The preparation,characterization, and properties of silver nanoparticle reinforced reduced graphene oxide–poly(amidoamine) nanocomposites

A simple approach was employed to synthesize silver nanoparticle (Ag NP) reinforced reduced graphene oxide–poly(amidoamine) (Ag‐r‐RGO–PAMAM) nanocomposites. The structural changes of the nanocomposites with the PAMAM and Ag NPs were confirmed by Fourier transform infrared spectroscopy, X‐ray photoelectron spectroscopy, X‐ray diffraction, Raman spectroscopy, and scanning electron microscopy. In addition, the performance was characterized with thermogravimetric and electrical conductivity instruments. The results indicate that the Ag NPs are well dispersed in fine size on the surface of the RGO–PAMAM composites, which results in an increase of at least 38% in thermostability and a certain enhancement in electrical conductivity. It is worth noting that the electrical conductivity of the nanocomposites was approximately 5.88 S cm^?1, which was higher than that of RGO–PAMAM, and increases with the rising content of silver nanoparticles. Meanwhile, the Ag‐r‐RGO–PAMAM nanocomposites still maintain a favorable dispersion in organic solvents. © 2017 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2017 , 134 , 45172.     

Mechanical and piezo‐resistive properties of styrene–butadiene–styrene copolymer covalently modified with graphene/styrene–butadiene–styrene composites

As novel piezoelectric materials, carbon‐reinforced polymer composites exhibit excellent piezoelectric properties and flexibility. In this study, we used a styrene–butadiene–styrene triblock copolymer covalently grafted with graphene (SBS‐g‐RGO) to prepare SBS‐g‐RGO/styrene–butadiene–styrene (SBS) composites to enhance the organic solubility of graphene sheets and its dispersion in composites. Once exfoliated from natural graphite, graphene oxide was chemically modified with 1,6‐hexanediamine to functionalize with amino groups (GO–NH₂), and this was followed by reduction with hydrazine [amine‐functionalized graphene oxide (RGO–NH₂)]. SBS‐g‐RGO was finally obtained by the reaction of RGO–NH₂ and maleic anhydride grafted SBS. After that, X‐ray diffraction, X‐ray photoelectron spectroscopy, Raman spectroscopy, scanning electron microscopy, transmission electron microscopy, thermogravimetric analysis, and other methods were applied to characterize SBS‐g‐RGO. The results indicate that the SBS molecules were grafted onto the graphene sheets by covalent bonds, and SBS‐g‐RGO was dispersed well. In addition, the mechanical and electrical conductivity properties of the SBS‐g‐RGO/SBS composites showed significant improvements because of the excellent interfacial interactions and homogeneous dispersion of SBS‐g‐RGO in SBS. Moreover, the composites exhibited remarkable piezo resistivity under vertical compression and great repeatability after 10 compression cycles; thus, the composites have the potential to be applied in sensor production. © 2018 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2018 , 135, 46568.     

A novel conductivity composite based on polyaniline/zirconium phenylphosphonate

A novel conductivity composite from polyaniline (PANI) and layered zirconium phenylphosphonate (ZrPP) was carried out through in situ chemical oxidation polymerization by the addition of an appropriate amount of ammonium peroxodisulfate solution, and the relevant structure and properties were investigated. The composites were characterized by Fourier transform infrared spectroscopy, X‐ray diffraction, and scanning electron microscopy. The electrical conductivity was measured by the four‐probe technique. The electrical conductivity of the composites improved with increasing ZrPP loading, and the materials had reasonably good electrical properties, even with 40 wt % loadings of ZrPP in the polymer matrix. The results reveal that π–π interaction was formed in the composites, which enhanced the electrical conductivity of the composites compared to that in neat PANI. © 2010 Wiley Periodicals, Inc. J Appl Polym Sci, 2011     

Room temperature preparation,electrical conductivity,and thermal behavior evaluation on silver nanoparticle embedded polyaniline tungstophosphate nanocomposite

An advanced nanocomposite, polyaniline tungstophosphate (PANI‐WP) cation exchanger, was synthesized by simple solution method and treated with silver nitrate resulting silver embedded PANI‐WP (PANI‐WP/Ag). Spectroscopic characterization of PANI‐WP/Ag was carried out by scanning electron microscopy, fourier transform infrared spectroscopy, UV‐Visible spectroscopy, and X‐ray diffraction. Electrical conductivity measurements and thermal effect on conductivity of PANI‐WP/Ag was studied after acid treatment. The dc electrical conductivity was found 3.06 × 10⁻³ S cm⁻¹ for HCl doped, measured by 4‐in line‐probe dc electrical conductivity measuring technique. Thermal conductivity is stable with all temperatures in isothermal studies showing excellent stability of PANI‐WP/Ag material. Hybrid showed better linear Arrhenius electric conducting response for semiconductors, stable upto 120°C. It was observed that conductivity is at the border of metallic and semiconductor region. POLYM. COMPOS., 37:2460–2466, 2016. © 2015 Society of Plastics Engineers     

Synthesis and characterization of polyaniline/carbon nanotube composites

The synthesis of polyaniline (PANI) containing different carbon nanotubes (CNTs) by in situ polymerization is reported in this study. The samples were characterized by X‐ray diffraction and scanning electron microscopy. Fourier transform infrared and ultraviolet–visible spectroscopy were used to determine the change in structure of the polymer/CNT composites. Thermogravimetric analysis showed that the composites had better thermal stability than the pure PANI. Photoluminescence spectra showed a blueshift in the PANI–single‐walled nanotube (SWNT) composite. Low‐temperature (77–300 K) electrical transport properties were measured in the absence and presence of a magnetic field up to 1 T. Direct‐current conductivity exhibited a nonohmic, three‐dimensional variable range hopping mechanism. The room‐temperature magnetoconductivity of all of the investigated samples except the PANI–SWNT composite were negative; however, it was positive for the PANI–SWNT composite, and its magnitude decreased with increasing temperature. © 2010 Wiley Periodicals, Inc. J Appl Polym Sci, 2011     

Characterization and electrical properties of honeycomb‐patterned poly(ε‐caprolactone)/reduced graphene oxide composite film

A novel biocompatible composite of poly(ε‐caprolactone) (PCL) was synthesized via in situ ring‐opening polymerization method of ε‐caprolactone in the presence of reduced graphene oxide (RGO). Fourier transform infrared (FTIR) and X‐ray photoelectron spectroscopy (XPS) studies support a strong interaction between PCL and RGO. The crystallization behavior and thermal stability of these composites were studied using differential scanning calorimetry (DSC) and thermogravimetric analysis (TGA), respectively. Honeycomb‐patterned thin films with regular structures were fabricated by casting the composite solution under humid conditions. The temperature‐dependent DC conductivity of the honeycomb‐patterned composite films was studied in the range of 290−330 K, which revealed a semiconducting behavior in the transport properties of the composite films. DC conductivity of the patterned films was increased by increasing the concentration of RGO in the composites and in the increased temperature. POLYM. COMPOS., 2012. © 2012 Society of Plastics Engineers     

Effect of exfoliated organophilic montmorillonite on the structure and conductivity of polypropylene/polyaniline composites

This study concentrates on the effect of organophilic montmorillonite (OMMT) nanolayers on conductivity, structure, morphology, and mechanical properties of the polypropylene/polyaniline (PP/PANI) composites. The composite was prepared by in situ polymerization of aniline at different composition ratios in the presence of PP powder. The structure and conductivity of ternary PP/PANI/OMMT nanocomposites were compared with those of PP/PANI composites. DC electrical conductivity measurements indicated that electrical conductivity decreased in the presence of OMMT layers. Scanning electron microscopy showed that the surface of ternary nanocomposites have more rough regions. The interaction between PANI and OMMT was confirmed by Fourier transform infrared spectroscopy. The distribution of OMMT layers in the polymer matrix, as an effective parameter on the properties of nanocomposite, was investigated and confirmed using X‐ray diffraction and transmission electron microscopy. The results showed an exfoliated array for OMMT layers in the nanocomposite structure. The shear storage modulus for PP/PANI composites was lower than that for pure PP; however, it was increased for PP/PANI/OMMT nanocomposites. The data from the tensile and izod impact strength showed that the Young's modulus and izod impact strength were increased slightly by the addition of OMMT, whereas the elongation at break was decreased. POLYM. COMPOS., 38:699–707, 2017. © 2015 Society of Plastics Engineers     

Synthesis of water soluble sulfonated polyaniline and determination of crystal structure

A polyaniline (PANI) was synthesized by the oxidative polymerization using ammonium persulfate as an oxidizing agent. The PANI was then stirred with excess fuming sulfuric acid at room temperature for 6 h to obtain water soluble sulfonated polyaniline (SPANI). The degree of sulfonation was found to be 93–94% from the Fourier transform infrared (FTIR) and elemental analysis. The solubility of the SPANI in water was 1.25 g/L at room temperature and appeared as a green color solution. Conductivity of the PANI was decreased after sulfonation. A proliferation of hydrophilic nature of the PANI after sulfonation was observed from the water contact angle measurement. From the UV analysis, it was revealed that the energies required for the π–π* and bipolaron/polaron transitions are less and the intensity of these transitions are lower in SPANI compared to those of PANI. A detailed study on the crystal structures of PANI and SPANI were accomplished from the powder X‐ray diffraction analysis. The SPANI exhibited a more ordered structure having a higher degree of crystallinity and crystallite sizes with an increased unit cell volume compared to the PANI. After sulfonation the morphology of PANI was transformed from a rod‐like shape to a flat‐plate shape. © 2010 Wiley Periodicals, Inc. J Appl Polym Sci, 2010     

Fabrication of novel polyaniline/flowerlike copper monosulfide composites with enhanced electromagnetic interference shielding effectiveness

Novel polyaniline (PANI)/flowerlike CuS composites with improved electromagnetic interference (EMI) shielding effectiveness (SE) were prepared through the in situ polymerization of PANI into the flowerlike CuS microspheres. X‐ray diffraction, scanning electron microscopy, Fourier transform infrared spectroscopy, ultraviolet–visible optical absorption spectroscopy, thermogravimetric analysis, electrical conductivity testing, and EMI SE testing were used to characterize the as‐obtained products. The results reveal that the flowerlike CuS was uniformly coated by a PANI shell. Most importantly, compared with the original CuS and pure PANI, the novel PANI/flowerlike CuS composites exhibited a remarkably enhanced SE. With a thickness of 3 mm, the optimal EMI SE of the PANI–CuS composites reached ?45.2 dB at 2.78 GHz, and an improved shielding efficiency below ?18 dB was also obtained over the frequency range from 300 kHz to 3 GHz. This suggested that these novel PANI/flowerlike CuS composites have promising applications in the field of shielding materials. © 2017 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2017 , 134 , 45232.     

Characterization and DC electrical conductivity of the composite films containing polyaniline‐carboxymethyl cellulose

New polymer composites containing polyaniline‐carboxymethyl cellulose (PANI‐CMC) were prepared via the polymerization of aniline hydrochloride using different concentration (wt%) of sodium CMC using ammonium persulfate as an oxidant. The thermal stability and embedded crystallinity of the composites were investigated using thermogravimetric and X‐ray diffraction analysis method, respectively. The electrical properties of the composites were examined using temperature‐dependent DC conductivity within 300–500 K. As compared to pure polyaniline the composites with increasing CMC in the PANI‐CMC composites shows the enhancement in the higher crystallinity and thermal stability, and higher electrical conductivities under equivalent conditions. POLYM. COMPOS., 2012. © 2012 Society of Plastics Engineers     

Preparation of polyaniline/nickel oxide nanocomposites by liquid/liquid interfacial polymerization and evaluation of their electrical,electrochemical and magnetic properties

A novel route has been developed to synthesize polyaniline (PANI)/nickel oxide (NiO) nanocomposites via liquid/liquid interfacial polymerization where NiO 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, thermogravimetric analysis, ultraviolet?visible absorption, X‐ray diffraction, and electrochemical, electrical conductivity and magnetic property measurements. NiO was dispersed uniformly within the PANI matrix. The composites exhibited noticeable improvement in thermal stability and electrical conductivity in comparison with pure PANI. The composites showed excellent electrochemical reversibility at a scan rate of 0.1 V s^?1 and good redox stability even up to 100 cycles. The room temperature magnetic hysteresis measurements show a low value of coercivity for the polymer composites in comparison with NiO. The remnant magnetization (M_r) values were found to be increased with increasing concentration of NiO in the composites. © 2013 Society of Chemical Industry     

Synthesis and electrochemical properties of poly(2,3‐dimethylaniline)/polyaniline composites

In this study, poly(2,3‐dimethylaniline)/polyaniline (P(2,3‐DMA)/PANI) composite was prepared by in situ polymerization of aniline on the surface of P(2,3‐DMA) particles in hydrochloric acid solution. Fourier transform infrared spectra and X‐ray diffraction results of the composites indicated that P(2,3‐DMA) was successfully modified by PANI. The electrochemical activity and electrical conductivity of the P(2,3‐DMA)/PANI composite were discussed by cyclic voltammetry and standard four‐probe tests, respectively. The results showed that the conductivity of the composite increased with the increasing aniline concentration, which can expand the potential applications of P(2,3‐DMA), such as use in anti‐static coatings or electronic devices. The P(2,3‐DMA)/PANI composite also showed better solubility and anticorrosive property than PANI. POLYM. COMPOS., 36:1541–1545, 2015. © 2014 Society of Plastics Engineers     

Solubility and electrochemical properties of chemically modified polyaniline‐gold/camphor sulfonic acid composites

Polyaniline nanocomposites encapsulating gold nanoparticles on camphor sulfonic acid (CSA) surface were prepared via the polymerization of aniline hydrochloride with different concentrations of CSA using HAuCl₄ as oxidant. The synthesized composites were characterized by Fourier transform infrared spectroscopy and UV–visible spectroscopy. Surface morphology was studied by scanning electron microscopy and transmission electron microscopy. The embedded crystallinity of the composites was investigated by X‐ray diffraction analysis. The solubility of the nanocomposites was studied using water, N‐methyl‐2‐pyrrolidinone, chloroform, and dimethylformamide solvents. The room temperature direct current conductivity of the composites was also observed in solution state. Electrical property of the composites was examined using cyclic voltammetric measurements at room temperature. The fabricated polymer nanocomposites with better solubility in water and some organic solvents will have various applications in electrical devices and biosensors. POLYM. COMPOS., 36:245–252, 2015. © 2014 Society of Plastics Engineers     

Preparation and characterization of polyaniline–polypyrrole composite from polyaniline dispersions

Polyaniline–polypyrrole (PANI‐PPy) composite was prepared by in situ polymerization of pyrrole in PANI dispersion using FeCl₃·6H₂O as oxidant and sodium dodecyl benzene sulfonate (SDBS) as surfactant. Different synthesis conditions of PANI dispersion including the relative concentration of aniline and SDBS and the amount of acid (HCl) on the morphology and conductivity of the resulting composites were investigated. Fourier transformation infrared (FTIR) spectra, X‐ray photoelectron spectroscopy (XPS), thermal gravimetric analysis (TGA), X‐ray diffraction (XRD) patterns, and contact angles of the composites showed there existed certain interaction between PANI (or PANI‐SDBS) and PPy. © 2007 Wiley Periodicals, Inc. J Appl Polym Sci 104: 3523–3529, 2007     

Preparation,characterization, and electrical properties of ZSM‐5/PEG composite particles

ZSM‐5/PEG composites were synthesized by a simple solution method with polyethylene glycol (PEG) and H‐ZSM‐5 zeolite (Si/Al = 11.4). The obtained composites were characterized using X‐ray powder diffraction and Fourier transform infrared spectroscopy. The obtained results indicated that the ZSM‐5 was physically combined with PEG. The thermal properties and thermal stability were investigated by thermogravimetric and differential thermal analyses. In situ electrical conductivity was used to follow‐up the changes in the electrical conductance during the heating of the ZSM‐5/PEG composite. It was found that ZSM‐5 is able to effectively enhance the electrical conductivity of PEG. The results showed that the obtained weight loss during the composite decomposition to charcoal is accompanied by a decrease in the electrical conductivity. Moreover, the removal of the formed charcoal is associated with an electrical conductivity increase. Calcining the ZSM‐5/PEG composite having a content of 30% results in many effects on the structural, textural, and electrical properties of the obtained products. POLYM. COMPOS., 35:1160–1168, 2014. © 2013 Society of Plastics Engineers     

Enhanced thermoelectric performance by alcoholic solvents effects in highly conductive benzenesulfonate‐doped poly(3,4‐ethylenedioxythiophene)/graphene composites

Benzenesulfonate‐doped poly(3,4‐ethylenedioxythiophene) (PEDOT‐Bzs)/graphene thermoelectric (TE) composites with various graphene filler contents were synthesized in five different kinds of solvents. Dodecylbenzenesulfonic acid (DBSA) was used to achieve good dispersion of graphene into the PEDOT matrix. Among the synthesized PEDOT materials, the one synthesized in methanol (PEDOT‐MeOH) had the highest electrical conductivity. X‐ray photoelectron spectroscopy (XPS) analysis showed almost the same charge carrier concentration for all PEDOT materials. However, the X‐ray diffraction (XRD) analysis highlighted the enhancement of PEDOT chain stacking by shorter‐chain alcoholic solvents, as a result of which the carrier mobility and electrical conductivity were increased. The electrical conductivity and the Seebeck coefficient of the PEDOT/graphene composites were significantly improved with increasing the graphene content, which strongly depended on increased carrier mobility. The thermal conductivity of the composites exhibited relatively small changes, attributed to phonon scattering effects. The maximum TE efficiency of the PEDOT‐MeOH/graphene composite with 75 wt % graphene showed a substantially improved value of 1.9 × 10^?2, higher than that of the other PEDOT/graphene composites. © 2015 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2015 , 132, 42107.     

Preparation and characterization of aluminum hypophosphite/reduced graphene oxide hybrid material as a flame retardant additive for PBT

Aluminum hypophosphite/reduced graphene oxide (AHP/RGO) hybrid flame retardant with high thermal stability was successfully prepared by a one‐step method consisting of the simultaneous reduction of graphene oxide and the deposition of AHP on graphene. The as‐prepared sample was characterized by X‐ray diffraction, Fourier transform infrared spectroscopy, scanning electron microscopy, transmission electron microscopy, Raman spectroscopy, and X‐ray photoelectron spectroscopy. The obtained sample was used as a flame retardant for polybutylene terephthalate, and the flame retardancy of the composites was investigated by a limiting oxygen index test, a UL‐94 test, and cone calorimetry. The results showed that AHP/RGO exhibited improved flame retardancy when compared with bare AHP. The addition of AHP/RGO to polybutylene terephthalate led to a significant reduction in the heat release rate and resulted in excellent anti‐dripping properties for the composites. Copyright © 2016 John Wiley & Sons, Ltd.     

Synthesis and characterization of tanninsulfonic acid doped polyaniline–metal oxide nanocomposites

Composites of conducting polymers and metal oxides have a potential role in electronic devices because of their enhanced physical and electronic properties. An in situ synthesis of metal oxide nanocomposites of polyaniline (PANI) and tanninsulfonic acid doped PANI was carried out at ?10°C with two different ratios of aniline to sodium persulfate (oxidant) and the simultaneous incorporation of TiO₂, Al₂O₃, and ZnO nanopowders. The products were characterized by X‐ray diffraction (XRD), thermal analysis, spectroscopy, and electrical conductivity measurements. XRD and thermogravimetric analysis confirmed the presence of the metal oxide in the final product, whereas the spectroscopic characterization revealed interactions among the tannin, metal oxides, and PANI. The electrical properties were determined by four‐point‐probe bulk conductivity measurements. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2012     

Synthesis and characterization of crosslinked chitosan immobilized on bentonite and its grafted products with polyaniline

Chitosan immobilized bentonite (CIB) namely chitosan‐coated bentonite (5% chitosan content) was synthesized in 2% acetic acid solution, followed by crosslinking, using epichlorohydrien (ECH). The so‐obtained crosslinked chitosan immobilized on bentonite (CIB‐ECH) and CIB composites were grafted with polyaniline (PANI) through oxidative‐radical copolymerization using ammonium peroxydisulfate in acidic medium to produce PANI‐grafted crosslinked chitosan immobilized on bentonite (PANI‐g‐CIB‐ECH) and PANI‐grafted‐chitosan immobilized on bentonite (PANI‐g‐CIB) composites, respectively. The resultant composites were characterized by using X‐ray diffraction (XRD), thermo gravimetric analysis/differential scanning calorimetry, scanning electron microscopy, Fourier transform infrared (FTIR), and electrical conductivity. XRD and FTIR analyses indicate that chitosan was not intercalated into the silicate layer. Also the electrical conductivity elucidates that the grafted composites fall in the range required for the application as electrostatic dissipation. © 2014 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2014 , 131, 41078.     

Preparation of nanosize polyaniline by solid‐state polymerization and determination of crystal structure

BACKGROUND: Nanosize polyaniline has several advantages in both the fabrication of nanodevices and for preparing nanoscale electrical connections in highly conducting polymer composites. RESULTS: Nanosize polyaniline with a diameter of 30–60 nm was prepared using a solid‐state polymerization process (PANI‐S) by mixing an equimolar quantity of ammonium persulfate and anilinium chloride crystals with a mortar and pestle. Polyaniline was also synthesized using a conventional oxidative polymerization method (PANI‐C) in an aqueous medium for comparison. Conductivity and contact angle measurements, infrared spectroscopy, ultraviolet spectroscopy, transmission electron microscopy and thermogravimetric analysis were carried out. An in‐depth investigation of the crystal structure of these polymers was carried out through powder X‐ray diffraction analysis. CONCLUSION: PANI‐S exhibited lower conductivity due to the presence of less emeraldine base form, lower crystallinity, greater d‐spacing and greater inter‐chain separation than PANI‐C. The hydrophilicity and thermal stability of PANI‐S were higher than those of PANI‐C. The unit cell volume of PANI‐S was much higher, resulting in a larger crystallite size and a greater number of atoms in the unit cell than PANI‐C. Copyright © 2009 Society of Chemical Industry