MoS2/polyaniline/functionalized carbon cloth electrode materials for excellent supercapacitor performance

A MoS2/PANI/functionalized carbon cloth (MoS2/PANI/FCC) was constructed by a drop-casting method. Its specific capacitances were higher than those of MoS2/CC and pure PANI/CC.

Electrical, Structural and Gas Sensing Properties of Polyaniline/DBSA-Fullerene Nanocomposite

By employing chemical route PANI/DBSA-C60 (Polyaniline/Dodechyl benzene sulfonic acid –Fullerene) nanocomposite is synthesized by using ammonium persulfate and DBSA as oxidizing agent and acid dopant respectively. Synthesized samples are characterized for FTIR (Fourier Transform Infrared Spectroscopy), SEM (Scanning Electron Microscope), XRD (X-ray diffraction), electrical conductivity using standard four probe method and methanol gas sensing properties. The FTIR spectrum illustrates the existence of interaction between polyaniline and fullerene. XRD spectra prove the formation of PANI/DBSA-C60. In collaboration with these, SEM images also indicate the highly branched chain structure of the PANI in the presence of C60. The PANI/DBSA-C60 showed the electrical conductivity more than over pure PANI/DBSA. The gas response of the PANI/DBSA-C60 nanocomposite towards different concentration of methanol was examined and compared with that of the pure PANI/DBSA. The PANI/DBSA-C60 was observed higher methanol gas sensing capacity compared to pure PANI/DBSA.

Preparation of a lignin/polyaniline composite and its application in Cr(VI) removal from aqueous solutions

Lignin/polyaniline composites were prepared by adding kraft lignin for the synthesis of polyaniline (PANI), a typical conductive polymer. The composites were utilized as an adsorbent for the removal of hexavalent chromium (Cr(VI)). When lignin alone was used as an adsorbent, the removal efficiency of Cr was low. However, when the lignin/PANI composite was used, lignin and PANI adsorbed Cr(III) together. The PANI reduced Cr(VI), which resulted in the efficient removal of Cr. In addition, as the dosage of the lignin/PANI composite decreased as an adsorbent, the Cr removal efficiency of the composite decreased considerably compared with pure PANI. However, the composite with a lignin-to-PANI ratio of 1:1 showed a Cr removal efficiency similar to that of pure PANI. The morphology of the lignin/PANI composite was observed to synthesize PANI around the lignin surface. Both Fourier transform infrared spectroscopy and X-ray photoelectron spectroscopy analyses showed that an interaction between the carbonyl groups of lignin and the amine groups of PANI occurred. This study is expected to provide an opportunity to increase the utilization of lignin in the field of environmental science and provide several benefits.

The Study of Optical Energy Gap, Refractive Index, and Dielectric Constant of Pure and Doped Polyaniline with HCl and H2SO4 Acids

Polyaniline (PANI) salt in its pure and doped forms find extensive applications in making devices such as polymer light emitting diodes, photovoltaic, sensors, batteries, and super capacitors. PANI salt has been synthesized successfully through chemically oxidative polymerization of aniline in the presence of hydrochloric acid (HCl) and sulfuric acid (H2 SO4 ) using ammonium peroxydisulfate as an oxidizing agent. The absorption spectra of pure PANI salt and its doped state, in HCl and H2 SO4 media, have been studied in the wavelength range from 200 to 1100 nm using ultraviolet and visible near infrared spectrophotometer. Tauc’s formula, Lambert-Beer’s relation, and Fresnel’s formula were employed in the MATLAB program to calculate the optical energy gap, refractive index, and dielectric constant. Results showed that doping with HCl and H2 SO4 acidic mediums caused a reduction in the direct energy gap of the pure PANI from 2.69eV to 2.42 eV and 2.54 eV, respectively. The reduction in optical energy gap is associated with the increase in refractive index. The refractive index (2.92) has a higher value of PANI doped with HCl. Higher refractive index values are for better-structured films.

Synthesis and electrical properties of conductive polyaniline/ SWCNT nanocomposites

The synthesis of conducting polyaniline (PANI) nanocomposites containing various concentrations of functionalized single-walled carbon nanotubes (f-SWCNT) were synthesized by in situ polymerization of aniline monomer. The morphological and electrical properties of pure PANI and PANI/SWCNT nanocomposites were examined by using Fourier transform- infrared spectroscopy (FTIR), and Atomic Force Microscopy (AFM) respectively. The FTIR shows the aniline monomers were polymerized on the surface of SWCNTs, depending on the -* electron interaction between aniline monomers and SWCNTs. AFM analysis showed increasing in the roughness with increasing SWCNT content. The AC, DC electrical conductivities of pure PANI and PANI/SWCNT nanocomposite have been measured in frequency range (50Hz - 600KHz) and in the temperature range from (30 to 160K). The results show the electrical conductivity of the nanocomposite is higher than pure PANI.

A Surfactant Directed Microcrystalline Cellulose/Polyaniline Composite with Enhanced Electrochemical Properties

In this study a cationic surfactant, cetyltrimethylammonium bromide (CTAB), was used as a soft template for in situ chemical polymerization of aniline on the surface of microcrystalline cellulose (MCC). The morphology of the wire-like and porous nanostructure of the resulting composite was highly dependent on the MCC and CTAB concentrations. The effect of the MCC and CTAB concentrations on the electrochemical and morphological properties of the polyaniline (PAni) nanocomposite was studied. Cyclic voltammograms of modified PAni/MCC/CTAB electrode displayed a high current response and the effect of scan rate on the current response confirmed a diffusion controlled process on the surface of the electrode that makes it suitable for sensor applications. The overlapping characteristic peaks of pure PAni and MCC caused peak broadening at 3263 cm−1 in the IR spectra of PAni/MCC/CTAB nanocomposite that revealed the interaction between NH of PAni and OH group of MCC via electrostatic interactions. The addition of MCC to PAni through chemical polymerization decreased the thermal stability of composite compared to pure PAni. Lower crystallinity was observed in the XRD diffractogram, with 2 theta values of 22.8, 16.5, and 34.6 for PAni/MCC, confirming the formation of PAni on the MCC surface.

Polyaniline/ZnO nanocomposites for the removal of methyl orange dye from waste water

In this paper, we report the safe removal of methyl orange (MO) dye from aqueous solution using chemical interaction of dye molecule with polyaniline/zinc oxide (PANI/ZnO) nanocomposite. PANI/ZnO nanocomposite has been prepared by in situ polymerization. PANI/ZnO nanocomposite was found to be the best promising candidate for adsorption of dyes due to more porosities compared to that of pure PANI. In the present investigation, PANI/ZnO nanocomposite was mixed in a solution of MO dye and used for adsorption process. Color removal was studied using UV-Vis spectroscopy and the spectra were recorded for specific time interval and validation of kinetic model has been applied. Absorbance of PANI/ZnO nanocomposite was found to be increased as compared to that of pure ZnO nanoparticles and pure PANI due to synergistic effect. Comparatively, the removal of dye was also found to be more by using PANI/ZnO nanocomposites. In order to evaluate kinetic mechanism the pseudo-first-order model, pseudo-second-order model and intraparticle diffusion models were verified by the linear equation analysis. Adsorption mechanism of pseudo-second-order model was systematically explained for removal of dye using PANI/ZnO nanocomposite. The results clearly demonstrated that the adsorption mechanism gives very novel and green method of removal of hazardous dyes from waste water.

Green Preparation of Sulfonated Polystyrene/Polyaniline/Silver Composites with Enhanced Anticorrosive Properties

Sulfonated polystyrene/polyaniline/silver (SPS/PANI/Ag) composites with enhanced anticorrosive properties have been successfully prepared by using SPS microspheres as substrates and utilizing polyvinylpyrrolidone (PVP) as reducing agent and stabilizing agent. Our method is an environmentally friendly method because of the absence of any toxic reagents in the whole process. Fourier transform infrared Spectrum (FTIR), field emission scanning electron microscopy (FESEM), and energy disperse spectroscopy (EDX) results confirmed the formation of pure PANI, SPS/PANI composites, and SPS/PANI/Ag composites. Powder X-ray diffraction (XRD) patterns indicate that the obtained Ag nanoparticles are crystalline. The anticorrosive studies indicate that both SPS/PANI composites and SPS/PANI/Ag composites have enhanced anticorrosive properties in comparison to pure PANI in various corrosive environments. Please find the scheme in PDF format.

Ammonia gas sensors based on In2O3/PANI hetero-nanofibers operating at room temperature

Indium nitrate/polyvinyl pyrrolidone (In(NO3)3/PVP) composite nanofibers were synthesized via electrospinning, and then hollow structure indium oxide (In2O3) nanofibers were obtained through calcination with PVP as template material. In situ polymerization was used to prepare indium oxide/polyaniline (In2O3/PANI) composite nanofibers with different mass ratios of In2O3 to aniline. The structure and morphology of In(NO3)3/PVP, In2O3/PANI composite nanofibers and pure PANI were investigated by scanning electron microscopy (SEM), Fourier transform infrared spectroscopy (FTIR), X-ray diffraction (XRD), transmission electron microscopy (TEM) and current–voltage (I–V) measurements. The gas sensing properties of these materials towards NH3 vapor (100 to 1000 ppm) were measured at room temperature. The results revealed that the gas sensing abilities of In2O3/PANI composite nanofibers were better than pure PANI. In addition, the mass ratio of In2O3 to aniline and the p–n heterostructure between In2O3 and PANI influences the sensing performance of the In2O3/PANI composite nanofibers. In this paper, In2O3/PANI composite nanofibers with a mass ratio of 1:2 exhibited the highest response values, excellent selectivity, good repeatability and reversibility.

Synthesis of carbon nanotube/ polyaniline nano composite electrode by insitu electrochemical polymerization

The synthesis of polyaniline (PANI) containing different carbon nanotubes (CNTs) by in situ electrochemical polymerization is reported in this study. The samples were characterized by 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. In addition, the electrochemical measurements such as cyclic voltametric (CV) curves showed that the conductivity of the obtained nanocomposite increased. The results of measuring cyclic voltammetry also showed that the specific capacitance of nanocomposite was much higher than the pure PANI and CNTs. This is due to the fact that the composites consisting of electroactive species and carbon materials with highly specific surface areas are significantly promote the energy density of supercapacitors. Such supercapacitors exhibit simultaneously both double layer capacitance and Faradic pseducapacitance in energy storage.