Characterization Of Polypyrrole Research Articles

Synthesis and characterization of polypyrrole/graphitic carbon nitride/niobium pentoxide nanocomposite for high‐performance energy storage applications

AbstractGraphitic carbon nitride (GCN) has been employed as a supercapacitor electrode because of its high carbon‐to‐nitrogen ratio and flexible structure. However, its low surface area and poor conductivity continue to be obstacles for practical usage. GCN's electrochemical characteristics are enhanced by the hybrid structure it forms with polypyrrole and Nb2O5. The synthesized polypyrrole (Ppy)/GCN/niobium pentoxide (Nb2O5) (Ppy/GCN/Nb2O5) nanocomposite electrode was tested for supercapacitance by cyclic voltammetry (CV) and Alternating current impedance techniques in 6 M Potassium hydroxide(KOH) electrolyte. The Ppy/GCN/Nb2O5 is linked to a network of agglomerated GCN and Nb2O5 nanoparticles with additional spherical shapes. The specific capacitance of Ppy/GCN/Nb2O5 was determined to be 1177 Fg−1 at a current density of 5 Ag−1. The Ppy/GCN/Nb2O5 electrode in KOH has average specific energy and specific power densities of 33 Wh kg−1 and 2991 W kg−1, respectively. The electrode showed excellent capacitance‐retention ability of 97% after 10,000 cycles. The results demonstrate the high stability and efficient performance of the Ppy/GCN/Nb2O5 electrode employed in supercapacitors. The performance of the Ppy/GCN/Nb2O5 electrode was found to be superior to those reported for other carbon‐based materials.

Synthesis and Characterization of Polypyrrole by Ammonium Persulfate as Oxidizing Agent and Study of Its Nanoparticles

Synthesis and Characterization of Polypyrrole by Ammonium Persulfate as Oxidizing Agent and Study of Its Nanoparticles

Facile synthesis and characterization of polypyrrole - iron oxide – seaweed (PPy-Fe3O4-SW) nanocomposite and its exploration for adsorptive removal of Pb(II) from heavy metal bearing water

Lead is a widely used heavy metal which is highly toxic to kidney, nervous system and reproductive system. A special featured polypyrrole based adsorbent, with admirable salinity confrontation, environmental stability and reusability, was engaged to remove lead ions from aqueous solution. The advantages of using polypyrrole based adsorbent for heavy metal removal are: ease of synthesis, biocompatibility and high metal selectivity. In this study, polypyrrole - iron oxide - seaweed nanocomposite was proposed to remove lead ions from aqueous solution. A new method was adopted for the synthesis of polypyrrole - iron oxide - seaweed nanocomposite. The nanocomposite was prepared within a short time using ultra-assisted polymerization technique. The synthesized nanocomposite adsorbent was characterized using FTIR, SEM, TEM, EDS, XRD, XPS and zeta potential analysis. The adsorption capability of polypyrrole - iron oxide - seaweed nanocomposite towards lead was explored. The influence of pH, contact time, adsorbent dosage, metal ion concentration and recyclability were investigated. The optimum condition of these parameters was found to be: pH- 5, temperature - 40 °C, initial concentration – 100 mg/L and contact time - 20 min and the results showed that the hybrid composite adsorbed 97.25% Pb (II). Different isotherms such as Langmuir, Freundlich, Temkin and D-R models were also studied for the adsorption of Pb ions. The kinetics of the adsorption process was examined by I order, II order and intra particle diffusion kinetic models. The mechanism of lead adsorption onto the nanocomposite was also explored.

Synthesis and Characterization of Polypyrrole (PPy) by In-situ Polymerization Technique

This work reports synthesize of polypyrrole nano powder by chemical in-situ polymerization of pyrrole in aqueous solution and ammonium persulfate solution which acts as oxidant. It is characterized by X-ray diffraction (XRD), Fourier infra-red spectroscopy (FTIR) and scanning electron microscopy (SEM). The XRD spectrum reveals that the materials are amorphous in nature. FTIR analysis confirms that all peaks are the main characteristic of PPy. SEM analysis showed that the powder has a uniform granular morphology and the size varies from ∼500 nm to 1 μm. The micrograph of polypyrrole reveals the presence of globular particles. The formed particles are irregular in nature. The results show that the fibers are chemically formed as spherical nanostructures.

Synthesis and characterization of polypyrrole and its composites coatings on flexible surface and its antibacterial properties

The main motivation of this work was to develop a simple and efficient way to obtain polypyrrole–Ag, polypyrrole–Au, and unmodified polypyrrole layers on non-conducting, flexible surfaces as advanced antibacterial agents. We used filtering paper as a substrate for conducting polymer and its composite polymerization. The material was covered by polypyrrole, polypyrrole–Au, and polypyrrole–Ag composites during electroless (chemical) polymerization occurring at a boundary of two immiscible liquids. A presence of metals in deposited PPy films was confirmed by EDS analyses. It was proven that PPy–Ag nanocomposites deposited on the flexible substrate exhibit good antibacterial properties against both Gram-negative and Gram-positive bacteria. The antibacterial properties of PPy–Au, and non-modified PPy materials were not observed. Both, PPy and PPy–Au deposits revealed low cytotoxicity on THP-1 cells line used as reference human cells. PPy–Ag films exhibited higher toxicity on THP-1 cells line, but much weaker than toxicity toward pathogenic bacteria. SEM imagining showed changes in the morphology of the cells and their activation in contact with conducting materials. Cyclic voltammetry experiments showed that the proposed procedure leads to obtain solid materials in conducting state. It is also an easy way of fabrication of conducting polymers deposited on non-conducting surfaces. Obtained materials possess good antibacterial properties and low cytotoxicity, which opens the broad applicability of those materials. Composites placed on flexible substrates are suitable for modification of inert electrodes surfaces, e.g., for enhancement of their electro-catalytical properties.

Magnetic and Electrically Conductive Polypyrrole Nanoparticles As Highly Effective Materials for Heavy Metal Removal and Sensing

Heavy metals such as arsenic, cadmium, chromium, nickel, and lead are a well-known source of pollution of air, water, and soil. Their presence in the environment can cause harmful effects in plants, animals, and humans. To address the consequences of heavy metals pollution, there is a need for technology to detect, capture and remove heavy metal contamination from the environment. This presentation reports the synthesis and characterization of polypyrrole (PPy) - magnetite (Fe3O4-PPy) nanoparticles, prepared via a chemical oxidative polymerization process using polyvinyl alcohol as a surfactant. The Fe3O4-PPy nanoparticles have spherical shape and size ranging from 110 to 220 nm and are characterized by high magnetic properties and good electrical conductivity. The particles displayed high sorption capacity for arsenic removal from contaminated water, evaluated using Atomic Absorption Spectroscopy (AAS). The high affinity for contaminants was also used to develop a highly sensitive electrochemical technique for the detection of metal ion exposure.

Preparation and characterisation of polypyrrole – carbon nanomaterial composite solid-phase microextraction fibres and their applications to the determination of fungicide residues in grape juice samples

ABSTRACT Present study describes the use of a lab-made polypyrrole (PPy) coated solid phase microextraction (SPME) fibres modified with carbonaceous nanomaterials for effective adsorption of volatile fungicides used in vineyards for subsequent determination by gas chromatography coupled with a mass spectrometer. The SPME fibres were fabricated electrochemically by dipping a stainless steel wire in a cell containing pyrrole monomer where the polymeric film was coated on the wire by cycling the potential between −0.5 and 2.0 V at a rate of 50 mV s−1. Then, the procedure was repeated in the presence of multi-walled carbon nanotubes (MWCNTs) or graphene (Gr) nanoplates dispersed in tartrate solution. The coated fibres were attached to a holder for subsequent headspace extraction of volatile fungicides in grape juice samples. Initial studies were conducted with commercial fibres adoptable to a fully automated system and optimal conditions were studied by using an 85 µm PA fibre. Then, the fabricated fibres have been tested manually under optimised conditions for unbiased comparison. Overall results have suggested that PPy-MWCNT-SPME and PPy-Gr-SPME have given the comparable results with commercial fibres in the concentration range of 1.0–50 ng mL−1 by allowing the determination of these fungicides at LOQ levels varied in the range of 0.55–6.94 ng mL−1 ranges. In comparison to the literature values, more results that are sensitive were obtained with these two fibres with satisfactory recovery values without any solvent consumption or labour-intensive pre-treatment processes.

Synthesis and characterization of polypyrrole – TiO2 coatings on AISI 304 stainless steel

The electrical properties of conducting polymers make them interesting materials to be used in a large number of technological applications. In recent years, an important effect on the anticorrosive properties of the conductive polymer was observed when inorganic particles such as nano-sized TiO2 are incorporated in the conductive matrix. In the present study, polypyrrole films were synthesized in the presence of TiO2 nanoparticles. A study of the electropolymerization conditions, thickness of the formed films and the effect of incorporation of TiO2 nanoparticles on the structure of the polymer matrix by Raman spectroscopy was performed. These results show that it is possible to obtain the adherent coatings, with thicknesses between 3-4 µm. However, the presence of TiO2 nanoparticles in the polymeric matrix influences the corrosion resistance of the polypirrole coatings, destabilizing the natural passive capacity on the surface of AISI 304 stainless steel.

Tubular-structured polypyrrole electrodes decorated with gold nanoparticles for electrochemical sensing

The electrosynthesis and characterisation of polypyrrole(PPy) films with a micro-tubular structure decorated with gold nanoparticles is described. The PPy films were characterised by means of voltammetric and electrochemical impedance spectroscopy measurements. The tubular structure of the PPy films were obtained under potentiostatic conditions in freshly prepared sodium salicylate solutions. Voltammetric response of the PPy films shows that its behavior turns more reversible as the electropolymerization charge of the film increases. SEM images show the appearance of the tubular structure for an electrodeposition time higher than 2 min. The tubular-structured PPy film showed an rms of ca. 600 nm as determined from AFM imaging. These PPy films were subsequently decorated with gold nanoparticles obtained by a double step potentiostatic electrodeposition routine that allowed fine control of deposit characteristics. Analysis of deposits was performed by means of SEM and AFM nanoscopy. Statistical analysis of particles size distribution show that the maximum value appeared for 60 nm, but a significant amount of particles between 100–200 nm were also observed. The sensing capability of these composite electrodes was tested for the determination of hydroxylamine, nitrite and their mixture in solutions of different pH. Results showed a successful route of synthesis of a nanocomposite electrode with promising applications in electrochemical sensing.

Synthesis and characterization of polypyrrole, polyaniline nanoparticles and their nanocomposite for removal of azo dyes; sunset yellow and Congo red

Abstract Polypyrrole, polyaniline nanoparticles and their nanocomposites were prepared using microemulsion polymerization method. For the synthesis of polypyrrole and polyaniline nanoparticles sodium dodecyl sulfate as a surfactant for two reasons was used; to the creation of a micro reactor vessel and to improve the physical properties of polymers such as stability, solubility in organic solvents, conductivity, and processability. These nanoparticles were dedoped through 20% NaOH solution. The removal of sunset yellow and congo red dyes was carried out using both doped and dedoped species and nanocomposites at room temperature and under ultrasound irradiation. Also, the effect of adsorbent dosage, initial pH, effects of contact time on adsorption and ultrasonic power as experimental parameters on the removal of the sunset yellow and congo red dyes was investigated. It was found that all of the premade species including multiwall carbon nanotubes, carboxylate-multiwall carbon nanotubes, polypyrrole, polyaniline, polypyrrole/multiwall carbon nanotubes and polyaniline/multiwall carbon nanotubes can be used for removal of anionic dyes such as sunset yellow and congo red from water solutions. The highest removal efficiency for sunset yellow dye (∼99%) was achieved at 0.007 g of polypyrrole/multiwall carbon nanotubes nanocomposite, at pH = 2, at ambient temperature and at ultrasonic irradiation power 500 W and for congo red dye the highest removal efficiency (∼98%) was achieved at 0.01 g of polypyrrole/multiwall carbon nanotubes nanocomposite, at pH = 2, at ambient temperature and at ultrasonic irradiation power 500 W. The polypyrrole/multiwall carbon nanotubes and the polyaniline/multiwall carbon nanotubes adsorbents, the recovery achieved more than 80% with the proportion of 55:45 from acetone: H2O. The strong adsorption capacity of polypyrrole/multi-walled carbon nanotubes and the polyaniline/multiwall carbon nanotubes nanocomposites prepared with ammonium per sulfate as initiator can be attributed to the π-π electron donor-acceptor interaction and electrostatic attraction. The nanoadsorbents multiwall carbon nanotubes, carboxylate-multi-walled carbon, polypyrrole/multiwall carbon nanotubes and the polyaniline/multiwall carbon nanotubes produced with ammonium per sulfate as initiator was used to removing azo dyes from H2O through efficient microscale filtration and can be scaled up for commercial and industrial applications.

Synthesis and characterization of polypyrrole and its application for solar cell

In this report, the fabrication of a solar cell device with the structures FTO/PPy/PTh/ZnO/Al was performed using wet chemical synthesis methods in open environment. The cost-effective methods like CBD, SILAR, and spin coating have been used for the synthesis. The effect of thickness of PPy active layer on the device performance is investigated. Features such as structural, morphological, and chemical bonding of the layers have been investigated using X-ray diffraction, field emission scanning electron microscopy, and Fourier transform infrared spectroscopy and are discussed herein. Effects of PPy thickness on current–voltage characteristics have been studied under dark and illumination at 1 Sun (100 mW/cm2, AM 1.5 G) condition to study the solar cell performance.

Electrochemical deposition and characterization of polypyrrole in electrolyte based on pyrrolidinium hydrogenosulfate protic ionic liquid

In this work, we investigated the electrochemical deposition of polypyrrole (Ppy) in an electrolyte containing the pyrrolidinium hydrogenosulfate [Pyrr][HSO4] protic ionic liquid. Herein, the Ppy films were prepared by sequenced and by continuous galvanostatic deposition methods. Cyclic voltammetry (CV) and electrochemical quartz crystal microbalance techniques were further used to investigate, in each case, the polymer growth, as well as, the involved doping and dedoping processes. Additionally, atomic force microscopy, fourier transform infrared spectroscopy, CV, and electrochemical impedance spectroscopy measurements were conducted to investigate the morphology and electrochemical properties of the formed Ppy films. Similar investigations were also conducted by using the conventional aqueous electrolyte (i.e., aqueous solution containing 1 mol dm−3 of Na2SO4) to assess then the performance of the pyrrolidinium hydrogenosulfate as a medium for the electrochemical deposition of Ppy. Based on this work, we observed that the properties of Ppy, such as the capacitance, morphology, and microstructure are strongly affected by the electrolyte formulation and by the deposition technique used. Best properties of Ppy were obtained by using the sequenced galvanostatic deposition in [Pyrr][HSO4]-based electrolyte.

Synthesis and Characterization of Polypyrrole and Graphene/Polypyrrole/Epoxy Composites

Conducting polypyrrole (PPy) nanoparticles were synthesized via four different radical polymerization systems changing the time and other parameters. The characterization of PPy nanoparticles was done by Fourier transform infrared spectrometer. Graphene was synthesized from intercalated graphite by exfoliation at 1000\({^{\circ}}\) C for 30 s in tube furnace, and particle size was assessed using scanning electron microscope. Polypyrrole/graphene nano-composites were prepared by mixing PPy with graphene. Prior to this, graphene was coated with silane to enhance the bonding between PPy and graphene. The PPy-coated graphene composite was mixed in epoxy resin and cured using curing agent. The amount of PPy in nano-composites varied in the range of 1–20% by weight. The effect of PPy/graphene nanoparticles on mechanical and electrical properties and thermal stability of epoxy nano-composites was investigated. Thermal gravimetric analysis has shown that incorporation of PPy nanoparticles has improved the thermal stability of the epoxy nano-composites. Two probe electrical conductivity measurements have shown that increasing amount of graphene in PPy/epoxy nano-composites increases the conductivity of PPy significantly. In order to improve the dispersion of graphene in PPy, mechanical disperser was employed. Composites prepared with disperser have exhibited improvement in mechanical and thermal properties.

A novel, rapid synthetic protocol for controllable sizes, conductivities and monomer units of soluble polypyrrole

We report a facile synthesis of polypyrrole spheres with controllable sizes, monomer units and conductivities using sodium nitrite and nitric acid in presence of the anionic surfactant sodium tetradecyl sulfate. The rapid synthesis of polypyrrole spheres was accomplished without employing any explicit oxidizing agents. The characterization of polypyrrole (PPy) is carried out using FTIR, XRD, SEM, TEM and TGA while the molecular weight is estimated from the MALDI TOF analysis. The precise tuning of various physicochemical properties is accomplished by altering the concentrations of sodium nitrite and is attributed to the in situ generation of NO2. The size of the PPy spheres varies from 45nm to 350nm depending upon the concentration of NaNO2. The dynamic light scattering studies provide mechanistic insights into the role of sodium nitrite in altering the pyrrole-incorporated micellar size of the surfactant, leading to different diameters of the PPy spheres. The surfactant-induced solubility of PPy is rationalized with the help of the X-ray diffraction patterns. The solution of PPy in dimethylsulfoxide has a remarkable ability of selectively detecting Cu2+ and Hg2+ among a host of other bimetallic ions, as inferred from colorimetry and UV–Visible absorption spectroscopy.

Enhanced electromagnetic shielding behaviour of multilayer graphene anchored luminescent TiO2 in PPY matrix

Present research is focussed on the development of a novel composite material for highly-efficient absorption of electromagnetic interference (EMI) pollution. Herein, we report synthesis and characterization of polypyrrole (PPY) composite containing multi-layered graphene (MLG) anchored with titanium dioxide (TiO2) via in-situ oxidative polymerization of pyrrole. The tuning of the microwave signals has achieved via composites with different weight ratios of MLG and TiO2. The maximum Total shielding effectiveness (SET), 53dB was observed for PPY/MLG/TiO2 (5% composite) in the frequency range of 12.4–18GHz. The observed results suggest that the composite material could be a new alternative for building block of electromagnetic shielding applications.

Electrochemical preparation and characterization of polypyrrole/stainless steel electrodes decorated with gold nanoparticles.

The electrosynthesis and characterization of polypyrrole(PPy)/stainless steel electrodes decorated with gold nanoparticles and the performance of the composite electrode for sensing applications is described. PPy films were grown in potassium perchlorate and sodium salicylate solutions under comparable electropolymerization conditions. Polymer films prepared in the presence of perchlorate ions exhibited worm-like structures, whereas columnar structures were obtained in salicylate-containing solutions. Voltammetric response of PPy films prepared in salicylate solutions was more reversible. PPy films were decorated with gold nanoparticles obtained by a double step potentiostatic electrodeposition routine that allowed fine control of deposit characteristics. Analysis of deposits was performed by means of SEM and confocal Raman spectroscopy. The electrocatalytic activity of the Au/PPy electrodes was assessed for the electro-oxidation of hydrazine and hydroxylamine. Results showed a successful optimization of the route of synthesis that rendered nanocomposite electrode materials with promising applications in electrochemical sensing.

Synthesis and characterization of polypyrrole nanotubes/multi-walled carbon nanotubes composites with superior electrochemical performance

Novel polypyrrole nanotubes/multi-walled carbon nanotubes (PPyNTs/MWCNTs) composites have been successfully synthesized via in situ chemical oxidation polymerization with methyl orange as soft template. Scanning electron microscopy and transmission electron microscopy images revealed that MWCNTs intertwined with the PPyNTs and PPyNTs/MWCNTs composites formed in water–ethanol solution. The obtained composites exhibited perfect electrochemical characteristic compared with PPyNTs and MWCNTs owing to the synergetic effect and the specific capacitance of the composites was strongly influenced by the mass ratio of pyrrole to MWCNTs. According to the galvanostatic charge/discharge analysis, the specific capacitance of PPyNTs/MWCNTs composites is up to 352 F g−1 at a current density of 0.2 A g−1 in 1 M KCl solution, much higher than that of the PPyNTs (178 F g−1) and MWCNT (46 F g−1), suggesting its potential application in supercapacitors.

Synthesis and characterization of polypyrrole‐platinum composite for use as electrode material

AbstractSynthesis and characterization of polypyrrole (PPy) supported platinum by a simple method is reported in this study. The porous structure of PPy and its tendency for doping with acids prompted us to utilize this property to incorporate platinum by adsorption followed by reduction on the PPy matrix. Dispersed platinum electro catalyst on the conducting PPy support provides favorable reaction site for redox reactions in electrochemical devices such as hydrox fuel cell. The mesoporous matrix of PPy as revealed by FESEM could facilitate effective contact between the reactant gases and electro catalyst. The cauliflower like structure of the PPy matrix could enhance the electrochemical active surface area of the catalyst. The composite material is characterized by cyclic voltammetry (CV), polarization study, four probe technique, density and porosity study. The CV highlights the use of PPy‐Pt hybrid as a capacitor and the Tafel plot infers on the high exchange current density of the hybrid material. POLYM. COMPOS. 2012. © 2012 Society of Plastics Engineers

Preparation and characterization of polypyrrole with dispersed metallic rhodium particles

AbstractPolypyrrole (PPy) with dispersed metallic Rh particles has been prepared by all‐chemical route, i.e. reduction of Rh3+ ions existing in RhCl3 aqueous solutions with sodium borohydride (NaBH4) carried out in the presence of the previously obtained PPy doped with chloride ions (PPyCl). PPy–Rh composites thus formed have been characterized using X‐ray diffraction (XRD), scanning and transmission electron microscopies (SEM, TEM) combined with energy dispersive X‐ray (EDX) microanalysis, Rh3d X‐ray photoelectron (XPS), and IR spectroscopies. This has made it possible to find out that metallic Rh nanoparticles, mainly of sizes below 10 nm, have been present in the composites. Agglomerates, with sizes up to 0.7 µm, have been formed in the systems containing higher amounts of Rh. PPy serving as the matrix in the composites has been doped. However, its doping level has been lower than that of the starting PPyCl. This has been explained by partial reduction of the polymer occurring during preparation of the composites.Catalytic properties of the PPy–Rh systems have been investigated using isopropyl alcohol conversion as a test reaction. It has been established that the composites are active redox catalysts. This makes them promising materials for applications as catalysts of various redox processes. Copyright © 2010 John Wiley & Sons, Ltd.

Synthesis and Characterization of Polypyrrole (PPy) Thin Films

Polypyrrole (PPy) was synthesized by chemical oxidative polymerization technique using monomer pyrrole and ammo-nium persulphate as an oxidant in a ratio of 1:1. Thin films of polypyrrole were prepared by dissolving polypyrrole in mcresol and cast using spin coating technique on glass substrates. Thin films of polypyrrole were characterized by X ray diffraction (XRD), Scanning electron microscopy (SEM), Fourier transform infra red spectroscopy (FTIR), UV visible spectroscopy and electrical resistivity by four probe method. The XRD spectra showed that the polypyrrole is amorphous in nature. SEM studies revealed a uniform granular structure of PPy. The FTIR spectra shows that the presence of all characteristics absorption peaks of polypyrrole that is, 890 cm?1 (=C–H out-of-plane vibration), 1040 cm?1 (=C–H in-plane vibration), 1170 cm?1 (N–C stretch bending) and 1410 cm?1 (pyrrole ring vibration). UV visible study shows PPy films exhibit absorption peak at 446 nm (2.77 eV). Room temperature electrical resistivity of PPy is in the critical regime of the metal –to –insulator (M-I) transition.