve the kinetics of redox reactions. Subsequently, the CuxO-C/PANI composite demonstrates a maximum specific capacitance of 1308 F g−1 at 1 A g−1 in a 3-electrode system. Additionally, as a fabricated device, CuxO-C/PANI//ZIF-8NPC shows an uppermost energy density of 55.1 W h kg−1 (at a 862.4 W kg−1 power density) and power density of 8668.2 W kg−1 (at a 30.1 W h kg−1 energy density), with 88.3% capacitance retention, even after 10000 cycles. Additionally, CuxO-C/PANI, as an efficient oxygen reduction catalyst, delivers an outstanding onset potential (0.94 V) and half-wave potential (0.76 V) against the reversible hydrogen electrode with good stability. Hence, these results show that the as-fabricated electrode material is an efficient alternative electrocatalyst for energy storage and oxygen reduction applications.

Lithium-sulfur (Li-S) batteries and lithium-selenium (Li-Se) batteries, as environmental protection energy storage systems with outstanding theoretical specific capacities and high energy densities, have become the hotspots of current researches. Besides, elemental S (Se) raw materials are widely sourced and their production costs are both low, which make them considered one of the new generations of high energy density electrochemical energy storage systems with the most potential for development. However, poor conductivity of elemental S/Se and the notorious “shuttle effect” of lithium polysulfides (polyselenides) severely hinder the commercialization of Li-S/Se batteries. Thanks to the excellent electrical conductivity and strong absorption of lithium polysulfide (polyselenide) about electronically conducting polymer, some of the above thorny problems have been effectively alleviated. The review presents the fundamental studies and current development trends of common electronically conducting polymers in various components of Li-S/Se batteries, which involves polyaniline (PANI) polypyrrole (PPy), and polythiophene (PTh) with its derivatives, e.g. polyethoxythiophene (PEDOT) and poly(3,4-ethylenedioxythiophene)-poly(styrenesulfonate) (PEDOT:PSS). Finally, the review not only summarizes the research directions and challenges facing the application of electronically conducting polymers, but also looks forward to the development prospects of them, which will provide a way for the practical use of electronically conducting polymers in Li-S/Se batteries with outstanding electrochemical properties in the short run.

In this study, novel anticorrosion coatings including doped polyaniline, reduced graphene oxide (RGO) and modified clay sodium montmorillonite (Na-MMT) were synthesized. The nanocomposite particles were coated on carbon steel after optimal mixing and dispersion in epoxy resin. In order to increase the dispersibility and increase the functional groups between the graphene plates, the initial graphene oxide nanoparticles were re-oxidized and finally reduced to have a better dispersibility in the composite environment. Sodium dodecyl benzene sulfonic acid (SDBS) was used as a secondary dopant and surfactant. Synthesized nanocomposites were characterized using Fourier-transform infrared spectroscopy (FTIR), X-Ray Diffraction (XRD), Scanning Electron Microscopy (SEM) and Transmission Electron Microscopy (TEM). Furthermore, Open Circuit Potential (OCP), Electrochemical Impedance Spectroscopy (EIS), Fourier-transform infrared spectroscopy (FFT), and salt spray test were used to investigate the electrochemical and anticorrosion behavior of the synthesized composite. The results showed that the initiative of adding certain ratios of RGO and Na-MMT to the polyaniline polymer significantly increased the anticorrosion properties of the coating. It was also found that at the same part ratios, the anticorrosion property of RGO is higher than the anticorrosion property of Na-MMT. According to the Tafel test, the corrosion current of the synthesized nanocomposite was 0.065 μA cm−2, which was lower than the corrosion current of other samples and shows the superiority of the anticorrosion property of this sample. Also, after 720 h of Salt spray test (In 3.5% wt NaCl), a very high and desirable durability of this sample (Sample a) has been observed.

In the present study, a novel nanocomposite (NCs) consisting; Yttrium iron garnet Y3Fe5O12 (YIG) magnetic material, La1.8Sr0.2Ni1-xCoxO4-CaCu3Ti4-xNbxO12 (LSNCO-CCTNO) (0

Flexible wearable electronics were developed for applications such as electronic skins, human-machine interactions, healthcare monitoring, and anti-infection therapy. But conventional materials showed impermeability, single sensing ability, and no designated therapy, which hindered their applications. Thus it was still a great challenge to develop electronic devices with multifunctional sensing properties and self-driven anti-infection therapy. Herein, flexible and breathable on-skin electronic devices for multifunctional fabric based sensing and self-driven designated anti-infection therapy were prepared successfully with cellulose nanocrystals/iron(III) ion/polyvinyl alcohol (CNC/Fe3+/PVA) composite. The resultant composite films possessed robust mechanical performances, outstanding conductivity, and distinguished breathability (3.03 kg/(m2·d)), which benefited from the multiple interactions of weak hydrogen bonds and Fe3+ chelation and synergistic effects among CNC, polyaniline (PANI), and PVA. Surprisingly, the film could be assembled as a multifunctional sensor to actively monitor real-time physical and infection related signals such as temperature, moisture, pH, NH3, and human movements even at sweat states. More importantly, this multifunctional device could act as a self-driven therapist to eliminate bacterial by the release of Fe3+, which was driven by the damage of metal coordination Fe-O bonds due to the high temperature caused by infection at wound sites. Thus, the composite films had potential versatile applications in electronic skins, smart wound dressings, human-machine interactions, and self-driven anti-infection therapy.

High ionic conductivity, good mechanical strength, strong electrode adhesion, and low volatilization are highly desired properties for flexible solid electrolytes. However, it is difficult to realize all these properties simultaneously, which needs a rational synergy of different electrolyte constituents. Here, we present the use of polyoxometalates as versatile enhancers to fabricate nonvolatile flexible hybrid polymer electrolytes with improved conductive, stretchable, and adhesive properties. These electrolytes are based on the molecular hybridization of a polyacrylate elastomer, phosphoric acid, and a commercial polyoxometalate H3PW12O40 (PW). PW can serve as a nanosized plasticizer to favor the chain relaxation of polyacrylate and improve stretchability. Meanwhile, PW as a solid acid can increase the proton concentration and form a hybrid hydrogen-bonding network to facilitate proton conduction. Besides, the strong adsorption ability of PW on solid surfaces enables the electrolytes with enhanced adhesion. The hybrid electrolyte with 30 wt % PW shows a break stress of 0.28 MPa, a break elongation of 990%, and a conductivity of 0.01 S cm-1 at 298 K, which are 1.8, 1.8, and 2.5 times higher compared to the case without PW, respectively. Moreover, PW enhances the adhesive strength of hybrid electrolytes on polypropylene, steel, and glass substrates. The flexible supercapacitors based on the hybrid electrolytes and polyaniline electrodes hold a stable electrode-electrolyte interface and exhibit a high specific capacitance of 592 mF cm-2 and an excellent capacitance retention of 84% after 6000 charge-discharge cycles. These results demonstrate great potential of polyoxometalates as multifunctional enhancers to design hybrid electrolyte materials for energy and electronic applications.

Free-standing flexible supercapacitive electrodes have practical application for wearable energy storage devices. In this paper, graphene paper (GP), a flexible electrode substrate, was prepared by one-step reduction of graphene oxide (GO) using HI solution. GP can be used independently as a flexible electrode with specific capacitance of 227 F/g. In order to make up for the shortage of GP specific capacitance storage, polyaniline (PANI) with high specific capacitance and good electrical conductivity was selected to composite with GP by electrochemical polymerization approach. This method to fabricate electrode material by direct electrochemical polymerization avoids the use of conductive binder and organic solvent. Owing to the specific capacitance contribution of PANI and GP, the PANI/GP composites exhibit higher specific capacitance when the polymerization time is 30 s and the polymerization voltage is 0.8 V. At 1 A/g current density, the specific capacitance of composite is up to 759 F/g, which is 3.34 times of neat GP.

This study reports on the electrical conductivity, dielectric, and electromagnetic interferenc (EMI) shielding properties of conductive epoxy/PAni blend containing various concentrations. Polyaniline (PAni) was synthesized using oxidative chemical polymerization technique and then dispersed into epoxy resin using a sonication bath. Infrared spectra confirm the curing of composites. Increasing the aspect ratio of PAni in epoxy increased the electrical conductivity and improves the microwave absorption properties of composites in the microwave range (0.1 GHz–20 GHz). Electrical conductivity was measured by using the four-probe method, and the maximum conductivity of the composite was achieved 3.51 × 10−13 Scm−1 with 30 wt% of PAni. The maximum porosity of the composite with 30 wt% of PAni was 15.5%. EMI shielding was measured by a vector network analyzer (VNA) in the microwave region (0.1 GHz–20 GHz), which gives the maximum value of 63 dB. IR shielding was measured by IR spectroscopy and less than 0.5% transmission was observed in NIR (700 nm–2500 nm) region. The average particle size of PAni is found to be 113 nm. These composites were used as a potential candidate for conductive coatings, EMI shielding purposes, and electronic applications.

Based on recent advancements, the emission of electromagnetic radiation has become a serious issue of electromagnetic interferences. These electromagnetic interferences comprise of various undesirable emission of radiation that can create unwanted deprivation of equipment or structure performance. If these complications remain unresolved can create extreme damage to the security operation or communication system of several electronic devices. Various studies have been made to resolve these problems. In past years, electrically conductive polyaniline has attained a unique position due to the prosperity of its features. The absorption of microwave and EMI shielding characteristics of the electrically conductive polyaniline can be described in the relation of great electrical conductivity with strong relaxation and, polarization effects due to the existence of stronger bonds or localized charges. In the present article, the advancement in electromagnetic interference shielding with the use of nanosized polyaniline particles and their derivative nanocomposites is discussed by various parameters such as the size of the particle, absorption properties, magnetic properties, reflective properties, electrical conductivities, and dielectric properties. The electromagnetic absorption performance of conducting polyaniline nanocomposites associated with dielectric nanomaterials (graphene) and magnetic materials (γ-Fe2O3) are widely discussed. The most appropriate polyaniline-based nanocomposites can be identified by this context. Due to increasing demand of electrically conductive polyaniline for shielding materials, it is considered to be review for better understanding in advancement. This article presents recent electromagnetic interference shielding materials knowledge of nanosized polyaniline and their nanocomposites as well as their possibilities and challenges.

In the present study, polyamide 6@polyaniline-reduced graphene oxide (PA6@PANI-rGO) core shell nanofibrous composite was prepared by exploiting several fabrication techniques. Firstly, PA6 nanofibers (the core) were produced via electrospinning method. Then, aniline monomers were polymerized on the surface of the PA6 nanofibers via in situ polymerization method, leading to PA6@PANI nanofibers. In the next step, PA6@PANI-GO was prepared by immersing PA6@PANI into a GO suspension. Finally, PA6@PANI-GO was reduced by hydrazine to achieve PA6@PANI-rGO. The final product was then characterized via field emission scanning electron microscopy (FESEM), transmission electron microscopy (TEM), X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), thermal gravimetric analysis (TGA), N2-adsorption–desoption method, tensile testing and water contact angle (WCA) analysis techniques. FTIR analysis demonstrated the successful synthesis of PA6@PANI-rGO, due to the existence of the PA6, PANI and rGO characteristic peaks in the final product spectrum. Furthermore, FESEM and TEM images showed the successful coating of rGO on the surface of the PA6@PANI nanofibers. In addition, PA6@PANI-rGO nanofibers exhibited improved hydrophilicity, lower WCA (40°) and higher porosity compared to the pristine PA6. A comparison of the tensile stress and thermal degradation of PA6 and PA6@PANI-rGO nanofibers exhibited that the existence of PANI and rGO coatings on the surface of PA6 improved the mechanical properties and thermal stability of the coated nanofibers of about 31% and 25%, respectively. Chromium (VI) removal studies for PA6@PANI-rGO showed its bright future in heavy metal elimination from the wastewater.

Adsorption of Cu(II), Co(II), Cd(II), Ni(II), Pb(II), Zn(II) and Fe(III) ions from aqueous solutions of their salts on the surface of pine sawdust in situ immobilized by polyaniline has been studied under static mode at various pH values. The adsorption of all the ions has been found to increase as the pH value grows. The sawdust in situ immobilized by polyaniline has been shown to adsorb as much as 56 mg/g of Fe(III) ions from slightly alkaline solutions (pH 8) within just the first several minutes of the experiment which could be used for the purification of industrial waste solutions from these ions. Such composites based on the sawdust in situ modified by polyaniline could also be potential adsorbents for purification of national water resourced contaminated by Pb(II) and Cd(II) in slightly alkaline solutions (pH 8) to reach their limit concentrations.

Supercapacitors (SCs) have received worldwide attention as energy devices for wearable smart systems. Biocompatibility and self-charging property of SCs require serious consideration, but the related studies are just in their infancy. Here, a “sweat-chargeable” on-skin SC using biocompatible NaCl electrolyte and freestanding polyaniline/carbon nanotube (PANI/CNT) electrodes is presented. Although the capacitance of the biocompatible SC is about half of that using conventional skin-irritated H2SO4 electrolyte, the potential window extends from 0.8 V to 1.4 V. Thus, a higher energy density can be obtained. The self-charging property is achieved by simply adding a piece of Zn foil on one electrode with silver paste, which provides energy source and maintains a super compact two-electrode configuration of SC. The sweat absorbed from human body could trigger the redox reaction between the added Zn foil and oxygen in air, resulting in the self-charging of the device to 0.652 V in 6 min. To demonstrate its wearability in real applications, a “sweat-chargeable” band is prepared that can spontaneously power a timer or a pedometer when the user is exercising. This work has made a further step in the development of biocompatible and practical wearable energy devices.

In the last years, the development of photocatalysts has gained a growing interest in the photoelectrochemical conversion. Here, we report a hetero-junction organic/inorganic (Polyaniline (PANI)) on n type Silicon substrate prepared by electrophoretic deposition (EPD). ZnO nanorods (NRs) are grown by chemical bath deposition (CBD) on seed layer of ZnO prepared by dip coating onto the PANI layer. The relief and morphological properties are investigated by both atomic force microscope (AFM) and scanning electron microscopy (SEM). The forbidden bands (Eg) of 1.12 and 3.26 eV are obtained for PANI and ZnONRS respectively. The optical and dielectric constants are determined by the diffuse reflectance where the extinction coefficient (k), the refractive index (n), optical conductivity, dissipation factor and relaxation time are extracted. The semi conductivity is highlighted by the capacitance measurement; a flat band potential (Efb = 0.541 V) for ZnONRs-PANI is deduced from the Mott-Schottky plot. The contributions of the bulk and grain boundaries of the electrode are evidenced from the electrochemical impedance spectroscopy (EIS). The as-fabricated samples show improved photoactivity compared to PANI and ZnONRs. Indeed, the hetero-junction exhibits a high stability and recyclability for the photodegradation of Orange II (OII) after six cycling runs. The current research offers a new understanding of designing a high performance of the photocatalyst under solar light based on PANI for the wastewater treatment.

A general strategy has been developed here to supramolecular self-assembly of nickel (Ⅱ)-substituted α-Keggin-type polyoxometalate and polyaniline coated Fe2O3 hollow nanospindle (Fe2O3 hollow nanospindle@PANI/α-SiW11Ni composites) via electrostatic attraction and hydrothermal method. Fe3+ was first hydrolyzed and polymerized into Fe2O3, then dissolved into [Fe(H2PO4)x]3−x, resulting in hollow structure. The polyoxometalate existed in polyaniline as a proton-doped counter-ion form, rather than as a separate crystalline state. The protons and anions entered the PANI main chain and combined with N atoms of amines and imines on the PANI chain ((-NH‧+ ​= ​)/α-[SiW11Ni(H2O)O39]6-) to form poles and bipolar delocalization into π bonds of the whole polyaniline molecular chain, which leaded to conductance and polarization. The Fe2O3 hollow nanospindle@PANI/α-SiW11Ni composites were proven to be excellent microwave absorber in terms of reflection loss (RL) and bandwidth. The maximum RL value was up to −53.6 ​dB at 3.5 ​mm and 6.9 ​GHz. The broadest absorption bandwidth exceeding −10 dB was 6.3 ​GHz at a thickness of only 1.9 ​mm. Moreover, the ternary composites presented obvious multi-band absorption with the matching thickness range of 1.5–5 ​mm. The absorption peaks bandwidth reached as wide as 14.3 ​GHz, which included all C-Ku bands. The hollow and core-shell structures could provide non-uniform interface for the induced polarization loss and space for the reflecting and scattering of microwave. The carrier, pair-ion carrier and hydrogen bond network could lead to conduction loss. The magnetic losses were caused by eddy current effect and natural resonance. This work can lay a theoretical foundation for the design and performance regulation of new absorbing materials.

The graphic carbon nitride/polyaniline (g-C3N4/PANI) hybrid composites were successfully synthesized by a facile in situ polymerization process under ice water bath. The photocatalytic activities of the g-C3N4/PANI composites were evaluated by using oxytetracycline (OTC) as model pollutants. The optimal g-C3N4/PANI composite (5%PANI: the g-C3N4/PANI hybrid with 5 wt.% of PANI) showed an enhancement degradation rate of 5-fold compared to that of conventional g-C3N4 under simulated-sunlight irradiation. In addition, the 5%PANI demonstrate significantly photocatalytic evolution H2 rate (163.2 μmol/(g⋅hr)) under the visible light irradiation. Furthermore, based on the results of optical performance and electrochemical testing, a possible mechanism was proposed, indicating that the incorporation of PANI into the traditional g-C3N4 can effectively tune the electronic structures, improve the photo-generated electrons-holes separation and enhance extensive absorption of visible light. Such a g-C3N4/PANI hybrid nanocomposites could be envisaged to possess great potentials in practical wastewater treatment and water splitting.

A new synthesized polyaniline/starch/hematite bio composite (PANI/S/Fe2O3 BC) has been studied as an effective material for on-site water remediation. PANI/S/Fe2O3 BC was developed by combining the techniques of co-precipitation and interfacial polymerization in the presence of aqueous starch solution in an acidic medium under ultrasonic irradiation. The nano-morphologies and structures of the designed PANI/S/Fe2O3 BC were evaluated by various techniques relative to PANI and Fe2O3 nanoparticles. In single and multiple systems, PANI/S/Fe2O3 BC was evaluated as a possible adsorbent for different heavy metals, including As3+, Zn2+, and Co2+, relative to PANI and Fe2O3 nanoparticles. In terms of pH value, operating temperature, initial heavy metal concentration, contact time, adsorbent dose and competitive ions in the solutions, the adsorption process was optimized. For 92% overall adsorption of Co2+ and 100% overall adsorption of both As3+ and Zn2+, the adsorption equilibrium was achieved within 60 and 120 min, respectively. In addition, adsorption thermodynamic analysis shows that the As3+ ions adsorption process was not random and the pseudo-second-order fitted with experimental results. Moreover, PANI/S/Fe2O3 BC was evaluated as an antibacterial agent against Gram-negative bacteria (Salmonella typhimurium) and Gram-positive bacteria (S. aureus, Methicillin-Resistant Staphylococcus, Aureus Clinical isolate and Bacillus subtilis). The reported performances indicated that the PANI/S/Fe2O3 BC is a potent candidate for industrial water bioremediation.