Effect Of Polyaniline Research Articles

Boosting biohydrogen production from dairy wastewater via sludge immobilized beads incorporated with polyaniline nanoparticles

In this study, the immobilization of anaerobic sludge in sodium alginate (SA) with polyaniline (PANI) nanoparticles (NPs) was performed for producing biohydrogen from dairy wastewater (DWW). The effect of PANI on immobilization in SA was investigated at different PANI concentrations (5, 10, 20, 40, and 80 mg L−1). DWW, PANI NPs, and immobilized beads were characterized through physicochemical analysis, surface area, X-ray diffractometry, and scanning electron microscopy (SEM). The results revealed that the immobilization of anaerobic sludge in SA with PANI NPs enhanced the degradation of organic matter in DWW into volatile fatty acids and biohydrogen yield. There is a direct relationship between PANI NPs concentration in SA, degradation in DWW, and bio-hydrogen production. The degradation of organic matter in terms of chemical oxygen demand reached 75.5% at the optimum dose of PANI NPs (40 mg L−1), which confirmed the high reactivity of PANI NPs with SA compared with the control sample. In addition, at 40 mg L−1 PANI NPs concentration, the maximum hydrogen yield were 54.5 mL g−1 VS from anaerobic fermentation was obtained with a 285% increase compared with the fermentation without using any PANI. The SEM image of beads before and after treatment indicated that the addition of PANI NPs up to 40 mg L−1 enhanced the production of bio-hydrogen yield through SA in a regular pattern, whereas increasing the concentration to 80 mg L−1 resulted in shrinking of SA surface and consequently decreased the biohydrogen yield.

Cyclic Voltametry Study of PANI/ZnOUrease Based Biosensor with Stainless Steel Electrode as Transducer

The electrochemical characteristic Cyclic Voltametry (CV) was studied for Electrodeposited Polyaniline (PANI)/ZnOnano composite onto a stainless steel transducer. The Cyclic Voltametry was studied during electrode position of PANI/ZnO on the stainless steel electrode. Good cyclic voltammogram for 15 wt% composition was observed as compared to others. The PANI/ZnO film also offers a more symmetrical voltammogram, with oxidation starting at a lower potential (0.05 to 0.08 V) compared to pure PANI, indicating that the presence of the ZnO promotes the electron-transfer of the oxidation process. Cyclic Voltametry of PANI/ZnO/Urease electrode shows the oxidation potential peaks occurs in CV of ZnO-PANI 15% film depicts the oxidized potential at around 0.2V, which is at higher potential as compared to other lower weight %, indicating larger surface area and larger potential window as compared to others. The magnitude of peak current gets increased with increasing concentration of ZnO, which ensure quick response time of the sensor. The CV of PANI/ZnO/Urease in potential window of -0.1 to 0.1V shows resistive effect of PANI. Also, the cyclic voltammogram of PANI/ZnO/Urease 15% shows more ohmic behavior as compared to other compositions and PANI.

Hydrothermally Assisted Synthesis of Porous Polyaniline@Carbon Nanotubes-Manganese Dioxide Ternary Composite for Potential Application in Supercapattery.

In this study, ternary composites of polyaniline (PANI) with manganese dioxide (MnO2) nanorods and carbon nanotubes (CNTs) were prepared by employing a hydrothermal methodology and in-situ oxidative polymerization of aniline. The morphological analysis by scanning electron microscopy showed that the MnO2 possessed nanorod like structures in its pristine form, while in the ternary PANI@CNT/MnO2 composite, coating of PANI over CNT/MnO2, rods/tubes were evidently seen. The structural analysis by X-ray diffraction and X-ray photoelectron spectroscopy showed peaks corresponding to MnO2, PANI and CNT, which suggested efficacy of the synthesis methodology. The electrochemical performance in contrast to individual components revealed the enhanced performance of PANI@CNT/MnO2 composite due to the synergistic/additional effect of PANI, CNT and MnO2 compared to pure MnO2, PANI and PANI@CNT. The PANI@CNT/MnO2 ternary composite exhibited an excellent specific capacity of 143.26 C g−1 at a scan rate of 3 mV s−1. The cyclic stability of the supercapattery (PANI@CNT/MnO2/activated carbon)—consisting of a battery type electrode—demonstrated a gradual increase in specific capacity with continuous charge–discharge over ~1000 cycles and showed a cyclic stability of 119% compared to its initial value after 3500 cycles.

Effect of PANI and PPy on Electrochemical Performance of rGO/ZnMn2O4 Aerogels as Electrodes for Supercapacitors

Conductive polymers, such as polyaniline (PANI) and polypyrrole (PPy), are widely used in the design of supercapacitors because of their high pseudo-capacitive performance as well as facile synthesis and low cost. In this study, hybrid aerogels based on reduced graphene oxide and ZnMn2O4 were modified by PANI and PPy. The 3D structure of the hybrid aerogels was obtained by using a one-step hydrothermal co-assembly method. Then, aniline and pyrrole were polymerized on and within the structure of the hybrid aerogel through in situ polymerization. The electrochemical properties of the hybrid aerogels were studied via cyclic voltammetry and galvanostatic charge–discharge testing to identify the effects of conductive polymers on the electrochemical properties of materials. It has been established that PANI and PPy facilitate an increase of the specific capacitance of rGO/ZnMn2O4 aerogels up to 297.8 F/g and 108.24 F/g at 0.2 A/g scan rate, respectively.

Effect of Addition of Polyaniline (PANI) on the properties of copper (II) Oxide nanoparticles

High resistivity (or low electrical conductance values) materials have found their applicational foot in those domains of electrical-electronical where resistors, heat filaments, space heaters, shunt resistors electric irons and etc. are broadly exercised on. This paper investigates the effect of addition of polyaniline (PANI) on the properties of copper (II) oxide (CuO) nanoparticles. Sol-Gel method was used to synthesize CuO nanoparticles while PANI was obtained by oxidative polymerization process. The structural characterizations of the composite material and the effect of PANI on the CuO nanoparticles are studied through FESEM, XRD, FTIR and Raman Spectroscopy. XRD confirmed the formation of CuO without the presence of CuO2. FESEM showed the clear formation monoclinic structure of CuO. EDX revealed that Cu and O-atoms are in stoichiometry, thus confirming the formation of CuO bond and peaks of C, N and O are also obtained depicting the PANI formation. The characteristic peaks are obtained for both CuO (402.99-678.74 cm−1) and PANI (1109.94-1568.54 cm−1 and 3058.81-3436.21 cm−1) through FTIR. The Raman analysis of CuO sample showed 3 peaks (290.01 cm−1, 333.51 cm−1 and 624.81 cm−1) and while PANI showed peaks in the range from 1166.48 cm−1 – 1582.81 cm−1. The dielectric properties were investigated using Maxwell-Wagner model and Koop’s phenomenological theory. The fore-mentioned composite material can also be considered to be devised in a resistor.

Effect of PANI on Thermal, Mechanical and Electromagnetic Properties of HDPE/LLDPE/PANI Composites

In this work, polyaniline (PANI) in emeraldine-base form, synthesized by chemical oxidation polymerization, was protonated with hydrochloric acid (HCl). Composites based on high-density polyethylene (HDPE) and linear-low density polyethylene (LLDPE) blends with PANI were prepared in molten condition using a torque rheometer. The effect of compatibilizer agent (maleic anhydride-grafted high density polyethylene, HDPE-g-MA) and different contents of PANI on the blends-based composites was also investigated. Thermal, mechanical, and electromagnetic (electric permittivity) measurements and morphological aspects of the composites were evaluated. The addition of PANI content in the composites decreases the degree of crystallinity of HDPE and LLDPE blends, which implies that PANI particles make it difficult for co-crystallization to occur in the HDPE and LLDPE, respectively. On the other hand, the addition of compatibilizer agent in the HDPE and LLDPE blends increased the degree of crystallinity. The complex parameters of permittivity in the frequency range of 8.2 to 12.4 GHz varied as a function of the PANI content in the blend. It was also observed that the compatibilizer agent increased the composite stiffness and decreased the electric permittivity values. This result shows that the increasing rigidity of the molecular structure of the polyethylene matrix hindered the dissipation of the electromagnetic energy in the sample.

Corrosion Resistance and Tribological Characteristics of Polyaniline as Lubricating Additive in Grease

Polyaniline (PANI) was doped as lubricating additive to afford grease. The effect of PANI on the physicochemical characteristics, corrosion resistance, and tribological performances of lubricating grease was investigated in details, and the tribological action mechanisms of lubricating grease were analyzed in relation to worn surface analyses by scanning electron microscopy (SEM) and energy dispersive X-ray spectroscope (EDS). Results indicate that the PANI-doped grease has superior conductive and thermal properties. And PANI-doped grease has an excellent corrosion resistance, which is attributed to the isolation effect and the compact passivated film generated by reaction of PANI and metal. In the meantime, the PANI-doped grease performs superior friction reduction and wear resistance under different applied loads and frequencies. It is mainly ascribed that the PANI can perform like spacers to avoid direct contact between the contact interfaces, and the protective tribofilm is generated by physical adsorption and chemical reaction.

Study on the reuse of marble and andesite wastes in epoxy‐based composites

Andesite‐ (AW) and marble‐dust wastes (MW) were recycled to be used in composite preparation. Both were obtained from local industrial sources. Commercially available epoxy resin (ER) and its modified version with polyaniline (PANI) were used as the neat polymer matrix. The dispersion of the fillers was investigated by X‐ray diffraction and scanning electron microscopy. The effects of PANI and waste loading on the mechanical, thermal, electrical, water sorption, and corrosion properties were investigated. The optimum loading levels for MW or AW in the composites were found to be 20 wt%. Using thermogravimetric analyses, thermal behavior and stability of the composites prepared were probed. The incorporation of PANI and waste fillers increased the T10 temperature by 10–33°C and the tensile strength by 4–51 MPa of neat ER. The composites containing 10–30 wt% AW filler were found to be semiconductive and electrical conductivity decreased with the increase in AW content. The PANI‐ER/AW composite showed perfect resistance to corrosion and also exhibited the best adhesion. POLYM. COMPOS., 39:3081–3091, 2018. © 2017 Society of Plastics Engineers

Structural and electrical studies on PVDF:PANI composite thin films and their application as buffer layer on hybrid solar cells

Hybrid (organic–inorganic) solar cells were fabricated and tested using buffer layer of polyaniline (PANI)–poly(vinylidene difluoride) (PVDF) composites. The effect of PANI:PVDF composite on the performance of the solar cells was explored and the cells were characterized by current voltage (I−V) measurements under a solar simulator generating AM1.5 light (1000 W/m2) irradiance. It was found that solar cells containing ITO/PANI:PVDF photo-anode are likely to improve photocurrent and power conversion efficiency in a way superior to that containing only ITO as photo-anode. Furthermore, PANI:PVDF composite enhanced the hole extraction at photo-anode/photo-active layer interface via the high electrical conductivity of PANI and the ferroelectricity of PVDF.

Synthesis and characterization of hybrid conducting composites based on polyaniline/magnetite fillers with improved microwave absorption properties

Hybrid organic/inorganic electromagnetic absorbing materials (EMAMs) based on polyaniline (PANI) and magnetite (Fe3O4) fillers dispersed in epoxy resin matrix were successfully prepared for electromagnetic applications. The effects of PANI and Fe3O4 loading on permittivity, permeability and microwave absorption properties were studied. The structure and the morphology of the elaborated composites were investigated by X-ray diffraction (XRD) and scanning electron microscopy (SEM). Electromagnetic properties and absorbing behaviors were performed over frequency range of 12.4–18GHz (Ku-band). The results show that synthesis parameters such as amount and particle size of PANI and used Fe3O4 affect significantly the morphology, the conductivity, and the microwave absorption properties of the final materials. It was revealed that the electromagnetic parameters were higher in hybrid PANI/magnetite/epoxy resin than in dielectric PANI/epoxy resin composites. The permittivity and the permeability parameters increased to high values with the rate of fillers in the composite and remained constant with the frequency. A minimum reflection coefficient (RC) of −42dB was observed at 16.3GHz with a thickness around 1mm for composites containing 15% of PANI and 10% of Fe3O4 (ɛ′=10) and −37.4dB at 14.85GHz for the composite of 15% of PANI and 25% of Fe3O4 (ɛ′=17). However, a composite made with only 20% of PANI (ɛ′=8.5) showed a minimum reflection coefficient of −11dB at 18GHz with the same thickness. The possibility to modulate the electromagnetic properties of the composite materials is of a great interest to fabricate microwave absorbing and electromagnetic shielding materials with high performances.

Synthesis of polyaniline nanofiber and anticorrosion property of polyaniline–epoxy composite coating for Q235 steel

Polyaniline (PANI) nanofibers were prepared by direct mixed oxidation in four kinds of inorganic acids. The characterization of scanning electron microscopy (SEM) showed that high quality PANI fibers with uniform diameter and several microns length can be obtained by direct mixed oxidation, especially in a sulfuric acid system. Structural characteristics of PANI products through IR and UV spectra indicated the consistent peak distribution with the classic spectrum of the doped PANI. In addition, composite coatings of PANI–epoxy resin were prepared by mechanical grinding. The effect of PANI’s content on anticorrosion property of the composite coatings for Q235 steel was studied by the electrochemical impedance spectroscopy (EIS). Results showed that the best shielding protective effect was obtained when the amount of PANI was around 0.5% (wt%). More importantly, the effects of four different inorganic acids on anticorrosion property of the composite coatings were studied by the EIS and Tafel polarization curve. Experiments showed that the different composite coatings of PANI doped by different inorganic acids provided different protective abilities for the Q235 steel. It can be concluded that both the morphology and counter-anion would impact the anticorrosion effect of the doped PANI.

Electrospun nanofibers of polymer composite as a promising humidity sensitive material

Nanofibers of a composite of a silicon-containing polyelectrolyte, polyethylene oxide and polyaniline (PANI) were obtained by electrospinning and heat treatment. The morphologies of the composite nanofibers were characterized by scanning electron microscopy, which showed that the nanofibers with a diameter of 250–500 nm formed a non-woven mat with highly porous structure. It was found that the polymer composite nanofibers showed impedance change from 6.3 × 10 6 to 2.5 × 10 4 Ω with the increment of relative humidity (RH) from 22 to 97% at room temperature, exhibiting high sensitivity and good linearity on a semi-logarithmic scale. In addition, they exhibited fast and highly reversible response characterized by very small hysteresis of ∼2% RH and short response time (t 90%: 7 s and 19 s for adsorption and desorption between 33 and 97%RH, respectively). The modification of the electrode with poly(diallyldimethylammonium chloride) prior to the deposition of nanofibers improved their humidity response, which may be related to the enhanced contact between the nanofibers and underlying substrate. The effect of PANI on the humidity response of the composite nanofibers was also investigated, and it was found that PANI effectively decreased the impedance of the nanofibers. The electrospun polymer composite nanofibers may find applications in the preparation of high performance humidity sensors.

An EPR investigation of conductive polyaniline–poly(methyl methacrylate‐co‐acrylic acid) blends

AbstractA conductive blend of polyaniline (PANI) with sodium form poly(methyl methacrylate‐co‐acrylic acid) copolymer (PMMAA) was prepared by in situ dispersion polymerization. The PANI‐PMMAA blends were characterized with UV–vis, FTIR, and electron paramagnetic resonance (EPR) spectra. The effects of PANI and temperature on the electronic properties of the PANI‐PMMAA blends were studied with EPR technique. The PANI and temperature affect the intermolecular interaction between PANI and PMMAA and then determines the EPR parameters (A/B ratio, g factor, T2, ΔHpp, Ns, and lineshape). POLYM. COMPOS., 2008. © 2008 Society of Plastics Engineers

The electrochemical properties of [formula omitted]/polyaniline composites

The La 0.7Mg 0.25Ti 0.05Ni 2.975Co 0.525 (AB 3) alloy was modified with different contents of polyaniline (PANI) through ball milling. XRD, SEM and FTIR were used to characterize the properties of the AB 3 / x PANI composites ( x = 1 , 2, 3 and 4 wt%). The effects of PANI on the electrochemical properties of AB 3 alloy electrode were studied by charge–discharge, electrochemical impedance spectroscopy (EIS), linear polarization (LP) and potentiostatic discharge experiments. The XRD, SEM and FTIR results showed that ball milling did not change the characterizations of PANI and AB 3 alloy but decreased the average particle size of AB 3 alloy. The charge–discharge results indicated that the maximum discharge capacity of AB 3 alloy electrode decreased with the addition of PANI. However, the discharge cycle stability of AB 3/PANI composite electrodes increased firstly and then decreased with the increase in PANI content. The EIS and LP curves showed the same trends with the discharge cycle stability. The hydrogen diffusion coefficients of AB 3/PANI composites were estimated from the potentiostatic discharge curves, indicated the opposite trend with the discharge cycle stability. When the PANI content was equal to 3 wt%, the AB 3/PANI composite electrode exhibited an optimal electrochemical kinetic property.

Ion-selective electrodes: polyaniline modification and anion recognition

A novel arrangement for polymeric membranes used in ion-selective electrodes is presented. The surface of a conventional plasticized poly(vinyl chloride) (PVC) membrane was coated with a chemically generated film of a conducting polymer, polyaniline (PANI). The effect of PANI on the anionic potentiometric response of PVC membranes derived from calix[4]pyrrole and tridodecylmethylammonium chloride (TDDMACl) is reported. Five different types of electrodes with the following membrane compositions were studied: (1) PVC/PANI (a reference experiment), (2) PVC + TDDMACl (as anion-exchanger)/PANI, (3) PVC + calix[4]pyrrole (as neutral carrier)/PANI, (4) PVC + calix[4]pyrrole + TDDMACl (uncoated membrane) and (5) PVC + calix[4]pyrrole + TDDMACl/PANI. Hydrophilicity of the uncoated and PANI-coated membrane surfaces was assessed by measurements of water contact angle, θ. In the protonated state, the neat PANI is more hydrophilic, θ =4 9 ◦ , than in its deprotonated base form, θ =9 4 ◦ . After surface deposition of thin PANI film, increased potentiometric sensitivity of the membranes, especially towards hydrophilic anions (F − ,H 2PO4 − ), was achieved. The distinct differences in the character of calix[4]pyrrole (neutral carrier) and TDDMACl (anion-exchanger) to sense anionic species were retained and became more pronounced. The PANI film may be regarded as a novel kind of an electrode modifier for anion-sensing. The role of the PANI film in the formation of the potentiometric response is discussed. It is proposed that the PANI film acts as an anion-exchanger. The transport of anions through a thin PANI film is also affected by the character of anions and by pH.

Corrosion protection using polyanujne coating formulations

Growing environmental concerns regarding the use of heavy metals in coating formulations has led to a new coating strategy employing inherently conducting polymers (ICP) as a key component. ICPs (such as polyaniline, polypyrrole and polythiophene) are electrically conductive owing to a system of conjugated double bonds. Observations of metal passivation complement this conductive nature and offer a viable alternative to traditional corrosion protection (1–8). A key potential advantage that the ICP coating technology offers is toleration of pin holes and minor scratches. The basis for this argument is that, since the ICP coating is conductive, the entire coating acts to passivate any areas of exposed metal. This paper describes a model for polyaniline (PANI) corrosion protection and presents data which clearly demonstrate significant corrosion protection in a salt fog environment. ESCA and electrochemica data are presented which show that an Fe-PANI complex is formed in the process of coating steel with PANI. The Fe-PANI complex is shown to catalytically reduce oxygen. Preliminary electrochemical impedance results are also presented which show an additional time constant at 20 kHz, which appears to correlate with the effectiveness of PANI toward corrosion protection.

Nonlinear Optical Effect of Polyaniline Solution

The conducting polymers as fast response nonlinear optical-materials with high third harmonic susceptibility have recently been studied because of their application in fast optical switches, transient and nonlinear memories and optical transistors. Polyaniline(PANI) has recently become an interesting subject because of its specific doping mechanism, unique chemical and physical properties, good environment stability and prospect of application in technology. Some papers concerning nonlinear optical effect of PANI have been published. We have also studied the third harmonic generation of