A Universal Strategy to Enhance Polarization Performance and Anode Reversal Tolerance by Polyaniline-Coated Carbon Support for Proton Exchange Membrane Fuel Cells.

Anode cell reversal typically leads to severe carbon corrosion and catalyst layer collapse, which significantly compromises the durability of proton exchange membrane fuel cells. Herein, three types of commercial carbon supports with various structures are facilely coated by polyaniline (PANI) and subsequently fabricated into reversal-tolerant anodes (RTAs). Consequently, the optimized PANI-coated catalyst RTAs demonstrate enhanced polarization performance and improved reversal tolerance compared to their uncoated counterparts, thus confirming the universality of this coating strategy. Essentially, the surface engineering introduced by PANI coating incorporates abundant N-groups and enhances coulombic interactions with ionomer side chains, which in turn reduces lower carbon exposure, promotes more uniform Pt deposition, and ensures better ionomer distribution. Accordingly, the membrane-electrode-assembly containing the Pt/PANI/XC-72R-1+IrO2 RTA presents a 100 mV (at 2500 mA cm-2) polarization performance improvement and 26-fold reduction in the degradation rate compared to the uncoated counterpart. This work provides a universal strategy for developing durable anodes and lays the groundwork for the practical fabrication of high-performance, low-degradation RTA.

Preparation and Characterization of Graphene Oxide/Carbon Nanotube/Polyaniline Composite and Conductive and Anticorrosive Properties of Its Waterborne Epoxy Composite Coatings.

The organic coating on the surface is common and the most effective method to prevent metal materials from corrosion. However, the corrosive medium can penetrate the metal surface via micropores, and electrons cannot transfer in the pure resin coatings. In this paper, a new type of anticorrosive and electrically conductive composite coating filled with graphene oxide/carbon nanotube/polyaniline (GO/CNT/PANI) nanocomposites was successfully prepared by in situ polymerization of aniline (AN) on the surface of GO and CNT and using waterborne epoxy resin (WEP) as film-forming material. The structure and morphology of the composite were characterized using a series of characterization methods. The composite coatings were comparatively examined through resistivity, potentiodynamic polarization curves, electrochemical impedance spectroscopy (EIS), and salt spray tests. The results show that the GO/CNT/PANI/WEP composite coating exhibits excellent corrosion resistance for metal substrates and good conductivity when the mass fraction of GO/CNT/PANI is 3.5%. It exhibits a lower corrosion current density of 4.53 × 10-8 A·cm-2 and a higher electrochemical impedance of 3.84 × 106 Ω·cm2, while only slight corrosion occurred after 480 h in the salt spray test. The resistivity of composite coating is as low as 2.3 × 104 Ω·cm. The composite coating possesses anticorrosive and electrically conductive properties based on the synergistic effect of nanofillers and expands the application scope in grounding grids and oil storage tank protection fields.

Chitosan-Polyaniline (Bio)Polymer Hybrids by Two Pathways: A Tale of Two Biocomposites.

Previous research highlights the potential of polyaniline-based biocomposites as unique adsorbents for humidity sensors. This study examines several preparative routes for creating polyaniline (PANI) and chitosan (CHT) composites: Type 1-in situ polymerization of aniline with CHT; Type 2-molecular association in acidic aqueous media; and a control, Type 3-physical mixing of PANI and CHT powders (without solvent). The study aims to differentiate the bonding nature (covalent vs. noncovalent) within these composites, which posits that noncovalent composites should exhibit similar physicochemical properties regardless of the preparative route. The results indicate that Type 1 composites display features consistent with covalent and hydrogen bonding, which result in reduced water swelling versus Type 2 and 3 composites. These findings align with spectral and thermogravimetric data, suggesting more compact structure for Type 1 materials. Dye adsorption studies corroborate the unique properties for Type 1 composites, and 1H NMR results confirm the role of covalent bonding for the in situ polymerized samples. The structural stability adopts the following trend: Type 1 (covalent and noncovalent) > Type 2 (possible trace covalent and mainly noncovalent) > Type 3 (noncovalent). Types 2 and 3 are anticipated to differ based on solvent-driven complex formation. This study provides greater understanding of structure-function relationships in PANI-biopolymer composites and highlights the role of CHT as a template that involves variable (non)covalent contributions with PANI, according to the mode of preparation. The formation of composites with tailored bonding modalities will contribute to the design of improved adsorbent materials for environmental remediation to versatile humidity sensor systems.

Recycled Jute Non-Woven Material Coated with Polyaniline/TiO2 Nanocomposite for Removal of Heavy Metal Ions from Water.

Growing volumes of textile waste and heavy metal pollution of water are emerging environmental challenges. In an attempt to tackle these issues, a non-woven sorbent based on jute fibers was fabricated by recycling the textile waste from the carpet industry. The influence of contact time, concentration, pH and temperature on the sorption of lead and copper ions from aqueous solutions was studied. In order to enhance the sorption capacity of the non-woven material, in situ synthesis of polyaniline (PANI) in the presence of TiO2 nanostructures was performed. The contribution of TiO2 nanoparticles and TiO2 nanotubes to the uniformity of PANI coating and overall sorption behavior was compared. Electrokinetic measurements indicated increased swelling of modified fibers. FTIR and Raman spectroscopy revealed the formation of the emeraldine base form of PANI. FESEM confirmed the creation of the uniform nanocomposite coating over jute fibers. The modification with PANI/TiO2 nanocomposite resulted in a more than 3-fold greater sorption capacity of the material for lead ions, and a 2-fold greater absorption capacity for copper ions independently of applied TiO2 nanostructure. The participation of both TiO2 nanostructures in PANI synthesis resulted in excellent cover of jute fibers, but the form of TiO2 had a negligible effect on metal ion uptake.

Lignosulfonate-doped polyaniline-reinforced poly(vinyl alcohol) hydrogels as highly sensitive, antimicrobial, and UV-resistant multifunctional sensors.

Flexible wearable strain sensors exist the advantages of high resolution, lightweight, wide measurement range, which have unlimited potential in fields such as soft robotics, electronic skin, and artificial intelligence. However, current flexible sensors based on hydrogels still have some defects, including poor mechanical properties, self-adhesive properties and bacteriostatic properties. In this study, A conductive hydrogel Sodium Ligninsulfonate (LGS)@PANI-Ag-poly(vinyl alcohol) (PVA) hydrogels consisting of lignosulfonate-doped polyaniline (LGS@PANI), silver nitrate, and PVA interactions were designed and prepared for sensing applications. Here, the abundant reactive functional groups of lignosulfonates not only improve the electrochemical and electrical conductivity of polyaniline, thereby increasing its potential for sensing and capacitor applications, but also provide excellent mechanical properties (0.71 MPa), self-adhesion (81.27 J/m2) and ultraviolet (UV) resistance (UV inhibition close to 100 %) to the hydrogel. In addition, the hydrogel exhibited rich multifunctional properties, including tensile strain resistance (up to 397 %), antimicrobial properties (up to 100 % inhibition of Escherichia coli and Staphylococcus aureus), high sensitivity (gauge factor, GF = 4.18), and a rapid response time (100 ms). The LGS@PANI-Ag-PVA hydrogels showed potential for wearable sensors that monitor various biosignals from the human body, as well as human-computer interaction, artificial intelligence and other diverse fields.

Microscopic and macroscopic analysis of hexavalent chromium adsorption on polypyrrole-polyaniline@rice husk ash adsorbent using statistical physics modeling.

This paper contributed with new findings to understand and characterize a heavy metal adsorption on a composite adsorbent. The synthesized polypyrrole-polyaniline@rice husk ash (PPY-PANI@RHA) was prepared and used as an adsorbent for the removal of hexavalent chromium Cr(VI). The adsorption isotherms of Cr(VI) ions on PPY-PANI@RHA were experimentally determined at pH 2, and at different adsorption temperatures (293, 303, and 313 K). Multi-layer model developed using statistical physics formalism was applied to theoretically analyze and characterize the different interactions and ion exchanges during the adsorption process for the elimination of this toxic metal from aqueous solutions, and to attribute new physicochemical interpretation of the process of adsorption. The physicochemical structures and properties of the synthesized PPY-PANI@RHA were characterized via Fourier transform infrared spectroscopy (FTIR). Fitting findings showed that the mechanism of adsorption of Cr(VI) on PPY-PANI@RHA was a multi-ionic mechanism, where one binding site may be occupied by one and two ions. It may also be noticed that the temperature augmentation generated the activation of more functional groups of the composite adsorbent, facilitating the interactions of metal ions with the binding sites and the access to smaller pore. The energetic characterization suggested that the mechanism of adsorption of the investigated systems was exothermic and Cr(VI) ions were physisorbed on PPY-PANI@RHA surface via electrostatic interaction, reduction of Cr(VI) to Cr(III), hydrogen bonding, and ion exchange. Overall, the utilization of the theory of statistical physics provided fruitful and profounder analysis of the adsorption mechanism. The estimation of the pore size distribution (PSD) of the polypyrrole-polyaniline@rice husk ash using the statistical physics approach was considered stereographic characterization of the adsorbent (here PPY-PANI@RHA was globally a meso-porous adsorbent). Lastly, the mechanism of Cr(VI) removal from wastewater using PPY-PANI@RHA as adsorbent was macroscopically investigated via the estimation of three thermodynamic functions.

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

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

Unique Core-Shell Structured Polyaniline Nanofibers Toward Ultrahigh-Rate Flexible All-Solid-State Supercapacitor.

Promoting charge storage and fast charging capability simultaneously is a long-standing challenge for supercapacitors. A facile flowing seed polymerization is adopted to prepare polyaniline (PANI) nanofibers, in which phytic acid (PA) doped oligomers are first produced as the seeds for promoting the highly oriented growth of PANI nanofibers accompanying with the copolymerization of m-aminobenzene sulfonic acid (ASA) and aniline occurred on the surface of PANI nanofibers, as a result, unique core-shell structured PANI nanofibers are continuously fabricated. Benefitting from compact nanofiber structure, excellent dispersion, and self-doping effect, as-prepared PANI nanofibers exhibit a specific capacitance of 671.2 F g-1 at 2 A g-1 and ultrahigh rate capability of 93.1% from 2 to 100 A g-1. Then assembled all-solid-state supercapacitor can deliver the highest energy density of 28.3 Wh kg-1 at a power density of 320.2 W kg-1 with remarkable rate capability (81.2% from 1 to 20 A g-1), cycle stability (77.5% after 5000 cycles) as well as light weight and flexibility. It is highly desirable that the present green and scalable approach can be further applied to fabricate other unique core-shell structured PANI nanofibers with appealing potentials in energy storage devices.

Valorization of polyurethane foam waste through the decoration with nano-polyaniline for dye decontamination from polluted water.

Two polyurethane polyaniline nanocomposites have been synthesized using two in situ polymerization routes of dried and wet bases to valorize the polyurethane waste. The physical and chemical properties of polyurethane-based nanocomposites were compared using SEM, XRD, FTIR, and Zeta potential. SEM images showed that the average particle size of the dried-based composite was 56 nm, while the wet-based composite had an average size of 75 nm. The separation efficiency for methylene blue (MB) and Congo red (CR) dyes was evaluated against free polyurethane foam waste. It was evident that pure polyurethane (PPU) achieved only 4.79% and 16.71% removal for MB and CR, respectively. These dye decontamination efficiencies were enhanced after nano polyaniline decoration of polyurethane foam either through dried base polymerization (DPUP) or wet base polymerization (WPUP). WPUP composite records 11.23% and 85.99% for MB and CR removal, respectively, improved to 26.69% and 90.07% removal using DPUP composite for the respective dyes. The adsorption kinetics, isotherms, and thermodynamics were investigated. The experimental results revealed the pseudo-second-order kinetic model as the most accurately described kinetics model for both CR and MB adsorption. The Langmuir model provided the best fit for the data, with maximum adsorption capacities of 110.98 mg/g for CR and 26.86 mg/g for MB, with corresponding R-squared values of 0.9974 and 0.9608, respectively. Regeneration and reusability studies of PPU, WPUP, and DPUP showed effective reusability, with DPUP displaying the highest adsorption capacity. These results aid in creating eco-friendly and cost-efficient adsorbents for dye removal in environmental sanitation.

Redox-Active Polyaniline Covalently grafted Black Phosphorus Nanosheets for Integrated Digital-Analogue Memristors.

Surface covalent modification of black phosphorus (BP) with organic polymers represents a promising strategy to enhance its stability and tailor its electronic properties. Despite this potential, developing memristive materials through suitable polymer structures, grafting pathways, and polymerization techniques remains challenging. In this study, polyaniline (PANI)-covalently grafted black phosphorus nanosheets (BPNS) are successfully prepared with redox functionalities via the in situ polymerization of aniline on the surface of 4-aminobenzene-modified BPNS. The PANI coating protects the BP from direct exposure to oxygen and water, and it endows the material with analog memristive properties, characterized by a continuously adjustable resistance within a limited voltage scan range. When subjected to a broader voltage scan, the Al/PANI-g-BPNS/ITO device demonstrates a typical bistable digital memristive behavior. The integration of both digital and analog memristive functionalities in a single device paves the way for the development of high-density, multifunctional electronic components.

Synergetic studies on the thermochemical activation and polyaniline integration on the adsorption properties of natural coal for chlorpyrifos pesticide: steric and energetic studies.

Three types of synthetic coal-derived adsorbents were characterized as potential enhanced structurers during the removal of chlorpyrifos pesticide. The raw coal (CA) was activated into porous graphitic carbon (AC), and both CA and AC were blended with polyaniline polymers (PANI/CA and PANI/AC) forming two advanced composites. The adsorption performances of the modified structures in comparison with CA were evaluated based on both the steric and energetic parameters of the applied advanced isotherm model (the monolayer model of one energy). The uptake performances reflected higher capacities for the PANI hybridized form (235.8 mg/g (PANI/CA) and 309.75 mg/g (PANI/AC) as compared to AC (156.9 mg/g) and raw coal (135.8 mg/g). This signifies the impact of activation step and PANI blending on the surface and textural properties of coal. The steric investigation determined the saturation of the coal surface with extra active sites after the activation step (Nm(AC) = 62.05 mg/g) and the PANI integration (Nm(PANI/CA) = 113.5 mg/g and Nm(PANI/AC) = 169.7 mg/g) as compared to raw coal (Nm(CA) = 39.6 mg/g). This illustrated the reported uptake efficiencies of the modified samples, which can be attributed to the enhancement in the surface area and the incorporation of additional chemical groups. The results also reflect that each site can be loaded with 3-4 molecules of chlorpyrifos, which are arranged vertically and adsorbed by multi-molecular mechanisms. The energetic studies (< 40 kJ/mol) suggested the physical uptake of pesticide molecules by dipole bonding and hydrogen bonding processes. The thermodynamic functions donate the exothermic properties of 47reactions that occur spontaneously.

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

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

Macromolecular sensing motors from conducting polymers: Polyaniline/methylcellulose composites as stable current sensing supercapacitors.

Sensing motors and supercapacitors are pivotal in empowering smart systems, honing energy management, and facilitating the seamless integration of responsive electronics. Harnessing the electrochemistry of methylcellulose-polyaniline (MC/PANI) composites, this research delves into their potential applications as reactive current sensing supercapacitors with single connectivity. The electrochemical traits of pristine polyaniline (PANI) and MC/PANI composites were analyzed and assessed for their potential applications in sensors and energy storage devices. With a specific capacitance of 300Fg-1, the MC/PANI_B3 composite-based device retained 87.01 % capacitance after 2000 cycles. Besides, based on electrical energy as the sensing parameter, the composite exhibited augmented cathodic and anodic current sensitivity of 8.77 mJmA-1 and -8.86 mJmA-1, respectively. The ameliorated supercapacitor and current sensing parameters of MC/PANI_B3 are ascribed to the percolation threshold content of the conducting phase, which is endowed with optimal hydrogen bond-mediated interactions with methylcellulose (MC), thus confers an expanded chain conformation.

Flexible and robust polyaniline/cross-linked collagen sponge with fibrils network structure as a piezoresistive sensing material.

The polyaniline/cross-linked collagen sponge (PANI/CCS) was synthesized by polymerizing PANI onto the collagen skeleton using mesoscopic collagen fibrils (CFs) as building blocks, serving as a piezoresistive sensing material. The structure and morphology of PANI/CCS were characterized using scanning electron microscopy (SEM), Fourier infrared spectroscopy (FTIR), X-ray photoelectron spectroscopy (XPS), and thermal analysis (TA). The mechanical properties of PANI/CCS could be controlled by adjusting the CFs content and polymerization conditions. PANI/CCS treated with pure water exhibited exceptional compressive elasticity under 1000 compression cycles, demonstrating a wide strain range (0-85 %), rapid response time (200 ms), recovery time (90 ms), and high sensitivity (6.72 at 40-50 % strain). The treatment of the ionic liquid further improved the elasticity and the strain sensing range (0-95 %). The presence of PANI nanoparticles and mesoscopic collagen fibrils imparted antibacterial properties, stability in solvents, and biodegradability to PANI/CCS. Utilizing PANI/CCS as a piezoresistive sensing material enabled monitoring human movement behavior through the assembled sensor, showing significant potential for flexible wearable devices.

Enhancing early warning: A DNA biosensor with polyaniline/graphene nanocomposite for label-free voltammetric detection of saxitoxin-producing harmful algae.

Yearly reports of detrimental effects resulting from harmful algal blooms (HAB) are still received in Malaysia and other countries, particularly concerning fish mortality and seafood contamination, both of which bear consequences for the fisheries industry. The underlying reason is the absence of a dependable early warning system. Hence, this research aims to develop a single DNA biosensor that can detect a group of HAB species known for producing saxitoxin (SXT), which is commonly found in Malaysian waters. The screen-printed carbon electrode (SPCE)-based DNA biosensor was fabricated by covalent grafting of the 3' aminated DNA probe of the sxtA4 conserved domain in SXT-producing dinoflagellates on the reverse-phase polymerized polyaniline/graphene (PGN) nanocomposite electrode via carbodiimide linkage. The introduction of a carboxyphenyl layer to the PGN nanotransducing element was essential to augment the carboxylic groups on the graphene (RGO), facilitating attachment with the aminated DNA. The synergistic effect of the asynthesized nanocomposite of PANI and RGO, tremendously enhanced the electron transfer rate of the ferri/ferrocyanide redox probe at the SPCE transducer surface, allowing for the label-free bioanalytical assay of complementary DNA targets. The developed DNA biosensor featuring the capacity to detect a broad range of Alexandrium minutum (A. minutum) cell concentrations, ranging from 10 to 10,000,000 cells L-1. The quantification of A. minutum cells from pure algal culture by the electrochemical DNA biosensor has been well-validated with traditional microscopic techniques. Furthermore, Alexandrium tamiyavanichii, another toxigenic HAB species, exhibited a similar electrochemical characteristic signal to those observed with A. minutum, whilst the biosensor yielded appreciably distinctive results when subjected to a non-toxigenic microalgae species as a negative control, i.e. Isochrysis galbana. A compendium DNA biosensor design and electrochemical detection strategy at laboratory scale serves as a precursor to the potential development of portable device for on-site detection, thus expanding the utility and scope of biosensor technology.

Molecularly Imprinted Polymers Electrochemical Sensing: The Effect of Inhomogeneous Binding Sites on the Measurements. A Comparison between Imprinted Polyaniline versus nanoMIP-Doped Polyaniline Electrodes for the EIS Detection of 17ß-Estradiol.

Molecularly imprinted polymers (MIPs) are synthetic receptors made by template-assisted synthesis. MIPs might be ideal receptors for sensing devices, given the possibility to custom-design selectivity and affinity toward a targeted analyte and their robustness and ability to withstand harsh conditions. However, the synthesis of MIP is an inherently random process that produces a statistical distribution of binding sites, characterized by a variety of affinities. This is verified both for bulk MIP materials and for MIP's thin layers. In the present work, we aimed at assessing the effects of inhomogeneous versus homogeneous imprinted binding sites on electrochemical sensing measurements, and the possible implications on the sensor's performance. In the example of an Electrochemical Impedance Spectroscopy (EIS) sensor for the 17ß-estradiol (E2) hormone, the scenario of inhomogeneous binding sites was studied by modifying electrodes with an E2-MIP polyaniline (PANI) thin layer, called the "Imprinted PANI layer". In contrast, the condition of discrete and uniform binding sites was epitomized by electrodes modified with a thin PANI layer purposedly doped with E2-MIP nanoparticles (nanoMIPs), which were referred to as "nanoMIP-doped PANI". The behaviors of the two EIS sensors were compared. Interestingly, the sensitivity of the nanoMIP-doped PANI was almost twice with respect to that of the imprinted PANI layer, strongly suggesting that the homogeneity of the binding sites has a fundamental role in the sensor's development. The nanoMIP-doped PANI sensor, which showed a response for E2 in the range 36.7 pM-36.7 nM and had a limit of detection of 2.86 pg/mL, was used to determine E2 in wastewater.

Small molecule π-π stacking promotes efficient photoelectrocatalytic splitting of aqueous hydrogen production from polyaniline.

The efficiency of photoelectrocatalysis is fundamentally dependent on the sufficient absorption of light and efficient utilisation of photogenerated carriers, but is largely limited by the reactivity from the inefficient charge transfer and surface sites of the catalyst. In this study, π-π stacking of polar small molecules on aromatic ring-rich polyaniline (PANI) was carried out to improve its photoelectrocatalytic splitting of water for hydrogen production. Detailed photoelectrochemical experiments and density-functional theory (DFT) calculations show that small molecules of p-aminobenzoic acid (PABA) and PANI have the best π-π stacking (compared to p-toluenesulfonic acid (PTA)), which promotes the separation of carriers on the PANI surface. In addition, the polar effect of the small molecules also improves the reactivity of the PANI surface and also reduces the potential barrier for H2 evolution. The current density of PANI-PABA reached -0.12 mA/cm2 (1.23 V vs. RHE) 2.53 times higher than that of pure PANI in linear voltammetric scanning tests under light. This strategy of introducing polar small molecules into organocatalysts via π-π stacking will provide new ideas for the preparation of efficient organic photoelectrocatalysis.

Advanced carbo-catalytic degradation of antibiotics using conductive polymer-seaweed biochar composite: Exploring N/S functionalization and non-radical dynamics.

Polyaniline (PANI) and Saccharina Japanica seaweed (kelp) biochar (KBC) composites were synthesized in-situ through polymerization. This study presents a novel approach to the degradation of sulfamethoxazole (SMX), a prevalent antibiotic, using a PANI-KBC composite to activate peroxymonosulfate (PMS). Extensive characterizations of the PANI-KBC composite were conducted, resulting in successful synthesis, uniform distribution of PANI on the biochar surface, and the multifunctional role of PANI-KBC in SMX degradation. A removal efficiency of 97.24% for SMX (10 mg L-1) was attained in 60 min with PANI-KBC (0.1 g L-1) and PMS (1.0 mM) at pH 5.2, with PANI-KBC showing effectiveness (>92%) across a pH range of 3.0-9.0. In the degradation of SMX, both radical (SO4•- and •OH) and non-radical (1O2 and electron transfer) pathways are involved. The reaction processes are critically influenced by the roles of SO4•-, 1O2 and electron transfer mechanisms. It was suggested that pyrrolic N, oxidized sulfur (-C-SO2-C-), structural defects, and O-CO were implicated in the production of 1O2 and electron transfer processes, respectively, and a portion of 1O2 originated from the conversion of O2•-. The study evaluated by-product toxicity, composite reusability, and stability, confirming its practical potential for sustainable groundwater remediation.

Disposable electrochemical sensors based on reduced graphene oxide/polyaniline/poly(alizarin red S)-modified integrated carbon electrodes for the detection of ciprofloxacin in milk.

An electrochemical sensor based on an electroactive nanocomposite was designed for the first time consisting of electrochemically reduced graphene oxide (ERGO), polyaniline (PANI), and poly(alizarin red S) (PARS) for ciprofloxacin (CIPF) detection. The ERGO/PANI/PARS-modified screen-printed carbon electrode (SPCE) was constructed through a three-step electrochemical protocol and characterized using FTIR, UV-visible spectroscopy, FESEM, CV, LSV, and EIS. The new electrochemical CIPF sensor demonstrated a low detection limit of 0.0021 µM, a broad linear range of 0.01 to 69.8 µM, a high sensitivity of 5.09 µA/µM/cm2, and reasonable selectivity and reproducibility. Moreover, the ERGO/PANI/PARS/SPCE was successfully utilized to determine CIPF in milk with good recoveries and relative standard deviation (< 5%), which were close to those with HPLC analysis.

Preparation and characterisation of NH3 gas sensor based on PANI/Fe-doped CeO 2 nanocomposite.

PANI/Fe-doped CeO 2 nanocomposite was synthesised by the in-situ process. The produced powders were characterised by XRD, XPS, FT-IR, Raman, HRTEM and SEM-EDS tests. The sensors' function was based on PANI/Fe-doped CeO 2 nanocomposite with thin film deposited on top of interdigitated electrodes (IDT). NH 3 detection with PANI/Fe-doped CeO 2 nanocomposite sensor could be successfully performed even at room temperature (RT) and relative humidity of 45 %. Results demonstrated that PANI/Fe-doped CeO 2 might be promising sensing materials for detecting the low NH 3 concentration (ppm). In addition, the sensor is selective to the interfering gases, including CO, CO 2 and NO 2 . This sensor displays acceptable repeatability and stability over time.