Synthesis Of Polyaniline Research Articles

A review of polyaniline based materials as anodes for lithiumion batteries

Conducting polyaniline is of great research interest to use as anode material for lithium-ion batteries. However, the development of polyaniline still remains significant challenges. For example, nowadays, it is not easy to effectively improve the electrochemical performance of ions batteries and promote its application. Herein, we introduce the structure, synthesis and properties of polyaniline firstly, then we summarize the recent advances and applications of PANI based hybrid materials in anodes for lithium-ion batteries. Special attentions were given on the following items: carbon-polyaniline composite, silicon-polyaniline composite, and metal oxides-polyaniline composite. The superior chemical nature of polyaniline enables it is promising to use as advanced anode material for Lithium-ion batteries.

Effect of different ratios of polyaniline:poly(styrene sulfonate) on the hole extraction ability in perovskite solar cells

In this work, synthesis and characterization of polyaniline:poly (styrene sulfonate) (PANI:PSS) is prepared with different ratios of the doping PSS for producing an efficient hole extraction layer in inverted planar perovskite solar cells. The PANI to PSS ratios are investigated using ratios of 1:3, 1:4, 1:5, 1:6 and 1:7 to find the optimum ratio for high performance perovskite cells. It is observed that decreasing the PSS content leads to increase the conductivity, which reached the maximum value at 1:4 ratio, then a slight decrease happens for 1:3 ratio. The hole extraction ability also increases with decreasing the PSS concentration. The optimum ratio of PANI:PSS is 1:4, which shows the best performance as HTL, the average short-circuit current density and fill factor are enhanced compared with the cells of the performance of 1:3 and 1:5 ratios. The highest cell performance for the cell with the ratio of 1:4 which has Jsc, Voc, FF and efficiency 22.5 mA/cm2, 0.87 V, 0.42 and 8.22 % respectively.

Electrochemical synthesis of polyaniline on activated carbon surface and its electromagnetic properties

In order to improve the electromagnetic properties of single polyaniline (PANI), polyaniline/activated carbon (PANI/AC) composites were prepared on the surface of an activated carbon-pencil core electrode (AC-PEC) by cyclic voltammetry of electrochemical synthetic method. The preparation conditions were optimized using charge of composite material, such as scanning potential range, scanning rate, aniline concentration, supporting electrolyte concentration, number of scanning cycles, applied neutral electrolyte concentration, concentration of activated carbon dispersion and effective conduction length of AC-PEC. The optimized results show that the as-prepared PANI/AC has the highest charge and the best stability when AC-PEC with 1.5 cm effective length (75mg/mL activated carbon dispersing liquid concentration) is put in a mixture solution (pH=0.22) containing 0.3 mol/L H₂SO₄, 0.2 mol/L KCl and 0.2 mol/L aniline (An) at the scanning speed of 0.04 V/s in a potential range from -0.4 V to 1.1 V with 8 cycles scanning successively. PANI/AC exhibits a kind of core-shell structure with good conductivity, and its impedance is lower than those of PANI and AC. It can absorb electromagnetic wave of 7.44-15.12 GHz in varying degrees, which is wider than that of pure PANI in the range from 10.48 GHz to 14.32 GHz.

Improvement of Polyaniline Processability by Graft Reaction of Polyaniline on Poly(glycidyl methacrylate-alt-maleic anhydride) Copolymer: Synthesis and Characterization

The present research describes a method of the synthesis of polyaniline grafted on poly(glycidyl methacrylate-alt-maleic anhydride) copolymer in order to improve the polyaniline processability. Polyaniline was prepared by a chemical synthesis under ultrasonic treatment. Then it was chemically grafted onto poly(glycidyl methacrylate-alt-maleic anhydride) copolymer to prepare a conductive comb copolymer. The grafted copolymer was identified by the FTIR and UV-visible spectroscopy. The analysis of the solubility and electrochemical properties showed an improved performance of grafted copolymer in comparison with pure polyaniline.

Effect of Cobalt Phthalocyanine on Synthesis and Physicochemical Properties of Polyaniline

AbstractOrganic transition metal complexes are successfully used in polymerization due to their catalytic activity in oxidative reactions. Here, polyaniline was synthesized with cobalt phthalocyanine as catalysts for the aniline oxidative polymerization. The conditions for obtaining polyaniline significantly affect the final product and the introduction of the component into the reaction mixture leads to a change in the physicochemical properties of the polymer. Thus, the effect of the catalyst on the polymer chain was determined using FTIR, UV‐visible spectral methods and atomic adsorption analysis. Electrical conductivity, thermal stability, electrochemical parameters (HOMO‐LUMO, band gap), surface morphology, and fluorescence emission spectra were estimated for the polymer samples obtained. The study of synthesized polymeric materials resulted that the use of cobalt phthalocyanines in the aniline oxidative polymerization process leads to better physicochemical properties, namely electrical conductivity, band gap and fluorescence quantum yield.

Effect of Additives on the in situ Laccase-Catalyzed Polymerization of Aniline Onto Bacterial Cellulose.

Laccase-mediated systems are a green route to accelerate the oxidation of aniline and obtain polyaniline with conductive properties. The synthesis of green polyaniline (emeraldine salt) was herein improved by the inclusion of additives like sodium bis (2–ethyl hexyl) sulfosuccinate (AOT) and potassium hexacyanoferrate (II) (KHCF) in the medium. The aniline polymerization was confirmed by the detection of the absorption band typical of emeraldine salt at 420 nm, typical of the semiquinoid radical cation, and of the polaron absorption band at 700–800 nm, corresponding to the distinctive signal of doped or partial doped aniline. The oligomers and/or polymers obtained were characterized by spectrometry techniques, namely 1H NMR and MALDI-TOF, and the bacterial cellulose (BC) conductivity was assessed by means of a four-point probe electrical conductivity technique. The best polymerization results were obtained with 5 mM AOT, 10 mM KHCF, and 25 U/mL of laccase. The synergistic effect between both additives in the presence of a catalyst leads to obtaining BC samples coated with green polyaniline with promising electric conductive properties.

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.

Aqueous Route Synthesis of PAni Electrodes by Chemical Bath Deposition and Their Cyclic Voltammetric Analyses at Different Scan Rates

AbstractThe present work elaborates the aqueous route synthesis of polyaniline (PAni) electrodes for supercapacitors using chemical bath deposition (CBD) method and study of effective of scan rate on the cyclic voltammetric (CV) behavior. In the synthesis work, 1 m aniline and 1 m H2SO4 were taken in 2:2 ratio and kept for constant stirring and 1 m aqueous solution of (NH4)2S2O8 was added slowly in it. Stainless steel substrates were immersed in the reaction bath at room temperature for 1 h. The formation of PAni was confirmed by FT‐IR spectroscopic study. XRD analysis confirms the amorphous nature of the prepared PAni thin films. Contact angle study shows the hydrophilic behavior of the PAni electrodes. Obtained electrodes were subjected to cyclic voltammetric study at various scan rate from 5 to 100 mV s–1 in 1 m KOH electrolyte. Observed maximum specific capacitance was 516.34 F g–1 at 5 mV s–1 scan rate.

Synthesis of Polyaniline for Environmental Monitoring

Synthesis of Polyaniline for Environmental Monitoring

Magnetite nanoparticles-catalysed synthesis of conductive polyaniline

Nowadays, there is a growing interest to find environmentally-friendly, simple and economical routes for the synthesis of polyaniline (PANI), one of the most important conducting polymers. For the oxidative polymerization approach hydrogen peroxide (H2O2) is highly recommended oxidant due to ecological aspects, since the product of its reduction is only water. However, its usage as an oxidant, aimed to produce conductive PANI with reasonable reaction rate, needs a catalyst. Here we report the preparation of conductive PANI in good yield by the oxidative polymerization of aniline using magnetite nanoparticles (Fe3O4 NPs) as a catalyst and H2O2 as an oxidant, with added very small amount of ammonium peroxydisulfate as the initiator. Synthesized Fe3O4 NPs (size 10–50 nm) were characterized by X-ray powder diffraction (XRPD) and scanning electron microscopy (SEM). It was found that without Fe3O4 NPs, under otherwise same conditions, the reaction product is not PANI. The effect of mass ratio Fe3O4 NPs/aniline and polymerization time on the structure and physicochemical properties of prepared PANI was studied by various techniques. FTIR, Raman, UV–vis-NIR and electrical conductivity measurements confirmed the existence of conducting emeraldine salt form of PANI. XRPD revealed unchanged crystalline structure of Fe3O4 NPs upon polymerization and semi-crystalline structure of PANI. EPR spectra showed peaks assigned to PANI and Fe3O4 NPs. Described simple, environmentally improved synthetic route opens possibilities for the syntheses of conductive PANI-like polymers from other aromatic amines by using environmentally-friendly oxidant H2O2 and Fe3O4 NPs catalyst which can replace more expensive catalysts such as peroxidase enzymes.

SYNTHESIS AND STUDY OF ATR SPECTRA OF POLYANILINE/GRA NANOCOMPOSITES

Nano composites are a particular class of materials resulting from combinations of two or more compounds by an appropriate method, which results in materials having unique physicochemical properties and large potential for application in diverse areas. Some of the distinctive properties of polymeric Nano composites can be derived from the successful combination of the uniqueness of the parent constituents into a particular polymer. These composites vary from the pure polymers in respect to some of the physical and chemical properties and hence are useful for many different applications. We synthesized Polyaniline (PANI) in Emeraldine form by chemical oxidation method using Ferric Chloride (FeCl3) as a catalyst and Hydrogen peroxide (H2O2), as an oxidant. Simultaneous synthesis of polyaniline (PANI)/ GRA Nano composites was also done by the same chemical oxidation method. The characteristic absorption peaks of Attenuated Total Reflectance (ATR) spectra for GRA, PANI and PANI/GRA provide information about the changes in the chemical structure of PANI. ATR spectra also give indication that the incorporation of GRA in the matrix of PANI seems to be effective for the improvement of the physicochemical properties of the Polyaniline.

A comparative study of ion exchange behavior and analytical applications of zirconium and tin based polyaniline hybrid cation exchangers

The present work reports the synthesis, characterization and ion exchange properties of polyaniline based hybrid cation exchangers such as polyaniline‑zirconium(IV) tungstate (PA/ZrW), polyaniline‑zirconium(IV) tungstomolybdate (PA/ZrWMo), polyaniline‑tin zirconium molybdate (PA/SnZrMo) and polyaniline‑tin cerium molybdate (PA/SnCeMo). The structural characterization and morphology of the hybrid cation exchangers were done by FT-IR, XRD, SEM-EDS and UV–Vis studies. Thermal stability of hybrid cation exchangers was analyzed by TGA study. The order of ion exchange capacity for alkali and alkaline earth metal ions on the synthesized hybrid materials was found to be in the sequence K+ > Na+ > Li+ for alkali metals and Ba2+ > Sr2+ > Ca2+ > Mg2+ for alkaline earth metals. The distribution coefficient of metal ions in de-mineralized water and different concentrations of HNO3, effect of pH, adsorbent dose, drying temperature and concentration of Pb2+ on Kd value were also investigated. It is clear from the distribution studies that all the hybrid cation exchange materials have more selectivity towards toxic metal ion, Pb2+ and Cd2+ and least affinity towards Zn2+, Co2+, Cu2+, Mg2+ and Ni2+ ions.

Variation of Ammonium Persulfate Concentration Determines Particle Morphology and Electrical Conductivity in HCl Doped Polyaniline

Polyaniline (PANI) is one of conducting polymers which is widely used in various applications especially energy field, like solar cells and batteries. PANI emeraldine salt (PANI ES) is the only type of conducting PANI which can be easily synthesized using a direct mixing method in an oxidizing solution. Ammonium persulfate (APS) is one example of a strong oxidizing agent which is often used in PANI synthesis. The APS concentrations used in this study ranged from 0.1 to 1 M. Infrared and Raman spectroscopy shows that the addition of APS concentrations above 0.5 M produces the non-conducting fully oxidized PANI and phenazine species. Scanning electron microscope (SEM) showed morphological changes of PANI ES from nanofiber (diameter 80 - 110 nm) to granules (diameter 20 - 70 nm) as APS concentration increases. Based on Electrochemical impedance spectroscopy (EIS), conductivity of PANI increases as APS concentration increases with maximum conductivity of 0.36 S cm−1 at 0.5 M.

Formation and behavior of negative ions in low pressure aniline-containing RF plasmas

This paper is focused on the formation mechanisms and the general behavior of negative ions in low pressure radio-frequency (RF) plasmas operated in a mixture of argon and aniline vapor. This type of plasma is mostly used for the synthesis of polyaniline, one of the most studied conductive polymers. Experiments based on mass spectroscopy measurements reveal the necessity to have a thin layer of plasma synthesized polyaniline on the electrodes to produce negative ions through complex surface reactions. In addition, thin-films deposited using this type of discharge are analyzed by means of Near Edge X-ray Absorption Fine Structure spectroscopy (NEXAFS). The material analysis gives a first indication about the possible contribution of negative ions to polyaniline deposition.

Polyaniline - BiVO4 nanocomposite as an efficient adsorbent for the removal of methyl orange from aqueous solution

Herein, we report the synthesis of Polyaniline - BiVO4 nanocomposites by in-situ oxidative polymerization using aniline monomer in the presence of hydrochloric acid and bismuth vanadate nanosheets. The physiochemical properties of the adsorbents were characterized by X-ray diffraction spectroscopy (XRD), field emission scanning electron microscopy, transmission electron microscopy (HR-TEM) and RAMAN spectroscopy. TEM images confirmed the formation of BiVO4 nanosheet on the PANi matrix. The surface area analysis showed that the PANi - BiVO4 nanocomposites have a high surface area (16.58 and 19.58 m2/g) than the PANi nanofiber (9.14 m2/g). The adsorption behavior of PANi and PANi - BiVO4 nanocomposites were evaluated by monitoring the adsorption of methyl orange dye within the time interval of 2 h. The PANi - BiVO4 nanocomposite shows 99% of adsorption efficiency which is higher than that of pure PANi (70%). The pseudo-first-order kinetics and Langmuir isotherm model represents the MO adsorption on PANi - BiVO4 was monolayer sorption and the adsorption sites were homogeneous. The reusability of the as-prepared nanocomposite was analyzed and it shows 78% of adsorption after five cycles.

Low-temperature thermoelectric performance of novel polyaniline/iron oxide composites with superior Seebeck coefficient

The large amount of heat loss at low temperatures (up to 250 °C), more than 70% of the total waste heat, motivates the market to develop new materials for low-temperature thermoelectric applications. To this end, organic materials can be excellent potential candidates with the additional advantages of light weight, ease of synthesis and processing, eco-friendly and being sustainable materials. Herein, we demonstrate the synthesis of polyaniline (PANI) in its conductive emeraldine form via a facile chemical oxidative polymerization process. The conductivity of the fabricated PANI, with exceptional low degree of protonation and additional structure deflection, originates from the excess Cl− anions/imines (–N=) interactions. Micro/nano-spheres and different regular shapes are formed with inherent nano-flakes/fibers structures. These structures are intrinsically ferric oxide clouds that finally result in a novel composite of PANI/ferric oxide, as confirmed via the FESEM, EDX, XRD and FTIR analyses. Different dopant concentrations (0.1–2 M HCl) and initiator concentrations (0.5–3 M FeCl3) were screened to identify the appropriate yield with the highest thermoelectric energy conversion efficiency. Our recipe with low degree of protonation resulted in semiconductor-to-metallic transformation point with a composite that has a superior Seebeck coefficient of 158 µV/k, which has not ever reported for pristine PANI and also with a moderate electrical conductivity of 0.0017 S/cm at 150 °C.

Synthesizing Polyaniline With Laccase/O2 as Catalyst.

The polymerization of aniline to polyaniline (PANI) can be achieved chemically, electrochemically or enzymatically. In all cases, the products obtained are mixtures of molecules which are constituted by aniline units. Depending on the synthesis conditions there are variations (i) in the way the aniline molecules are connected, (ii) in the average number of aniline units per molecule, (iii) in the oxidation state, and (iv) in the degree of protonation. For many possible applications, the synthesis of electroconductive PANI with para-N-C-coupled aniline units in their half-oxidized and protonated state is of interest. This is the emeraldine salt form of PANI, abbreviated as PANI-ES. The enzymatic synthesis of PANI-ES is an environmentally friendly alternative to conventional chemical or electrochemical methods. Although many studies have been devoted to the in vitro synthesis of PANI-ES by using heme peroxidases with added hydrogen peroxide (H2O2) as the oxidant, the application of laccases is of particular interest since the oxidant for these multicopper enzymes is molecular oxygen (O2) from air, which is beneficial from environmental and economic points of view. In vivo, laccases participate in the synthesis and degradation of lignin. Various attempts of synthesizing PANI-ES with laccase/O2 in slightly acidic aqueous media from aniline or the linear aniline dimer PADPA (p-aminodiphenylamine) are summarized. Advances in the understanding of the positive effects of soft dynamic templates, as chemical structure guiding additives (anionic polyelectrolytes, micelles, or vesicles), for obtaining PANI-ES-rich products are highlighted. Conceptually, some of these template effects appear to be related to the effect “dirigent proteins” exert in the biosynthesis of lignin. In both cases intermediate radicals are formed enzymatically which then must react in a controlled way in follow-up reactions for obtaining the desired products. These follow-up reactions are controlled to some extent by the templates or specific proteins.

Normal and reverse AOT micelles assisted interfacial polymerization for polyaniline nanostructures

We report here the synthesis of polyaniline (PANI) nanomaterials using sodium bis (2-ethylhexyl) sulfosuccinate (AOT) micelles assisted chemical oxidative interfacial polymerization. We have employed two interfaces (chloroform-water and hexane-water) and two oxidizing agents (ammonium persulfate and ferric chloride). The anionic surfactant sodium bis (2-ethylhexyl) sulfosuccinate (AOT) forms normal micelles in aqueous solution and reverse micelles in hydrophobic solvents like hexane or chloroform. The factors influencing the properties and morphologies of polyaniline nanomaterials such as monomer: surfactant ratio, monomer: oxidant ratio, types of interfaces and oxidants used have been studied. Powder X-ray diffraction of the polyaniline nanomaterials have revealed that polyaniline samples were semi-crystalline in nature. Morphology of polyaniline samples studied by scanning electron microscopy (SEM) and transmission electron microscopy (TEM) have revealed that most of the polyaniline nanomaterials synthesized using ferric chloride possess spherical nature, whereas polyaniline samples synthesized using ammonium persulfate (APS) possess short nanofibers especially at lower aniline/AOT mole ratio in feed (12.5–6.5). The four probe electrical conductivity of the samples were found to be of the order of 1.8 × 10−1 to 8.6 × 10−1 S/cm. Thermal stability of the polyaniline samples recorded by thermogravimetric analysis (TGA) have revealed that polyaniline samples were thermally stable up to 275 °C for 10% weight loss. Interfacial polymerization of aniline monomer using reverse micelles of AOT in hexane phase and ammonium persulfate as oxidizing agent in aqueous phase have been proved to be efficient method for the synthesis of short polyaniline nanofibers.

Influence of Electric Field during the Chemical Synthesis of Polyaniline on the Surface of Heterogeneous Sulfonated Cation-Exchange Membranes on the Their Structure and Properties

The influence of electric field in the chemical synthesis of polyaniline on the surface of sulfonated cation-exchange membranes on their structure and properties has been investigated. By using standard contact porosimetry, it has been found that surface modification of heterogeneous membranes with polyaniline, both in static conditions and in an external electric field, does not significantly affect the distribution of water over the effective pore radii and binding energies. It has been shown that the structural heterogeneity of the ion-exchange membrane, rather than the aniline polymerization conditions, has a more significant effect on the morphology of the polyaniline layer on its surface and, hence, on the electrotransport properties. A decrease in the electrical conductivity of the composites obtained with an increase in the quantity of electricity passed during the synthesis of polyaniline on their surface has been revealed. Based on the analysis of the current–voltage characteristics of the samples and their electrical conductivity, the conditions for obtaining materials with the most pronounced asymmetry of the electrotransport properties have been determined.

Synthesis and Characteristics of Polyaniline (PANI) Filled by Graphene (PANI/GR) nano-Films

In this research polyaniline (PANI) was synthesized by using chemical oxidative polymerization method. The structural properties of polyaniline nano films pure and filled by graphene (GR) at different weight percentage of graphene like (1%, 3% and 5%) were investigated. The nano films prepared by using spin coating technique and deposited on glass substrate at room temperature. The structural and surface morphology of the nano films are evaluated by FT-IR, XRD and AFM. The results showed that FT-IR spectra of pure PANI is similar to tha spectra of PANI/GR composites, While the results of XRD singular that the PANI has amorphous nature, As well as the results of AFM for all nano films of pure PANI and filled by graphene(PANI/GR) composites showed that Roughness average (Ra), Root mean square (Rms) value and average grain size (G.S) increase with increasing addition of GR ratio.