Morphology Of Polyaniline Research Articles

Fabrication of Polyaniline Structures for Enhanced Supercapacitance: Effect of PANI Morphologies

This work is conducted with the aim to see the effect of Polyaniline (PANI) morphologies on the specific capacitance of the electrode material. The paper presents a low-temperature synthesis and electrochemical analysis of PANI morphologies (granular, pebbles, spheres, tubes, flakes, and fibers). The supercapacitive behavior of all fabricated electrodes was tested via a two-electrode setup in 0.1 M H2SO4 electrolyte. The electrochemical analysis showed that amongst all the PANI morphologies, nanofibers had the highest specific capacitance (752.27 Fg-1), a good energy density (66.86 Whkg-1), and a good retention rate (40%). The reason may be attributed to a larger π-π stacking interaction with maximum d-spacing (3.52 Aº) that gives a desirable contact surface area for the electrolyte ions to transport efficiently across the electrolyte. Also, it has a low value of Rb (4.67 W), Rct (0.56 W), a good (251 Hz), a very less relaxation time (0.0039s), and a high knee frequency value (825.2 Hz). PANI fibers can prove to be an effective electrode material that could enhance the specific capacity of the electrode at the same time is economical and environmentally friendly.

Porous polyaniline tube-like/TiO2 nano-heterostructure for sensing hydrogen gas at environmental conditions

In this study, porous polyaniline tube-like/TiO 2 nano-heterostructure (PPTH) was prepared by a chemical oxidative polymerization to be used in H 2 sensing. The surface morphology of polyaniline, the content of one-dimensional TiO 2 nanostructures (1D TiO 2 ), and the porosity of PPTH significantly affected the sensing performance of the samples. The response and response/recovery time of gas sensing for H 2 were considered by morphological change of TiO 2 at ambient conditions. The p-n contacts between polyaniline matrix and 1D TiO 2 provided more active sites and facilitated the electrons transport, hence promoting the physisorption of gas molecules. R20 exhibited the highest sensitivity of 9.05 towards 2500 ppm of H 2 gas at the respective response and recovery times of 94 and 374 s. The sensor designed based on F30 exhibited proper long-term stability after one year. The sensing mechanism of PPTH was also studied in detail. • A porous polyaniline tube-like/TiO 2 nano-heterostructure (PPTH) based H 2 sensor. • A high sensitivity, low response/recovery time to H 2 gas at ambient conditions. • A good long-term response. • H 2 gas sensing mechanism of PPTH has also been studied in details.

Research Progress on Polyaniline-Ionic liquids for Long Cycle-Stable Supercapacitors with High Capacitance

Ionic liquids have been used either as polymerization medium or as electrolytes for polyaniline (PANI) electrodes to produce long cycle-stable supercapacitors with high capacitance. As a polymerization medium, ionic liquids play the role of a soft template agent and induce the formation of nanostructured PANI morphology. Nanorod, nanowire, or spherical PANI morphology has been obtained in ionic liquids instead of agglomerated particles resulted in the conventional media. The well-defined one-dimensional PANI morphology ensures a short charge transfer distance in the PANI materials and low contact resistance between PANI and electrolyte interfaces. The efficiency of ionic liquids as a soft template agent is related to their structure as well as to their proportion in the reaction medium. As electrolytes, “neat” ionic liquids provide low but stable specific capacitance of PANI over more than hundreds of cycles. Binary mixtures of ionic liquids and solvents (e.g. acetonitrile, water) have increased both the specific capacitance and the capacitance retention of PANI compared with the performances resulting in the conventional aqueous acid electrolytes. Using ionic liquids to carry out both the synthesis and the electrochemical characterization of PANI is an effective approach to improve PANI cycle life. The key parameter is to choose the convenient ionic liquids. This review covers the most significant studies conducted on PANI/ionic liquids for supercapacitor applications.

Antibacterial Activity of Polyaniline Coated in the Patterned Film Depending on the Surface Morphology and Acidic Dopant.

We have fabricated poly(ε-caprolactone) (PCL) films with flat and honeycomb-patterned (HCP) structures to coat polyaniline (PANI) on the film surface. In addition, the effect of chemical modification of PANI by sulfuric acid (H2SO4) was also studied for antibacterial activity. The flat and HCP PCL films were obtained by simple evaporation of the solvent and via the breath figure (BF) method, respectively. The morphology and chemical composition of PANI coated on the film surface were evaluated by scanning electron microscopy (SEM) and X-ray spectroscopy (EDX). Fourier transform infrared spectroscopy (FT-IR) and thermogravimetric analyses (TGA) were obtained to identify the PANI coating. The wettability and conductivity of the films were also measured. Applicational aspects were evaluated by assessing antibacterial and antibiofilm activity against Escherichia coli (E. coli) and Staphylococcus aureus (S. aureus). The EDX, TGA, and FT-IR findings indicated chemical modification of PCL film by PANI and H2SO4. The conductivity of the films was increased by the coating of PANI to the patterned surface and additionally increased by the chemically modified PANI. The antibacterial activity was 69.79%, 78.27%, and 88% against E. coli, and 32.73%, 62.65%, and 87.97% against S. aureus, for flat PANI, HCP PANI, and H2SO4-treated HCP films, respectively. Likewise, the PANI coated flat, HCP, and H2SO4-treated HCP films inhibited E. coli biofilm formation by around 41.62%, 63%, and 83.88% and S. aureus biofilm formation by 17.81%, 69.83%, and 96.57%, respectively. The antibacterial activity of the HCP film was higher than that of flat PANI films, probably due to the higher coating of PANI on the HCP surface. Moreover, sulfonation of the HCP film with H2SO4 might have improved the wettability, thereby enhancing the antibacterial and antibiofilm properties. Our results showed that topographical changes, as well as doping, offer simple and cost-effective ways to modify the structural and functional properties of films.

Structure, morphology and anti-corrosion performance of polyaniline modified molybdenum sulfide/epoxy composite coating

A novel nanoparticle of PANI modified MoS2 was synthesized by in-situ polymerization and the composite coating of it and epoxy resin was prepared. The results of FT-IR, XRD and EDS proved that PANI and MoS2 were successfully compounded. SEM showed that when the ratio of PANI to MoS2 was 7:1, the MoS2 lamellas of i-PANI@MoS2-7 had been covered completely and evenly by PANI, so that it could well be dispersed in epoxy resin and had the highest conductivity. The conductivity, hydrophobicity and barrier performance of i-PANI@MoS2-7/EP improved with the increase of i-PANI@MoS2-7 and reached the maximum when the content was up to 8%, then decreased because of agglomeration. The results of electrochemical analysis further showed that 8%i-PANI@MoS2-7/EP had the most excellent anti-corrosion performance, which was mainly because good electrical conductivity and excellent dispersibility of 8%i-PANI@MoS2-7/EP with the passivation effect of PANI on the substrate and the barrier effect of MoS2 on the corrosive medium. The TGA results showed that the addition of i-PANI@MoS2-7 could increase the thermal stability of EP coating with the formation of a thermal conductivity network.

In situ Polymerization of Polyaniline/Samarium Oxide - Anatase Titanium Dioxide (PANI/Sm2O3-TiO2) Nanocomposite: Structure, Thermal and Dielectric Constant Supercapacitor Application Study.

Pure and varying weigh ratio of Sm2O3-TiO2 modified polyaniline nanocomposite has been successfully synthesized using in situ polymerization of aniline solution with Sm2O3-TiO2 binary oxide. The nanocomposite have been characterized by X-ray diffraction (XRD), Fourier-transform infrared spectroscopy (FT-IR), X-photoelectron microscopy (XPS), Field emission-scanning electron microscope (FE-SEM), transmission electron microscopy (TEM) thermogravimetric analysis (TGA) and LCR meter. The XRD results show synthesis anatase TiO2 phase with tetragonal structure and (monoclinic and cubic) mixture structure of Sm2O3. The FE-SEM and TEM measurements appear preparing spherical nanoparticles that covered fiber morphology of polyaniline and successfully in situ polymerization process. The TGA measurements are obtain high thermal stability for polyaniline after incorporation by Sm2O3-TiO2 binary oxide nanoparticles. LCR measurement is obtained that the DC conductivity, dielectric constant and dielectric loss of nanocomposite is larger than pure polyaniline and the electric properties increase with increasing the concentration of nanoparticles.

Regulation of nanostructured polyaniline synthesis and its properties through organic solvent in interfacial polymerization

Tuning of the polyaniline (PANI) morphologies and properties during interfacial polymerization at various organic/aqueous interfaces (o-xylene/aq., Chlorobenzene/aq., Toluene/aq., Benzene/aq., CHCl3/aq., CCl4/aq., DCM/aq.) by chemical oxidation has been presented. The effect of various organic solvents on the grown PANIs properties has been investigated by SEM, XRD, FT-IR, UV–Vis, elemental, TGA, MALDI-TOf and AC impedance spectroscopic analyzes. Distinctly visible morphologies with changed spectroscopic properties of PANI have been obtained in various systems. Obtained PANIs properties have been correlated with the organic solvent’s octanol-water partition coefficient (log P), density, etc. and a very clear understanding has been established towards this correlation. PANI electrical properties, band structure, crystallinity, thermal properties have a clear sequence with the property of organic solvent or nature of interface. Diffusion controlled interaction of constituents for polymerization, nucleation and growth of PANI at the interface is dependent on the log P values and other properties of the organic solvent in the various organic/aq. systems.

Sintesis Soluble Polianilin dengan Variasi Jenis dan Konsentrasi Dopan

This study reports the synthesis of soluble polyaniline by the oxidation polymerization method with various dopants HCl, H2SO4, and Fumaric acid (FA). This dopant variation is carried out to obtain polyaniline with optimum solubility and electrical conductivity. The results of FTIR characterization showed several characteristic polyaniline bonds from the samples that had been synthesized. PANi/FA with a concentration of 1M has the best solubility compared to PANi/HCl and PANi/H 2 SO 4 , with a solubility value of 5.7% in NMP solvents. The electrical conductivity of all samples was measured by the two-point probe method. PANi / HCl with a concentration of 1M has the best conductivity than PANi/FA and PANi/H 2 SO 4 with a value of 48 x10 -4 S/cm. The morphology of the oxidized polyaniline powder was observed using SEM. SEM results showed the morphology of polyaniline in the form of an interconnected sponge.

Carboxylation-induced polyaniline morphology on surfaces of barium hexaferrite nano particles with enhanced microwave absorbing properties

Surface carboxylation of barium hexaferrite (BaM) has been successfully established, which effectively promotes the interaction of BaM and PANI chains and provides activated points for the preferential growth of polyaniline (PANI) on the surfaces of BaM particles. Based on this, the morphology of PANI layer has been tuned from irregular shape to convex rods and dendrite. Both convex rods and dendrite-like morphology activate electron transport in the PANI chain and enhance interfacial polarization between PANI and BaM, resulting in an improved complex permittivity. BaM particles with PANI convex rods on the surfaces exhibit an excellent and broad microwave absorption due to enhanced electromagnetic wave dissipation in the local micro-domains and the combination of dielectric loss, magnetic loss as well as interfacial loss.

Synthesis and characterization of a novel polyaniline@ montmorillonite-copper (II) sulfate nanocomposite

Polyaniline (PANI) and its nanocomposites (PANI\\MMT and PANI\\MMT-Cu) were prepared with montmorillonite nanoparticles well as the preparation of nanocomposite polyaniline with adjusted copper sulfate montmorillonite clay. As X-ray fluorescence and X-ray diffraction technology were used to calculate nanocomposite type and crystal sizes of PANI, PANI\\MMT, PANI\\MMT-Cu, respectively, samples were measured. The FTIR charts revealed new absorption peaks for nanocomposites that varied from polyaniline absorption values, and this is proof of nanocomposite preparation. UV calculations were often used to calculate the overall wavelength, red, and blue shifts. To inspect the morphology of polyaniline and its nanocomposites, FESEM was also carried out.

Research on surface morphology of polyaniline film affecting NH3 gas sensor efficiency at room temperature

In this paper, the authors presented some research results on the various surface morphologies of polyaniline (PANi) film, directly synthesised on Pt/SiO2interdigitated microelectrode area by electrochemical method. Theoutcomes of surface morphology and chemical composition structure analysis of PANi film were studied by Field-emission scanning electron microscopy (FE-SEM) and Fourier-transform infrared (FT-IR), respectively. The PANi film was fabricated with the nanowires (NWs) form with their diameter from 50÷100 nm. The length of several micrometers depends on aniline concentration and synthesis condition. The obtained consequences demonstrated that the PANi - NWs are fully potential objects for the detection of NH3gas at room temperature.

Synthesis of walnut‐like polyaniline by using polyvinyl alcohol micellar template with excellent film transmission

AbstractThough there have been many reports on various morphologies of polyaniline (PANI), the research on fabricating new morphologies remains to be explored. In this work, with the help of polyvinyl alcohol (PVA) micelles as templates, walnut‐like PANI having a rough periphery is successfully synthesized at room temperature by a static reaction. In addition, the effects of the amount of PVA, the concentration of HCl solution and the type of surfactant on the morphologies of PANI are studied in detail. Outcomes demonstrate that the fabrication of PANI walnuts is a result of the cooperation effect of the amount of PVA and the concentration of HCl solution. Moreover, PANI walnuts exhibit good thermal stability, which begins to degrade at up to about 300°C. Thin film coated by PANI walnuts possesses excellent transmittance. When PANI sample is prepared in the presence of 0.50 g PVA and 0.010 M HCl solution, the film transmittance can reach a maximum of 74% at 1200 nm. The sample presented herein have potential to be used in optical devices.

Improved Performance of All-Solid-State Flexible Supercapacitor Based on the Stress-Compensation Effect.

This work presents a facile strategy to develop a flexible polyaniline (PANI)-based supercapacitor (SC) with both high energy density and good capacitance retention. An electrode with a symmetrical sandwich-structured configuration (PANI/flexible porous support/PANI) is used as both working and counter electrodes for this supercapacitor. For a conventional electrode with PANI depositing on single side of the support (PANI/flexible support), the flexible support bends severely during the PANI electrodeposition process, which results in poor PANI deposition. On the contrary, for the symmetrical sandwich-structured electrode, due to the stress-compensation effect induced by this configuration, the support bending is significantly suppressed and thus PANI films with a good uniformity are realized. Moreover, the stress-compensation effect involved in the symmetrical sandwichstructured electrode can also effectively balance the stress caused by PANI expansion/shrinkage during its electrochemical charge/discharge operation, thus improving the mechanical stability. The symmetrical sandwich-structured electrode has larger PANI mass loading, better PANI morphologies and stronger mechanical stability than those of the conventional electrode. Consequently, the SC constructed by the symmetrical sandwich-structured electrode displays better electrochemical performance in terms of its larger specific areal capacitance (369.2 mF·cm-2 at a current density of 0.25 mA·cm-2), higher energy density (0.031 mWh·cm-2 at a power density of 1.21 mW·cm-2) and better cycling retention (93.2% of the retained capacity over 6000 cycles) than the SC constructed by the conventional electrode.

One–step template–free fabrication and capacitive properties of flower–like polyaniline in strong acidic solution

Three-dimensional hierarchical nanostructured polyaniline (PANI) was constructed through a simple and efficient template-free frozen polymerization of aniline in strong acid condition for fabricating high performance electrode for supercapacitor. The morphology and structure of flower-like PANI was investigated, and its charge storage ability was evaluated. The PANI electrode exhibited the specific capacitance of 428.5 F g−1 at a current density of 1 A g−1, the capacitive retention remains 78.8% from 1 to 10 A g−1, and cycling retention of 62 % after 1000 cycles, exhibiting its great potential application as the supercapacitor electrode materials.

Pani Addition to Improve Contact Between CdTe/CdS Semiconductors

This paper presents the study of the addition of the polyaniline polymer (PANI), at the junction of the cadmium telluride and cadmium sulfide (CdTe/CdS) layers in order to improve the contact between the layers, to decrease the air gap that limit the conversion photovoltaic. The morphology of CdS, CdTe and polyaniline (PANI) were characterized with multiple techniques including scanning electron microscopy (SEM), energy dispersive spectroscopy (EDS), X-ray diffraction (XRD) and optical absorption. The Metrohm Autolab LED Driver Kit system was used for data collection, and it was possible to obtain the current and voltage parameters of the cells. The inclusion of PANI thin film in CdS/CdTe hybrid solar cells increases the energy conversion efficiency from 0.0075% to 0.15%, this gives a 20-fold increase in efficiency.

Enhanced electrical and thermal properties of semi-conductive PANI-CNCs with surface modified CNCs.

Cellulose nanocrystals (CNCs) are the most commonly used natural polymers for biomaterial synthesis. However, their low dispersibility, conductivity, and poor compatibility with the hydrophobic matrix hinder their potential applications. Therefore, we grafted sulfate half-ester and carboxylic functional groups onto CNC surfaces (S-CNC and C-CNC) to overcome these shortcomings. The effect of the dopants, surfactant ratios, and properties of CNCs on the thermal stability, conductivity, and surface morphology of polyaniline (PANI)-doped CNC nanocomposites were investigated through emulsion and in situ polymerization. The higher electrical conductivity and well-dispersed morphology of SCNC–PANI30 (1.1 × 10−2 S cm−1) but lower thermal stability than that of CCNC–PANI30 (T0: 189 °C) nanocomposites are highly related to dispersibility of S-CNCs. However, after 4-dodecylbenzenesulfonic acid (DBSA) was added, the conductivity and thermal stability of SCNC/PANI increased up to 2.5 × 10−1 S cm−1 and 192 °C with almost no particle aggregation because of the increase in charge dispersion. The proposed biodegradable, renewable, and surface-modified S-CNC and C-CNC can be used in high-thermal-stability applications such as food packaging, optical films, reinforcement fillers, flexible semiconductors, and electromagnetic materials.

Significant role of thorny surface morphology of polyaniline on adsorption of triiodide ions towards counter electrode in dye-sensitized solar cells

Revealing the adsorption behavior of polyaniline with thorny surface morphology towards triiodide ions and its impact on the dye-sensitized solar cell performance.

Controllable length adjustment of polyaniline particle with temperature sensitive block copolymer as template

Although the diameter of conductive polymer nanoparticles can be controlled effectively, the uniformity of particle length is still very challenging. In this study, with the temperature‐sensitive block copolymer PS111‐b‐PNIPAM114 as the template, the morphology and size of polyaniline (PANI) particles had been controllably adjusted through the change of temperature. Additionally, the electrochemical performance of each sample was investigated. After PS111‐b‐PNIPAM114 was synthesized through the reversible addition‐fragmentation chain transfer radical polymerization (RAFT), with its vesicular micelle as the “template”, the PANI particles with uniform length distribution were prepared successfully at 40°C. The average length of PANI particles after template removal was 254.07 nm with a short tail distribution, which was closer to the average than the standard normal distribution. Electrochemical results of PANI showed that it had good electrochemical activity with fast charge and discharge ability. And, with the current density of 1 A·g−1, its discharge‐specific capacitance could reach up to 805.61 F·g−1.

Synthesis, characterization and study of optical property of (PANI)1-x(MWCNT)x nanocomposites

The present paper deals with study of (PANI)1-x(MWCNT)x nanocomposites to find its materialistic possibilities in the application field of actuators, sensors, electronic devices and supercapacitors. The effect of doping concentration of multi walled nanotube (MWCNT) on surface morphology, structural and chemical properties of polyaniline (PANI), samples has been characterized by SEM and FTIR. SEM images show the appearance of lumps and holes into smooth PANI samples by addition of MWCNT nanoparticles. FTIR spectra also confirm the formation of PANI/ MWCNT nanocomposites. UV–VIS–NIR spectrophotometer is used to study the absorption spectra of the composite samples. The band gap energy (Eg) of the nanocomposites is determined using Tauc’s relationship. It has been observed that the increasing the MWCNT concentration in composites reduces the optical band gap which attributes the enhancement in electron delocalization along the polymer chain. Also, the increment in protons with MWCNT concentration extends the density of states more into visible region of EM spectra.

Improved electrocatalytic performance from graphene quantum dots/three-dimensional graphene/polyaniline doped powder to layer-by-layer self-assembled membrane materials

In this paper, three-dimensional network graphene and graphene quantum dots were prepared using graphite powder as the initial raw material. After that, the method of self-assembly of graphene quantum dots (GQDs) on the surface of three-dimensional graphene (3D-G) was used to prepare GQDs/3D-G composite to solve the problem of easy agglomeration of graphene in the process of composite preparation, and then it was mixed with polyaniline (PANI) aqueous solution in different contents to form graphene quantum dots/three-dimensional graphene/polyaniline (GQDs/3D-G/PANI) doped composite. The obtained GQDs/3D-G/PANI doped materials exhibited a specific morphology of nanoscale polyaniline firmly attached to the 3D networked graphene layer, which was attributed to the good dispersion of 3D network graphene and polyaniline in water. Graphene quantum dots facilitated close contact between the three-dimensional graphene sheet and the polyaniline particles, which significantly reduced agglomeration. In addition, driven by the strong electrostatic force between the positively charged polyaniline and the negatively charged GQDs/3D-G and the π-π interaction, the nano-scale GQDs/3D-G/PANI thin film layer was obtained by layer-by-layer self-assembly on the hydroxylated ITO plate, which showed the morphology of an interconnected layer network and exhibited good electrochemical catalytic activity for H2O2.