Preparation and Characterization of Graphene Oxide/Polyaniline/Carbonyl Iron Nanocomposites

Nano coatings for anti−corrosion and electromagnetic wave absorbing can simultaneously implement the functions of assimilating electromagnetic waves and reducing the corrosion of materials caused by corrosive environments, such as seawater. In this work, a composite material for both electromagnetic wave absorption and anti−corrosion was prepared by an in−situ chemical oxidation and surface coating method using carbonyl iron powder (CIP), graphene oxide (GO) and aniline (AN). The synthesized composite material was characterized by scanning electron microscopy (SEM), infrared spectroscopy (FT−IR) and XRD. The carbonyl iron powder−graphene oxide−polyaniline (CIP−GO−PANI) composite material was used as the functional filler, and the epoxy resin was the matrix body for preparing the anticorrosive wave−absorbing coating. The results show that CIP had strong wave−absorbing properties, and the anti−corrosion property was greatly enhanced after being coated by GO−PANI.

DL-Polylactide (DL-PLA) Based Polyaniline Composite for Hydrogen Gas Sensors

Different inorganic acids like HCl, HNO3, H2SO4 and H3PO4-doped based DL-PLA/PANI-ES composites were synthesized by in-situ chemical oxidation polymerization technique using liquid aniline as precursors. The doped composite have observed fibril-like morphology with different average sized diameter (178 nm for HCl doped composite, 162 nm (H2SO4 doped composite), 153 nm (H3PO4 doped composite) and 163 nm (HNO3 doped composite), respectively. Analysis of presence of functional groups and other chemical groups of as prepared composites was done by FTIR experiment in ATR mode. The optical (direct) band gap was estimated from UV-Visible absorption spectra. The estimated band gap values are to be 160 eV, 1.37 eV, 1.46 eV, and 1.69 eV for HCl, HNO3, H2SO4 and H3PO4-doped DL-PLA/PANI-ES composite, respectively. The electrical conduction mechanism of HCl-, H2SO4- and H3PO4-doped DL-PLA/PANI-ES composites were taken to study the conduction mechanism in detail in the low temperature regime (77-300 K) with and without applied of the magnetic field. Different models such as variable range hopping (VRH) and Arrhenius model were taken to explain the conduction mechanism of as prepared composites. In the Mott type VRH model, the density of states at the Fermi level, which is constant in the temperature range of 77-300 K were estimated. In the absence of magnetic field, DC conductivity of HCl-, H2SO4- and HNO3-, H3PO4- doped DL-PLA/PANI-ES composite was measured. Also, magnetoresistance (MR) was measured at room temperature for as prepared doped DL-PLA/PANI-ES composites and showed negative MR. In addition, we were discussed the response of hydrogen (H2) gas with polyaniline-based sensor materials.

Inorganic Acid Doped Polyaniline Based Carbon Monoxide (Co) Sensor

Simple in situ chemical oxidation method was employed to prepare different molar of HCl doped DL−PLA/PANI composites using AnHCl as precursor. Surface morphology, ATR−FTIR, UV–Visible, and band gap were studied. PANI nanowires with different diameter and smooth surface were observed for composites. The lowest direct band gap was found to be 1.68 eV for 2 (M) HCl doped DL−PLA/PANI. DC conductivity at room temperature was measured and followed the ohmic behaviour. The calculated highest DC conductivity at room temperature was found to be 0.1628 × 10−2 (S/cm) for 2 (M) HCl doped DL−PLA/PANI. Temperature variation (70−300 K) DC conductivity without magnetic field of as prepared composites was analysed using linear four probe techniques and showed semiconducting nature. The conductivity in the range of temperature (70−300 K) follows 3D VRH hopping mechanism. In kivelson model, the exponents are increased with increasing dopant concentration and was obeyed the power law. MR of the prepared DL−PLA/PANI composite films is strongly dependent on temperature, magnetic field, and concentration of HCl dopant. Negative MR is discussed in terms of a wave function−shrinkage effect on hopping conduction. In addition, we were discussed the response of carbon monoxide (CO) gas with polyaniline-based sensor materials.

A Highly Sensitive Ammonia Gas Sensor Using Micrometer-Sized Core–Shell-Type Spherical Polyaniline Particles

A highly sensitive NH3 gas sensor based on micrometer-sized polyaniline (PANI) spheres was successfully fabricated. The PANI microspheres were prepared via a facile in situ chemical oxidation polymerization in a polystyrene microsphere dispersion solution, resulting in a core–shell structure. The sensor response increased as the diameter of the microspheres increased. The PSt@PANI(4.5) sensor, which had microspheres with a 4.5 μm average diameter, showed the largest response value of 77 for 100 ppm dry NH3 gas at 30 °C, which was 20 times that of the PANI-deposited film-based sensor. Even considering measurement error, the calculated detection limit was 46 ppb. A possible reason for why high sensitivity was achieved is simply the use of micrometer-sized PANI spherical particles. This research succeeded in providing a new and simple technology for developing a high-sensitivity NH3 gas sensor that operates at room temperature.

Preparation of Poly O-Toluidine/Titanium Dioxide by In situ Chemical Oxidation Polymerization and Application for Solar Cell.

Various treatments on the PEDOT:PSS films were carried out to investigate it’s influence on the conductivity, morphology, transmittance and the corresponding impact of the performance of the organic photovoltaic devices based on the PCPDTBT:PCBM and P3HT:PCBM blends. These processing including doping PEDOT:PSS with DMF and ME solvents and exposing these films to the vapor of DMF and ME solvents, separately. A considerable enhancement of the conductivity and transmittance of PEDOT:PSS was observed after doping solvent into the PEDOT;PSS solution followed by solvent treatment through exposing these films to solvents environment. The best organic PV doped devices based on either PCPDTBT:PCBM or based on P3HT:PCBM with power conversion efficiency were 2.93% compared to 1.87% for the pristine PV devices or 2.79% compared to 1.77% for the pristine devices, respectively. The conductivity improvement was highly influenced by solvent treatment.