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Eco-friendly inhibitors have attracted considerable interest due to the increasing environmental issues caused by the extensive use of hazardous corrosion inhibitors. In this paper, environmentally friendly PDG-g-PANI/Al2O3 composites were prepared by a low-cost inverse emulsion polymerization for corrosion inhibition of mild steel (MS) and stainless steel (SS). The PDG-g-PANI/Al2O3 composites were characterized by different techniques such as X-ray diffraction (XRD), UV/Vis, and FTIR spectroscopy. XRD measurements show that the PDG-g-PANI/Al2O3 composite is mostly amorphous and scanning electron micrographs (SEM) reveal a uniform distribution of Al2O3 on the surface of the PDG-g-PANI matrix. The composite was applied as a corrosion inhibitor on mild steel (MS) and stainless steel (SS), and its efficiency was investigated by potentiodynamic polarization measurement in a 3.5% NaCl and 1 M H2SO4 solution. Corrosion kinetic parameters obtained from Tafel evaluation show that the PDG-g-PANI/Al2O3 composites protect the surface of MS and SS with inhibition efficiencies of 92.3% and 51.9% in 3.5% NaCl solution, which is notably higher than those obtained with untreated epoxy resin (89.3% and 99.5%). In particular, the mixture of epoxy/PDG-g-PANI/Al2O3 shows the best performance with an inhibition efficiency up to 99.9% on MS and SS. An equivalent good inhibition efficiency was obtained for the composite for 1M H2SO4. Analysis of activation energy, formation enthalpy, and entropy values suggest that the epoxy/PDG-g-PANI/Al2O3 coating is thermodynamically favorable for corrosion protection of MS and exhibits long-lasting stability. [ABSTRACT FROM AUTHOR]

Eco-friendly inhibitors have attracted considerable interest due to the increasing environmental issues caused by the extensive use of hazardous corrosion inhibitors. In this paper, environmentally friendly PDG-g-PANI/Al2O3 composites were prepared by a low-cost inverse emulsion polymerization for corrosion inhibition of mild steel (MS) and stainless steel (SS). The PDG-g-PANI/Al2O3 composites were characterized by different techniques such as X-ray diffraction (XRD), UV/Vis, and FTIR spectroscopy. XRD measurements show that the PDG-g-PANI/Al2O3 composite is mostly amorphous and scanning electron micrographs (SEM) reveal a uniform distribution of Al2O3 on the surface of the PDG-g-PANI matrix. The composite was applied as a corrosion inhibitor on mild steel (MS) and stainless steel (SS), and its efficiency was investigated by potentiodynamic polarization measurement in a 3.5% NaCl and 1 M H2SO4 solution. Corrosion kinetic parameters obtained from Tafel evaluation show that the PDG-g-PANI/Al2O3 composites protect the surface of MS and SS with inhibition efficiencies of 92.3% and 51.9% in 3.5% NaCl solution, which is notably higher than those obtained with untreated epoxy resin (89.3% and 99.5%). In particular, the mixture of epoxy/PDG-g-PANI/Al2O3 shows the best performance with an inhibition efficiency up to 99.9% on MS and SS. An equivalent good inhibition efficiency was obtained for the composite for 1M H2SO4. Analysis of activation energy, formation enthalpy, and entropy values suggest that the epoxy/PDG-g-PANI/Al2O3 coating is thermodynamically favorable for corrosion protection of MS and exhibits long-lasting stability.

We prepared Ba3−xYxCo2Fe24O41 (Y‐Co2Z, x = 0, 0.2, and 0.4) by the solid‐state reaction method. Y‐Co2Z and polyaniline (PANI) composites (named as Y‐P0, Y‐P2, and Y‐P4) were prepared by using the in‐situ polymerization method. The Y‐doping played an important role in the variation of lattice parameters, a and c. The combination of Y‐doping and PANI modified the magnetic properties of the composites, which could be observed by the changing of the saturation magnetization and coercivity. This combination had also affected the electromagnetic properties of composites through the measurements of complex permittivity and permeability. Using the transmission line theory, we calculated refection loss (RL) of composites with the variation thickness of 1.00–2.50 mm. Our composites tuned the minimum RL from the X band (RL = −29.6 dB at 11.4 GHz for Y‐P2) to Ku band (RL = −16.3 dB at 15.7 GHz for Y‐P4 and RL = −26.4 dB at 16.6 GHz for Y‐P4). For maximum effective bandwidth, our composites covered a huge range from the S and C bands (Y‐P0 with 3.9 GHz in the range of 3.4–7.3 GHz) through the X band (Y‐P2 with 3.9 GHz in the range of 9.0–12.9 GHz) to the Ku band (Y‐P4 with 4.0 GHz in the range of 13.8–17.8 GHz). Those properties proved that the composites could act as promising absorbers in the S, C, X, and Ku bands. [ABSTRACT FROM AUTHOR]

Abstract A multi-hierarchical porous polyaniline (PANI) composite which could be used in good performance pressure sensor and adjustable sensitivity gas sensor has been fabricated by a facile in situ polymerization. Commercial grade sponge was utilized as a template scaffold to deposit PANI via in situ polymerization. With abundant interconnected pores throughout the whole structure, the sponge provided sufficient surface for the growth of PANI nanobranches. The flexible porous structure helped the composite to show high performance in pressure detection with fast response and favorable recoverability and gas detection with adjustable sensitivity. The sensing mechanism of the PANI/sponge-based flexible sensor has also been discussed. The results indicate that this work provides a feasible approach to fabricate efficient sensors with advantages of low cost, facile preparation, and easy signal collection.

In the present study, mixed-metal ceramic Fe0.01Al0.5La.0.01Zn0.98O particles and their composites with polyaniline (PANI) were prepared via sol-gel and in situ free-radical polymerization techniques, respectively. Particles and composite formation was confirmed by FT-IR spectroscopy. SEM studies showed the Fe0.01Al0.5La.0.01Zn0.98O particle's homogeneous dispersion in the polymer matrix. Ceramic particles were found to be in microdimensions. XRD analysis confirmed crystallite size in the range from 22 to 28 nm. Extensive rheological characterization was performed to check the durability of the materials for possible applications. Flow-curve tests suggested that the prepared materials are non-Newtonian (shear thinning) in nature. Increasing temperature have no appreciable effect on the viscosity which confirmed the mechanical stability of the materials. Based on frequency sweep test findings, the mechanical rigidity of the polymer has been enhanced (G′ = 2 × 102−5.22 × 103 Pa) by the introduction of ceramic particles. Conversely, creep compliance has been decreased considerably. [ABSTRACT FROM AUTHOR]

AbstractThe present work reports the synthesis of PANI composite with hexamminecobalt(III) chloride metal complex as dopant via in situ oxidative polymerization by ammonium persulphate in non-aqueous DMSO medium. The dopant metal complex has been synthesized by known method and characterized by using FTIR, XRD and SEM analysis. The synthesized PANI/[Co(NH3)6] Cl3 composite was characterized by FTIR, XRD, UV-Vis and SEM techniques. FTIR of PANI composite showed its successful synthesis with the presence of some dopant peaks in its FTIR spectrum. XRD spectra of composite revealed its crystalline nature having almost same spectra as that of dopant metal complex with slight shift in the position of peaks. Electrical measurement of the composite was made using four probe conductivity meter and the thermal studies have been done by thermal gravimetric (TG) technique. The results showed improvement in the thermal stability of PANI composite together with increase in its conductance, thereby making it a possible future material for high temperature application purposes. Electronic properties of the composite were investigated using UV-Vis spectroscopy which revealed decrease in the energy band gap of the composite on irradiation. This is attributed to the distortion of polymer chains on exposure to radiations, which results in decrease in conjugation and hence increases in band gap energy.

Bio-plasticizer based polyaniline (PANI)/lithium perchlorate (LiClO) composites were synthesized by the facile in situ method. The composites were characterized using the Fourier transform infrared spectroscopy (FT-IR) to identify the chemical interactions. A band appeared at 1502 cm due to the presence of the -HCO- group and CH scissor mode vibration for the PAL15% composite. This considerable change in the morphology of LiClO homogeneous dispersion in a PANI matrix was investigated by scanning electron microscopy (SEM). The UV-Visible absorption (UV-Vis) showed 300-400 nm attributed to the π- π* transition and exhibited a red shift from 535 nm to 617 nm in the visible region, indicating a decrease in band gap. The variations in dielectric constant with the addition of lithium perchlorate (LiClO) at different temperatures and in the frequency range of 20 Hz-1 MHz were assessed through impedance analysis. The temperature dependent electrical conductivity increased with increasing temperature as well as dopant concentration. High conductivity of 1.41 × 10 S/cm corresponding to activation energy of 0.02 eV and 2.95 eV optical band gap for 15 wt.% of LiClO concentration was observed. The cyclic voltammetry measurement revealed a typical rectangular shape of the integral area, suggesting that the composite has strong electrochemical strength and is a possible candidate for electrochemical super capacitor and solar cell applications. [ABSTRACT FROM AUTHOR]

A multi-hierarchical porous polyaniline (PANI) composite which could be used in good performance pressure sensor and adjustable sensitivity gas sensor has been fabricated by a facile in situ polymerization. Commercial grade sponge was utilized as a template scaffold to deposit PANI via in situ polymerization. With abundant interconnected pores throughout the whole structure, the sponge provided sufficient surface for the growth of PANI nanobranches. The flexible porous structure helped the composite to show high performance in pressure detection with fast response and favorable recoverability and gas detection with adjustable sensitivity. The sensing mechanism of the PANI/sponge-based flexible sensor has also been discussed. The results indicate that this work provides a feasible approach to fabricate efficient sensors with advantages of low cost, facile preparation, and easy signal collection. [ABSTRACT FROM AUTHOR]

In the present work, different composites of polyaniline (PANI) with various contents of Zr-Co-substituted nickel ferrite with formula (NiFe1.2Zr0.4Co0.4O4) (12.5, 25, 37.5, and 50% w/w) nanoparticles (NPs) were synthesized. These composites were characterized by X-ray diffraction (XRD), UV/Visible, Brunauer–Emmett–Teller (BET), X-ray photoelectron spectrometer (XPS), and scanning electron microscopy (SEM) analysis, and are used for the photodegradation of methylene blue (MB) from aqueous media. Effects of reaction time, NPs concentration, and degradation kinetics studies have been investigated. The structure of nickel ferrite was confirmed by XRD analysis while surface area, pore size, and morphology were investigated by BET and SEM analyses. The elements oxidation states were confirmed by XPS analysis while the optical studies were investigated by UV/Visible analysis. The degradation rate was observed fast at initial stages and then became slow. The degradation of MB follows the first-order kinetic. The NPs amount present in the composite shows remarkable influence on the degradation efficiency and is increased with the increase in nickel ferrite contents. The maximum degradation of MB was found to be 97% for the PANI/NPs composite containing 50% w/w NPs. The percentage degradation in the present work is much higher as compared to other photocatalysts reported earlier in the literature. [ABSTRACT FROM AUTHOR]