Oxidative Polymerization Of Pyrrole Research Articles

An electroanalytical sensor based on overoxidized polypyrrole-gold composite for the detection of tyramine in fermented food

This study develops an electroanalytical sensor using overoxidized polypyrrole-gold composite (Au/PPyox) for the detection of tyramine in fermented foods. Tyramine, a biogenic amine, serves as an essential quality marker, but at higher concentrations can pose health hazards, particularly for individuals with specific metabolic disorders. Current detection methodologies require complex equipment and specialized personnel, impeding their routine use. We synthesized Au/PPyox via oxidative polymerization of pyrrole and developed an Au/PPyox-based sensor, exhibiting substantial selectivity and sensitivity towards tyramine. The sensor exhibited a limit of detection as low as 0.01 μM, demonstrating its high sensitivity. Moreover, it retained stability, selectivity, and reproducibility over two weeks under ambient conditions. Practical application of the sensor in various fermented foods illustrated its potential for routine use. The results indicate that the Au/PPyox-based electroanalytical sensor can serve as a reliable, cost-effective, and user-friendly tool for tyramine detection in fermented foods.

Carbonized Leather Waste with Deposited Polypyrrole Nanotubes: Conductivity and Dye Adsorption.

This paper reports the conversion of a waste to a conducting material, exploiting the ability to adsorb pollutant organic dyes. Leather waste was carbonized at 800 °C in an inert nitrogen atmosphere. The resulting biochar was used for in-situ deposition of polypyrrole nanotubes produced by the oxidative polymerization of pyrrole in the presence of methyl orange. The composites of carbonized leather with deposited polypyrrole nanotubes of various composition were compared with similar composites based on globular polypyrrole. Their molecular structure was characterized by infrared and Raman spectra. Both conducting components formed a bicontinuous structure. The resistivity was newly determined by a four-point van der Pauw method and monitored as a function of pressure applied up to 10 MPa. The typical conductivity of composites was of the order of 0.1 to 1 S cm-1 and it was always higher for polypyrrole nanotubes than for globular polypyrrole. The method also allows for the assessment of mechanical features, such as powder fluffiness. The conductivity decreased by 1-2 orders of magnitude after treatment with ammonia but still maintained a level acceptable for applications operating under non-acidic conditions. The composites were tested for dye adsorption, specifically cationic methylene blue and anionic methyl orange, using UV-vis spectroscopy. The composites were designed for future use as functional adsorbents controlled by the electrical potential or organic electrode materials.

Low-Level Quantification of Cefixime and Cefdinir in Human Plasma Using Ultrasound-and Magnetic-Assisted Dispersive Micro-Solid-Phase Extraction (MSPE) Based upon Carbon Quantum Dots (CQDs) Functionalized with Magnetite/Zeolitic Imidazolate Framework 71/Polypyrrole Combined with High-Performance Liquid Chromatography (HPLC)

A promising and reusable nanohybrid based on carbon quantum dots immobilized with Fe3O4/zeolitic imidazolate framework-71/polypyrrole (CQD/Fe3O4/ZIF-71/PPy) was fabricated as a sorbent for ultrasound-and magnetic-assisted dispersive micro-solid-phase extraction (US-M-A-DMSPE) followed by high-performance liquid chromatography with ultraviolet detection (HPLC-UV) for simultaneous trace determination of cefixime (CFX) and cefdinir (CFD) in human plasma. In order to improve the contact between the analyte and the sorbent, the surface of the CQDs was modified by individual materials involving zeolitic imidazolate framework and polypyrrole via an in-situ synthesis of ZIF-71 followed by oxidative polymerization of pyrrole. The structure of the prepared sorbent was characterized by x-ray diffraction (XRD), Fourier transform-infrared spectroscopy (FT-IR), scanning electron microscopy (SEM) and energy-dispersive X-ray spectroscopy (EDX). Under the optimized conditions, the nanosorbent provided high adsorption and selectivity toward the analytes. The limits of detection for CFX and CFD were 0.15 and 0.04 ng mL−1, respectively. The coefficients of determination (r2) were between 0.990 and 0.993, with dynamic ranges of 0.5–1750.0 and 0.2–1500.0 ng mL−1. The method was used for quantifying CFX and CFD in plasma samples to evaluate the pharmacokinetic aspects, including the half-life (T½), the time to reach the maximum concentration (Tmax), the maximum plasma concentration (Cmax), area under the curve (AUC0-24) and area under the curve at infinite time (AUC0-∞). Reliable reproducibility as the intra- assay (≤ 6.3%) and inter-assay (≤ 8.7%) together with reasonable accuracy (≤ 8.8%) were obtained.

Preparation of ferrocenyl-furan modified graphene oxide via Diels-Alder click reaction and using of its polypyrrole nanocomposites as supercapacitor electrode material

In the present study, the 1-(2-furyl)acryloylferrocene was prepared as a suited scaffold for Diels–Alder reaction with graphene oxide. In order to increasing of conductivity, the ferrocenyl functionalized graphene oxide (GO-FcFu) was physically mixed with polypyrrole. Polypyrrole as an organic polymer was obtained by oxidative polymerization of pyrrole. The obtained GO-FcFu/PPy nanocomposite were tested as hybrid supercapacitor with dual features of electrical double layer capacitance and pseudocapacitive arising from GO and ferrocene species, respectively. The improved surface area (33.41 m2 g−1), high mass specific capacity of 231.31 mAh g−1 (1 A g−1), and the capacity retains 89% of initial capacity after 5000 cycles were estimated the sufficiency of final composite for use as electrode material.

N‐Doped Activated Carbons from Polypyrrole – Effect of Steam Activation Conditions

AbstractPolypyrrole (PPy) has been prepared by oxidative polymerization of pyrrole and used as a raw material for the preparation of N‐doped activated carbons. Thus, PPy has been pyrolyzed at 900 °C and then activated with steam under different activation conditions (time and temperature). This has allowed for the preparation of activated carbons with different porosity development and nitrogen content, as well as distinctive distribution of nitrogen species. It has been observed that the presence of nitrogen functionalities favors water adsorption at low relative pressures but, at relative pressures higher than 0.5 it is determined by the porosity development.

Biocompatible polypyrrole/zeolite composite for chromate removal and detoxification

This study assessed the Cr(VI) removal efficiency, detoxification, and biocompatibility of polypyrrole/zeolite (PPy/Ze) nanocomposite. The composite was prepared by oxidative polymerization of pyrrole with zeolite. Structural study through scanning electron microscope showed that PPy/Ze nanocomposite was circular in shape with size ranging from 30 to 80 nm. The Fourier transform infrared spectra peaks of the composite confirm the presence of zeolite and polypyrrole in the composite. The composite removed 83.5% of Cr(VI) within 50 min and consequently detoxified Cr(VI) through reduction process. Energy dispersive X-ray spectrum supports the adsorption of Cr(VI) onto the composite and X-ray diffraction spectra corresponding to Cr2O3 attest Cr(VI) reduction. Cytotoxicity and antimicrobial assay confirmed that the composite was non-toxic and do not retard Listeria monocytogenes and Salmonella typhimurium growth. These results confirm that PPy/Ze composite is an useful and eco-friendly material for Cr(VI) removal and reduction from wastewaters.

Synthesis and Mechanism of Spherical Ag-doped Polypyrrole Assisted by Complexing Agents

Highly dispersed Ag-doped Polypyrrole (PPy) spherical composites can be efficiently synthesized via oxidative polymerization of pyrrole with FeCl3 in an aqueous Ag+-containing solution in the presence of trisodium citrate, followed by concentrated ammonia treatment. However, the formation mechanisms involved in how to control the shape and how to get the metallic Ag0 need further investigation. In order to elucidate the formation mechanisms, the intermediates in different reaction stage were collected and investigated. Combining the experimental phenomenon and the structure characterization of the samples, it was found that citrate ions make a role of complexing Ag+ to produce [Ag3(C6H5O7)n+1]3n− complexes in the early reaction stage, then mainly play a role of steric stabilizer of AgCl micelles and are responsible for the shape tailoring of PPy composite as well as the reduction of Ag+ in the process of ammonia treatment. Evidently, negative-charged AgCl micelles become the main nucleation sites of pyrrole polymerization through the electrostatic attraction between the negative and positive ions. Concentrated ammonia is adopted to eliminate AgCl cores from the precursor of Ag-doped PPy composites obtained by chemical redox reaction and provides an accelerated reaction condition for reduction of Ag+ by reductants (citrate ion or pyrrole monomer). Ag-containing micelles induction method is a facial chemical method to obtain uniform Ag-doped composites and can be broadened to design other Ag-containing functional materials.

Monodisperse Porous Carbon Nanospheres with Ultra‐High Surface Area for Energy Storage in Electrochemical Capacitors

AbstractHighly porous carbon nanoparticles are very suitable materials for supercapacitor electrodes due to their combination of large surface area for ion adsorption and short pathways for fast ion diffusion. Herein we describe the synthesis of highly porous carbon nanospheres (d=90 nm) by a simple strategy that involves the preparation of monodisperse nanoparticles by the oxidative polymerization of pyrrole, followed by their direct chemical activation with KHCO3. The morphology of the nanospheres is well retained after activation, and the inorganic impurities are removed by a simple washing step with water. The porous nanospheres possess a high electrical conductivity and specific surface areas exceeding 3000 m2 g−1 due to their high content of micropores and small mesopores (<4 nm). Their highly developed and readily available porosity make these materials promising for use as supercapacitor electrodes. In the aqueous 1 M H2SO4 electrolyte, the porous nanospheres reach a capacitance of 262 F g−1 and withstand an ultrahigh current density of 80 A g−1 maintaining a capacitance above 100 F g−1. In the organic 1 M TEABF4/AN and EMImTFSI/AN electrolytes, the nanoparticles reach 175 and 155 F g−1, and the supercapacitors could be cycled up to 50 A g−1 delivering 30 Wh kg−1 at a power density of 20 kW kg−1 and 31 Wh kg−1 at a power density of 31 kW kg−1, respectively. These results demonstrate the potential of these nanoparticles for energy storage applications.

One-Pot Synthesis of Magnetic Polypyrrole Nanotubes for Adsorption of Cr(VI) in Aqueous Solution

A novel and efficient route is proposed to fabricate Fe3O4/polypyrrole (Fe3O4/PPy) nanotubes via a one-pot process. The one-pot strategy involves the synthesis of Fe3O4/PPy nanotubes by oxidative polymerization of pyrrole (Py) monomer using Fe3+ as an oxidant in the presence of methyl orange (MO) and Fe3+ used as iron source to form Fe3O4 simultaneously in basic conditions without adding any additional iron source and oxidant. The effects of Fe3+ concentration on the morphology and adsorption capacity of the Fe3O4/PPy nanotubes were investigated. The Fe3O4/PPy nanotubes exhibit a tubular structure. Fe3O4 nanoparticles are well dispersed among the PPy nanotubes. The Fe3O4/PPy nanotubes exhibit excellent magnetic property, which make them easy to separate from wastewater by magnetic separation. The diameter of the PPy nanotubes decreased with the increase of the Fe3+ concentration. The Fe3O4/PPy nanotubes showed strong adsorption capability for Cr(VI) with the maximum adsorption capacity of about 451.45 mg·g−1, which is significantly higher than bare Fe3O4 nanoparticles. Cr(VI) was adsorbed on Fe3O4/PPy nanotubes by ion exchange and chelation, where Cr(VI) was partially reduced to Cr(III) due to the existence of −NH+ on the Fe3O4/PPy nanotubes. Furthermore, the Fe3O4/PPy nanotubes are recyclable, retaining 90% of the initial removal efficiency after 5 adsorption/desorption cycles.

Non-fluorinated and durable photothermal superhydrophobic coatings based on attapulgite nanorods for efficient anti-icing and deicing

Superhydrophobic coatings are promising for anti-icing, however, preparation of those with both excellent passive anti-icing and active deicing functions is very challenging, especially via eco-friendly approaches. Here, we report non-fluorinated and durable photothermal superhydrophobic coatings based on natural attapulgite nanorods for efficient anti-icing and deicing. The attapulgite nanorods were coated with polypyrrole by oxidation polymerization of pyrrole, and then coated with hexadecyl polysiloxane by hydrolytic condensation. The photothermal superhydrophobic coatings were prepared by spray-coating the mixture of the modified attapulgite suspension and a silicone resin onto aluminum plates. The coatings show (i) excellent superhydrophobicity (water contact angle = 162.7°, sliding angle = 2.7°) due to the three-tier hierarchical micro-/nanostructure and low surface energy, (ii) excellent photothermal effect (increase in surface temperature to 70 °C in 3 min under 1 sun) due to the enlarged surface area of polypyrrole exposed to sunlight by the hierarchical micro-/nanostructure, and (iii) good mechanical, chemical and thermal stability. Consequently, in both simulated and outdoor environments, the coatings show excellent anti-icing and deicing performances, e.g., significantly prolonged water freezing time, greatly reduced ice adhesion force, fast photothermal deicing and efficient long-term (4 weeks) outdoor anti-icing/deicing. The coatings are very promising for practical applications due to the excellent performances and eco-friendly method.

Facile pyrrole oxidative polymerization with ionic liquid to modify ceramic membrane for sustainable fouling control

Ceramic membrane bioreactor (CMBR) is an attractive alternative for wastewater treatment, although still subjects to fouling problem. This study facilely modified CM by oxidative polymerization of pyrrole with ionic liquid, to greatly enhance its conductivity and hydrophilic, and to sustainably mitigate fouling in an electric CMBR. Highly conductive ceramic membrane, BVIMBF4-CM, was facile obtained involving an ionic liquid 1-vinyl-3-butylimidazolium tetrafluoroborate (BVIMBF4) on the base CM (Base-CM). After simple modification, the electrical resistance of CM was reduced significantly from 1017 Ω/sq to 349 Ω/sq, while its water contact angle decreased from 44.0° to 30.5°. With the assistant of minute electric field, BVIMBF4-CM exhibited a high rejection efficiency of over 85% Cu2+, 65% Ni2+ and 93% bovine serum albumin (BSA). The interaction energy analysis verified BVIMBF4-CM itself prevent BSA from the membrane surface by the positive total interfacial energy. Meanwhile, the electrophoretic force provided by electric field enhanced the removal efficiency and antifouling capability of the BVIMBF4-CM. By using this modified CM to form an E-CMBR, a comparable removal efficiency as the CMBR could be stably obtained, which especially demonstrated significantly anti-fouling performance, as fouling rate decreased by 31.4–43.5%, and the total membrane resistance was only 60.8% of the Base-CM, under a minute electric field of 0.8 V/m. Enhanced hydrophilicity and conductivity of the BVIMBF4-CM take major responsible for this stable fouling alleviation in the E-CMBR. The new and facile method for CM modification proposed herein can serve as a reliable effort towards the application of antifouling E-CMBR system in wastewater treatment.

Enhancement of visible light photocatalytic activity of BiVO4 by polypyrrole modification

In this study, the different amounts of polypyrrole modified BiVO4 photocatalyst were synthesized by oxidative polymerization of pyrrole. The photocatalytic activity of polypyrrole and vanadate bismuth (PPy/BiVO4) composite was determined by photocatalytic degradation of Rhodamine B (RhB) under visible light irradiation. The results showed that PPy could not only affect the crystal structure and the morphology of BiVO4 photocatalyst, but also had a great influence on the photocatalytic activity of pure BiVO4. It was also found that PPy/BiVO4 with the highest photocatalytic activity when the doping amount of PPy was 5%, and the RhB degradation rate could reach 95.72%. This paper also discussed the possible mechanism of enhanced activity: the photogenerated holes in the valence band of BiVO4 can be directly transferred to the π orbital of PPy. At the same time, photogenerated electrons can be transferred to the conduction band of BiVO4, resulting in charge separation and stabilization, thereby effectively preventing the recombination of photogenerated electrons and holes.

Decontamination of N95 and surgical masks using a treatment based on a continuous gas phase-Advanced Oxidation Process.

A gas-phase Advanced Oxidation Process (gAOP) was evaluated for decontaminating N95 and surgical masks. The continuous process was based on the generation of hydroxyl-radicals via the UV-C (254 nm) photo-degradation of hydrogen peroxide and ozone. The decontamination efficacy of the gAOP was dependent on the orientation of the N95 mask passing through the gAOP unit with those positioned horizontally enabling greater exposure to hydroxyl-radicals compared to when arranged vertically. The lethality of gAOP was independent of the applied hydrogen peroxide concentration (2-6% v/v) but was significantly (P<0.05) higher when H2O2 was introduced into the unit at 40 ml/min compared to 20 ml/min. A suitable treatment for N95 masks was identified as 3% v/v hydrogen peroxide delivered into the gAOP reactor at 40 ml/min with continuous introduction of ozone gas and a UV-C dose of 113 mJ/cm2 (30 s processing time). The treatment supported >6 log CFU decrease in Geobacillus stearothermophilus endospores, > 8 log reduction of human coronavirus 229E, and no detection of Escherichia coli K12 on the interior and exterior of masks. There was no negative effect on the N95 mask fitting or particulate efficacy after 20 passes through the gAOP system. No visual changes or hydrogen peroxide residues were detected (<1 ppm) in gAOP treated masks. The optimized gAOP treatment could also support >6 log CFU reduction of endospores inoculated on the interior or exterior of surgical masks. G. stearothermophilus Apex spore strips could be applied as a biological indicator to verify the performance of gAOP treatment. Also, a chemical indicator based on the oxidative polymerization of pyrrole was found suitable for reporting the generation of hydroxyl-radicals. In conclusion, gAOP is a verifiable treatment that can be applied to decontaminate N95 and surgical masks without any negative effects on functionality.

Fine-tuning of conductive and dielectric properties of polypyrrole/TiO2 nanocomposite-coated polyamide fabric

ABSTRACT Structural, conductive and dielectric properties of hybrid Polypyrrole (PPy)-TiO2 nanocomposite-coated polyamide fabric (PA-PPy/TiO2) synthesized by in-situ oxidative polymerization of pyrrole on the surface of polyamide in the presence of colloidal TiO2 NPs (d ~ 4.5 nm) have been studied. Raman spectra confirmed salt form of PPy in both neat PPy and PPy/TiO2-coated PA fabric and indicated its complete coverage. SEM/EDX analysis confirmed presence of TiO2 NPs and changes in granular structure of PPy deposited on the surface of PA fiber depending on the amount of TiO2 NPs. The PA-PPy/TiO2 nanocomposite sample with lowest content of TiO2 NPs (6.79 At.% Ti) showed highest conductivity (~10−6 S/cm) and dissipation factor (tan δ) in the entire frequency range. The lowest amount of TiO2 NPs in the PA-PPy/TiO2 nanocomposite induced two to four orders of magnitude higher tan δ value, compared to neat PPy covered PA fabric, depending on the frequency range. Frequency dependence of real (ϵ′) and imaginary part (ϵ″) of the complex permittivity for neat PA and PPy/TiO2-coated PA fabrics follow the trend of changes in dissipation factor for the same TiO2 NPs concentrations. The presence of TiO2 NPs could be exploited for tuning the conductive and dielectric properties of a conductive layer.

Synthesis and characterization of conducting polypyrrole/bentonite nanocomposites and in-situ oxidative polymerization of pyrrole: adsorption of 4-nitrophenol by polypyrrole/bentonite nanocomposite

Oxidative polymerization of pyrrole in aqueous medium was used for the preparation of the Polypyrrole/Bentonite nanocomposites. Iron chloride hexahydrate was preferred as the oxidant. The nanocomposites were characterized by using several techniques such as Fourier transform infrared spectroscopy (ATR-FT-IR), X-ray diffraction (XRD), scanning electron microscopy-energy dispersive X-ray analysis (SEM-EDX), thermogravimetric analysis/differential thermal analysis (TGA-DTA), differential scanning calorimetry (DSC) and dynamic light scattering (DLS). X-ray diffraction analysis indicated that the polypyrrole was intercalated into the bentonite layers. The results of FT-IR and XRD spectroscopy proved that the structure was a composite. The conductivity of composites was measured using four-point techniques. TGA was used to analyze the thermal stability of the nanocomposites. Moreover, the adsorption of 4-nitrophenol (4NP) by the composite from aqueous solution was studied both thermodynamically and kinetically. Equilibrium data were acquired from adsorption of 4NP solutions that have the initial concentrations from 25 to 300 mg L−1 by adsorption of the nanocomposite at different temperatures (25, 35 and 45 °C) according to Langmuir and Freundlich adsorption isotherms. Qmax (maximum adsorption capacity) was defined as 96 mg g−1 via the Langmuir isotherm model. The parameters of thermodynamic (ΔHo, ΔGo and ΔSo) were calculated as well, and adsorption process was determined to be exothermic.

Influence of clay modification process in polypyrrole-layered silicate nanocomposite

This work focuses mainly on the preparation and characterization of polypyrrole/organically modified clay nanocomposites. Organoclay/polypyrrole nanocomposites were prepared by oxidative polymerization of pyrrole in aqueous medium using ferric chloride as the oxidant. Initially, cetyltrimethyl-ammonium bromide and tetrabutyl-ammonium hydrogen sulphate were used as organophilic to modify clay and form an organic clay. After that, polypyrrole/organically modified clay nanocomposites were synthesized by in situ polymerization process in which pyrrole was polymerized in the presence of different proportions of organic clay. The effects of the nature of the organic clays and the preparation method were studied in order to evaluate their structural, morphological and thermal properties. X-ray diffraction (SAXS), Fourier transform infrared spectroscopy, scanning electron microscopy, thermogravimetric analysis, transmission electron microscopy, were used to define the characteristics of the materials obtained. The obtained results confirm the intercalation of molecules of salt in the clay layers, and good interaction with the polymer. Thermogravimetric analysis showed better thermal stability of nanocomposites compared to pure polypyrrole. The conductivity behaviour of nanocomposites was also examined.

Polypyrrole Modified E-Coat Paint for Corrosion Protection of Aluminum AA1200

This article reports the potential of Polypyrrole (PPy) particles as anticorrosive additive on an epoxy water-based paint to increase the corrosion protective property of aluminum-coated panels. AA1200 aluminum panels were painted using the electrophoretic deposition method and the coatings with different concentrations of PPy particles tested. PPy particles were synthetized by oxidative polymerization of pyrrole (Py) with iron (III) chloride hexahydrate (FeCl3.6H2O) in the presence of dodecylbenzenesulfonic acid (DBSA). Electrically conducting PPy particles (6.5 S.cm-1) were obtained with a size average of 154 nm. The as-prepared PPy particles were added into a water-based epoxy paint and AA1200 panels were coated via electrophoretic deposition method. The corrosion protective properties of e-coated AA1200 panels were evaluated by means of electrochemical impedance spectroscopy over prolonged exposure time in neutral non-aerated 0.1 M NaCl electrolyte. In particular, the addition of 0.4 wt. % PPy has improved the coating corrosion protective property with respect to epoxy clearcoat and exhibited the highest value among the studied coatings.

Nano-hybrid based on polypyrrole/chitosan/grapheneoxide magnetite decoration for dual function in water remediation and its application to form fashionable colored product

Water treatment has become immensely challenging. Exploring new, quick and cost-effective technique with high efficacy is a great demand for remedying polluted water. A new synthesis route for generating magnetic hybrid based on magnetite-polypyrrole/chitosan/grapheneoxide (M-PPy/CS/GO) nanohybrid material has been reported. First, intercalated CS/GO was prepared followed by oxidative polymerization of pyrrole and in-situ development of magnetite (Fe3O4) nanoparticles on the nanohybrid. Fe(ш) ions is employed as both oxidant for pyrrole to initiate polymerization and as precursor of Fe3O4. Exfoliated GO sheets decorated with spherical and rod magnetic cubic phase was observed. This strategy seems easy without employing additional oxidant or complicated steps. The zero-charge point of the hybrid was well-defined using pH drift method to be 7.2. The synthesized hybrid has saturated magnetization of 17 emu/g. The prepared hybrid showed high adsorption efficiency relevant to purification of Ponceau 4R (P4R) dye contaminated water with easily magnetic separation. Furthermore, the prepared magnetic hybrid showed antimicrobial and antifungal efficacy against E. coli and Fusarium fungi respectively. A few significant parameters influencing the adsorption of dye for example; sorbent mass (0.005, 0.007, 0.01, 0.015, 0.02 g), dye concentration (2.4, 2.88, 3.36, 3.84, 4.32 ppm), pH (2, 4, 6, 8, 10, 12), salt concentration (0.05, 0.1, 0.137 M), temperature (303, 308, 313, 323 K) and contact time (210 minutes) were considered. The highest removal efficiency was attained (85%) at pH = 2, and the most favorable factors accomplished are: adsorbent quantity (0.01 g), initial dye concentration (2.88 ppm) with a good stability up to 4 reuse cycles. Adsorption processes of M-PPy/CS/GO possibly will illustrated by Langmuir isotherm and pseudo-second-order kinetic model. The adsorption method was an endothermic and spontaneous process as confirmed from thermodynamic parameters. Also, the resulted hybrid loaded dye was immobilized onto polymethylmethacrylate in the presence of urea to form colored fashionable product.

Synthesis of sodium cholate mediated rod-like polypyrrole-silver nanocomposite for selective sensing of acetone vapor

Nanostructured conducting polymer provides higher surface area for analyte vapor sensing. This investigation aims to synthesize rod-like polypyrrole (PPY) silver nanocomposite tailored by sodium cholate surfactant as soft template for sensing of acetone vapor. During oxidative polymerization of pyrrole by ferric chloride Ag nanoparticle gets deposited on PPY by simultaneous reduction of silver nitrate. The crystal structure, surface morphology and nature of interfacial interactions between the two components of the prepared PPY-silver nanocomposite (PPY-Ag) are analyzed by standard characterization techniques. The Ag nanoparticles deposition on rod-like PPY increases with increasing silver nitrate concentration up to an optimum level. The PPY-Ag nanocomposites show chemiresistive type dynamic sensing responses toward methanol, ethanol and acetone vapor in a mixture with air. A comparative evaluation of typical vapor sensing parameters (% response, response time, recovery time, reproducibility, and selectivity) of PPY-Ag nanocomposite sensor obtained for different volatile organic compounds with those of the pristine PPY sensor is reported. Interestingly, the rod-like PPY-Ag nanocomposite is found to selectively sense acetone vapor showing better % response than that of the other analytes, viz., methanol, ethanol, propanol, water vapor and formaldehyde. The differences in their responses for the different analytes and the selectivity toward acetone vapor are established by considering the difference in their interactions with the nanocomposite.

Enhanced specific capacitance of a novel ternary polypyrrole incorporated with prussian blue and mesoporous carbon black for high performance supercapacitor applications

A facile ternary composite of polypyrrole (PPy), prussian blue (PB) and carbon black (CB), PPy-PB-CB is synthesized by oxidative polymerization of pyrrole and formation of PB on CB to achieve efficient electrode material for supercapacitor. The polymer composite is characterized structurally and morphologically; CV, GCD and EIS techniques are used to evaluate the capacitive behavior of the ternary composite. PPy-PB-CB electrode exhibits a specific capacitance of 163.7 F g−1 in neutral electrolyte, KCl which is superior to PPy, PPy-PB and PPy-CB electrode materials. Moreover, the ternary composite retains 98.35% of its initial capacitance even after 2000 cycles, exhibits high specific power, 10.78 kW kg−1 and high specific energy, 18.1 Wh kg−1. The excellent performance of the ternary polymer composite is attributed to the synergistic effect of high specific capacitance of pseudocapacitive electrodes, namely, PPy, and PB and better reversible nature of EDLC electrode, CB and its porosity.