Synthesis,characterization, and properties of cashew gum graft poly(acrylamide)/magnetite nanocomposites

Graft copolymer nanocomposites based on cashew gum and poly(acrylamide) with different concentrations of nano‐iron‐oxide particles (Fe₃O₄) have been prepared by an in situ polymerization method. The characterization of graft copolymer composite was carried out by FTIR, UV, XRD, SEM, DSC, and TGA, electrical conductivity, and magnetic property [vibrational sample magnetometer (VSM)] measurements. The shift in the spectrum of UV and FTIR peaks shows the intermolecular interaction between metal oxide nanoparticles and the graft copolymer system. The spherically shaped particles observed from the SEM images clearly indicating the uniform dispersion of nanoparticles within the graft copolymer chain. The XRD studies revealed that the amorphous nature of the graft copolymer decreases by the addition of Fe₃O₄ nanoparticles. The glass transition temperature studied from DSC increases with increase in concentration of metal oxide nanoparticles. Thermal stability of composite was higher than the pure graft copolymer and thermal stability increases with increase in content of nanoparticles. Electrical properties such as AC conductivity and dielectric properties of the composites increased with increase in concentration of metal oxide nanoparticles. The magnetic property of graft copolymer nanocomposites shows ferromagnetic and supermagnetism and the saturation of magnetism linearly increased with increasing the Fe₃O₄ content in the polymer composite. © 2016 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2016 , 133, 43496.     

Investigation of crystal structure,dielectric properties,impedance spectroscopy and magnetic properties of (1-x)BaTiO3 – (x)Ba0.9Ca0.1 Fe12O19 multiferroic composites

Composites having composition (1-x)BaTiO₃?(x)Ba_0.9Ca_0.1Fe₁₂O₁₉ (x = 0.10, 0.20, 0.30) were synthesized by conventional solid-state reaction technique. X-ray diffraction (XRD) was used to examine the phase formation. Rietveld refinement has been done using the FullProf suite which predicted the dual phase symmetry consisting hexagonal (P63/mmc) and tetragonal (P4mm) phases in the prepared composites. The dielectric properties of the obtained composites were investigated at different temperatures as a function of frequency in the range of 100 Hz to 7 MHz. The dielectric constant increases with an increase in Ca doped barium ferrite content. The composites showed usual dielectric dispersive behaviour with increasing frequency. The conduction mechanism and dielectric relaxation were examined by complex impedance spectroscopy (CIS). Nyquist plots of all composites showed two semicircles and their centers lied below the real axis. Magnetic characterization was performed by using a vibrating sample magnetometer (VSM) up to a field of 15 kOe at room temperature. The hysteresis loops reveal the ferromagnetic nature of the composites. The values of saturation magnetization, magnetic moment per formula unit, and corresponding coercivity increases with ferrite content and are maximum at x = 0.3. AC conductivity also increases with ferrite content. The variation of frequency exponent ‘n' of the power-law with temperature suggests that the overlapping large polaron tunneling (OLPT) model is appropriate to explain the mode of conduction in all samples.     

Ozone Decomposition over Cobalt Supported on Olive Stones Activated Carbon: Effect of Preparation Method on Catalyst Activity

Aqueous ozone decomposition was studied over highly dispersed cobalt nanoparticles supported on olive stones activated carbon (AC) prepared by: wetness impregnation (Co/AC_w) and incipient wetness impregnation (Co/AC_iw) with respect to pore volume. Nitrogen adsorption-desorption at 77K, SEM, XRD and XPS analyses were used to characterize the catalysts. Analyses results show that Co/AC_w was more uniformly dispersed on the AC than Co/AC_iw. The effect of the presence of tert-butanol as radical scavenger was also studied. Higher catalytic activity was measured for Co/AC_w than Co/AC_iw. Ozone decomposition extent goes to 99% in only 3 min in the presence of Co/AC_w compared to 60% and 58% using Co/AC_iw catalyst and AC, respectively.     

The illumination intensity and applied bias voltage on dielectric properties of au/polyvinyl alcohol (Co,Zn‐doped)/n‐Si Schottky barrier diodes

The Au/polyvinyl alcohol (PVA) (Co, Zn‐doped)/n‐Si Schottky barrier diodes (SBDs) were exposed to various illumination intensities. Illumination effect on the dielectric properties has been investigated by using capacitance–voltage (C–V) and conductance–voltage (G/ω–V) characteristics at 1 MHz and room temperature. The values of dielectric constant (ε′), dielectric loss (ε″), loss tangent (tanδ), electric modulus (M′ and M″), and AC electrical conductivity (σ_AC) were found strongly intensity dependent on both the illumination levels and applied bias voltage especially in depletion and accumulation regions. Such bias and illumination dependency of these parameters can be explained on the basis of Maxwell–Wagner interfacial polarization and restructuring and reordering of charges at interface states. In addition, the ε′–V plots also show an intersection feature at ～ 2.8 V and such behavior of the ε′–V plots appears as an abnormality compared with the conventional behavior of an ideal SBD. The obtained results revealed that illumination intensity enhances the conductivity of Au/PVA(Co, Zn‐doped)/n‐Si SBD. © 2010 Wiley Periodicals, Inc. J Appl Polym Sci, 2011     

Dielectric and electric properties of plasticized PEO‐AgCF3SO3‐SiO2 nanocomposite polymer electrolyte system

The effect of plasticizer poly(ethylene glycol) (PEG) on dielectric and electrical properties of an ionically conducting polymer nanocomposite electrolyte PEO: AgCF₃SO₃: SiO₂: PEG has been investigated. The variation of relative dielectric constant and tangent loss peak with frequency have been discussed. The ionic and polymer segmental motions have been analyzed by electrical modulus and dielectric permittivity. The electrical modulus formalism is used to study the ionic relaxation process in these composites in terms of conductivity relaxation time. On addition of plasticizer, the modulus peak shifts toward higher frequency side suggesting the speeding up of the relaxation time. The frequency dependence of AC conductivity follows the universal power law. POLYM. COMPOS., 2012. © 2012 Society of Plastics Engineers     

Fabrication,Characterization and Dielectric Studies of NBR/Hydroxyapatite Nanocomposites

Nitrile rubber (NBR) based nanocomposite consists of different concentrations of hydroxyapatite nanoparticles (HA) were prepared and characterized by FTIR, UV and X-ray diffraction studies. The surface morphology of the nanocomposites were analyzed using SEM and optical microscopy. The glass transition temperature and thermal stability of NBR and its nanocomposites were done by DSC and TGA respectively. The electrical properties such as AC conductivity, dielectric constant and dielectric loss tangent were investigated in the frequency range of 10²–10⁶ Hz at room temperature. The FTIR spectra confirmed the interfacial interaction between NBR and the HA nanoparticles. The shift in the UV peak with broadness of composite indicates the formation of nanoparticles within the macromolecular chain of NBR. XRD pattern ascertained the ordered arrangement of nanoparticles with a decrease in the amorphous nature of parent polymer. Both the glass transition temperature and the thermal stability of the nanocomposites were higher than pure NBR and the glass transition temperature improved with the increase in concentration of nanoparticles in NBR composite indicating the strong interfacial adhesion between the polymer and nanoparticles. From DSC studies, thermodynamic parameters such as enthalpy and entropy change of the composites were also evaluated. AC conductivity of the nanocomposite was much greater than NBR and the magnitude of conductivity enhanced with the addition of nanoparticles. The observed enhancement in dielectric constant and dielectric loss tangent of composite with the increase in concentration of nanoparticle was attributed to the increase in number of interfacial interaction between the polymer and the nanoparticles.     

1H NMR,thermal, and conductivity studies on PVAc based gel polymer electrolytes

The lithium‐ion conducting gel polymer electrolytes (GPE), PVAc‐DMF‐LiClO₄ of various compositions have been prepared by solution casting technique. ¹H NMR results reveal the existence of DMF in the gel polymer electrolytes at ambient temperature. Structure and surface morphology characterization have been studied by X‐ray diffraction analysis (XRD) and scanning electron microscopy (SEM) measurements. Thermal and conductivity behavior of polymer‐ and plasticizer‐salt complexes have been studied by differential scanning calorimetry (DSC), TG/DTA, and impedance spectroscopy results. XRD and SEM analyses indicate the amorphous nature of the gel polymer‐salt complex. DSC measurements show a decrease in T_g with the increase in DMF concentrations. The thermal stability of the PVAc : DMF : LiClO₄ gel polymer electrolytes has been found to be in the range of (30–60°C). The dc conductivity of gel polymer electrolytes, obtained from impedance spectra, has been found to vary between 7.6 × 10^?7 and 4.1 × 10^?4 S cm^?1 at 303 K depending on the concentration of DMF (10–20 wt %) in the polymer electrolytes. The temperature dependence of conductivity of the polymer electrolyte complexes appears to obey the VTF behavior. © 2008 Wiley Periodicals, Inc. J Appl Polym Sci, 2008     

Structural,magnetic, electrical and dielectric properties of MnxNi1−xFe2O4 spinel nanoferrites prepared by PEG assisted hydrothermal method

Mn_xNi_1?xFe₂O₄ (x=0.2, 0.4, 0.6) nanoparticles were synthesized by a polyethylene glycol (PEG)-assisted hydrothermal route. We present a systematic investigation on the structural, magnetic, electrical and dielectric properties of the products by using XRD, FT-IR, SEM, TGA, VSM and dielectric spectroscopy, respectively. Single phased cubic spinel structure was confirmed for all samples and the average crystallite size of the products was estimated using Line profile fitting and ranges between 6.5 and 11 nm. The nanoparticles have ferromagnetic nature with small coercivity. The samples showed semiconducting behavior which is revealed from temperature dependent conductivity measurements. Temperature and frequency dependent dielectric property; dielectric permittivity (ε) and ac conductivity (σ_AC) studies for the samples indicated that the dielectric dispersion curve for all samples showed usual dielectric dispersion confirming the thermally activated relaxation typical for Debye-like relaxation referring to it as the Maxwell–Wagner relaxation for the interfacial polarization of homogeneous double structure. The particle size, saturation magnetization, coercive field, conductivity and dielectric constant of the samples are strictly temperature dependent and increased with Mn concentration.     

Effect of neodymium‐doped titanium dioxide nanoparticles on the structural,mechanical, and electrical properties of poly(butyl methacrylate) nanocomposites

Nanocomposites based on neodymium‐doped titanium dioxide (Nd‐TiO₂)/poly(n‐butyl methacrylate) (PBMA) have been prepared by an in situ polymerization of butyl methacrylate monomer with varying concentrations of Nd‐TiO₂ nanoparticles. The resulting nanocomposites have been analyzed by ultraviolet (UV)–Visible spectroscopy, Fourier‐transform infrared spectroscopy (FTIR), X‐ray diffraction (XRD), transmission electron microscopy (TEM), scanning electron microscope (SEM), differential scanning calorimetry (DSC), thermogravimetric analysis, and impedance analyzer (TGA). The results of UV and FTIR spectroscopy have indicated the interaction of nanoparticles with the PBMA matrix. Spherically shaped nanoparticles with an average size of 10–25 nm have been revealed in the TEM and their homogeneous dispersion, and interaction of polymer matrix has been confirmed by SEM and XRD studies. The thermal stability and glass transition temperature of the composites were significantly enhanced by the addition of nanoparticles. The AC conductivity and dielectric properties of nanocomposites have been found to be higher than pure PBMA, and the maximum electrical properties have been observed for 7 wt% composite. The reinforcing nature of the nanoparticles in PBMA has been reflected in the improvement in tensile strength measurements. The result indicated that the tensile strength of nanocomposites have greatly enhanced by the addition of Nd‐TiO₂ nanoparticles whereas the elongation at break decreases with the loading of nanofillers. To understand the mechanism of reinforcement, tensile strength values have been correlated with various theoretical modeling. The research has been found to be promising in the development of novel materials with enhanced tensile strength, dielectric constant, and thermal properties, which may find potential applications in energy storage and nanoelectronic devices. J. VINYL ADDIT. TECHNOL., 25:9–18, 2019. © 2018 Society of Plastics Engineers     

Influence of modified natural rubber and structure of carbon black on properties of natural rubber compounds

Carbon black‐filled natural rubber composites were prepared using various types of natural rubber: unmodified natural rubber, epoxidized natural rubber with two levels of epoxy groups at 25 and 50 mol % [epoxidized natural rubber (ENR)‐25 and ENR‐50], and maleated natural rubber. Two types of carbon black (HAF and ECF) with different structure and surface area were used. The functional groups present in natural rubber and carbon black were characterized by FTIR and ¹H‐NMR. Furthermore, cure characteristics, mechanical, morphological, and electrical properties of composites and gum rubber compounds were investigated. It was found that the presence of polar functional groups in rubber molecules and the different structures of carbon black significantly affected the cure characteristics and mechanical properties. This is attributed to physical and chemical interactions between carbon black surfaces and rubber molecules. It was also found that natural rubber filled with ECF showed the highest Young's modulus and hardness, which is due to the high‐surface area and structure of the ECF causing an increase in the degree of entanglement between rubber chains and carbon black particles. Frequency dependency of the dielectric constant, loss tangent, and AC conductivity was also investigated. An increase in dielectric constant, loss tangent, and AC conductivity was observed in the ENR/ECF composites. High‐carbon black loading level caused network formation of these conductive particles, increasing the AC conductivity of the composites. POLYM. COMPOS. 2012. © 2012 Society of Plastics Engineers     

Synthesis and dielectric relaxation behavior of 55B2O3–15SiO2– 30Na2O: WO3 glass system

55 B₂O₃ – 15 SiO₂ – 30 Na₂O: x WO₃, (x ranging from 0 to 5 wt%) glass composites were prepared according to the melt-quenching procedure. The prepared samples were characterized via X-ray diffraction and broad band dielectric spectroscopy (viz., dielectric constant (ε₁), tanδ and AC conductivity (σ_AC) over a wide range of frequency and temperature). No sharp peaks were shown in the XRD pattern and is evidence of the amorphous nature of the samples. It turns out that the values of ε₁ and ε₂ are increasing at higher temperatures particularly at lower frequencies. The energy barrier height, W_M values decreased as 0.27, 0.25 and 0.22 while showed value of 0.29 eV for 5.0 wt% WO₃. In the dielectric modulus plots, two relaxation processes are found especially on the higher temperature side. It also shifted a higher frequency with increasing temperature. The values of exponent s have been found to lie between 0.48 and 0.74, which confirms that the conduction mechanism in the glass samples follows the correlated barrier hopping model. By calculating the activation energy associated with the relaxation processes and DC conductivity, it was found that the values are close, which indicates that the same charges contribute to the two processes.     

New composites with high thermal conductivity and low dielectric constant for microelectronic packaging

Three composites based on cyanate (CE) resin, aluminum nitride (AlN), surface‐treated aluminum nitride [AlN(KH560)], and silicon dioxide (SiO₂) for microelectronic packaging, coded as AlN/CE, AlN(KH560)‐SiO₂(KH560)/CE, and AlN‐SiO₂/CE composite, respectively, were developed for the first time. The thermal conductivity and dielectric constant of all composites were investigated in detail. Results show that properties of fillers in composites have great influence on the thermal conductivity and dielectric constant of composites. Surface treatment of fillers is beneficial to increase the thermal conductivity or reduce dielectric constant of the composites. Comparing with binary composite, when the filler content is high, ternary composites possess lower thermal conductivity and dielectric constant. The reasons leading to these outcomes are discussed intensively. POLYM. COMPOS., 2010. © 2009 Society of Plastics Engineers     

Molecular composites obtained by polyaniline synthesis in the presence of p‐octasulfonated calixarene macrocycle

Polyaniline (PANI) molecular composites were synthesized by chemical oxidative polymerization of the aniline and aniline dimer, N‐phenyl‐1,4‐phenylendiamine, in the presence of a macrocycle, calix[8]arene p‐octasulfonic acid (C8S), using ammonium peroxidisulfate as oxidant. The macrocycle has acted both as acid dopant and surfactant to obtain processable PANI‐ES. The PANI/calix[8]arene p‐octasulfonic acid composite was also obtained by a simple doping of PANI emeraldine base form with calix[8]arene sulfonic acid. The structure of materials was confirmed by Fourier transform infrared, UV–vis and nuclear magnetic resonance spectroscopy. All synthesized composite materials are amorphous and soluble in chloroform, dimethylsulfoxide, NMP, showing excellent solution‐processing properties combined with electrical conductivity. Cyclic voltammetry evidenced a good electroactivity for the composite films. Dielectric properties (dielectric constant and dielectric losses) were determined and are comparable with those of other PANI/ionic acid polymer composites. Preliminary studies have evidenced a high dielectric constant (10⁴ at 100 Hz) and electrical conductivity of 6 × 10^?3 S/cm for PANI composites. From sulfur elemental analysis of the PANI/calixarene, it results that the content in macrocycle is ～30% (weight). © 2012 Wiley Periodicals, Inc. J. Appl. Polym. Sci., 2013     

The order addition effect of carbon black/graphite on the electrical properties of rubber composites

Acrylonitrile‐butadiene rubber (NBR) filled with two types of fillers [high abrasion furnace carbon black (C), and graphite (G)] is made to find out the effect of order addition of C and G on the electrical conductivity of the composites. The temperature and frequency dependence of the (dc and ac) conductivity and dielectric constants have been measured. The values of the thermal expansion and thermal conduction coefficient of NBR rubber lead to the difference in I–V characteristics between CB‐ and G‐NBR rubber composites during the measurement. When graphite is first added to NBR, the electrical conductivity of (GC_20‐20) matrix is larger than that of the (CG_20‐20) matrix, whereas the carbon black is added first. At low temperature (T < 90°C), the higher values of the dielectric constant (ε′) for the sample GC_20‐20 compared with that of the CG_20‐20 sample is due to the conducting nature and structure of graphite, whereas the carbon shows less crystallinity and conductivity than graphite. Opposite behavior is noticed at temperature higher than 90°C. The dc conductivity of all composites increases with increasing temperature exhibiting a positive temperature coefficient of conductivity (PTCσ). The conductivity at high temperatures region is controlled by the thermal excitation transport mechanism, whereas at low temperatures region is dominated by tunneling process. The increase in the value of dielectric constant (ε′) with temperatures for the sample GC_20‐20 compared with the sample CG_20‐20 is due to the conducting nature and structure of graphite, and the carbon less crystalline than the graphite. © 2012 Wiley Periodicals, Inc. J Appl Polym Sci, 2012     

The influence of vanadium pentoxide on the structure and dielectric properties of poly(vinyl alcohol)

Polymers containing metal oxides of nanoscale dimensions have attracted attention because of their unique properties and new findings concerning technological applications. Polymers containing vanadium pentoxide (V₂O₅) have attracted our interest in respect of their potential applications in memory and switching devices. Poly(vinyl alcohol) (PVA) containing different concentrations of V₂O₅ ranging from 0 to 0.5 wt% were prepared. The synthesized PVA/V₂O₅ composites were cast as self‐standing flexible films. The composites were characterized using X‐ray diffraction (XRD) and Fourier transform infrared (FTIR) spectroscopy. An attempt was made to study the relaxation characteristics of PVA/V₂O₅ samples. The permittivity and dielectric loss were determined as a function of V₂O₅ concentration. The results show that the optimum concentration is 0.3 wt%. The electrical conductivity and dielectric modulus in the temperature range 303–433 K at various frequencies (10–100 kHz) for the optimum concentration were investigated. XRD and FTIR results show that the addition of V₂O₅ reduces the crystallinity of PVA due to the interaction of vanadium ions with the OH groups of PVA. The application of the dielectric modulus formulism gives a simple method for evaluating the activation energy of the dielectric relaxation. The frequency dependence of the electrical conductivity follows the Jonscher universal dynamic law. The conductivity in the direct regime is described by the small polaron model. The electrical conductivity and dielectric properties show that Hunt's model is well adapted to PVA/V₂O₅ films. Copyright © 2010 Society of Chemical Industry     

Polystyrene/calcium phosphate nanocomposites: Morphology,mechanical, and dielectric properties

Matrix mediated synthesis of nanoparticles was utilized to prepare calcium phosphate nanoparticles with a size of 10 nm. The particles were characterized by X‐ray diffraction (XRD) and transmission electron microscopy (TEM) techniques. Nanocomposites of polystyrene and nano‐calcium phosphate were prepared by the melt‐mixing technique. The composites were characterized by TEM to assess the dispersion of the nanoparticles. SAXS measurements of the composites and the fit with Beaucage model described the fractal dimensions of the particles. Mechanical properties of the composites significantly improved with the addition of nanofillers. Dielectric behavior of the nanocomposites was measured with respect to the filler content, temperature, and frequency. The dielectric constant increases with increase in temperature and decreases with increase in frequencies. Dielectric constant increased with filler content in all frequencies; however, lower frequencies showed marked effect. α‐Relaxation of the composites from the dissipation factor of the composites showed higher values for the lower frequencies. Electrical conductivity increased with respect to the filler content and volume resistivity showed the reverse trend. The theoretical prediction of the dielectric constant showed close agreement with the experimental value. POLYM. ENG. SCI. 2012. © 2011 Society of Plastics Engineers     

Effect of calcination temperature of TiO2 on the crystallinity and the permittivity of PVDF‐TrFE/TiO2 composites

Composite membranes of poly(vinylidene‐trifluoroethylene)/titanium dioxide (PVDF‐TrFE/TiO₂) were prepared by the solution cast method. The crystallization behavior and dielectric properties of the composites with TiO₂ calcined at different temperatures were studied. Transmission electron microscopy and X‐ray diffraction (XRD) results showed that the TiO₂ nanoparticles calcined at different temperatures were well dispersed in the polymer matrix and did not affect the structure of the PVDF‐TrFE matrix. XRD and differential scanning calorimeter measurements showed that the crystallinity of PVDF‐TrFE/TiO₂ composites increased as the addition of TiO₂ with different calcination temperatures. The dielectric property testing showed that the permittivity of PVDF‐TrFE/TiO₂ membrane increased rapidly with the increase of TiO₂ content and the calcination temperature of TiO₂ at constant TiO₂ content, but the dielectric loss did not change much. © 2012 Wiley Periodicals, Inc. J. Appl. Polym. Sci., 2013     

Exploring the Combined Effect of Electron Beam and Conductive Carbon Black on the Mechanical,Dynamic Mechanical,Thermal, and Electrical Properties of Ethylene Acrylic Elastomer

The electron beam-crosslinked and conductive carbon black-reinforced ethylene acrylic elastomer composites have been developed for various applications. The inter-connectivity of conductive carbon black agglomerates are clearly observed from the high-resolution transmission electron photo micrographs. The tensile strength of the composites has remarkably increased with increasing conductive carbon black loading up to 350 radiation dose. The dielectric permittivity (?′) and AC conductivity (σ_ac) increase with an increase in conductive carbon black loading. The electron magnetic shielding interference of the developed composites has been measured using X-band frequency range, and the electron magnetic shielding interference increases with an increase in conductive carbon black loading.     

High dielectric constant and superparamagnetic polymer-based nanocomposites induced by percolation effect

To obtain the high dielectric constant and superparamagnetic composites for application in dielectric energy storage capacitors and other electromagnetic devices, the Fe₃O₄ nanoparticles have been embedded into polyvinylidene fluoride (PVDF) polymer. As expectation, a distinct percolation effect has been found in these composites, because of the good conductivity of Fe₃O₄ nanoparticles. The composites exhibit great increase of the dielectric constants and conductivities near the percolation threshold. The maximum of dielectric constant is up to 5240 at 100 Hz, which is the highest value reported to date among the PVDF based percolative composites. Meanwhile, the dielectric loss is controlled in the range of 0–2.2. These composites also exhibit superparamagnetic with the presence of Fe₃O₄ nanoparticles. The maximum of saturation magnetization is 30.8 emu/g. © 2012 Wiley Periodicals, Inc. J Appl Polym Sci, 2012     

Synthesis and characterization of novel poly(dimethylsiloxane)/polyindole composites

A series of composites of polyindole (PIN) and poly(dimethylsiloxane) (PDMS) were synthesized chemically using FeCl₃ as an oxidant agent in anhydrous media. The composites were characterized by FTIR and UV‐visible spectroscopies, thermogravimetric analysis (TGA), differential scanning calorimetry (DSC), scanning electron microscopy (SEM), X‐ray diffraction (XRD), elemental analysis, inductively coupled plasma‐optic emission spectroscopy (ICP‐OES), magnetic susceptibility, stress–strain experiments, and conductivity measurements. The conductivities of PIN at different temperatures were also measured and it was revealed that their conductivities were slightly increased with increasing temperature. Moreover, the freestanding films of PDMS/PIN composites were prepared by casting on glass Petri dishes to examine their stress–strain properties. From thermogravimetric analysis results it was found that PDMS/PIN composites were thermally more stable than PIN. Thermal stabilities of PDMS/PIN composites increased with increasing PIN content. It was found that the conductivities of PDMS/PIN composites depend on the indole content in the composites. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2011