In situ intercalative polymerization of conducting polypyrrole/montmorillonite nanocomposites

Conducting polypyrrole (PPy)‐montmorillonite (MMT) clay nanocomposites have been synthesized by the in situ intercalative polymerization method. The PPy‐MMT nanocomposites are characterized by field‐emission scanning electron microscopy (FE‐SEM), transmission electron microscopy (TEM), X‐ray diffraction (XRD), ultraviolet–visible (UV–vis) spectroscopy, thermogravimetric analysis (TGA), and Fourier‐transform infrared (FTIR) spectroscopy. XRD patterns show that after polymerization by the in situ intercalative method with ammonium persulfate and 1 M HCl, an increase in the basal spacing from 1.2 to 1.9 nm was observed, signifying that PPy is synthesized between the interlayer spaces of MMT. TEM and SEM micrographs suggest that the coexistence of intercalated MMT layers with the PPy macromolecules. FTIR reveals that there might be possible interfacial interactions present between the MMT clay and PPy matrix. The study also shows that the introduction of MMT clay results in thermal stability improvement of the PPy. © 2008 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys 46: 2279–2285, 2008     

Nanocomposite prepared from in situ grafting of polypyrrole to aminobenzoyl‐functionalized multiwalled carbon nanotube and its electrochemical properties

We reported the functionalization of multiwalled carbon nanotube (MWCNT) with 4‐aminobenzoic acid by a “direct” Friedel–Crafts acylation reaction in a mild polyphosphoric acid (PPA)/phosphorous pentoxide (P₂O₅) medium. The resulting 4‐aminobenzoyl‐functionalized MWCNT (AF‐MWCNT) was used as a platform for the grafting of polypyrrole (PPy) in ammonium persulfate (APS)/aqueous hydrochloric acid solution to produce PPy‐grafted MWCNT (PPy‐g‐MWCNT) composite. After dedoping with alkaline treatment, PPy‐g‐MWCNT displayed 20 times higher electrical conductivity than that of PPy. The current density and cycle stability of PPy‐g‐MWCNT composite were also remarkably improved compared with those of PPy homopolymer, suggesting that an efficient electron transfer between PPy and MWCNT was possible through covalent links. In addition, PPy‐g‐MWCNT displayed high electrocatalytic activity for oxygen reduction reaction (ORR). © 2011 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem, 2011     

Electromagnetic properties of Fe3O4‐functionalized graphene and its composites with a conducting polymer

Hybrid materials of Fe₃O₄‐decorated reduced graphene oxide (Fe₃O₄‐RGO) and poly(3,4‐ethylenedioxythiophene) (PEDOT) were prepared by poly(ionic liquid)‐mediated hybridization. In this hybrid material, poly(ionic liquid) was found to perform multiple roles for: (1) stabilizing Fe₃O₄‐RGO against aggregation in the reaction medium, (2) transferring Fe₃O₄‐RGO nanomaterials from aqueous into organic phase, and (3) associating Fe₃O₄‐RGO nanomaterials with PEDOT. The hybrid materials of Fe₃O₄‐RGO with PEDOT showed the lowest surface resistivity of 80 Ω sq^?1 at an RGO‐Fe₃O₄ loading of 1 wt %, and exhibited superparamagnetic behavior with an electromagnetic interference shielding effectiveness of 22 dB. © 2011 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem, 2012     

Click coupled graphene for fabrication of high‐performance polymer nanocomposites

An effective technique of using click coupled graphene to obtain high‐performance polymer nanocomposites is presented. Poly(ε‐caprolactone) (PCL)‐click coupled graphene sheet (GS) reinforcing fillers are synthesized by the covalent functionalization of graphene oxide with PCL, and subsequently the PCL‐GS as a reinforcing filler was incorporated into a shape memory polyurethane matrix by solution casting. The PCL‐click coupled GS has shown excellent interaction with the polyurethane matrix, and as a consequence, the mechanical properties, thermal stability, thermal conductivity, and thermo‐responsive shape memory properties of the resulting nanocomposite films could be enhanced remarkably. In particular, for polyurethane nanocomposites incorporated with 2% PCL‐GS, the breaking stress, Young's modulus, elongation‐at‐break, and thermal stability have been improved by 109%, 158%, 28%, and 71 °C, respectively. This click coupling protocol offers the possibility to fully combine the extraordinary performance of GSs with the properties of polyurethane. © 2012 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys, 2013     

Magnetic ionic liquid‐assisted synthesis of polypyrrole/AgCl nanocomposites

The synthesis of polypyrrole (PPy)/AgCl nanocomposites with their size ranging around 70–100 nm are achieved by using magnetic ionic liquid as the oxidant in the interface polymerization system. The interface polymerization leads to the formation of uniform and unaggregated nanocomposites with a relatively narrow size distribution confined to submicrometer‐sized domains. The morphology and structure of the nanocomposites are characterized by transmission electron microscopy (TEM), Fourier transform infrared (FTIR) spectroscopy, Raman spectroscopy, and X‐ray diffraction (XRD). The potential application of PPy/AgCl nanocomposites as a H₂O₂ biosensor is also reported. Copyright © 2010 John Wiley & Sons, Ltd. Erratum: Magnetic ionic liquid‐assisted synthesis of polypyrrole/AgCl nanocomposites     

Physicochemical properties of hybrid guest-host nanocomposites based on polyaniline

The study concerns the influence of the method of preparation of hybrid guest-host nanocomposites based on polyaniline (a conducting polymer) on their structure, conductivity, electrochemical characteristics, electronic state, and redox activity__________Published in Russian in Izvestiya Akademii Nauk. Seriya Khimicheskaya, No. 3, pp. 643–649, March, 2005.     

Physical and dielectric properties of poly(vinylidene fluoride)/polybenzimidazole functionalized graphene nanocomposites

Polymer‐based nanocomposites with good dielectric behavior have engrossed research devotion because of their distinctive benefits in electronic applications. An in situ synthetic process for the polybenzimidazole functionalized graphene oxide (GBI) and its nanocomposite with poly(vinylidene fluoride) (PVDF) is described. GBI shows good dispersion in the bulk PVDF matrix implying a strong interaction of polybenzimidazole with PVDF as evident from morphological and FTIR studies. A gradual increment of GBI in PVDF increases its piezoelectric β‐polymorph formation with a maximum of 73% for 10 wt % GBI in PVDF (GBF10) which also exhibits highest thermal stability. An exhaustive study of frequency dependent electrical properties of GBF10 indicates significantly higher dielectric constant (61), low dielectric loss (0.42), and low AC conductivity value of 1.17 × 10^?10 S/cm at 100 Hz which are the key properties of a suitable capacitor. GBF10 also shows hydrophobic behavior (water uptake 2.89%) and low swelling ratio (1.143), providing an opportunity to use the composite film in fuel cell application. © 2018 Wiley Periodicals, Inc. J. Polym. Sci., Part B: Polym. Phys. 2019 , 57, 189–201     

Synthesis and characterization of polypyrrole/graphite oxide composite by in situ emulsion polymerization

This work demonstrates a feasible route to synthesize the layered polypyrrole/graphite oxide (PPy/GO) composite by in situ emulsion polymerization in the presence of cationic surfactant cetyltrimethylammonium bromide (CTAB) as emulsifier. AFM and XRD results reveal that the GO can be delaminated into nanosheets and well dispersed in aqueous solution in the presence of CTAB. The PPy nanowires are formed due to the presence of the lamellar mesostructured (CTA)₂S₂O₈ as a template. The results of the PPy/GO composite indicate the PPy insert successfully into GO interlayers, and the nanofiber‐like PPy are deposited onto the GO surface. Owing to π–π electron stacking effect between the pyrrole ring of PPy and the unoxided domain of GO sheets, the electrical conductivity of PPy/GO composite (5 S/cm) significantly improves in comparison with pure PPy nanowires (0.94 S/cm) and pristine GO (1 × 10^?6 S/cm). © 2010 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys 48: 1329–1335, 2010     

Sulfonated polyaniline‐graphene oxide hybrids: Synthesis and effect of monomer composition on the electrochemical signal for direct DNA detection

A variety of sulfonated polyaniline‐graphene oxide (SPAN‐GNO) nanocomposites based on GNO, aniline (ANI) and m‐aminobenzenesulfonic acid (ABSA) are prepared via changing the mole ratio of ANI to ABSA for the comparison of DNA sensing behavior. Self‐signals of SPAN‐GNO are employed for estimating the effect of preparation conditions [component, monomer composition (mole ratio of ANI to ABSA), and reaction time] on DNA immobilization and hybridization detection. Then, we find herein that the mole ratio of ANI to ABSA plays a lead role over other factors on hybridization efficiency. Meanwhile, the parallel experiments using methylene blue as the classic indicator verifies this conclusion. The results show that, by comparison with other mole ratio SPAN‐GNO nanocomposites‐modified electrodes, the mole ratio (2:3) exhibits the widest dynamic detection range from 1.0 × 10^?14 to 1.0 × 10^?6 M, as well as the lowest detection limit (3.06 × 10^?15 M). © 2016 Wiley Periodicals, Inc. J. Polym. Sci., Part A: Polym. Chem. 2016 , 54, 1762–1773     

Facile one‐step synthesis of electromagnetic functionalized polypyrrole/Fe3O4 nanotubes via a self‐assembly process

This article reports a simple self‐assembly process for facile one‐step synthesis of novel electromagnetic functionalized polypyrrole (PPy)/Fe₃O₄ composite nanotubes using p‐toluenesulfonic acid (p‐TSA) as the dopant and FeCl₃ as the oxidant. The key trick of the present method is to use FeCl₃ as the oxidant for both PPy and Fe₃O₄ in the same time to synthesize PPy/Fe₃O₄ composite nanotubes in one‐step. This facile one‐step method is much simpler than the conventional approach using the Fe₃O₄ nanoparticles as the additives. Compared to the similar composites synthesized using the conventional method, the as‐prepared PPy‐p‐TSA/Fe₃O₄ composite nanotubes using the facile one‐step self‐assembly process show much higher room‐temperature conductivity. Moreover, the composite nanotubes display interesting ferromagnetic behavior. The electrical properties of the PPy‐p‐TSA/Fe₃O₄ composite nanotubes are dominated by the amount of FeCl₃ while their magnetic properties are controlled by the amount of FeCl₂. © 2009 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 48: 320–326, 2010     

Synthesis of conducting polypyrrole by radiolysis polymerization method

Conducting polypyrrole (PPy) has been synthesized by the in situ gamma radiation‐induced chemical oxidative polymerization method. This method takes advantages of the specialties of radiation‐induction, and a highly uniform polymer morphology was obtained. The resultant nanosize polypyrrole particles were characterized by Elemental Analysis, Fourier transform infrared (FT‐IR), scanning electron microscope (SEM), transmission electron microscopy (TEM) and X‐ray Diffraction (XRD). Measurements of polymer particle sizes were obtained at <500 nm. A standard four‐point probe revealed that the chemical synthesis of PPy has a good electrical property. Also thermal stability, checked by Thermal Gravimetric Analysis in air, was ensured by this novel synthesis. Copyright © 2007 John Wiley & Sons, Ltd.     

Synthesis and characterization of magnetoelectric polymer nanocomposites

Magnetoelectric polymer nanocomposite structures are synthesized using conducting polyaniline and nanosized BFO particles through in situ sol–gel polymerization. The effect of nanosized BFO in polyaniline matrix is studied. The SEM, XRD, VSM, FTIR, and UV–Vis studies were made to understand the morphology, crystalline structure, magnetic, and optical properties of PANI/BFO composites with various concentrations of nanofiller. © 2008 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys 46: 2418–2422, 2008     

Initiating electropolymerization on graphene sheets in graphite oxide structure

Because of its special chemical composition, graphite oxide has peculiar influences on electrochemical processes. The existence of various functional groups significantly affects electropolymerization processes and the formation of conductive polymers. Electrochemical synthesis of polyaniline (as a prototype of conductive polymers) on a paste‐based substrate of graphite oxide was investigated. In this case, the electropolymerization is significantly different from conventional cases, and the polymer is generated just during the first potential cycle. This can be attributed to the fact that graphite oxide can assist the monomer oxidation. Alternatively, electropolymerization was successfully performed inside the graphite oxide layers via electrochemical treatment of aniline‐intercalated graphite oxide in the supporting electrolyte. Although these phenomena are related to the chemical composition of graphite oxide, the graphite prepared by the reduction of graphite oxide also displayed some advantages for the electropolymerization (over natural graphite). There is an emphasis on the morphological investigations throughout this study, because novel morphologies were observed in the system under investigation. © 2010 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 48: 2204–2213, 2010     

A comparison of fracture and permanganic etching of polypyrrole films

The internal organization within electrochemically polymerized films of the conducting polymers polypyrrole p-toluene sulphonate and polypyrrole sulphate has been examined by scanning electron microscopy (SEM) following transverse fracture and permanganic etching of microtomed cross sections. X-ray scattering studies have shown these two materials to exhibit very different internal ordering: polypyrrole p-toluene sulphonate is thought as being anisotropic, with the counter ions and polypyrrole chains lying down preferentially in the plane of the work electrode, whereas polypyrrole sulphate is considered to be isotropic. Comparison of the internal textures following the two different preparative techniques shows significant differences. Whereas the morphology revealed in transverse fracture surfaces correlates closely with x-ray scattering data, etched surfaces exhibit a morphology that is in good agreement with the direct examination of sections prepared by ultramicrotomy. Despite the apparent contradiction in these two sets of data, a consistent picture of the true morphology (as revealed by permanganic etching) can be deduced and reconciled with the fracture surface micrographs. © 1996 John Wiley & Sons, Inc.     

Plasma-based preparation of polyaniline/graphene and polypyrrole/graphene composites for dye-sensitized solar cells as counter electrodes

This study presents the preparation of graphene (GR) nanocomposites with polyaniline (PANI) and polypyrrole (PPy) through the fast, versatile and environmentally friendly process of radio frequency (RF)-plasma polymerization. Morphological characterization of the nanocomposites is performed using scanning electron microscopy (SEM) and shows that the PANI and PPy conducting polymers coated the GR surface. The surface properties of the GR nanocomposites are determined using Fourier transform infrared spectroscopy (FTIR), X-ray photoelectron spectroscopy (XPS), and X-ray diffraction (XRD). The prepared GR nanocomposites are then used as counter electrodes in dye-sensitized solar cells (DSSCs). The conversion cell efficiencies for iodine-doped DSSC samples are found to be 0.086%, 5.41%, and 5.60% for I₂-PANI, I₂-PANI-GR and I₂-PPy-GR, respectively, while the corresponding undoped samples reaches power conversion efficiencies of 3.82%, 1.30%, and 0.077% for PPy-GR, PANI-GR and PANI, respectively. The incident photon-to-current efficiency (IPCE) of iodine-doped composite-based DSSCs is significantly enhanced.     

Effect of oxidant on electronic transport in polypyrrole nanotubes synthesized in the presence of methyl orange

Polypyrrole nanotubes with diameter 60–400 nm are synthesized with methyl orange as template and various oxidants, iron(III) chloride hexahydrate, iron(III) sulfate hydrate, and ammonium peroxydisulfate. The highest electrical conductivity of compressed pellets, 66 S cm^?1, is found for iron(III) chloride. Regions with 3D variable range hopping in series with ordered regions near metal–insulator transition govern the charge transport. Other oxidants and globular morphology provide less conducting samples, <10 S cm^?1. The transport mechanism is identified with the heterogeneous model of tunneling between (bi)polaronic clusters with parallel contribution of Arrhenius‐like activated conductivity. The results of conductivity are correlated with the protonation level reflected in the infrared spectra and with the ratio of bipolaron/polaron bands revealed by Raman spectroscopy. © 2015 Wiley Periodicals, Inc. J. Polym. Sci., Part B: Polym. Phys. 2015 , 53, 1147–1159     

Synthesis,characterization and optical properties of graphene oxide–polystyrene nanocomposites

The synthesis of graphene oxide (GO)–polystyrene (PS) Pickering emulsions, as environment‐friendly nanostructures suitable for novel applications, has received significant attention in recent years. In this work, the synthesis and characterization of GO–PS nanocomposites through seeded emulsion polymerization and the selective light reflection properties of dry films have been reported. Amphiphilic molecule sulfonated 3‐pentadecyl phenol was used as a co‐surfactant to stabilize GO dispersions during the emulsion polymerization process. The particle size of the dispersions as measured by dynamic light scattering decreases from 540 nm, for PS without any GO, to 88 nm with 1 wt% GO content. Scanning electron microscopy studies show a uniform size distribution of the composite particles prepared with GO. The dried films show a structural color that varies with the GO content. The self‐assembly behavior of the dried film was further studied using reflectance spectroscopy, which shows a red shift of the reflectance maximum from 440 to 538 nm as the GO loading was increased from 0.2 to 0.5 wt%, respectively, indicating a different microstructure. X‐ray diffraction, transmission electron microscopy (TEM) and atomic force microscopy (AFM) were used to study the morphology and structure of the composite particles on drying. The AFM study confirms the non‐spherical shape of the particles. Thermogravimetric analysis shows improved thermal decomposition characteristics of the nanocomposite films. Copyright © 2015 John Wiley & Sons, Ltd.     

Reactive Template Synthesis of Polypyrrole Nanotubes for Fabricating Metal/Conducting Polymer Nanocomposites

Unique nanocomposites of polypyrrole/Au and polypyrrole/Pt hybrid nanotubes are synthesized employing polypyrrole (PPy) nanotubes as an advanced support by solution reduction. The conducting polymer PPy nanotubes are fabricated by using pre‐prepared MnO₂ nanowires as the reactive templates. MnO₂ nanowires induce the 1D polymerization of pyrrole monomers and the simultaneous dissolution of the templates affords the hollow tube‐like structure. The loading content of metal nanoparticles in the nanocomposites could be adjusted by simply changing the amount of metal precursors. This work provides an efficient approach to fabricate an important kind of metal/conducting polymer hybrid nanotubes that are potentially useful for electrocatalyst and sensor materials.     

Comparative study of 2‐amino and 3‐aminobenzoic acid copolymerization with aniline synthesis and copolymer properties

Polyanilines soluble in an aqueous basic medium were synthesised by copolymerization of aniline (ANI) with both 2 and 3‐aminobenzoic acids (ABA). Different composition copolymers were prepared by varying the ANI/ABA feed ratio. Poly(aniline‐co‐2‐aminobenzoic acid) (PANI2ABA) and poly(aniline‐co‐3‐aminobenzoic acid) (PANI3ABA) displayed differences in their properties, such as specific charge and fluorescence behavior because the reactivity of 2‐aminobenzoic (2ABA) and 3‐aminobenzoic (3ABA) acids are very different. The new materials were characterized by X‐ray photoelectron, Fourier transform infrared, and Raman spectroscopies. © 2004 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 42: 5587–5599, 2004     

Synthesis and characterization of polypyrrole dispersions prepared with different dopants

Stable polypyrrole dispersions were prepared by chemical oxidative polymerization of pyrrole in an aqueous medium containing different anionic salts - sodium benzoate, potassium hydrogen phthalate and sodium hydrogen succinate. Results of the elemental analysis and FT-IR spectroscopy confirmed that the anionic salts are incorporated in the conducting polymers and functioned as the dopants. The retardation of pyrrole polymerization was observed when a certain amount of the salt was used as dopant. SEM images of polypyrrole dispersions indicate large spherical particles (150-180nm). The conductivity of polypyrrole composites has also been investigated.