Polymer Polypyrrole Research Articles

Multifunctional green synthesized silver nanoparticle and polypyrrole-based e-textile for wearable thermoregulation applications

Electronic textiles (e-textiles) build upon existing technologies to develop truly smart textiles: garments that sense, react, and adapt. Thermoregulatory e-textiles are an area of significant interest across the field. Designing e-textiles that satisfy electrical performance and simple construction is a significant challenge. To address these issues, a simple dip-coating and in-situ polymerization method was used to develop the first example of a thermoregulatory e-textile using green synthesized silver nanoparticles (AgNP) and polypyrrole (Ppy), based on the method previously reported (Naysmith, A.; Mian, N.S.; Rana, S. Development of conductive textile fabric using Plackett–Burman optimized green synthesized silver nanoparticles and in situ polymerized polypyrrole. Green Chemistry Letters and Reviews 2023, 16 (1)). This methodology was optimized using a Taguchi statistical design determining the optimal AgNP-Ppy synthesis method to obtain high performance Joule heating e-textiles, novel within the field of e-textiles. Reactant concentration and reaction time had the largest effects on the electrical resistance of subsequent e-textiles. The result is the first example of an e-textile heater based on green synthesized AgNPs. The e-textile demonstrated exceptional Joule heating (120°C), low electrical resistance (37 Ω), resistive temperature sensing behavior (negative TCR = −0.0046), and increased thermal conductivity (19.55 l (Wm−1 K−1)); the strain sensing behavior (gauge factor = −0.07). This work extends knowledge of the development and challenges within e-textile technologies as the field creates the next generation of textiles.

Tailoring polypyrrole morphology and electronic properties through CTAB-SDS self-assembly

This study explores the polymerization of polypyrrole (PPy) within a self-assembled catanionic surfactant composed of cetyltrimethylammonium bromide (CTAB) - sodium dodecyl sulfate (SDS), aiming to control its morphology and electronic properties. The research systematically investigates how varying the compositions of CTAB and SDS surfactants influence the structural and electronic characteristics of PPy. Our findings indicate that the surfactant composition predominantly impacts the shape of PPy rather than its crystallinity. Despite the absence of significant crystallinity, variations in surfactant composition notably alter the electronic properties of PPy. Specifically, an increase in CTAB content results in electrical conductivity increasing from 0.34 to 0.01 S/m. Conversely, higher SDS content enhances the bipolaron-to-polaron ratio, particularly in the C−H deformation region, contributing to improved electronic characteristics. Additionally, packing density analysis reveals that the ordered or disordered acyl chain arrangement within the catanionic surfactant system varies significantly with surfactant composition, further influencing the morphology and electronic properties of PPy. These findings provide valuable pave for designing conductive polymers with tailored electronic properties by a catanionic surfactant, where precise control over such properties is crucial.

A Reactor based on P‐N Heterojunction of Polypyrrole and Porous Silicon for Photocatalytic and Electro‐assisted Photocatalytic Performance

AbstractIn this work, a photoelectrochemical reactor with an anode based on hybrid structure between conducting polymer polypyrrole (PPy) and porous silicon (PSi) was fabricated and utilized to evaluate the photocatalysis and electro‐assisted photocatalysis for degradation of rhodamine B (RhB) solution. The PSi was made of n‐type silicon single‐crystal wafer by the metal‐assisted chemical etching (MACE). The anode PPy/PSi formed following a polymerization of the PPy on the PSi from the vapour‐phase route using oxidant FeCl3. Typical material characterizations of the PPy, PSi and PPy/PSi were investigated via scanning electron microscope (SEM), and spectroscopies of Fourier‐transform infrared (FTIR), Raman scattering and UV‐vis. Under visible light radiation (halogen light with the wavelength region of 400–700 nm), photocatalytic and electro‐assisted photocatalytic processes of the reactor were conducted by degradation of the RhB solution. A heterojunction (p‐n) of the PPy/PSi was proposed to explain the efficient catalytic performance of the reactor.

Study of Ion-to-Electron Transducing Layers for the Detection of Nitrate Ions Using FPSX(TDDAN)-Based Ion-Sensitive Electrodes.

The development of ISE-based sensors for the analysis of nitrates in liquid phase is described in this work. Focusing on the tetradodecylammonium nitrate (TDDAN) ion exchanger as well as on fluoropolysiloxane (FPSX) polymer-based layers, electrodeposited matrixes containing double-walled carbon nanotubes (DWCNTs), embedded in either polyethylenedioxythiophene (PEDOT) or polypyrrole (PPy) polymers, ensured improved ion-to-electron transducing layers for NO3- detection. Thus, FPSX-based pNO3-ElecCell microsensors exhibited good detection properties (sensitivity up to 55 mV/pX for NO3 values ranging from 1 to 5) and acceptable selectivity in the presence of the main interferent anions (Cl-, HCO3-, and SO42-). Focusing on the temporal drift bottleneck, mixed results were obtained. On the one hand, relatively stable measurements and low temporal drifts (~1.5 mV/day) were evidenced on several days. On the other hand, the pNO3 sensor properties were degraded in the long term, being finally characterized by high response times, low detection sensitivities, and important measurement instabilities. These phenomena were related to the formation of some thin water-based layers at the polymer-metal interface, as well as the physicochemical properties of the TDDAN ion exchanger in the FPSX matrix. However, the improvements obtained thanks to DWCNT-based ion-to-electron transducing layers pave the way for the long-term analysis of NO3- ions in real water-based solutions.

Electronically Conductive Polymer Enhanced Solid-State Polymer Electrolytes for All-Solid-State Lithium Batteries

All-solid-state lithium batteries (ASSLBs) have gained enormous interest due to their potential high energy density, high performance, and inherent safety characteristics for advanced energy storage systems. Although solid-state ceramic (inorganic) electrolytes (SSCEs) have high ionic conductivity and high electrochemical stability, they experience some significant drawbacks, such as poor electrolyte/electrode interfacial properties and poor mechanical characteristics (brittle, fragile), which can hinder their adoption for commercialization. Typically, SSCE-based ASSLBs require high cell stack pressures exerted by heavy fixtures for regular operation, which can reduce the energy density of the overall battery packages. Polymer–SSCE composite electrolytes can provide inherently good interfacial contacts with the electrodes that do not require high cell stack pressures. In this study, we explore the feasibility of incorporating an electronically and ionically conducting polymer, polypyrrole (PPy), into a polymer backbone, polyvinylidene fluoride-co-hexafluoropropylene (PVDF-HFP), to improve the ionic conductivity of the resultant polymer–SSCE composite electrolyte (SSPE). The electronically conductive polymer-incorporated composite electrolyte showed superior room temperature ionic conductivity and electrochemical performance compared to the baseline sample (without PPy). The PPy-incorporated polymer electrolyte demonstrated a high resilience to high temperature operation compared with the liquid-electrolyte counterpart. This performance advantage can potentially be employed in ASSLBs that operate at high temperatures. In our recent development efforts, SSPEs with optimal formulations showed room temperature ionic conductivity of 2.5 × 10−4 S/cm. The data also showed, consistently, that incorporating PPy into the polymer backbone helped boost the ionic conductivity with various SSPE formulations, consistent with the current study. Electrochemical performance of ASSLBs with the optimized SSPEs will be presented in a separate publication. The current exploratory study has shown the feasibility and benefits of the novel approach as a promising method for the research and development of next-generation solid composite electrolyte-based ASSLBs.

Polypyrrole as photo-thermal-assisted modifier for BiVO4 photoanode enables high-performance photoelectrochemical water splitting

Herein, iron nickel oxide (FeNiOx) and conductive polymer polypyrrole (PPy) with excellent hole transport property and catalytic oxidation ability combine with bismuth vanadate (BiVO4) based photoanode to obtain a remarkable improvement of photocurrent density. More importantly, due to the photo-thermal effect of PPy, the operating temperature of the photoanode reaches 323.15 K under AM 1.5G illumination without infrared light source, thus activating the photoanode surface and accelerating the water splitting reaction. As a result, when the temperature of electrolyte reaches 323.15 K, the photocurrent density of BiVO4/FeNiOx/PPy photoanode achieves 6.91 mA cm−2 at 1.23 V versus reversible hydrogen electrode (vs. RHE), which is 3.04 folds of pristine BiVO4 (2.27 mA cm−2). Such a photo-thermal-assisted enhancement strategy based on the temperature sensitivity of BiVO4 provides a new way for the breakthrough of the performance bottleneck of BiVO4 photoanode and the design of the next generation PEC catalyst materials.

Extraordinary Hydrogen Evolution and Oxygen Evolution Reaction Activity From PPy@FeCo-LDH/NF Bifunctional Electrocatalyst in Alkaline Solution

Alkaline water electrolysis is a promising technique for the production of hydrogen and oxygen. Nevertheless, the development of low-cost, high-activity metal-based electrocatalysts that can effectively catalyze the hydrogen evolution reaction (HER) and oxygen evolution reaction (OER) remains a significant challenge. Herein, we polymerized Polypyrrole (PPy) with FeCo layered double metal hydroxide grown in situ on nickel foam (NF) (FeCo-LDH/NF) by electrochemical polymerization to acquire composite material PPy@FeCo-LDH/NF. As a promising electrocatalyst with dual functionality for the HER and OER, the HER overpotential of PPy@FeCo-LDH/NF was 153 mV, and the OER overpotential was 245 mV at a current density of 10 mA·cm−2. It was because that PPy increased the number of active adsorption sites, which in turn regulated the ion transfer rate between the electrolyte and the prepared catalyst. At the same time, after 24 h of stability testing, the HER and OER capacitance retention rates were 96.7% and 97.1%, respectively.

Effect of polypyrrole incorporation amounts on the optical and electrical properties of PVA/CMC blended polymer for optoelectronic applications

In the present work, hybrid flexible blended polymers of polypyrrole (PPy)/polyvinyl alcohol (PVA)/carboxymethyl cellulose (CMC); PVA/CMC/x wt % PPy; were constructed as promising blended materials to be used in various optoelectronics applications. X-ray diffraction and scanning electron microscopy techniques were used to investigate the structure and the surface morphology of polymer nanocomposites. The doped blends have better absorption of the three types of ultraviolet (UVA, UVB, and UVC), as well as the visible spectrum. The transmittance values in the visible range dropped from 90 % to 63 % as the PPy concentration reached 0.5 wt%. At x = 0.5, the minimum direct and indirect optical band gap energy values of (4.82, 4.39, 4.23) eV and (3.76, 3.84, 3.62, 2.93) eV, respectively, were obtained. The incorporation of PPy into the PVA/CMC blend led to a regular rise in the refractive index value within the visible range. The blend doped with 0.5 wt % PPy exhibited the highest optical dielectric constant values within the visible range. The enhancement/reduction in the fluorescence intensity depended on the excitation wavelength and the amount of PPy doping in the blended polymers. The effect of voltage, temperature and the amount of PPy doping on the current behavior of the resulting electric current in all blends was explored. The ohmic and nonohmic natures and the charge transport mechanisms of different blends were determined.

Effective removal of uranium (VI) with a SDBS doped PPy-SUS304 electrode from alkaline wastewater using electrodeposition strategy

The immobilization of uranium in nuclear wastewater is of paramount importance for environmental and human health. However, there is a paucity of research on the immobilization of uranium in alkaline wastewater, particularly with regards to the application of novel electrodes. This article presents the utilization of an electrochemically polymerized polypyrrole stainless steel (PPy-SUS304) electrode for the effective electrochemical deposition and removal of uranium from alkaline wastewater containing uranium. According to the electrodeposition results, the uranium deposition efficiency of the novel electrode reached 96.82 %, with a uranium deposition rate of 0.048 mg U/(h·cm2) and a charge efficiency of 0.055 mg U/C. These findings demonstrate the successful electrochemical reduction of UO2(CO3)34- in alkaline uranium-containing wastewater using the novel electrode, resulting in improved charge deposition efficiency. The electrode surface products were investigated using scanning electron microscopy (SEM), Energy-dispersive X-ray spectroscopy (EDS), and X-Ray Photoelectron Spectroscopy (XPS). The SEM and EDS results demonstrate the formation of a uniform PPy film on the surface of SUS304. In addition, the White light interferometer (WLI) test reveals that the PPy-SUS304 electrode exhibits increased roughness compared to the SUS304 electrode. The XPS results revealed that the electrode surface products of PPy-SUS304 were actually U compounds constituted of U(IV) oxides or hydroxides. This study provides a new perspective for the development of novel electrodes to suppress side reactions and efficiently recover uranium from alkaline uranium-containing wastewater.

Smart versatile hydrogels tailored by metal-phenolic coordinating carbon and polypyrrole for soft actuation, strain sensing and writing recognition

Biomimetic intelligent conductive hydrogels integrating flexibility, signal sensing, and contactless actuation has become ideal candidates for the production of electronic skins, wearable devices, and soft robotics. However, the development of multifunctional smart hydrogels capable of both sensing and actuating simultaneously to enhance intelligent interaction interfaces remains a significant challenge. Herein, a multifunctional hydrogel composite with integrated sensing and actuating capabilities is proposed through the incorporation of Fe3+-tannic acid (TA) coordination compound-coated carbon nanotubes (Fe-TA@SWNT) and the in-situ formation of conductive polymer polypyrrole (PPy) inside the hydrogel networks composed of carboxymethylcellulose (CMC) and a copolymer of acrylic acid (AA) and [2-(methacryloyloxy) ethyl]dimethyl-(3-sulfopropyl) ammonium hydroxide (SBMA). Benefiting from multiple effective dynamic interactions within the internal matrix, the prepared hydrogel exhibits excellent stretchability (1283.42 % elongation) and toughness (1.11 MJ/m3). Additionally, the catechol groups carried by Fe-TA@SWNT, along with the zwitterionic monomer SBMA, provide the hydrogel with repeatable self-adhesion performance. Based on the outstanding photothermal effect of Fe-TA@SWNT and PPy, the hydrogel demonstrates reversible and stable photothermal responsiveness, exhibiting exceptional actuation performance under near-infrared (NIR) radiation. As a strain sensor, the hydrogel shows excellent sensitivity (GF = 3.32), rapid response time, and reliable stability, enabling precise monitoring of various physiological signals in the human body, including joint movements, facial expressions, and heartbeats. Therefore, this work significantly expands the application prospects of multifunctional smart hydrogels in fields of wearable electronics, soft robotics, and remote light-controlled devices.

HiPSC-derived cardiomyocyte cultivation and measurement of electrophysiological properties on gelatine/glucose/polypyrrole scaffold

Abstract Funding Acknowledgements Type of funding sources: Public grant(s) – EU funding. Main funding source(s): EU Horizon 2020 Framework Programme (H2020) under Grant agreements No. 953138 (EMAPS-Cardio) Purpose Cardiotoxicity is one of the main side effects limiting development of new medicines and resulting in withdrawal of drugs from the market. There are different mechanisms of drug-induced cardiotoxicity, including arrhythmia, disruption of mitochondria function, apoptosis, altered growth factor signalling [1]. Heart on a chip model for drug testing seems attractive approach to evaluate the possible cardiotoxic effects on cell biological, but mostly electrophysiological properties. Our aim was to create a 3D system with a biocompatible scaffold, coated with a conductive layer, suitable for culturing and maturation of human induced pluripotent stem cell derived cardiomyocytes (hiPSC-CMs) and compatible with electrophysiology parameter measurement techniques. Methods Elastic scaffold was fabricated by electrospinning of gelatin-glucose microfibers followed by the vapor-phase and electrochemical deposition of conductive polymer polypyrrole (PPy) to create electroconductive layer. hiPSC-CMs at different maturation levels (at 6 vs 14 weeks) were used to test biocompatibility of the scaffold. To increase cell attachment, scaffold was treated with 0.1 M HCl and coated with Geltrex. Cells were stained with fluorescent dyes (Calcein AM, DAPI). Electrophysiological properties were analysed using intracellular calcium imaging (Cal520) and action potential recordings with sharp electrodes. HiPSC-CMs on coverslips were used as a 2D control. Results Calcein AM staining showed that high number of hiPSC-CMs attached to gelatine/glucose/PPy scaffold proving that the scaffold is biocompatible and cells remain viable even after long term incubation (> 2 weeks). HiPSC-CMs at lower maturity (6 weeks) had better attachment properties to it, indicating that more mature cardiomyocytes (14 weeks) gradually lose their capacity to attach to PPy surface. Intracellular calcium imaging showed that both types of cells generated synchronous spontaneous calcium oscillations on gelatine/glucose/PPy scaffolds. Action potential recordings in 3D were similar to those in 2D, and confirmed differences in hiPSC-CMs maturation levels – at lower maturation level hiPSC-CMs had lower upstroke velocity as compared to more matured hiPSC-CMs. Conclusions Gelatine/glucose/PPy scaffold is biocompatible for hiPSC-CMs cultivation, and suitable for evaluation of cardiomyocyte electrophysiological properties. Such electromechanoactive scaffold can be further employed for development of heart-on-a-chip model.

UV‐Curable 3D‐Printable Microwave‐Absorbing Material with a Sword‐Sheath Structure Based on Multiwalled Carbon Nanotube/Polypyrrole Nanotube/Fe3O4 Composites

Multiwalled carbon nanotube (MWCNT)/polypyrrole nanotube (PPyNT)/triiron tetraoxide (Fe3O4) composites with a sword‐sheath structure are added to a UV‐curable resin to form a unique highly microwave‐absorbing material with a low absorbent content. Specifically tailored for high‐precision stereolithography three‐dimensional (3D) printers, the low absorbent content ensures an efficient curing and molding of the photosensitive resin. The conducting polymer polypyrrole is coated on the MWCNTs via free‐radical polymerization, forming a sheath structure. The initiator of the free‐radical polymerization, FeCl3, is converted into Fe3O4 and loaded onto the sheath structure. This ternary composite material is uniformly dispersed in the photosensitive resin with interconnected sword‐sheath structures, ensuring a favorable dielectric loss performance even at a low absorbent content. Importantly, the material exhibits both dielectric loss and magnetic loss properties. Using a UV‐cured microwave‐absorbing material with an absorbent content of 0.5 wt%, an electromagnetic loss of −22.5 dB can be achieved with a thickness of 1 mm. This UV‐cured microwave‐absorbing material facilitates the high‐precision 3D printing of microwave structures with various intricate shapes, broadening the application scope of microwave‐absorbing materials.

Conductive polypyrrole: synthesis, characterization, thermal, and electrical properties for different applications

Pyrrole monomer (mPPy) in an aqueous solution was used to create the conductive polymer polypyrrole (a homo-PPy) using a chemical oxidative polymerization process over a period of several hours at room temperature. Ferric chloride (FeCl3) oxidant was used, and sodium dodecyl sulphate (C12H25NaO4S), a surfactant. The produced PPy samples were characterized using a variety of methods, including X-ray diffraction (XRD), the Fourier transform infrared (FTIR), differential scanning calorimetry (DSC), Differential Thermal analysis (DTA), Thermogravimetric analysis (TGA), and scanning electron microscopy (SEM). SEM images revealed that nanoparticles of a homo-PPy with radii of 60–90 nm were well evenly distributed in the structure. The thermal stability and electrical conductivity of homo-PPy nanoparticles were observed to rise with a solvent ethylene glycol. As temperature rises, the conductivity of homo-PPy samples is significantly raised, and electrical conductivities ranging from.0.44 to 2.2 (Ω.m)−1. Results from FTIR and XRD analysis confirmed the structural formation of a homo-polypyrrole during synthesis from pyrrole monomer. Because of their improved electrical conductivity and thermal stability, homo-PPy nanoparticles have potential applications in energy storage, adsorption and contamination elimination, electromagnetic protection, and resistance to corrosion.

Layer-by-layer assembling redox wood electrodes for efficient energy storage

The exploration of redox-active organic materials and low tortuous thick-electrodes is attractive for energy storage. The in-situ valorized lignin on raw wood surface accompanied by layer-by-layer deposition of electro-active materials endow such spatially distributed wood electrodes with high specific capacitance. Here, we report a layer-by-layer assembled ca.1.5 mm-thick redox wood hybrid electrode with 20 mg cm-2 electro-active mass loading for efficient energy storage. The in-situ modified surface lignin in treated wood (TrW) holds promise as redox-active material with enriched nanoporosity, carbonyl functionalities, and multi-phase ionic transport structure. The carbon nanotubes (CNTs) networking with in-situ polymerized polypyrrole (PPy) nanorods three-dimensionally in the lumen of TrW afford a wool-like, highly porous nanostructure. Such a hierarchical structured PPy@CNTs@TrW electrode offers a high areal capacitance of 1.46 F cm-2 with an extraordinary energy density of 0.983 mWh cm-3 (3.68 Wh kg-1) and power density of 5.4 mW cm-3 (20.25 W kg-1). Here, the valorized surface lignin contributes contributes to electrochemical energy storage accompanied by spatially distributed PPy@CNTs in low tortuous electrodes. The electrode offers extremely low electrochemical impedance of 0.61 Ω electrode resistance and 1.57 Ω electrolyte resistance. The hybrid wood electrode showcases even higher conductivity and energy/power density than thin carbonized wood and other state-of-the-art thin electrodes made of highly conductive three-dimensional networks. This work highlights the potential of in-situ valorized lignin in developing high-performance eco-friendly thick-electrodes for electrochemical energy storage applications.

Rational design of CdS-enwrapped polypyrrole nanoparticles for wastewater treatment: removal of hazardous pollutants in aqueous solutions.

The modern world requires a chemical industry that can run at low production costs while producing high-quality products with minimal environmental impact. The development of environmentally friendly, cost-effective, and efficient wastewater treatment materials remains a majorproblem for the sustainable approach. We prepared nanoscale cadmium sulfide (CdS)-enwrapped polypyrrole (PPy) polymer composites for degradation of organic pollutants. The prepared CdS@PPy nanocomposites were characterized by powder X-ray diffraction, scanning electron microscope (SEM), field emission scanning electron microscope (FESEM), Fourier transform infrared spectroscopy (FTIR), and ultraviolet-visible(UV) absorption spectroscopy, indicating proper intercalation between CdS and PPy. Consequently, the catalytic efficiency of the synthesized hybrid nanocomposites was analyzed through the degradation of methylene blue (MB) and rhodamine B (Rh B) under visible light irradiation. The measured degradation efficiency of the dye solutions under the photolysis process is about 18% and 23% for MB and Rh B dye, respectively. Furthermore, the recycle test result concludes that the CdS@PPy composite exhibits 91% and 89% of MB and Rh B dye degradation efficiency even at the 4th cycle, respectively. The positive synergistic impact of CdS and PPymay be the result of effective photocatalytic degradation of MB and RhB.

Polypyrrole Coating via Lemieux-von Rudloff Oxidation on Magnetite Nanoparticles for Highly Efficient Removal of Chromium(VI) from Wastewater.

An alternative way for the coating of polypyrrole (PPy) polymer on hydrophobic magnetite (Fe3O4) nanoparticles is reported here to capture toxic chromium ions, Cr (VI), present in water. Iron oxide magnetic nanoparticles (Fe3O4) were synthesized by the conventional coprecipitation technique using FeCl3·6H2O and FeSO4·7H2O iron precursors and subsequently modified with oleic acid (OA). Then OA-Fe3O4 hydrophobic nanoparticles were oxidized using the Lemieux-von Rudloff reaction to transfer OA into hydrophilic azelaic acid (AA) (HOOC(CH2)7COOH-modified magnetic nanoparticles (AA-Fe3O4). Finally, a PPy polymer coating was formed by a seeded polymerization of pyrrole, using AA-Fe3O4 as seeds. The average size of PPy/Fe3O4 nanocomposites is 12.33 nm and is almost spherical in shape. The surface composition is confirmed by FTIR and thermogravimetry analyses. An X-ray diffraction study confirmed the formation of highly crystalline Fe3O4 nanoparticles, and the crystallinity was retained after the surface modification. The adsorption study suggested that the Cr(VI) ion adsorption is highly pH-dependent and the maximum amount of adsorption is obtained at pH 2.0. The adsorption results revealed that the Langmuir model provided the best fit for the isotherm, with a maximum adsorption capacity reaching approximately 173.22 mg g-1 at 323 K. Spontaneous and endothermic adsorption processes were confirmed by evaluating the thermodynamic parameters obtained in this investigation. The kinetics study showed that the interaction between Cr(VI) ions and magnetic nanocomposites was directed by a pseudo-second-order rate process indicating chemisorption. The prepared PPy/Fe3O4 nanocomposites would be promising adsorbents to purify water by eliminating Cr(VI) metal ions from wastewater.

Bimetal Pyrophosphate of CoNiP2O7@polypyrrole Nanocomposite‐ Based Electrode for Hybrid Supercapacitor Applications

A significant challenge in the realm of asynchronous capacitors is the development of innovative electrode materials with improved electrochemical behaviour and increased cycles. In this article, a new method is proposed for the facile synthesis of bi metal pyrophosphate anchored on polypyrrole (CoNiP2O7/NF@PPy) utilizing the hydrothermal and polymerization procedures. Cobalt nickel pyrophosphate nanoarrays are created, and they are successfully used as an electrode material for supercapacitors. The novelty of this work, a novel electrode of binder free mixed metal pyrophosphate (CoNiP2O7) composited to conducting polymer of polypyrrole is developed. Then, the prepared CoNiP2O7/NF CoNiP2O7/NF@PPy electrodes capacitive and diffusive mechanism discussed by using Trassati method. In electrochemical experiments, the CoNiP2O7/NF@PPy composite showed considerably enhanced specific capacity (1202 mAhg−1), which is much greater than that of pure CoNiP2O7/NF (819 mAhg−1). Additionally, the hybrid supercapacitor (CoNiP2O7/NF@PPy//AC) device manufactured had the highest energy density of 94.6 Wh kg−1. These findings indicate that this composite is a promising option for electrochemical capacitors.

Controllable Fabrication of Polypyrrole Nanopillar/Hair Arrays by Oxygen Plasma Treatment and Their Applications as Antibacterial Flexible pH Sensors

AbstractFlexible pH sensors have attracted a great deal of attention in numerous applications, such as wearable healthcare devices, smart wound bandages, and other pH monitor sensors for chemical and bioprocess control. Herein, a facile approach to fabricate conducting polymer polypyrrole nanopillar arrays is proposed, and its potential as an advanced pH sensing interface is shown. Using oxygen plasma treatment as the etching tool, polypyrrole nanopillar/hair arrays can be prepared after etching 3D polypyrrole network structures. Conductive polypyrrole nanopillar arrays possessed unique advantages in sensing: their featured nanopillars has enhanced antibacterial properties; their structures showed excellent hydrophilicity and are favorable for interaction with analytes in small‐volume liquids. A flexible polypyrrole nanopillar array‐based potentiometric pH sensor integrated with a solid‐state reference electrode is further designed and fabricated. Superior performance with a near‐Nernstian response of 60.1±1.0 mV pH−1, excellent repeatability, high stability, and reproducibility is verified in the physiological pH range. The reliabilities of flexible and small‐volume sample testing, as well as the applicability for artificial sweat sample pH sensing, are examined. Provided with the advantages of antibacterial properties and hydrophilicity, the proposed flexible pH sensor is promising for trace analysis in biological, medical, and healthcare applications.

A molecular dynamics study on the size effects of Fe3O4 nanoparticles on the mechanical characteristics of polypyrrole/Fe3O4 nanocomposite

ABSTRACT Nanoparticle size effects on elastic properties of polymeric bio-nanocomposites were studied using atomistic molecular dynamics (MD) simulations. Spherical magnetite nanoparticles (MNPs) were placed at the centre of amorphous polypyrrole (PPy) polymer in three models with different sizes. Three models of nanocomposites with the same particle volume fractions with different sizes were considered. The Lennard-Jones 6-12 potential modelled the interface interaction between polymer and particles. Initially, the obtained mechanical properties for pristine PPy and magnetite in the bulk state showed an acceptable agreement with experimental data. Subsequently, simulation results illustrated that incorporating MNP into the PPy matrix improves the elastic modulus of the matrix by 28-58%, and more importantly, decreasing the size of the nanoparticle from 2.40 to 1.80 nm in the system leads to increasing Young's modulus of the nanocomposite from a 3.20 to 3.94 GPa. Furthermore, the atomic investigation demonstrated that this change in elastic modulus is due to the change in interatomic interaction between nanoparticle and polymer when the nanoparticle size changes. Finally, the comparison between the results of MD and micromechanical analysis shows that as the size of the nanoparticle in nanocomposites increases, the elastic properties of nanocomposites converge with the results obtained by the micromechanical approach.

Antibacterial conductive polyacrylamide/quaternary ammonium chitosan hydrogel for electromagnetic interference shielding and strain sensing

The utilization of biomass-based conductive polymer hydrogels in wearable electronics holds great promise for advancing performance and sustainability. An interpenetrating network of polyacrylamide/2-hydroxypropyltrimethyl ammonium chloride chitosan (PAM/HACC) was firstly obtained through thermal-initiation polymerization of AM monomers in the presence of HACC. The positively charged groups on HACC provide strong electrostatic interactions and hydrogen bonding with the PAM polymer chains, leading to improved mechanical strength and stability of the hydrogel network. Subsequently, the PAM/HACC networks served as the skeletons for the in-situ polymerization of polypyrrole (PPy), and then the resulting conductive hydrogel demonstrated stable electromagnetic shielding performance (40 dB), high sensitivity for strain sensing (gauge factor = 2.56). Moreover, the incorporation of quaternary ammonium chitosan into PAM hydrogels enhances their antimicrobial activity, making them more suitable for applications in bacterial contamination or low-temperature environments. This conductive hydrogel, with its versatility and excellent mechanical properties, shows great potential in applications such as electronic skin and flexible/wearable electronics.