Polymer Polypyrrole Research Articles

Conducting Polymer Composites As Multifunctional Electrode Matrices for Lithium-Ion Batteries

The rising number of lithium-ion battery cells fabricated to power electric vehicles has raised concerns about the environmental impacts of battery electrode fabrication process. Typically, N-Methyl-2-pyrrolidone (NMP) solvent is used to blend active materials and electrode matrices, which are normally polyvinylidene fluoride/carbon-black (PVDF/C) mixtures. The use of NMP solvent, however, requires extensive energy for electrode drying and toxic solvent recovery. In addition, the PVDF/C electrode matrix offers weak interactions with active materials, which results in poor morphological integrity and rapid capacity fading, especially for high-volume-change electrode materials. Using water-processable binders such as carboxymethyl cellulose (CMC) and styrene-butadiene rubber (SBR) has been proven to enable a greener electrode-casting process as well as improve electrode performance. However, the electrical conductivity of these electrodes relies mainly on carbon additives, which are subjected to agglomeration and volumetric-capacity reduction. In this study, new electrode matrices are developed from in situ polymerized polypyrrole:carboxymethyl-cellulose (PPy:CMC) composites with water-processable and electrical-conductive features. By forming a composite structure in which CMC acts as an anionic dopant for PPy conducting polymer, the PPy:CMC composites show good electrical conductivity, allowing them to be used as mono-component electrode matrices. As a result, carbon-additive-free LiCoO2/PPy:CMC electrodes can cycle at different C-rate. More importantly, the PPy:CMC composites enable aqueous slurry electrode casting, addressing the environmental pollution associated with NMP solvent utilization. The study introduces another potential application of conducting polymer composites in Li-ion batteries.Keywords: aqueous electrode casting, conducting polymers, polypyrrole.

A novel fiber-shaped asymmetric supercapacitor prepared by twisting carbon fiber/carbon nanotube/MnO2 and carbon fiber/carbon nanotube/polypyrrole electrodes+

In the study, a novel fiber-shaped asymmetric supercapacitor with high specific capacitance has been successfully constructed by twisting two self-made composite electrodes. Prior to manufacturing these electrodes, carbon nanotube is first deposited on carbon fiber by electrophoretic deposition to obtain carbon fiber/carbon nanotube composites. Subsequently, the positive and negative composite electrodes are prepared by the electrochemical deposition of manganese dioxide and electrochemical polymerization of polypyrrole, respectively. As a result, the novel fiber-shaped asymmetric supercapacitor performs a wide potential window of 1.7 V and a high energy density of 22.8 μWh cm−1 at the current density of 0.5 A g−1. Meanwhile, it still maintains great capacitance retention of 91.6% and 86.1% from 500 bending repetitions and 5000 cycles, respectively, which is due to the excellent flexibility and long cycle life. It is significant that the promising performance of the novel fiber-shaped asymmetric supercapacitor is of greatly potential for portable and wearable electronics in the future.

Functionalized phosphorene/polypyrrole hybrid nanomaterial by covalent bonding and its supercapacitor application

A functionalized phosphorene/polypyrrole (FPPY) hybrid nanomaterial was prepared via a mechanochemical process and chemical oxidative polymerization. The polymerization of polypyrrole (PPY) on the surface of two-dimensional phosphorene was investigated in detail. The amide bond formation of the FPPY hybrid improved the interfacial interaction between the PPY and phosphorene. The specific capacitance of the FPPY was 411.5Fg−1, which was approximately four times that of pristine PPY (106Fg−1). Additionally, hybridization improved the structural stability of PPY, yielding a cycle stability 2 times higher than that of pristine PPY. To the best of our knowledge, this is the first report on the potential of phosphorene hybridized with conducting polymers for practical energy-storage applications.

Study of biocompatible polymer blend films with tuneable band gap

In present communication, an attempt is made to prepare and study structural, optical, and electrical properties of biocompatible polyvinylchloride (PVC)-polyvinylpyrrolidone (PVP) blend films taken in ratio of 1:1 doped with conducting polymer Polypyrrole (PPy).The XRD spectra revealed amorphous nature of all the films under investigation. The Fourier transform infra-red spectroscopy (FTIR) study of conducting polymer doped blend films indicate a significant change in the intermolecular/intramolecular interactions taking place. The study on electrical properties of conducting polymer doped blend films show better conduction of current as compared to that of blend film without conducting polymer and dopant concentration dependent electrical conductivity and conduction mechanism. The results of optical study of conducting polymer doped blend films revealed the possibility of band gap modification from wide band gap to small band gap with suitable doping concentration. These biocompatible blend films with tuneable optical and electrical properties can be potential material for use in fields of photonic biosensors, solar cell and optoelectronics field.

Electrochemical Immunosensor for Detection of CCR4 Cancer Biomarker in Human Serum: An Alternative Strategy for Modification of Disposable ITO Electrode.

Herein, a new strategy for the fabrication of a sensitive immunosensor capable of determination of CC Chemokine receptor 4 (CCR4) in complex serum samples is developed through the polymer modification on the disposable indium tin oxide electrode. Anti-CCR4 antibodies, which are utilized as sensing biomolecules, are covalently attached on the succinimide groups of polypyrrole polymer (PPyr-CSsg). The constructed immunosensor illustrates promising performances for the quantification of CCR4 antigen, with a linear detection range of 0.024-12 pg mL-1 and a low detection limit of 7.3 fg mL-1 , calculated at a signal-to-noise ratio of 3. In addition, the impedimetric immunosensor displays a very successful analytical performance in terms of sensitivity, selectivity, repeatability, reproducibility, and long-term stability as well as successful applicability for the accurate quantification of CCR4 in human serum samples. The constructed immunosensor is successfully used for quantification of CCR4 antigen in human serums. In addition, the immunosensor displays only 27.54% loss in its initial signal after nine weeks storage at 4°C. Moreover, the fabricated immunosensor is economical, highly sensitive, and selective for CCR4 antigen detection, and suitable for potential application in clinical diagnosis.

Physical and electrochemical appraisal of cotton textile modified with polypyrrole and graphene/reduced graphene oxide for flexible electrode

The aim of this study was to prepare a flexible fabric electrode for electronic devices. Cotton fabric (CT) was used as the substrate for coating graphene oxide (GO) and reduced graphene oxide (RGO) as electroactive materials, then subjected to the chemical polymerization of polypyrrole (PPy) . The sheet resistances and surface morphologies of the as-prepared composite textiles were evaluated by means of using van der Pauw technique and FESEM, respectively. XPS results showed a reduction of around 17% in the ratio of O/C in RGO/CT in comparison with the GO/CT, which could be related to the reduction of GO to RGO. The PPy/RGO/CT composite fabric exhibited sheet resistance of 7.5 Ω/sq, whereas PPy/GO/CT samples presented a sheet resistance of 308.3 Ω/sq. Charge-transfer resistance of PPy/GO/CT was 10 times of PPy/RGO/CT, which showed the insulating role of GO in this composite. Therefore, PPy/RGO/CT can hold a significant promise in flexible electrode applications.

3D structure of lightweight, conductive cellulose nanofiber foam

We investigate the three-dimensional (3D) structuring of cellulose nanofiber (CNF) foam-based ink using direct ink writing 3D printing and the transformation of CNF foam from an insulator to a conductor. The colloidal stability of a CNF foam is critical to producing a solid CNF foam which can be used as a template for the synthesis of conducting polymers. Liquid CNF foam ink is produced by simple stirring of CNF suspension with sodium dodecyl sulfate as an emulsifier. The shear thinning behavior of the liquid CNF foam ink enables printing through a needle. Flexible design of CNF foam structures is enabled by 3D printing using computer-aided design. Lightweight conductive CNF foams are prepared via in situ polymerization of polypyrrole on a solid CNF foam. The topological features of the resultant porous conductive CNF foams are observed, and their conductivity is investigated.

Metallic Surface Coating of Polymeric Parts Produced by Additive Manufacturing Process

Metal coating films were deposited on the surface of the pieces of non-conducting polymers, acrylonitrile butadiene styrene (ABS), high impact polystyrene (HIPS) and poly (lactic acid) (PLA). These three polymers have been used since they are the main raw materials available for fusion and deposition molding equipment. In order to achieve surface metallization by electrodeposition, it was necessary to apply a pre-treatment using the chemical polymerization technique in solution with the electroconductive polymer polypyrrole (PPy) was deposited on the specimens. A uniform layer of PPy was deposited on the surface of the specimens of the ABS and HIPS polymers, while in the specimen of the polymer PLA this layer showed uniformity faults. After this pretreatment was possible to perform copper electrodeposition, creating the metallic coatings on the ABS / PPy, HIPS / PPy and PLA / PPy surfaces. This metallic coating was uniform in all specimens except the one of the PLA polymer that was not sanded. The adhesion of the coating was evaluated by the adhesion test with tape and the quality of the appearance (absence of visual defects), the morphology, the uniformity, the thickness, the conductivity and the adhesion quality of the films were analyzed.

Self-Powered Humidity Sensor Based on Polypyrrole/Melamine Aerogel for Real-Time Humidity Monitoring

Measuring or monitoring air humidity is an increasing demands in the various fields. In this work, a simple and convenient method was utilized to prepare a melamine aerogel (MA) based sensor for humidity measurement. The sensing material was made from polymerization of polypyrrole (PPy) in the matrix of MA. The surface morphology was characterized by scanning electron microscopy (SEM) to examine the inner structure of the sensing material. MA was chosen as the substrate owing to the porous structure, which facilities the adsorption of water molecules from the air. The self-powered humidity sensor was manufactured by adhering conductive tapes on both side of PPy modified MA (PPy@MA). The sensor has a flexible, ultralight and ultraporous structure, and could generate humidity-induced open-circuit voltage from the concentration gradient of the H <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">+</sup> ions. The PPy@MA sensor exhibited the response and recovery time of 1.1 s and 4.5 s, respectively, when it is used for sensing the flowing wet air (RH 75 %). Furthermore, the sensitivity of the self-powered humidity sensor was evaluated by assessing the moisture changes of the human skin, and the moisture from the human breath.

Complex Optical Studies on Conducting Polypyrrole Doped with ZnO Nanoparticles

AbstractThe conducting polymer polypyrrole and polypyrrole/ZnO nanocomposites are synthesized by in situ polymerization method at 0°C–5°C temperature with ammonium persulphate as an oxidizing agent. The optical band gap of polypyrrole/ZnO nanocomposites have been studied at different weight percentage such as 10%, 30%, and 50%, at room temperature. The obtained absorption spectra in the wavelength range 200–800 nm by T90+ UV/Vis Spectrophotometer. The PXRD pattern confirmed the hexagonal wurtzite structure of the ZnO product. The particle size is calculated by using the Debye–Scherrer relation and it is found to be in the range of 20–50 nm. The absorption spectra at 385 nm obtained is the characteristic peak of ZnO and it is observed for all weight percentages of nanocomposites. Further, the peaks that occurred at 300and 469 nm (3.71 eV) confirm the formation of polypyrrole in nanocomposites. The optical properties of such conducting polymer nanocomposites are used in the field of optoelectronic devices and its wide band gap is useful in biomedical applications.

N-doped carbon nanoweb-supported Ni/NiO heterostructure as hybrid catalysts for hydrogen evolution reaction in an alkaline phase

The design of the cost-effective, efficient, and durable electrocatalysts for hydrogen evolution reaction (HER) is of great importance in the field of clean and renewable energies. In this study, Ni/NiO nanocomposite supported on N-doped carbon nanoweb (Ni/NiO/NCW) hybrid materials are proposed as an efficient electrocatalyst for HER in alkaline media. A series of Ni/NiO/NCW hybrid catalysts were prepared via polymerization of polypyrrole (PPy) in the presence of a surfactant, followed by incipient wetness impregnation and heat treatment techniques. The resulting Ni/NiO/NCW hybrid catalysts exhibit an excellent electrocatalytic properties with a lower overpotential of 105.3 mV (vs RHE) at 10 mA cm−2, a smaller value of Tafel slope (55.2 mV dec−1) and almost 100% Faradaic efficiency. It also shows good stability in performance attenuation during continuous cyclic voltammetry sweeps for 1000 cycles. Its excellent electrocatalytic performance for alkaline hydrogen evolution reaction can be attributed to the synergistic effect associated with the morphological benefit of 3D N-doped carbon nanoweb and Ni/NiO heterostructure with the optimal ratio of Ni to NiO.

Axonal extension from dorsal root ganglia on fibrillar and highly aligned poly(lactic acid)-polypyrrole substrates obtained by two different techniques: Electrospun nanofibres and extruded microfibres

The biological behaviour of Schwann cells (SCs) and dorsal root ganglia (DRG) on fibrillar, highly aligned and electroconductive substrates obtained by two different techniques is studied. Mats formed by nanometer-sized fibres of poly(lactic acid) (PLA) are obtained by the electrospinning technique, while bundles formed by micrometer-sized extruded PLA fibres are obtained by grouping microfibres together. Both types of substrates are coated with the electrically conductive polymer polypyrrole (PPy) and their morphological, physical and electrical characterization is carried out. SCs on micrometer-sized substrates show a higher motility and cell-cell interaction, while a higher cell-material interaction with a lower cell motility is observed for nanometer-sized substrates. This higher motility and cell-cell interaction of SCs on the micrometer-sized substrates entails a higher axonal growth from DRG, since the migration of SCs from the DRG body is accelerated and, therefore, the SCs tapestry needed for the axonal growth is formed earlier on the substrate. A higher length and area of the axons is observed for these micrometer-sized substrates, as well as a higher level of axonal sprouting when compared with the nanometer-sized ones. These substrates offer the possibility of being electrically stimulated in different tissue engineering applications of the nervous system.

Aptamer-based electrochemical biosensing strategy toward human non-small cell lung cancer using polyacrylonitrile/polypyrrole nanofibers.

In the present study, a sensitive electrochemical aptamer-based biosensing strategy for human non-small cell lung cancer (NSCLC) detection was proposed using nanofiber-modified disposable pencil graphite electrodes (PGEs). The composite nanofiber was comprised of polyacrylonitrile (PAN) and polypyrrole (PPy) polymers, and fabrication of the nanofibers was accomplished using electrospinning process onto PGEs. Development of the nanofibers was confirmed using scanning electron microscopy (SEM). The high-affinity 5'-aminohexyl-linked aptamer was immobilized onto a PAN/PPy composite nanofiber-modified sensor surface via covalent bonding strategy. After incubation with NSCLC living cells (A549 cell line) at 37.5°C, the recognition between aptamer and target cells was monitored by electrochemical impedance spectroscopy (EIS). The selectivity of the aptasensor was evaluated using nonspecific human cervical cancer cells (HeLa) and a nonspecific aptamer sequence. The proposed electrochemical aptasensor showed high sensitivity toward A549 cells with a detection limit of 1.2 × 103 cells/mL. The results indicate that our label-free electrochemical aptasensor has great potential in the design of aptasensors for the diagnostics of other types of cancer cells with broad detection capability in clinical analysis. Graphical abstract.

Investigation of Microwave Absorption Performance of CoFe2O4/NiFe2O4/Carbon Fiber Composite Coated with Polypyrrole in X-Band Frequency.

The current research reports the preparation of a microwave absorber containing CoFe2O4/NiFe2O4/Carbon fiber (H/S/CF) coated with polypyrrole polymer (PPy@H/S/CF) through sol-gel and in-situ polymerization processes. X-ray diffraction (XRD), field emission scanning electron microscopy (FESEM), vibrating sample magnetometer (VSM), and a vector network analyzer (VNA) are utilized to evaluate the features of the prepared composite. The microstructure analysis results revealed carbon fibers well decorated with submicron-size particles having hard/soft magnetic phases and thoroughly coated with polymer. The paraffin-based microwave absorber sample filled with 45 wt.% of PPy@H/S/CF has simultaneously both magnetic and dielectric losses in the 8.2–12.4 GHz frequency range. The absorber is used in a Salisbury screen configuration aiming at reducing the radar cross-section of objects. A minimum reflection loss of −55 dB at 10.6 GHz frequency with 5 GHz bandwidth is obtained for the sample with a 2 mm thickness. Different mechanisms, such as interfacial polarization, ferromagnetic resonance, and electron hopping, are the main factors for achieving such an appropriate microwave absorption. These results suggest that the PPy@H/S/CF composite is an ideal candidate for microwave absorption applications requiring high performance and low thickness.

In Situ Polymerization of Polypyrrole @ Aluminum Fumarate Metal–Organic Framework Hybrid Nanocomposites for the Application of Wastewater Treatment

Composite metal–organic frameworks combine large and accessible surface areas with low density and high stability. Herein, we present novel nanocomposites of polypyrrole/aluminum fumarate metal–organic framework (PPy/AlFu MOF), which were synthesized via in situ oxidative polymerization with the aim of MOF functionalization to enhance its thermal stability and increase the specific surface area so that these nanocomposites may be used as potential adsorbents. The synthesized nanocomposites were characterized by various techniques, such as powder X-ray diffraction, scanning electron microscopy, and Fourier-transform infrared spectroscopy (FTIR). The successful functionalization of aluminum fumarate MOF was confirmed by FTIR, and the Brunauer–Emmett–Teller (BET) surface area of the PPy/MOF nanocomposite slightly increased from 795 to 809 . Thermogravimetric analysis data also show that the weight loss of the composite is up to 30% at temperatures up to 500 . Remarkably, lead (50 ppm) sequestration using the composite was tested, and the atomic absorption spectrometry data demonstrate that PPy/MOF is a super-adsorbent for heavy metal ions. This work shows that the novel polymer–MOF composites are promising materials for the selective removal of lead from wastewater streams.

Effect of yarn interlacement pattern on the surface electrical conductivity of intrinsically conductive fabrics

The fundamental fabric construction of a conductive textile has a vital impact on its overall electrical properties. In the present study, a comprehensive assessment entailing the influence of yarn interlacement pattern on the surface conductivity of intrinsically conductive fabric (i-CF) has been undertaken. The different interlacement designs, namely, woven 1 × 1 plain, 2 × 2 basket, 2 × 1 twill, 5 × 1 twill, and weft knit single jersey were each prepared using polyester and cotton yarn. Electrical conductivity was imparted to the pristine and He/O2 plasma irradiated textile substrates via in-situ polymerization of polypyrrole (PPy) in an oxidative environment. Additionally, change in yarn surface morphology due to He/O2 plasma irradiation was studied using scanning electron microscopy (SEM), Fourier-transform infrared spectroscopy (FTIR), and X-ray photoelectron spectroscopy (XPS). Surface activation caused by the plasma-treatment enabled a higher PPy uptake and better retention. The enhanced PPy retention was quantified through the abrasion fastness test by measuring i-CF conductivity after 500, 1000, 2000, and 4000 rubbing cycles. In conclusion, it was observed that collectively, woven i-CFs exhibited superior surface conductivity (of order 10−3 – 10-4 Siemens sq.) than the knitted i-CFs (of order 10-6 Siemens sq.). This was primarily due to the high pore size and active ‘canal effect’ in the latter that hampered proper PPy coating and its subsequent retention on the i-CF surface. Besides pore size, factors including crimp %, number of interlacement points, degree of warp/weft float, fabric thickness, and weight add-on % come into play to synergistically determine the resultant properties of the conductive fabrics.

Guided Electrokinetic Assembly of Polystyrene Microbeads onto Photopatterned Carbon Electrode Arrays

Assembly of microdevices from constituent parts currently relies on slow serial steps via direct assembly processes such as pick-and-place operations. Template Electrokinetic Assembly (TEA), a guided, noncontact assembly process, is presented in this work as a promising alternative to serial assembly processes. To characterize the process and its implementation of electrokinetic, dielectrophoretic, and electro-osmotic phenomena, we conducted studies to examine the assembly of polymer microparticles at specific locations on glassy carbon interdigitated electrode arrays (IDEAs). The IDEAs are coated with a layer of lithographically patterned resist, so that when an AC electric field is applied to the IDEA, microparticles suspended in the aqueous solution are attracted to the open regions of the electrodes not covered by photoresist. Interplay between AC electro-osmosis and dielectrophoretic forces guides 1 and 5 μm diameter polystyrene beads to assemble in regions, or "wells", uncovered by photoresist atop the electrodes. It was discovered that AC electro-osmosis under an applied frequency of 1 kHz is sufficient to effectively agglomerate 1 μm beads in the wells, whereas a stepwise process involving the application of a 1 MHz signal, followed by a 1 kHz signal, is required for the positioning of 5 μm beads, which are mainly affected by dielectrophoretic forces. Permanent entrapment of the microparticles is then demonstrated via the electropolymerization process of the conducting polymer polypyrrole.

Bi-functional catalytic performance of silver manganite/polypyrrole nanocomposite for electrocatalytic sensing and photocatalytic degradation

Detection and degradation of perilous polluting materials are important in the study of health and environmental issues. Nowadays, researches are on the path to invent dual functional materials. On that basis, we have designed a simple one-pot synthesis of silver manganite incorporated polypyrrole polymer nanocomposite (AMNPY). The physicochemical, morphological, electrical and optical properties of as-synthesized nanocomposites were characterized using PXRD, XPS, FESEM, TEM, EDX, Elemental Mapping, UV-DRS, FTIR, CV, DPV and EIS techniques. Incorporation of polypyrrole (PPy) with silver manganite (AMN) was initially studied using FTIR spectral data. The microscopic images have revealed the particles into nano range and show better correlation with the average particle size, which was calculated from PXRD analysis. Furthermore, the photocatalytic and electrocatalytic potential of the as-synthesized nanocomposite were evaluated. AMNPY exhibits excellent activity in the photocatalytic degradation of methyl orange dye (99.6 %) and chloramphenicol drug (98.9 %) within 30 min. The photocatalyst was highly recyclable which was evaluated and confirmed up to 5 cycles. Further, on the evaluation of electrochemical sensing activity of AMNPY modified screen printed carbon electrode (AMNPY/SPCE) demonstrated an excellent sensing in the detection of antibiotic drug furazolidone. The AMNPY/SPCE exhibited two wide linear response ranges (0.1 μM to 10 μM; 18 μM to 906 μM) along with lower detection limit of about 3 nM. In addition to this, the potential sensor proved an outstanding sensitivity of 6.95 μA μM−1 cm-2 and prominent selectivity even in the presence of biomolecules, metal ions and strong interfering derivatives.

Size controlled V2O5-WO3 nano-islands coated polypyrrole matrix: A unique nanocomposite for effective room temperature ammonia detection

Unique metal oxide nanomaterials represent prominent interest owing to their low cost, ease of fabrication and vast number of detectable gases in resistive based gas sensors. Unfortunately they are limited by their dependence of operating temperature, power consumption, poor sensitivity and deterioration of sensing material after continuous usage. To get the better of, conducting polymer polypyrrole has been widely used for fulfilling the requirement as ideal sensing material in sensing field due to its chemical stability, high electron affinity, controllable electrical conductivity and excellent room temperature operation. In this article, we report room temperature responsive ammonia gas sensing material PPy with V2O5 and WO3 developed by in situ chemical oxidation polymerization method. Characterizations carried out using the UV–vis, FTIR, XRD, XPS, SEM, HR-TEM, AFM analysis techniques. Physical and chemical analysis results reveal that the nanocomposite was synthesized successfully without other impurities. The morphological analysis exhibits that V2O5 and WO3 nanoparticles were wrapped and connected over PPy surface as nano islands provides enhanced sensing properties towards selectively NH3with ultrahigh sensitivity of 85 % with response time of 73 s and recovery time 101 s. The outstrip performance of gas sensing esteems were corresponds to the valid p-n heterojunctions of V2O5-WO3 and excellent surface effect of PPy.

Skin Conformal and Antibacterial PPy‐Leather Electrode for ECG Monitoring

AbstractThe commonly used electrocardiogram monitoring electrodes (hydrogel electrodes, fabric electrodes, etc.) suffer from fast degradation of signal quality due to water loss. Therefore, such electrodes are not suitable for long‐term monitoring. Herein, the conductive polymer polypyrrole (PPy) is polymerized in situ on goat leather, and the obtained conductive leather is used as a wearable dry electrode to contact human skin and collect electrophysiological signals for daily health monitoring. Because of its own surface structure, the wearable dry leather electrode obtained by a simple method can form a conformal contact with the skin to reduce noise during electrical signal acquisition. In addition, PPy‐leather electrodes have good antibacterial properties and are more breathable and comfortable than the commercial Ag/AgCl gel electrode. Such an electrode is more suitable for long‐term health monitoring.