Enhanced electromagnetic wave absorption of engineered epoxy nanocomposites with the assistance of polyaniline fillers

In this work, the engineered polyaniline (PANI)/epoxy composites reinforced with PANI-M (physical mixture of PANI spheres and fibers) exhibit significantly enhanced electromagnetic wave absorption performance and mechanical property. Due to the synergistic effect of PANI fillers with different geometries, the reflection loss of 10.0 wt% PANI-M/epoxy could reach − 36.8 dB at 17.7 GHz. Meanwhile, the mechanical properties (including tensile strength, toughness, and flexural strength) of PANI/epoxy were systematically studied. Compared with pure epoxy, the tensile strength of epoxy with 2.0 wt% PANI-M was improved to 86.2 MPa. Moreover, the PANI spheres (PANI-S) and PANI fibers (PANI-F) were prepared by the chemical oxidation polymerization method and interface polymerization method, respectively. The characterizations including scanning electron microscope, Fourier transform infrared spectra, and X-ray diffraction were applied to analyze the morphology and chemical and crystal structures of PANI filler. This work could provide the guideline for the preparation of advanced engineered epoxy nanocomposites for electromagnetic wave pollution treatment. Graphical abstract

High Crystalline Quality Conductive Polypyrrole Film Prepared by Interface Chemical Oxidation Polymerization Method

The authors report that polypyrrole (PPy) films with large area and high crystalline quality have been achieved using an interfacial chemical oxidation method. By dissolving different reactants in two immiscible solvents, the PPy is synthetized at the interface region of the two solutions. The PPy films have sharp XRD diffraction peaks, indicating that the molecular chains in the film are arranged in a high degree of order and that they reflect high crystalline quality. High crystal quality is also conducive to improving electrical conductivity. The conductivity of the as prepared PPy film is about 0.3 S/cm, and the carrier mobility is about 5 cm2/(Vs). In addition, the biggest advantage of this method is that the prepared PPy film has a large area and is easy to transfer to other substrates. This will confidently broaden the application of PPy in the future.

Inorganic Doped Dl-Polylactide Polyaniline Based Composite for Methane (Ch4) Gas Sensing

Polyaniline (PANI) nonofibriles have been successfully synthesised by simple chemical-oxidation polymerization method using aniline as a predecessor at room temperature. It was synthesized using H3PO4 dopants. The structure, chemical groups, and electronic transition were investigated by SEM, FTIR, and UV Visible. We present the methane gas response of as-prepared H3PO4 doped DL−PLA/PANI-ES composite film at different concentration. The percentage (%) methane gas response was found to be 9 % at 500ppm.

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.

Preparation of PANI Modified ZnO Composites via Different Methods: Structural, Morphological and Photocatalytic Properties

Polyaniline modified zinc oxide (PANI-ZnO) photocatalyst composites were synthesized by focusing on dissolution disadvantage of ZnO. In-situ chemical oxidation polymerization method was performed under neutral conditions (PANI-ES) whereas in hybridization method physical blending was applied using emeraldine base of polyaniline (PANI-EB). PANI-ZnO composites were prepared in various ratios of aniline (ANI) to ZnO as 1%, 3%, 6% and 9%. The alterations on the structural and morphological properties of PANI-ZnO composites were compared by Fourier Transform Infrared (FT-IR), Raman Spectroscopy, X-Ray Diffraction (XRD) and Scanning Electron Microscopy-Energy Dispersive X-ray Analysis Unit (SEM-EDAX) techniques. FT-IR and Raman spectroscopy confirmed the presence of PANI in all composites. SEM images revealed the morphological differences of PANI-ZnO composites based on PANI presence and preparation methods. Photocatalytic performances of PANI-ZnO specimens were investigated by following the degradation of methylene blue (MB) in aqueous medium under UVA irradiation. The effects of catalyst dose and initial dye concentration were also studied. MB degradation was followed by both decolorization extents and removal of aromatic fractions. PANI-ZnO composites expressed enhanced photocatalytic performance (~95% for both methods) as compared to sole ZnO (~87%). The hybridization method was found to be more efficient than the in-situ chemical oxidation polymerization method emphasizing the significance of the neutral medium.

Surface Modification of Cellulose Nanofiber with Polyaniline using Aniline Monolayer as Seed for Chemical Oxidation Polymerization of Aniline

A simple method is adopted to prepare conducting polyaniline thin film on cellulose filter paper by chemical oxidative polymerization. In order to improve the adhesion of polyaniline on cellulose nanofiber aniline terminal, silane monolayer was used as catalyst to initiate polymerization reaction. It was also showed that aniline dimer modified cellulose nanofiber shows an enhanced polyaniline growth and acting as seed for the polyaniline growth. The polyaniline modified cellulose fibre filter paper was then characterized with UV-visible spectroscopy, FT-IR, FE-SEM and electrochemical studies. Polyaniline modified filter paper strips can be used for naked eye sensing of ammonia and hydrazine in environmental samples

Controllable construction of core–shell CuCo2S4@polypyrrole nanocomposites as advanced anode materials for high-performance sodium ion half/full batteries

Core–shell CuCo2S4@polypyrrole (CS-CuCo2S4@PPy) nanocomposites, as advanced anode materials for sodium ion batteries with outstanding cycling stability and rate capability, were prepared by a facile solvothermal strategy and subsequent in-situ chemical oxidation polymerization.

Effects of Doping on Zeta Potential and pH of Polyaniline Colloidal Suspension

Polyaniline (PANI) has successfully been prepared by chemical oxidation polymerization of aniline monomer. The prepared polymer was confirmed by XRD. The conducting form of PANI known as emeraldine salt (ES) through different concentrations of formic acid; 0.4 mmol/ L, 2mmol/ L, 6 mmol/ L, 8 mmol/ L, 10 mmol/ L, and 12 mmol/L is prepared from its insulating emeraldine base (EB) by levels of doping. The objective is to establish a correlation between the levels of doping, the zeta potential of the suspension. Positive zeta potential values (24.75, 27, 33.25, 36.75, 40.50, and 42) mV were obtained for the various PANI suspension. This showed the acquisition of positive charges by the PANI after doping. The observation was made that zeta potential values increases as formic acid concentration increased. This was correlated using UV/VIS spectra and electrophoretic coating with the polyaniline suspensions.

Effect of Polypyrrole on the Electrical, Dielectric and Mechanical Properties of Waterborne Epoxy Coatings

In this context, conducting composite based on waterborne epoxy system and polypyrrole (PPy) was investigated. The polypyrrole was synthesized by chemical oxidation polymerization. Its morphology and chemical structure were confirmed by using field emission scanning electron microscopy (FESEM) and Fourier transform infrared spectroscopy (FTIR). Then, PPy was well-dispersed in the epoxy coating and had a good compatibility with the matrix. The effects of PPy on dielectric, electrical and mechanical properties of epoxy/PPy composites was examined. The dielectric constant and electrical conductivity of the coatings increased with addition of PPy fillers. Over to 15 wt. % of PPy loading, the volume resistivity of samples slightly decreased from 6.7 × 1010 to 1.5 × 1010 Ω cm. In contrast, the presence of PPy diminished both impact and abrasion resistance of the epoxy/PPy composites, down to 160 kg cm and 10.2 L/mil, respectively, but they stayed acceptable for the coatings. The results reveal that the epoxy containing polypyrrole is suitable for various electrical and dielectric applications.