Synthesis of urethane acrylate based electromagnetic interference shielding materials

In this work, a new method, consists of synthesis of urethane acrylate (UA) followed by in situ polymerization of pyrrole using cerium (IV) as an oxidant and UV‐curing of the composites, for preparing polypyrrole–UA (PPy–UA) composite films was described. It appeared that dielectric constants of the composites increased with increasing the PPy content and decreased with increasing the frequency from 10^?2 to 10⁷, indicating an interfacial Maxwell–Wagner contribution to the permittivity. An incorporation of a small amount of PPy (15% Py) to UA matrix increased their dielectric constants more than 4 × 10⁴ (41,259) at 10^?2 Hz. So, the incorporation of PPy was very effective for enhancing the dielectric properties of UA matrix. Furthermore, the significant enhancement in dielectric properties (loss tangent and dielectric constant) contributes to the improvement in electromagnetic interference shielding efficiency. Composite films were characterized using Fourier transform infrared attenuated total reflectance (FTIR‐ATR) spectrophotometer and ¹H‐NMR. It was seen that PPy is blended with the UA matrix at the molecular level through H‐bonding interactions. A linear relationship was also observed between the characteristic groups' absorbances of PPy (from FTIR‐ATR) and dielectric constant values (from dielectric spectrometer). © 2012 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2013     

Dielectric studies of composite paper reinforced with polypyrrole coated pulp fibers from wasted egg holders

Development of thin, flexible, light‐weight, renewable, low‐cost, and environmentally friendly electrode materials are highly feasible in era of modern disposable electronic technology. This article presents the synthesis and dielectric studies of polypyrrole (PPy) coated pulp fibers, directly collected from wasted egg holder's tray. PPy coated pulp fibers converted into compact sheet for the development of potential renewable and low‐cost electrode materials. The morphology, chemical structure, and thermal stability of naked and PPy coated pulp fibril sheets were investigated by scanning electron microscopy (SEM), Fourier transform infrared (FTIR) and thermogravimetric analysis (TGA), respectively. PPy coated pulp fibers revealed better thermal stability and compactness of sheet morphology. Impedance measurements showed a high value of dielectric constant of 1.15 × 10⁶ at 0.5 Hz and conductivity of 7.45 × 10^?4 S/cm at room temperature for PPy coated pulp fibril sheet. © 2015 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2015 , 132, 42422.     

Optimization of adhesive joints of low density polyethylene (LDPE) composite laminates with polyolefin foam using corona discharge plasma

In this work, surface modification of low density polyethylene (LDPE) film has been carried out to optimize adhesive joints with polyolefin foam for uses in technological applications. LDPE films were modified in a continuous way using corona discharge plasma with different powers, ranging from 200 to 600 W and several film advance rates in the 5–20 m min^?1 range. Changes in surface wettability have been studied with contact angle measurements and subsequent solid surface energy calculation. A polyurethane adhesive was used to join the LDPE film to a polyethylene foam. Mechanical performance of the adhesive joints has been determined by T‐peel tests and also the aging effects of several hydrothermal conditions have been studied to evaluate the usefulness of these laminate composites in technological applications. Results show that corona discharge powers between 400 and 600 W are suitable in terms of wettability improvement; on other hand, a slight decrease in surface wettability as the film advance rate increases is detected but the overall changes as a consequence of the film advance rate in the 5–20 m min^?1 range are small if compared to changes derived from working powers in the 200–600 W range. Adhesive joints offer excellent mechanical performance and good durability in hydrothermal conditions thus being appropriate for technical applications. © 2009 Wiley Periodicals, Inc. J Appl Polym Sci, 2009     

Fumed SiO2 nanoparticle reinforced biopolymer blend nanocomposites with high dielectric constant and low dielectric loss for flexible organic electronics

In the present study, fumed silica (SiO₂) nanoparticle reinforced poly(vinyl alcohol) (PVA) and poly(vinylpyrrolidone) (PVP) blend nanocomposite films were prepared via a simple solution‐blending technique. Fourier transform infrared spectroscopy (FTIR), ultraviolet–visible spectroscopy (UV–vis), X‐ray diffraction (XRD), and scanning electron microscopy (SEM) were employed to elucidate the successful incorporation of SiO₂ nanoparticles in the PVA/PVP blend matrix. A thermogravimetric analyzer was used to evaluate the thermal stability of the nanocomposites. The dielectric properties such as dielectric constant (?) and dielectric loss (tan δ) of the PVA/PVP/SiO₂ nanocomposite films were evaluated in the broadband frequency range of 10^?2 Hz to 20 MHz and for temperatures in the range 40–150 °C. The FTIR and UV–vis spectroscopy results implied the presence of hydrogen bonding interaction between SiO₂ and the PVA/PVP blend matrix. The XRD and SEM results revealed that SiO₂ nanoparticles were uniformly dispersed in the PVA/PVP blend matrix. The dielectric property analysis revealed that the dielectric constant values of the nanocomposites are higher than those of PVA/PVP blends. The maximum dielectric constant and the dielectric loss were 125 (10^?2 Hz, 150 °C) and 1.1 (10^?2 Hz, 70 °C), respectively, for PVA/PVP/SiO₂ nanocomposites with 25 wt % SiO₂ content. These results enable the preparation of dielectric nanocomposites using a facile solution‐casting method that exhibit the desirable dielectric performance for flexible organic electronics. © 2016 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2017 , 134 , 44427.     

Synthesis and electrochemical properties of graphene oxide/nanosulfur/polypyrrole ternary nanocomposite hydrogel for supercapacitors

A method for synthesizing Graphene oxide (GO)/nano‐sulfur/polypyrrole (PPy) ternary nanocomposite hydrogel is depicted. The higher surface area of GO, PPy porous structure and their excellent conductivity are utilized, and the GO hydrogel can be made easily. The products are characterized by field‐emission scanning electron microscopy (FESEM), X‐ray diffraction (XRD), Fourier transform infrared (FTIR) spectra, and electrochemical workstation. The results demonstrated that GO/nano‐S/PPy ternary nanocomposite hydrogel is successfully synthesized. The electrochemical properties are investigated by cyclic voltammetry, galvanostatic charge/discharge measurements, and cycling life in a three‐electrode system in 1M Li₂SO₄ electrolyte solution. The GO/nano‐S/PPy ternary nanocomposite hydrogel exhibit a high specific capacitance of 892.5 F g^?1 at scan rates of 5 mV s^?1 and the capacitance retain about 81.2% (594.8 F g^?1) of initial capacitance (732.5 F g^?1) after 500 cycles at a current density of 1 A g^?1. © 2014 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2014 , 131, 40814.     

Enhanced dielectric performances of polypropylene films via polarity adjustment by maleic anhydride‐grafted polypropylene

Maleic anhydride‐grafted polypropylene (MA‐g ‐PP) was hybridized with pure PP to form hybrid films with the aim to enhance the dielectric performances of the PP film via polarity adjustment. The changes of microstructure and crystallinity of PP matrix by MA‐g ‐PP incorporation were studied, and the polarity change was identified by the surface wettability. The dielectric behaviors of the hybrid films were explored. Increasing polarity of PP film leads to increase in dielectric constant but decrease in breakdown strength, and a balance is achieved in 10 vol % MA‐g ‐PP/PP hybrid film, with the maximum discharge energy density reaching 1.96 J cm^?3 and charge–discharge efficiency as high as 96%. The ultralow loss is attributed to the dense and homogeneous microstructure together with increased crystallinity induced by incorporation of MA‐g ‐PP. These PP‐based films with increased polarity not only show enhanced dielectric performances but also provide a type of matrix that would be compatible with polar fillers to further increase dielectric properties. © 2017 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2017 , 134 , 45029.     

Preparation and characterization of electrospun polyurethane–polypyrrole nanofibers and films

Polyurethane (PU)–polypyrrole (PPy) composite films and nanofibers were successfully prepared for the purpose of combining the properties of PU and PPy. Pyrrole (Py) monomer was polymerized and dispersed uniformly throughout the PU matrix by means of oxidative polymerization with cerium(IV) [ceric ammonium nitrate Ce(IV)] in dimethylformamide. Films and nanofibers were prepared with this solution. The effects of the PPy content on the thermal, mechanical, dielectric, and morphological properties of the composites were investigated with differential scanning calorimetry (DSC), dynamic mechanical analysis (DMA), Fourier transform infrared (FTIR)–attenuated total reflection (ATR) spectroscopy, dielectric spectrometry, and scanning electron microscopy. The Young's modulus and glass-transition temperatures of the composites exhibited an increasing trend with increases in the initially added amount of Py. The electrical conductivities of the composite films and nanofibers increased. The crystallinity of the composites were followed with DSC, the mechanical properties were followed with DMA, and the spectroscopic results were followed with FTIR–ATR spectroscopy. In the composite films, a new absorption band located at about 1650 cm⁻¹ appeared, and its intensity improved with the addition of Py. The studied composites show potential for promising applications in advanced electronic devices. © 2012 Wiley Periodicals, Inc. J Appl Polym Sci, 2012     

Electrochemical behavior of a Nafion‐membrane‐based solid‐state supercapacitor with a graphene oxide—multiwalled carbon nanotube—polypyrrole nanocomposite

In this study, we sprayed a graphene oxide–multiwalled carbon nanotube (GM) suspension in isopropyl alcohol–water onto a Nafion membrane. The electrodeposition of polypyrrole (PPy) was carried out on Nafion to complete the fabrication of a solid‐state symmetric supercapacitor. Nafion 117 membranes are used as electrolyte separators in the preparation of supercapacitors. The characterization of the symmetric supercapacitor was done by X‐ray diffraction, field emission scanning electron microscopy, and transmission electron microscopy. The electrochemical properties of the symmetric solid‐state supercapacitor were investigated by cyclic voltammetry, galvanostatic charge–discharge, and electrochemical impedance spectroscopy techniques in 1M lithium chloride. A specific capacitance of 90.4 mF/cm² (258.3 F/g¹) was obtained for the supercapacitor at a scan rate of 10 mV s^?1. Maximum energy and power densities of 10 W h/kg and 6031 W/kg were obtained for the fabricated supercapacitor. In such a symmetric configuration, the highly interconnection networks of GM–PPy provided good structure for the supercapacitor electrode, and the good interaction between PPy and GM provided fast electron‐ and charge‐transportation paths so that a high capacitance was achieved. © 2017 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2017 , 134 , 44926.     

Electrical conduction in plasma polymerized thin films of γ‐terpinene

Plasma polymerized γ‐terpinene (pp?GT) thin films are fabricated using RF plasma polymerization. MIM structures are fabricated and using the capacitive structures dielectric properties of the material is studied. The dielectric constant values are found to be in good agreement with those determined from ellipsometric data. At a frequency of 100 kHz, the dielectric constant varies with RF deposition power, from 3.69 (10 W) to 3.24 (75 W). The current density–voltage (J?V) characteristics of pp–GT thin films are investigated as a function of RF deposition power at room temperature to determine the resistivity and DC conduction mechanism of the films. At higher applied voltage region, Schottky conduction is the dominant DC conduction mechanism. The capacitance and the loss tangent are found to be frequency dependent. The conductivity of the pp?GT thin films is found to decrease from 1.39 × 10^?12 S/cm (10 W) to 1.02 × 10^?13 S/cm (75 W) and attributed to the change in the chemical composition and structure of the polymer. The breakdown field for pp–GT thin films increases from 1.48 MV/cm (10 W) to 2 MV/cm (75 W). A single broad relaxation peak is observed indicating the contribution of multiple relaxations to the dielectric response for temperature dependent J?V. The distribution of these relaxation times is determined through regularization methods. © 2015 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2015 , 132, 42318.     

One‐pot synthesis,characterization, and field emission investigations of composites of polypyrrole with graphene oxide,reduced graphene oxide,and graphene nanoribbons

Pyrrole monomer was polymerized by a chemical oxidative route in the presence of graphene oxide (GO), reduced GO (rGO), and graphene nanoribbons (GNR) separately to prepare composites of polypyrrole (PPy) as PPy–GO, PPy–rGO, and PPy–GNR, respectively. The morphological, chemical, and structural characterization of the as‐synthesized products was carried out using scanning electron microscopy, Raman spectroscopy, and Fourier transform infrared spectroscopy. Field emission studies of the PPy–GO, PPy–rGO, and PPy–GNR emitters were performed at the base pressure of 1 × 10^?8 mbar in a planar “diode” configuration. The turn‐on field values, corresponding to an emission current density of 1 µA/cm², are observed to be 1.5, 2.2, and 0.9 V/µm for the PPy–GO, PPy–rGO, and PPy–GNR emitters, respectively. The maximum emission current density of 2.5 mA/cm² is drawn from PPy–GO at an applied electric field of 3.2 V/µm, 1.2 mA/cm² at 3.6 V/µm from the PPy–rGO, and 8 mA/cm² at 2.2 V/µm from the PPy–GNR emitters. All of the composites exhibit good emission stability over more than 2 h. The results indicate the potential for a facile route for synthesizing composites of conducting polymers and graphene‐based materials, with enhanced functionality. © 2017 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2017 , 134 , 45170.     

Synthesis and properties of conducting polypyrrole,polyalkylanilines, and composites of polypyrrole and poly(2‐ethylaniline)

Conducting polymers of alkylanilines, pyrrole, and their conducting composites were synthesized by oxidation polymerization. The oxidants used were KIO₃ and FeCl₃ for the polyalkylanilines and polypyrrole (PPy), respectively. Among the polyalkylanilines synthesized with KIO₃ salt, the highest conductivity was obtained with poly(2‐ethylaniline) (P2EAn) with a value of 4.10 × 10^?5 S/cm. The highest yield was obtained with poly(N‐methylaniline) with a value of 87%. We prepared the conducting composites (PPy/P2EAn and P2EAn/PPy) by changing synthesis order of P2EAn and PPy. The electrically conducting polymers were characterized by IR spectroscopy, ultraviolet–visible spectroscopy, thermogravimetric analysis, and X‐ray diffraction spectroscopy. From the results, we determined that the properties of the composites were dependent on the synthesis order of the polymers. The thermal degradation temperature of PPy was observed to be higher than that of the other polymers and composites. We determined from X‐ray results that the structures of the homopolymers and composites had amorphous regions (88–95%) and crystal regions (5–12%). From the Gouy balance magnetic measurements, we found that the polymers and composites were bipolaron conducting mechanisms. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 101: 241–249, 2006     

Synthesis of polypyrrole nanoparticles in natural rubber–polystyrene blend via emulsion polymerization

Nanoparticles of polypyrrole (PPy) in 40/60 wt % natural rubber (NR)–polystyrene (PS) blends were synthesized by emulsion polymerization using ferric sulfate [Fe₂ (SO₄)₃], sodium dodecyl sulfate (SDS), and n‐amyl alcohol as the oxidant, surfactant, and cosurfactant, respectively. The NR/PS/PPy blends were characterized by Fourier transform infrared spectroscopy (FTIR), elemental analysis, thermogravimetric analysis (TGA), and field emission scanning electron microscopy (FESEM). FESEM micrographs showed that NR/PS/PPy blends were homogeneous, and PPy nanoparticles were well distributed throughout the binary matrix of NR/PS. The size of PPy particles in the blends was in the range of 26–80 nm. The electrical conductivities of the pellets prepared from NR/PS/PPy blends increased as the composition of PPy nanoparticles was increased, which were in the range of 8.9 × 10^?8 – 2.89 × 10^?4 S/cm. Thermal stability of the blends increased as the content of PPy was increased, as shown by TGA thermograms. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2012     

Fabrication of carbon nanotubes/polypyrrole/carbon nanotubes/melamine foam for supercapacitor

The carbon nanotubes (CNTs) have been loaded on the melamine foam (MF) to form the composite (CNTs/MF) by dip‐dry process, then polypyrrole (PPy) is coated on CNTs/MF (PPy/CNTs/MF) through chemical oxidation polymerization by using FeCl₃·6H₂O adsorbed on CNTs/MF as oxidant to polymerize the pyrrole vapor. Finally, CNTs are coated on the surface of PPy/CNTs/MF to increase the conductivity of the composite (CNTs/PPy/CNTs/MF) by dip‐dry process again. The composites have been characterized by X‐ray diffraction spectroscopy, scanning electron microscopy and electrochemical method. The results show that the structure of the composites has obvious influence on their capacitive properties. According to the galvanostatic charge/discharge test, the specific capacitance of CNTs/PPy/CNTs/MF is about 184 F g^?1 based on the total mass of the composite and 262 F g^?1 based on the mass of PPy (70.2 wt % in the composite) at the current density of 0.4 A g^?1, which is higher than that of PPy/CNTs/MF (120 F g^?1 based on the total mass of the composite and 167 F g^?1 based on the mass of the PPy). Furthermore, the capacitor assembled by CNTs/PPy/CNTs/MF shows excellent cyclic stability. The capacitance of the cell assembled by CNTs/PPy/CNTs/MF retains 96.3% over 450 scan cycles at scan rate of 20 mV s^?1, which is larger than that assembled by CNTs/PPy/MF (72.5%). © 2013 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2014 , 131, 39779.     

Preparation,morphology, and conductivity of waterborne,nanostructured, cationic polyurethane/polypyrrole conductive coatings

To endow cellulose fiber papers with good conductivity and simultaneously retain the mechanical strength of the conductive paper, a kind of waterborne, nanostructured, cationic polyurethane (CPU)/polypyrrole (PPy) conductive coatings were developed to modify the paper surface. Fourier transform infrared spectroscopy, atomic force microscopy, and thermogravimetry–differential thermogravimetry demonstrated that the peak associated with hydrogen bonding between ? NH and C?O of CPU was shifted, and chemical bonds between CPU and PPy were formed. Good compatibility between CPU and PPy was simultaneously established. Transmission electron microscopy and atomic force microscopy also suggested that PPy was encased and embedded in the CPU colloidal particles in a uniform style, and the surface of the CPU/PPy film was covered with a smooth, coherent conductive layer. With increasing pyrrole (Py) content from 5 to 20 wt %, the particle size increased from 55.08 to 74.59 nm, and the dispersity index (DPI) decreased. In addition, the conductivity of CPU/PPy increased from 0.1 to 5.0 S/cm. When the Py content was greater than 20 wt %, apparent increases in the particle size and DPI were detected as was particle coagulation; this resulted in decreased conductivity. Compared with the uncoated paper, the paper coated with CPU/PPy dispersions displayed different surface morphologies. The surface of the paper was completely enwrapped by the CPU/PPy conductive films when the coating amount was 45.42 g/m². With increasing coating amounts from 10.35 to 67.86 g/m², the conductivity of the conductive coated paper increased from 2.78 × 10^?3 to 2.16 S/cm, the tensile strength increased from 35.3 to 60.4 N m/g, and the conductive coated paper displayed good conductivity stability. © 2014 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2015 , 132, 41445.     

Electrochemical polymerization of phenanthrene in mixed electrolytes of boron trifluoride diethyl etherate and concentrated sulfuric acid

A novel high‐quality polyphenanthrene (PPH) film with electrical conductivity of 10^?1 S cm^?1 was synthesized electrochemically by direct anodic oxidation of phenanthrene in boron trifluoride diethyl etherate containing 10% concentrated sulfuric acid (v/v). The oxidation onset potential of phenanthrene in this medium was measured to be only 0.91 V versus saturated calomel electrode (SCE), which was lower than that determined in acetonitrile + 0.1 mol L^?1 Bu₄NBF₄ (1.56 V versus SCE). As‐formed PPH films from this medium showed good electrochemical behavior and stability. De‐doped PPH films were thoroughly soluble in dimethylsulfoxide or CHCl₃. The structure and morphology of the polymer were investigated using UV‐visible and Fourier transform infrared (FTIR) spectroscopy and scanning electron microscopy. FTIR and ¹H NMR spectra showed that the PPH was grown via the coupling of the monomer mainly at the C₄, C₅, C₉ and C₁₀ positions. Fluorescence spectral studies indicated that PPH was a blue‐green light emitter. Copyright © 2007 Society of Chemical Industry     

Interfacial synthesis of polypyrrole/graphene composites and investigation of their optical,electrical and electrochemical properties

We report the development of a novel route for the synthesis of polypyrrole/graphene (PPy/GR) composites by liquid ? liquid interfacial polymerization, where GR and the initiator were dispersed in the aqueous phase and the monomer was dissolved in the organic phase. The synthesized samples were characterized by Fourier transform infrared spectroscopy, scanning electron microscopy, ultraviolet–visible spectroscopy, Raman spectroscopy, X‐ray diffraction, thermogravimetric analysis, electrochemical and electrical conductivity measurements. Structural analysis reveals a uniform dispersion of GR sheets in the PPy matrix. The composites showed noticeable improvement in thermal stability and electrical conductivity (8.45 S cm^?1) and excellent electrochemical reversibility in comparison with pure PPy. A specific capacitance of 260 F g^?1 at a current density of 100 mA g^?1 was achieved for the composite during the charge–discharge process. © 2013 Society of Chemical Industry     

Fabrication of Tiron‐doped polypyrrole/MWCNT composite electrodes with high mass loading and enhanced performance for supercapacitors

In this study, the aromatic sulfonate compound Tiron with high charge to mass ratio is used as an anionic dopant for synthesis of polypyrrole (PPy). The fabricated PPy is investigated for electrochemical supercapacitor (ES) application. Testing results show that Tiron allows reduced PPy agglomeration, smaller particle size and improved charge storage properties of PPy. High capacitance and improved capacitive retention at high scan rates are achieved by the fabrication of PPy/multiwalled carbon nanotube (MWCNT) composite electrode using safranin (SAF) as a co‐dispersant. The Tiron‐doped PPy electrode shows the highest capacitance of 7.8 F cm^?2 with a mass of 27 mg cm^?2. The Tiron‐doped PPy/MWCNT composite electrode shows good capacitance retention with a capacitance of 1.0 F cm^?2 at the scan rate of 100 mV s^?1. Symmetric supercapacitor cells are fabricated using PPy based active materials. An energy density of 0.36 mWh cm^?2 is achieved. The energy/power density and capacitance retention of the Tiron‐doped PPy/MWCNT ES is significantly improved in comparison with PPy‐based ES, prepared without Tiron or MWCNT. The Tiron‐doped PPy/MWCNT symmetric supercapacitor presents good cycling performance with 91.4% capacitance retention after 1000 charge–discharge cycles. The PPy/MWCNT composites, prepared using Tiron and SAF co‐dispersant, are promising electrodes for ES. © 2015 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2015 , 132, 42376.     

Laccase‐catalyzed synthesis of polypyrrole‐multiwalled carbon nanotube composites as energy storage materials for capacitors

Multiwalled carbon nanotubes (MWNTs) were coated with polypyrrole (PPy) using in situ enzymatic polymerization of pyrrole catalyzed by a laccase (benzenediol:oxygen oxidoreductase, EC 1.10.3.2) from Trametes versicolor. Transmission electron microscopy revealed that the MWNTs were uniformly coated with very thin layers of PPy without any indication of globular polymer aggregate formations. The enzymatic synthesis of the MWNTs/PPy composites was quite simple being performed in a one‐pot aqueous solution (pH 4.0) under mild reaction conditions. The potential of the composites with respect to the development of energy storage devices was demonstrated by fabricating a two‐electrode coin cell capacitor (diameter 20 mm, thickness 1.6 mm) utilizing the composites as electrode materials. The capacitance of the cell was 28.0 F g^?1 for the electrode material as measured by a galvanostatic charge–discharge method. The energy density and power density were 2.55 and 805 W kg^?1, respectively, which were close to those of the capacitors classified as ultracapacitors. © 2015 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2016 , 133, 43307.     

Disposable potentiometric citrate sensor based on polypyrrole‐doped films for indirect determination of sildenafil in pharmaceuticals formulations

A new sensitive and selective disposable potentiometric sensor based on polypyrrole (PPy) films for determination of sildenafil citrate (SC) was proposed. The pyrrole polymerization was performed in presence of citrate ions under galvanostatic conditions which resulted in a membrane of PPy doped with citrate anion at graphite pencil electrode surface. Experimental conditions (e.g., pH and conditioning time) and instrumental parameters (e.g., current density and electrical charge) were evaluated in order to reach the best potentiometric response for the proposed sensor. Under optimized conditions, the device presented a linear dynamic range (LDR) for citrate ions concentrations varying from 0.034 to 1.7 mmol L^?1 with a Nernstian slope of 57.2 mV dec^?1 and a limit of detection (LOD) of 30 µmol L^?1. The developed potentiometric sensor was applied for sildenafil citrate (SC) determination (pharmaceutical formulations) and results compared with an official spectrophotometric method indicating a good agreement for a confidence level of 95%. Effect of concomitants species on the potentiometric response of the proposed device and morphologic characterization using microscopy of atomic force (AFM) were realized. The surface roughness of PPy films (synthesized in citrate solution and chloride) showed poorly affected by changing the doping anion, probably because the polypyrrole nodules grow three‐dimensionally simultaneously. © 2016 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2016 , 133, 43762.     

Composite sodium p‐toluene sulfonate–polypyrrole–iron anode for a lithium‐ion battery

In this study, p‐toluene sulfonate (TsONa) doped polypyrrole (PPy) was synthesized for an anode in a lithium‐ion battery via a one‐step facile electropolymerization on Fe foil. The obtained TsONa–PPy–Fe composite electrode was investigated with scanning electron microscopy, energy‐dispersive X‐ray spectroscopy, Fourier transform infrared spectroscopy, and galvanostatic charge–discharge profiling. As expected, many irregular microspherical particles of TsONa‐doped PPy formed and combined tightly with the surface of Fe foil. Furthermore, the obtained TsONa–PPy–Fe anode also delivered satisfactory electrochemical performances. For example, the reversible capacity was still about 105–115 mAh/g, even after at least 50 cycles. The high lithium storage activity of PPy and the high conductivity of the TsONa‐doped PPy jointly contributed into the satisfactory electrochemical performances. © 2017 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2017 , 134, 44935.