Porous Polyaniline Research Articles

Novel High-Strength and High-Temperature Resistant Composite Material for In-Space Optical Mining Applications: Modeling, Design, and Simulation at the Polymer and Atomic/Molecular Levels.

This study explores the modeling, design, simulation, and testing of a new composite material designed for high-strength and high-temperature resistance in in-space optical mining, examining its properties at both the polymer and atomic/molecular levels. At the polymer level, the investigation includes mechanical and thermal performance analyses using COMSOL Multiphysics 6.1, employing layerwise theory, equivalent single layer (ESL) theory, and a multiple-model approach for mechanical modeling, alongside virtual thermal experiments simulating laser heating. Experimentally, porous Polyaniline (PANI) films are fabricated via electrochemical polymerization, with variations in voltage and deposition time, to study their morphology, optical performance, and electrochemical behavior. At the atomic and molecular levels, this study involves modeling the composite material, composed of Nomex, Kevlar, and Spirooxazine-Doped PANI, and simulating its behavior. The significance of this work lies in developing a novel composite material for in-space optical mining, integrating it into optical mining systems, and introducing innovative thermal management solutions, which contribute to future space exploration by improving resource efficiency and sustainability, while also enhancing the understanding of PANI film properties for in-space applications.

Lightweight and compressible PANI/Ti3C2Tx/EVA composite foam for tunable microwave absorption

Dynamic deformation and absorbing regulation are still challenging for designing lightweight and high-efficiency microwave absorbing materials, which are of great indispensability to satisfy changeable and complex electromagnetic environments. Herein, a compressible composite foam with sea-island structure was prepared by loading porous polyaniline (PANI)/Ti3C2Tx composites on ethylene/vinyl acetate (EVA) skeleton via a thermally induced phase separation strategy. The composite foam exhibits a minimum reflection loss (RLmin) of −57.84 dB and an effective absorption bandwidth (EAB, RL ≤ −10 dB) of 1.86 GHz (8.2–10.05 GHz) at 3.4 mm. Notably, the microwave absorption (MA) performance can be precisely regulated by simply adjusting the compression ratio of composite foam. The RL peaks shift towards higher frequencies with increasing compression ratios, originating from changes in the internal conductive network. Even under 30 % compression strain, the composite foam still maintains RLmin of −21.53 dB and broadens EAB up to 2.71 GHz at 2.0 mm. This combination of compression capabilities and dynamically tunable MA performance may expand a novel approach to designing multifunctional polymer-based foam.

A robust polyaniline hydrogel electrode enables superior rate capability at ultrahigh mass loadings

Simultaneously achieving high mass loading and superior rate capability in electrodes is challenging due to their often mutually constrained nature, especially for pseudocapacitors for high-power density applications. Here, we report a robust porous polyaniline hydrogel (PPH) prepared using a facile ice-templated in situ polymerization approach. Owing to the conductive, robust, and porous nanostructures suitable for ultrafast electron and ion transport, the self-supporting pure polyaniline hydrogel electrode exhibits superior areal capacitance without sacrificing rate capability and gravimetric capacitance at an ultrahigh mass loading and notable current density. It achieves a high areal capacitance (15.2 F·cm−2 at 500 mA·cm−2) and excellent rate capability (~92.7% retention from 20 to 500 mA·cm−2) with an ultrahigh mass loading of 43.2 mg cm−2. Our polyaniline hydrogel highlights the potential of designing porous nanostructures to boost the performance of electrode materials and inspires the development of other ultrafast pseudocapacitive electrodes with ultrahigh loadings and fast charge/discharge capabilities.

Porous polyaniline/flower-like hybrid phase MoS2/phosphorus-doped graphene ternary nanocomposite for efficient room temperature ammonia sensors

Ammonia, a ubiquitous gas with diverse industrial applications, demands reliable and cost-effective sensing technologies for monitoring and control. In this context, this study presents the development of a novel ternary nanocomposite comprised of porous polyaniline (PANI), hybrid phase molybdenum disulfide (MoS2), and phosphorus-doped graphene (PGO) for the realization of highly efficient room temperature ammonia sensors. The synergistic combination of these three materials leverages their individual properties, such as high surface area, excellent electrical conductivity, and enhanced catalytic activity, to create a robust sensing platform. The PANI/1 T-2 H MoS2/PGO nanocomposites were synthesized by a combination of solvothermal processing and in-situ polymerization techniques. The morphological and structural characteristics of the PANI/1 T-2 H MoS2/PGO nanocomposites were conducted using advanced analytical techniques, that include, Scanning Electron Microscopy (SEM), X-ray Diffraction (XRD), Raman spectroscopy, Transmission Electron Microscopy (TEM), and X-ray Photoelectron Spectroscopy (XPS), and Brunauer-Emmett-Teller method (BET). The enhanced surface area of PANI/1 T-2 H MoS2/PGO (54.72 m2/g) compared to PANI (31.8 m2/g) has a positive impact on the sensing characteristics of PANI/1 T-2 H MoS2/PGO. The PANI/1 T-2 H MoS2/PGO nanocomposite sensor has shown sensing response values of ∼1070 %, response time of 12 s, recovery time of 30 s towards 100 ppm of NH3, and detection limit is 0.01 ppm (10 ppb). A highly linear gas response of the PANI/1 T-2 H MoS2/PGO sensor is observed in a range of 10–100 ppm ammonia concentration. The development of the PANI/1 T-2 H MoS2/PGO nanocomposite sensor aims to meet the increasing need for temperature-efficient, cost-effective, and energy-efficient gas sensing technologies that can be used in various fields including environmental monitoring and industrial safety.

Functionalization of Carbon Electrode Surface Using Polyaniline and Gold Nanoparticles for Protein Immobilization

This study presents a screen-printed carbon electrode surface functionalization to immobilize proteins. The process involves the deposition of gold nanoparticles on the carbon electrode and subsequent surface modification to immobilize bovine serum albumin–fluorescein isothiocyanate conjugate (BSA-FITC). A combination of conducting polymer and gold nanoparticles was employed to enhance the electrode contact area and current transmission. The electrode surface morphology and properties were evaluated by scanning electron microscopy (SEM) and Raman spectroscopy, showing the porous polyaniline (PANI) film has been formed on the carbon electrode surface with the network of dendritic nanofibers. Gold nanoparticles were evenly distributed on the PANI film to form a nanocomposite material layer on the carbon electrode. The observed size of these gold nanoparticles was significantly smaller than those on the electrode without a PANI film. Additionally, the current transmission of this composite material layer has been verified by cyclic voltammetry (CV). The results show that the amplitude of the redox peak was doubled compared to the bare carbon electrode and gold nanoparticle-only deposited electrode. Moreover, the success of the process was verified by fluorescence and cyclic voltammetry. The fluorescent green color observed under the microscope indicated that BSA-FITC was on the electrode surface. The change of CV signal after each step verified the formation of a new layer on the electrode surface. These results are anticipated to play an important role in developing high-sensitivity immunosensors in the future.

Electrochromic Polymers: From Electrodeposition to Hybrid Solid Devices

This paper reports on the linear colorimetric and electrochromic (EC) characteristics of electrodeposited polyaniline (PANI) films. This paper also investigates the infrared EC properties of acid-doped PANI films. The electrochemical polymerization method was employed to create a porous and thin PANI film layer onto PET-ITO substrates. This layer was capped with WO3 film to create a gel electrolyte sandwich structure that demonstrates the compatibility of PANI films with cathodic WO3 films in full devices. The electrodeposition of the film was fabricated by applying different voltages and time, with the optimal film quality achieved with the 1.7 V voltage and a 20 min deposition period. The surface morphology, optical performance, electrochemical behavior, and molecular structure evolution are comprehensively studied in this work. The linear colorimetric behaviors and the corresponding significant changes in the structure in Raman spectra build direct strong quantitative relations in EC polymers. The well-defined oxidation and reduction peaks observed in the cyclic voltammetry indicate the ion-diffusion dominant process in the electrochromism of PANI. Significant transitions between the benzene and quinone phases in the Raman spectra are found in the bleached and colored states of polymers. This study enhances the understanding of PANI film structure and electrochemical and associated optical properties, providing more insights into the dual-function EC charge storage polymers and other energy-related functional materials.

In situ construction of ultra-thin PANI/CeOx layer on proton exchange membrane for enhanced oxidation resistance in PEMFC

Free radical degradation of proton exchange membranes (PEMs) under in situ conditions commonly leads to performance losses in proton exchange membrane fuel cells (PEMFCs). Blending or doping with antioxidative additives in the polymer matrix has been widely exploited to mitigate oxidative degradation. However, this approach commonly has additional challenges, including reductions in proton conductivity and diffusion loss of antioxidative additives, leading to the overall loss of fuel cell performance. Herein, we develop an alternative strategy of in situ growth of thin porous polyaniline (PANI) film on the proton conductive sulfonated poly (biphenyl indole) membrane (SBPIM), encapsulating free radical scavenger (ceria oxide, CeOx) inside. The porous PANI film functions as a scaffold to suppress agglomeration or diffusion loss of CeOx. Ex situ Fenton's reagent and in situ durability tests demonstrate that this PANI/CeOx thin layer significantly prevents free radical attack on the PEM without sacrificing fuel cell performance. A H2/O2 PEMFC test exhibits a promising peak power density (988 mW cm−2 at 80 °C with 100 % RH) and at least 400 h open circuit voltage (OCV) durability.

Highly porous polyaniline- or polypyrrole-derived carbons: Preparation, characterization, and applications in adsorption

Highly porous polyaniline- or polypyrrole-derived carbons: Preparation, characterization, and applications in adsorption

Three‐dimensional porous magnetic polyaniline supported Ag nanoparticles nanocomposites as an efficient and recyclable catalyst for nitrophenol reduction

AbstractAg nanoparticles (Ag NPs) nanocomposites are promising catalysts for nitro compound reduction, but simultaneously meeting the requirements of high catalytic activity, stability, recyclability and facile preparation is highly difficult. Herein, the three‐dimensional (3D) porous magnetic polyaniline (PANI) was synthesized using phytic acid (PA) as the dopant/crosslinker, and a recyclable PANI/Ag NPs nanocomposite (PMPA) was obtained through the in situ redox between PANI and AgNO3. Characterization results demonstrate that PMPA exhibits a typical 3D porous structure constructed by coral‐like PANI framework with well‐dispersed Ag NPs (10–20 nm) firmly anchored. The PMPA can efficiently catalyze the 4‐nitrophenol (4‐NP) reduction, with a reaction rate constant of 9.5 × 10−3 s−1 (and 1067.4 s−1 g−1), which is highly competitive to the previously reported high‐performance Ag NPs catalysts. This is probably due to the favorable mass/electron conduction of 3D porous structure and strong interaction between PA and Ag. Moreover, the magnetism renders PMPA recyclability via a simple magnetic attraction, and the reaction rate constant remains at a high level after six reuse cycles, up to 4.8 × 10−3 s−1. This work highlights the important role of 3D porous PANI in structure of Ag NPs nanocomposites, and paves a new way to develop recyclable catalysts with facile preparation and high catalytic performance.Highlights Facile synthesis via in situ reaction between 3D porous PANI and AgNO3. Stable dispersion and strong anchor attributed to phytic acid. Conductive porous structure to facilitate mass/electron transportation. Outstanding catalytic performance for 4‐NP reduction and recycle by magnetism.

2D/3D porphyrin-based porous polyaniline derivatives for highly efficient adsorption of Au3+ ions

Developing multi-functional porous organic polymers (POPs) to solve metal ions environmental pollution still faces challenges. In this work, two-dimensional (2D) and three-dimensional (3D) porphyrin-based porous polyaniline derivatives were obtained by chemical oxidation polymerization. Benefiting from their large pore structure, good hydrophilic properties and excellent coordination ability, they showed excellent adsorption properties. The adsorption results show that they have high adsorption selectivity and efficiency for Au3+ ions. The maximum adsorption efficiency of Au3+ ions was 99.7%, and the maximum adsorption capacity was 1152 mg g−1. The adsorption mechanism was investigated and discussed, providing theoretical support for the design of novel porphyrin-based POPs for Au3+ ions adsorption. This work opens up a new path for the development of novel porphyrin-based POPs.

Synergistic effect of electrochemically fabricated polyaniline nanofibers and silver for efficient solar steam generation

Solar steam generation (SSG) has been recognized as a promising and green technology to resolve the scarcity of drinking water in the near future. On the other hand, there are still several challenges associated with SSG system to its practical utilization. Design of suitable photothermal materials with high solar absorption and conversion efficiency is one of the challenges associated with the SSG technology. Herein, we demonstrated a strategy for the fabrication of bilayer structure of porous polyaniline (PANI) nanofibers and conducting silver (Ag) on a carbon cloth (PANI/Ag@CC) substrate using a facile electrochemical deposition approach. As prepared binder-free PANI/Ag@CC showed an excellent steam generation rate of 2.21 kg/m2h with superior evaporation efficiency of 98.0 % under 1 sun illumination when used for the SSG application. Furthermore, the bilayered PANI/Ag@CC exhibited excellent durability, effective seawater desalination and wastewater purification. The superior SSG performance is associated with the synergistic effect of surface plasmon resonance of Ag and porous PANI nanofibers. Therefore, practically simple fabrication, outstanding evaporation rate and water purification properties convince that the PANI/Ag@CC structure can be a promising candidate for SSG applications.

Enhanced desalination performances by using porous polyaniline-activated carbon composite flow-electrodes in capacitive deionization system

Flow electrodes capacitive deionization (FCDI) is a promising CDI variant, and has been used in various fields like brackishwater desalination and nutrients recovery. Activated carbon (AC), a prevalent FCDI electrode, suffers from low ion adsorption capacity, poor electric conductivity, and large viscosity, which restrict their large-scale applications. In this study, situ polymerization was utilized to prepare porous polyaniline and activated carbon composite (pPANI-AC) electrode with the assistance of ice template. This innovative electrode took advantages of the pseudocapacitive effects of porous polyaniline and the ion channels was increased by exposing the pores and surface of the porous activated carbon. The new composite electrode has an increase in specific surface area from 213.5 m2 g−1 to 616.1 m2 g−1, and an increase in capacitance from 93 to 178 F g−1, and the viscosity flow electrodes decreases from 127 to 21 Pas. Reduced viscosity and intrinsic impedance of the flow electrode result in an increase in flow electrode conductivity and ionic capacity of the FCDI system that has a 70 % increase in desalination capacity. This study developed a low-cost and environmentally friendly active material for high-efficient flowable electrodes, which will pave way for the real applications of FCDI technology.

Achieving Stable Zinc Metal Anode Via Polyaniline Interface Regulation of Zn Ion Flux and Desolvation

AbstractAqueous zinc‐ion batteries feature high safety, low cost, and relatively high energy density; however, their cycle life is hindered by severe Zn dendrite formation and water‐induced parasitic reactions. Herein, a porous polyaniline (PANI) interfacial layer is developed on the surface of Zn metal anode to regulate the transport and deposition of Zn2+, achieving an ultra‐stable and highly reversible Zn anode. Specifically, the abundant polar groups (NH and N) in PANI have a strong attraction to H2O, which can trap and immobilize H2O molecules around Zn2+. Moreover, the protective layer regulates ion flux and deposition behavior of Zn2+ through the ion confinement effect. Consequently, the Zn@PANI anode exhibits improved reversible plating/stripping behavior with a low nucleation overpotential (37.9 mV) at 2.0 mA cm‐2 compared to that of bare Zn anode. The MnO2//Zn@PANI cell demonstrates a high capacity retention of 94.3% after 1000 cycles at 1.0 A g−1. This study lays the foundation for accessible interface engineering and in‐depth mechanistic analysis of Zn anode.

Incorporating polyimide cathode materials into porous polyaniline xerogel to optimize the zinc-storage behavior

Polyimide is a kind of promising organic-based electrode material for zinc ion batteries (ZIBs), with the merits of resource sustainability, environmental friendliness and structural diversity. At present, however, the study on polyimide-based electrode for ZIBs is fairly few, and the limited conductivity and capacity are also needed to be overcome. Here, a polyimide cathode material denoted as PUI is synthesized by using perylene-3,4,9,10-tetracarboxylic dianhydride and urea, and the zinc-storage performance is comprehensively optimized by taking advantage of a 3-D porous polyaniline (PANI) xerogel carrier, for instance, the specific capacity of PUI/PANI composite is 72 % higher than that of PUI, and the rate performance and cycling stability are both improved as well. The analysis of electrochemical kinetics reveals that the 3-D porous PANI can facilitate fast electron/ion transportation and high capacitive contribution during discharging and charging. Moreover, the mechanism analysis demonstrates the synergistically enhanced zinc-storage capacity of CO (in PUI) and N (in PANI) in PUI/PANI. This work promotes the application potential of polyimide-based cathode materials, and also highlights the valuable role of porous conducting polymer (e.g., PANI) in constructing high-performance cathode materials for ZIBs.

In-situ construction of electrodeposited polyaniline/nickel-iron oxyhydroxide stabilized on nickel foam for efficient oxygen evolution reaction at high current densities

We report an in-situ construction method for the NiFe-based oxyhydroxide OER electrocatalyst supported on the nickel foam (NF) substrate with the polyaniline (PANI) interlayer by sequential electrochemical deposition steps (NF/PANI/NiFe–OH). The ultra-thin nanosheet for the nickel-iron (oxy)hydroxides tightly grown on the porous PANI exhibits the enhanced electrochemical characteristics associated with the promotion roles of the PANI layer, which increases the number of active sites, facilitates the charge transfer, and accelerates water transport across the interfaces of the electrode. The as-prepared NF/PANI/NiFe–OH has reliable lower overpotentials of 260, 340, and 490 mV without iR-correction at 50, 100, and 200 mA cm−2 of high current densities, respectively. The smaller Tafel slope, larger ECSA, and TOF values of the electrode reveal its high intrinsic activity. Moreover, the electrode shows good stability and durability without the damage of morphology, change of surface chemical state, and substantial loss of active components at high current density.

Facile synthesis of 3D porous polyaniline composite with MnO2-decorated fiber morphology and enhanced electrochemical performance

3D porous polyaniline (PANI) with the inherent characteristics of nanoporous structure, large specific surface area, and fast electron/ion transport is an ideal candidate of electrochemical electrode. Herein, in an effort to further enhance the electrochemical performance, manganese sulfate was added into precusor solution of PANI gel, and the PANI/MnO2 composite with porous structure constructed by MnO2 decorated PANI nanofibers was formed via self-assembly, in situ reaction and hydrothermal treatment. As a result, the specific capacitance of PANI/MnO2 (328 F g−1, 0.5 A g−1) increased by 35.5% compared with 3D porous bare PANI (242 F g−1, 0.5 A g−1), and the superb charge transfer behavior was also retained. In addition, the quantitative analysis of kinetics on PANI/MnO2 showed that both capacitive and diffusion-controlled behaviors contributed to the electrochemical performance. Moreover, the symmetric supercapacitor (SSC) assembled by two identical PANI/MnO2 electrodes exhibited an ultra-high potential window (2.2 V), so that it achieved high energy density of 25.5 Wh kg−1 at power density of 499 W kg−1. The enhanced electrochemical should be attributed to superior ion/electron conduction and structural stability enable by the nanoporous structure and continuous fiber conductive framework, and the synergistically electrochemical behavior between PANI and MnO2. The present work well promoted the development of 3D porous polyaniline composite electrode materials with the ideal nanostructure and electrochemical activity for high-performance supercapacitors.

Spatiotemporal Mapping of Extracellular Electron Transfer Flux in a Microbial Fuel Cell Using an Oblique Incident Reflectivity Difference Technique.

Extracellular electron transfer (EET) is a critical process involved in microbial fuel cells. Spatially resolved mapping of EET flux is of essential significance due to the inevitable spatial inhomogeneity over the bacteria/electrode interface. In this work, EET flux of a typical bioanode constructed by inhabiting Shewanella putrefaciens CN32 on a porous polyaniline (PANI) film was successfully mapped using a newly established oblique incident reflectivity difference (OIRD) technique. In the open-circuit state, the PANI film was reduced by the electrons released from the bacteria via the EET process, and the resultant redox state change of PANI was sensitively imaged by OIRD in a real-time and noninvasive manner. Due to the strong correlation between the EET flux and OIRD signal, the OIRD differential image represents spatially resolved EET flux, and the in situ OIRD signal reveals the dynamic behavior during the EET process, thus providing important spatiotemporal information complementary to the bulky electrochemical data.

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

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

Porous polyaniline tube-like/TiO2 nano-heterostructure for sensing hydrogen gas at environmental conditions

In this study, porous polyaniline tube-like/TiO 2 nano-heterostructure (PPTH) was prepared by a chemical oxidative polymerization to be used in H 2 sensing. The surface morphology of polyaniline, the content of one-dimensional TiO 2 nanostructures (1D TiO 2 ), and the porosity of PPTH significantly affected the sensing performance of the samples. The response and response/recovery time of gas sensing for H 2 were considered by morphological change of TiO 2 at ambient conditions. The p-n contacts between polyaniline matrix and 1D TiO 2 provided more active sites and facilitated the electrons transport, hence promoting the physisorption of gas molecules. R20 exhibited the highest sensitivity of 9.05 towards 2500 ppm of H 2 gas at the respective response and recovery times of 94 and 374 s. The sensor designed based on F30 exhibited proper long-term stability after one year. The sensing mechanism of PPTH was also studied in detail. • A porous polyaniline tube-like/TiO 2 nano-heterostructure (PPTH) based H 2 sensor. • A high sensitivity, low response/recovery time to H 2 gas at ambient conditions. • A good long-term response. • H 2 gas sensing mechanism of PPTH has also been studied in details.

Performance comparison of electro-polymerized polypyrrole and polyaniline as cathodes for iodine redox reaction in zinc-iodine batteries

At present, Zinc-iodine (Zn//I) batteries have attracted much attention due to their high safety and capacity. However, how to suppress the shuttling of polyiodide ions generated during charging processes is still a tricky problem. Herein, polyaniline (PANI) and polypyrrole (PPy) are electro-polymerized on carbon felt (CF) by constant current and used as cathodes for zinc-iodine (Zn//I) batteries. Electrochemical tests of the PANI@CF and PPy@CF electrodes prove that the PANI@CF electrode has a higher capacity, a stronger ability to suppress shuttling of polyiodine ions, and more excellent cyclic stability than the PPy@CF electrode. According to the material characterizations, the differences of both electrodes in electrochemical performances are mainly caused by the microstructures of PANI and PPy in both electrodes. The PANI has a micro-nano porous structure while the PPy is very dense. The porous PANI not only has more channels for the infiltration of electrolyte, but also can provide more active adsorption sites to minimize the shuttling of polyiodide ions to anode, ensuring the excellent performances of the PANI@CF. However, dense PPy seriously hinders the electrolyte diffusion and triggers the formation of an insulating dense iodine film, bringing poor performances to the PPy@CF. Ultimately, the PANI@CF electrodes achieves the most specific capacity of 235.9 mAh g−1 at 0.35 A g−1 (∼1.7 C) and performs out long cycle life with high stability (75.7% capacitiy rention after 10,000 cycles) at 3.5 A g−1 (∼17 C) in Zn//I battery, manifesting the porous PANI@CF electrode is a greatly promising candidate as cathode for Zn//I batteries in actual application.