Chemical Oxidative Polymerization Research Articles

Synthesis and Characterization of Polythiophene and Polypyrrole

Polythiophene and polypyrrole are two well-known conducting polymers with diverse properties and several potential applications in sectors such as electronics, sensors, and energy storage. This paper delves further into the synthesis and analysis of polythiophene and polypyrrole. Polypyrrole and polythiophene were synthesized using chemical oxidative polymerization with suitable oxidizing agents. The methods employed to analyze these polymers included spectroscopy (UV-Vis, FTIR), thermal analysis (TGA, DSC), microscopy (SEM, TEM), and electrochemical analysis (cyclic voltammetry). Several features of polypyrrole and polythiophene production were investigated and linked to their electrochemical, thermal, morphological, and structural properties. We also discuss how these conducting polymers may be employed in electrical devices, sensors, and energy storage systems due to the unique properties revealed by their characterization. Polythiophene and polypyrrole may now be employed in a wide range of high-tech applications since their synthesis and properties are better known.

Effective move of Polypyrrole/TiO2 hybrid nanocomposites on removal of methylene blue dye by photocatalytic activity

Polypyrrole (PPy) was synthesized effectively by chemical oxidative polymerization of pyrrole. Organic-inorganic hybrid materials PPy-TiO2 with different PPy weight percents were prepared by mechanical mixing, by using titanium oxide nanoparticles. The characterizations of PPy-TiO2 hybrid nanocomposites were analyzed by FTIR, UV-Vis, XRD, TGA & DSC and SEM & EDAX. Fourier transform infrared (FTIR) spectra and X-ray diffraction (XRD) were used to distinguish the structure of the attained PPy-TiO2 hybrid nanocomposites. UV-vis techniques are proved the polymerization of pyrrole monomer and the strong interaction between PPy and TiO2 nanoparticles. Thermogravimetric analyzer (TGA-DSC) curves revealed that TiO2 can decrease the weight loss of nanocomposite and increase the thermal stability of synthesized nanocomposites. The residual mass of the pure Pyy-36.51%, PPy-TiO2 (25%)-64.82%, PPy-TiO2 (50%)-60.82%, PPy-TiO2 (75%)-70.50% and pure TiO2- 96.69% nanocomposites at the residual temperature 497.80 °C. The morphology and molecular structure of the hybrid nanocomposite were characterized by scanning electron microscope & Energy dispersive X-ray analysis spectroscopy (SEM & EDAX). These characterization results confirmed the polymerization of pyrrole and the strong interaction between PPy and TiO2. The material with outstanding absorption capability that meet in optical application is the challenging way, thus the photocatalytic analysis of PPy-TiO2 hybrid nanocomposites is merely a admissible results. It is notably the favorable degradation efficiency of pure PPy, the PPy+TiO2 (25% 50% & 75%) nanocomposites are 82%, 66%, 67% and 53% respectively.

Synthesis and characterization of enhanced azo-azomethine doped PANI/HCl conducting polymers for electrochemical applications

In this study, conducting polymers composed of polyaniline hydrochloric acid (PANI/HCl) with varying concentrations of a newly synthesized azo-azomethine dye (4-(((Z)-2-hydroxy-5-((Z)-(4-hydroxyphenyl)diazenyl)-3-methoxybenzylidene)amino)benzoic acid) were synthesized using a chemical oxidative polymerization technique. The synthesized azo-azomethine was characterized by FTIR, 1H-NMR, 13C-NMR, and HRMS. The effects of varying the concentration of the dopant azo-azomethine in PANI/HCl on its optical, structural, thermal, and electrical properties were examined using FTIR, UV–Vis, XRD, FESEM, TEM, cyclic voltammetry, and electrical impedance spectra. The results indicate that the optical, direct, and indirect band gaps of the doped polymers decreased from 4.48 and 3.96 eV to 3.91 and 2.49 eV, respectively. The crystalline structure and phase transitions in the doped polymers were examined using X-ray diffraction. Cyclic voltammetry demonstrated that the doped polymers exhibited higher electrochemical conductivity compared to the pure polymer, with the specific capacitance increasing from 161.17 to 816.9 F/g. The electrical impedance spectra revealed the bulk resistance and conductivity of the material. Among all the doped polymers, PANI/HCl with an azo-azomethine concentration of 5 × 10−5 M exhibited lower bulk resistance (10 Ω) and higher electrical conductivity (σ = 50.09 × 10−3 S cm−1).

Detecting low-concentration ammonia with a surface acoustic wave sensor using a silver nanoparticles–graphene–polypyrrole hybrid nanocomposite film

In this study, a surface acoustic wave (SAW) resonator coated with graphene/polypyrrole hybrid nanocomposite films decorated with silver nanoparticles (AgNPs-G/PPy) is proposed for detecting ammonia (NH3) in parts-per-billion concentrations. The AgNPs-G/PPy hybrid nanocomposite film was synthesized via in situ chemical oxidative polymerization. Scanning electron microscopy, energy-dispersive X-ray spectroscopy, and X-ray diffraction were used to characterize the AgNPs-G/PPy hybrid nanocomposite film, confirming its successful synthesis and identifying a wrinkled multilayered structure. The AgNPs-G/PPy hybrid nanocomposite film was spin-coated onto the surface of a stress-compensated temperature-cut quartz SAW resonator having an operating frequency of 98.5 MHz to create an NH3 gas sensor. NH3 adsorption by the AgNPs-G/PPy hybrid nanocomposite film modulated the acoustic wave velocity, and the corresponding frequency shift served as a sensing signal. The synergistic interaction between the three constituent materials (AgNPs, graphene, and polypyrrole) enhanced the sensitivity, selectivity, and response speed of the sensor for NH3 detection. At room temperature, the proposed sensor exhibited a positive frequency shift of 568 Hz when exposed to 50 ppb of NH3 gas and a rapid response time of less than 60 s. In addition, the SAW sensor exhibited excellent selectivity.

High‐performance supercapacitors using nanostructured polyaniline‐based carbon: Effect of electrolytes

AbstractDeveloping high‐performance materials for electrochemical energy storage devices such as batteries, and supercapacitors is a significant topic in material chemistry‐based research. The high consumption and limited availability of numerous materials used in energy devices lead to the development of alternative, effective, and cost‐effective materials exhibiting superior electrochemical chemical performance. A porous activated carbon, derived from polyaniline (PANI) synthesized through chemical oxidative polymerization, can be considered a viable solution in this context. In this study, the electrochemical window of the nitrogen‐doped porous activated carbon was enhanced through a combined synthesis process involving the carbonization and activation of PANI nanotubes with KOH. Moreover, alternations in surface area and porosity were evaluated using BET analysis for the samples having PANI to KOH ratios 1:0.5, 1:1, and 1:2. The results revealed a significant improvement in surface area and pore volume, increasing from 18 to 3535 m2/g from pure PANI to chemically treated samples. Among those materials, the PANI to KOH ratio of 1:1 exhibited the highest surface area of 3535 m2/g and the highest pore volume of 0.7131 cm3/g. Subsequently, the electrochemical performance of all materials was evaluated using a three‐electrode cell system and a symmetrical coin‐cell device. Electrodes fabricated with PANI to KOH ratio of 1:1 by weight showed better electrochemical performance in an aqueous electrolyte (6 M KOH) in both systems. This material exhibited the highest capacitance of 378 F/g (at 0.5 A/g) in the three‐electrode system and 143 F/g (at 0.5 A/g) in the SCCD. The SCCD achieved a maximum energy density of 23 Wh/kg with a power density of 544 W/kg. Additionally, these supercapacitors provided a good Coulombic efficiency of about 99% with capacitance retention of 97% at 7 A/g current density after 10 000 charge–discharge cycles. Further, this study expanded by investigating variations of electrochemical performance across various electrolytes, including aqueous, organic, and ionic liquids in coin‐cell supercapacitors. The findings reveal promising results, suggesting potential commercial applications for this facile approach to synthesize nitrogen‐doped activated carbon, especially for supercapacitors with aqueous electrolytes.

Trimethylamine N-oxide detection by electrochemical sensor based on screen printed electrode modified with molecularly imprinted polypyrrole-molybdenum(III) sulfide nanosheets

Trimethylamine N-oxide (TMAO) is a gut metabolite produced by dietary L-carnitine and choline metabolism. Its altered level in the serum has been implicated in human health and diseases such as colorectal cancer, chronic kidney diseases, cardiovascular diseases, etc. Early detection of TMAO in body fluids has been presumed to be significant in understanding the pathogenesis and treatment of many diseases. Hence, developing reliable and rapid technologies for its detection may augment our understanding of pathogenesis and diagnosis of diseases. Hence, in the present work, polypyrrole (Ppy)@molybdenum(III)sulfide (Mo2S3) nanosheets (NS) composite molecularly imprinted polymer (MIP) (Ppy@Mo2S3-MIP) based electrochemical sensor has been fabricated for the detection of TMAO. Polypyrrole (Ppy) and Mo2S3 NS have been synthesized by chemical oxidative polymerization and hydrothermal techniques, respectively. The synthesized nanocomposite has been validated using different techniques such as X-ray diffraction (XRD), Raman spectroscopy, Fourier transform infrared spectroscopy (FTIR), scanning electron microscopy (SEM), and transmission electron microscopy (TEM). The fabricated Ppy@Mo2S3-MIP sensor showed a linear detection range from 30 µM to 210 µM, a sensitivity of 1.21 μA μM−1 cm−2 and a limit of detection as 1.4 μM for the detection of TMAO and found more robust and improved when compared with Ppy-MIP using identical parameters. The fabricated sensor is also highly selective towards TMAO. It can be further used to detect TMAO in human samples such as urine quickly.

In situ polymerization of a poly(3,4-ethylenedioxythiophene):poly(sodium–styrennesulfonate) conductive layer for electro-assisted ultrafiltration and fouling mitigation

Electrification can enhance the antifouling performance of ultrafiltration membranes and improve the sustainability of membrane technologies. The design of high-performance conductive membrane materials remains one of the core technologies in electro-assisted ultrafiltration. Here, conductive PVDF/PEDOT:PSS composite membranes were prepared via in situ chemical oxidation polymerization on a PVDF surface. The PVDF/PEDOT:PSS membranes were subsequently used for electro-filtration to study the effect of the applied potential on humic acid fouling. When a voltage of 3 V was applied, the PVDF/PEDOT:PSS20 membrane was continuously polluted for 5 cycles. The results showed that after simple hydraulic cleaning, the membrane flux recovery rate reached 91 %. Compared with that of the PVDF membrane, the irreversible fouling of the PVDF/PEDOT:PSS20 membrane decreased by 65 %. The modified Poisson Boltzmann equation indicates that applying cathodic potential on the surface of PEDOT:PSS conductive layer increases the cumulative concentration of counter ions on the membrane surface and the thickness of the charged layer, thereby promoting the migration of peak forces on the membrane surface to the bulk solution, changing the fouling behaviour of HA from cake filtration to standard blocking.

Super capacitive electrode performance analysis of facile synthesized α-Fe2O3 aerogel and its nanocomposite with in-situ formed polyaniline (α-Fe2O3/PANI)

This paper presents the synthesis of an α-Fe2O3-assisted polyaniline (α-Fe2O3/PANI) nanocomposite using a straightforward two-step process. Initially, α-Fe2O3 aerogels with cratered nanohexagon structures are synthesized through a solution combustion method assisted by noni (Morinda citrifolia) fruit extract. In the second step, these nanohexagons facilitate the preparation of α-Fe2O3/PANI via in-situ chemical oxidative polymerization of anilinium chloride. The structural, optical, and morphological properties were characterized using X-ray diffraction (XRD), Fourier-transform infrared spectroscopy (FTIR), and scanning electron microscopy with energy-dispersive X-ray analysis (SEM-EDAX). Electrical conductivity, wettability, and electrochemical properties of the prepared materials were assessed. The results indicate that the 2D cratered α-Fe2O3 aerogel is effectively embedded within PANI, forming a modified nano α-Fe2O3/PANI composite. The composite exhibited altered DC conductivity and electrolyte wettability. After 200 cycles of cyclic voltammetry (CV), the specific capacitance of the nano α-Fe2O3/PANI was determined to be 153 Fg⁻¹ at a scan rate of 10 mVs⁻¹, retaining approximately 90% of its cycle stability. Electrochemical impedance spectroscopy (EIS) revealed significantly lower charge transfer and equivalent series resistance values for the nano α-Fe2O3/PANI electrode compared to the pure α-Fe2O3-based electrode. Galvanostatic charge-discharge (GCD) tests further demonstrated the superior electrochemical performance of the α-Fe2O3/PANI nanocomposite electrode. Therefore, this α-Fe2O3/PANI is an advanced conducting polymeric electrode for electrochemical applications.

Impact of varying magnetite nanoparticle concentrations on the structural, electrical, and magnetic properties of polyaniline-based magnetic nanocomposites

We report the synthesis of polyaniline/magnetite nanocomposites (PMNCs) via in situ chemical oxidation polymerization of aniline with magnetite nanoparticles (MNPs) at 5, 12, and 25 wt%. The objective was to evaluate how the MNPs’ proportion affects the electrical, magnetic, and structural properties, which were investigated using XRD, EDXRF, TEM, EIS, ESR spectroscopy, Mössbauer spectroscopy, and VSM. EDXRF confirmed the formation of MNPs, while XRD revealed the crystalline nature of MNPs and the semicrystalline structure of PANI, with a decrease crystallinity index as the MNPs percentage increased. TEM showed PANI encapsulating MNPs with average diameters of 9.7 ± 2, 9.9 ± 2, and 13.1 ± 3 nm for PMNC25, PMNC12, and PMNC5, respectively. Conductivity values of PANI, PMNC25, PMNC12 and PMNC5 were 7.96 ×10⁻⁴, 1.38 ×10⁻⁴, 2.19 ×10⁻⁴ and 2.31 ×10⁻⁴ S/cm, respectively. ESR indicated cationic radicals responsible for conductivity. Saturation magnetization (Ms) for MNPs, PMNC25, PMNC12 and PMNC5 were 93.4, 24.6, 11.8 and 5.6 emu/g, respectively, with superparamagnetic behavior observed. Our findings show that incorporating MNPs into the PANI matrix modulates electrical conductivity and magnetic properties while maintaining the nanocomposite’s structure, highlighting the multifunctional potential of these composites.

Effective thermoelectric properties with polyselenophene/CuxS composites

In this study, polyselenophene (PSe), which has more raw materials, lower cost, and can be processed more easily than inorganic thermoelectric materials, was synthesized as a polymeric thermoelectric material with a simple method by chemical oxidative polymerization in aqueous medium. Copper sulfide (CuxS) was synthesized and taken from it in different ratios compared to PSe, PSe/CuxS composites were prepared. The Seebeck coefficient of PSe is 160 μVK−1, while that of PSe/CuxS composite containing 30% CuxS is 410 μVK−1. The PSe/CuxS3 composite with 30% CuxS had the highest Seebeck coefficient and power factor, measuring 410 μVK−1 and 5043 μWm−1K−2, respectively. The electrical conductivity of PSe and PSe/CuxS composites obtained in this study is relatively high, ranging from 10 to 405 Scm−1. PSe and its composites were characterized by FTIR, UV–Vis., XRD, TGA, EDX, and FESEM.

Electrochemical properties of novel redox active electrode coatings based on heterocyclic polyazines and its nanocomposites with carbon nanomaterials

This work aims to study electrode materials based on unsubstituted polyazines and composites which will allow further advancing both in the molecular design of redox polymers, composites and materials and evaluating their potential applicability. The polymers were prepared by two-phase chemical oxidative polymerization. Polymer-carbon nanocomposites (NC) based on unsubstituted polyphenoxazine were prepared for the first time. The physicochemical and electrochemical properties were compared for NCs based on polyphenothiazine (PPTA), polyphenoxazine (PPOA) and carbon nanomaterials (CNM). The used CNMs comprise reduced graphene oxide (RGO), single-walled and multi-walled carbon nanotubes (SWCNT and MWCNT). The NC structure and morphology were studied by means of FT IR spectroscopy, XRD, FE-SEM and TEM. The limited solubility of some monomers prevents their electrochemical deposition on electrodes. Therefore, to study the electrochemical, spectroelectrochemical behavior and electrochemical impedance of novel redox active electrode coatings, suspensions of synthesized polymers or their NCs were applied onto electrodes and dried. The effect of NC composition on the conductivity and redox activity thereof was discovered. In general, composites have a higher conductivity than individual polymers. Despite differences in electrical conductivity, all samples exhibited electrocatalytic behavior demonstrated for example of Fe(II)/Fe(III) cyanide redox transition on a planar electrode in a K3[Fe(CN)6] solution in 1 M H2SO4. The electronic absorption spectra were recorded in-situ in an electrochemical cell by varying the working electrode potential and showed an electrochromic effect for PPTA and CNM/PPTA. The proposed common equivalent electric circuit allowed explaining the different electrochemical properties of polymers and CNM composites thereof.

PEDOT-Doped Mesoporous Nanocarbon Electrodes for High Capacitive Aqueous Symmetric Supercapacitors.

Poly(3,4-ethylenedioxythiophene) (PEDOT) and PEDOT-functionalized carbon nanoparticles (f-CNPs) were synthesized by in situ chemical oxidative polymerization and pyrolysis methods. f-CNP-PEDOT nanocomposites were prepared by varying the concentration of PEDOT from 1 to 20% by weight (i.e., 1, 2.5, 5, 10, and 20 wt%). Several characterization techniques, such as field-emission scanning electron microscopy (FESEM), attenuated total reflectance-Fourier transform infrared (ATR-FTIR), X-ray diffraction (XRD), N2 Brunauer-Emmett-Teller (BET) and Barrett-Joyner-Halenda (BJH) analyses, as well as cyclic voltammetry (CV), galvanostatic charge discharge (GCD), and electrochemical impedance spectroscopy (EIS), were applied to investigate the morphology, the crystalline structure, the N2 adsorption/desorption capability, as well as the electrochemical properties of these new synthesized nanocomposite materials. FESEM analysis showed that these nanocomposites have defined porous structures, and BET surface area analysis showed that the standalone f-CNP exhibited the largest surface area of 801.6 m2/g, whereas the f-CNP-PEDOT with 20 wt% exhibited the smallest surface area of 116 m2/g. The BJH method showed that the nanocomposites were predominantly mesoporous. CV, GCD, and EIS measurements showed that f-CNP functionalized with 5 wt% PEDOT had a higher capacitive performance compared to the individual f-CNPs and PEDOT constituents, exhibiting an extraordinary specific capacitance of 258.7 F/g, at a current density of 0.25 A/g, due to the combined advantage of enhanced electrochemical activity induced by PEDOT doping, and highly developed porosity of f-CNPs. Symmetric aqueous supercapacitor devices were fabricated using the optimized f-CNP-PEDOT doped with 5 wt% of PEDOT as active material, exhibiting a high capacitance of 96.7 F/g at 1.4 V, holding practically their full charge, after 10,000 charge-discharge cycles at 2 A/g, thus providing the highest electrical electrodes performance. Hereafter, this work paves the way for the potential use of f-CNP-PEDOT nanocomposites in the development of high-energy-density supercapacitors.

Poly-m-aminophenol/CoFe2O4 (p-n) heterojunction: Sustainable decontamination of BPA, ciprofloxacin pollutants from water and its study of antimicrobial performance

The remarkable ability of magnetic p-n heterojunction catalyst constructed with p-type poly-m-aminophenol (PmAP)/n-type Cobalt ferrite (CoFe2O4) catalyst to degrade BPA, ciprofloxacin drug (CIF) and its antibacterial activity in killing the microbes was explored on Gram-positive (S. aureus) and Gram-negative (E. coli). The p-n heterojunction photocatalyst was synthesized easily via hydrothermal reaction followed by chemical oxidative polymerization process. PXRD, FTIR, SEM, HRTEM, XPS, EDX, PL/TRPL, BET surface area, VSM and Uv-DRS techniques were used to confirm the synthesized catalyst's physicochemical characteristics and structural details. At ambient conditions, the synthesized catalyst showed rapid mineralisation of the organic pollutants by nearly 100 % at a concentration of 50 ppm in just one hour, with a catalyst loading of 0.1 g. The mineralisation pathways of the organics were illustrated through the GC–MS and TOC analysis. Furthermore, the disinfection capacity of the heterojunction had showed 5 fold quicker than the individual catalysts. This p-n heterojunction catalyst show excellent activity and quick magnetic separable quality which make it a catalyst for sustainable water purification process in future.

Conjugated polymers decorated lignocellulosic nanocomposites for malachite green contaminated water remediation

Various novel conjugated polymer composites were synthesized via in situ chemical oxidative polymerization on lignocellulosic waste, notably Azadirachta indica sawdust. The composites, including Azadirachta indica/polyindole (AIS/PIn), Azadirachta indica/polyaniline (AIS/PAn), Azadirachta indica/polythiophene (AIS/PTh), and Azadirachta indica/polypyrrole (AIS/PPy), were investigated for their porous structure, ease of synthesis, unique adsorptive properties, and adjustable morphology. The synthesized composites were characterized using SEM/EDS, TEM/SAED, XRD, BET, TGA, and FTIR, revealing detailed insights into their structural and morphological features. The potential of these composites as efficient adsorbents for removing malachite green (MG) dye from water was a vital focus of this research. Batch experiments were conducted to assess the impact of various factors on adsorption, such as adsorbent/adsorbate contact time (0–280 min.), adsorbent dosage (0.4–20.0 g/L), initial adsorbate concentration (25–100 ppm), pH (2–13), and temperature (30–60 °C). The results indicate a remarkable removal efficiency of 89.98 % for MG with an initial concentration (Co) of 50 mg/L, achieved within 120 min using 0.4 g/L of AIS/PIn at a pH above 8.3. The Langmuir adsorption isotherm model provided the best fit for the experimental data, with maximum adsorption capacities of 384.61 mg g−1 for AIS/PIn, 344.82 mg g−1 for AIS/PAn, 277.77 mg g−1 for AIS/PTh, and 256.41 mg g−1 for AIS/PPy. This suggests monolayer adsorption. The adsorption kinetics conformed to a pseudo-second-order model, with the process being endothermic, feasible, and associated with positive entropy, thereby underlining its favorability and spontaneity. The desorption studies determined that 0.1 M HCl was the most effective desorbing agent compared to NaOH, NaCl, CH3COOH, and H2O. The spectral and effect of pH analyses suggested that the adsorption mechanisms might involve multiple interactions, prominently including electrostatic interactions, hydrogen bonding, π-π interactions, and n-π interactions. Based on the findings, it is submitted that the conjugated polymer decorated biomass composite adsorbents exhibit reasonable recyclability over multiple cycles, versatility, and potent efficacy as low-cost adsorbents for eliminating MG dye from aqueous systems.

Elucidating the role of Ag+, Cu2+, and Fe3+ in tuning the electrical characteristics of polyaniline prepared through post-doping method

Abstract Conducting polymers possess inherent electrical conductivity, attracting significant attention in engineering applications, including dye-sensitized solar cells, gas sensors, and energy storage electrodes. Of various conducting polymers, Polyaniline has gained much attention due to its low cost of monomer, ease of bulk synthesis, high flexibility, and good environmental stability. Nevertheless, the conductivity of polyaniline is rather low when it is prepared under an un-doped state. Despite that, there is no clear information regarding how the valency of a metal dopant and its concentration can affect the electrical characteristics and other physicochemical properties of doped polyaniline. This study aims to fill this research gap by elucidating the changes in the electrical characteristics of polyaniline through metal doping. Polyaniline was synthesized through chemical oxidative polymerization in an HCl medium, followed by a post-doping to produce metal-codoped polyaniline. Three dopant materials, namely AgNO3, Cu(NO3)2, and Fe(NO3)3, were used in this synthesis, representing mono-, di-, and tri-valent metal ions, respectively. Results showed that bare PANI (which was doped with HCl only) exhibited a higher electrical conductance value of 8.44 x 10-7 S, while 1 M of Ag-codoped polyaniline, 1 M of Cu-codoped polyaniline, and 1 M of Fe-codoped polyaniline exhibited electrical conductance values of 1.73 x 10-7 S, 4.27 x 10-8 S, and 2.33 x 10-6 S, respectively. Apparently, the trivalent metal dopant was able to improve the conductivity of polyaniline; however, a detrimental effect resulted when the concentration of Fe3+ was increased to 1.5 M (overdose), resulting in a drop in electrical conductance to 4.66 x 10-8 S. In terms of morphological property, Ag-doped polyaniline exhibited a mixture of plate-like and globule-like structures, while both Cu-doped polyaniline and Fe-doped polyaniline predominantly displayed tiny globule-like structures, likely attributed to the stronger acidity of the Cu(NO3)2 and Fe(NO3)3 solutions. Meanwhile, the presence of several common bands of polyaniline such as N-H, C=N, C-H aromatic, quinoid and benzoid units are detected in the produced samples. The project outcomes are expected to guide tailored development of metal-doped polyaniline for specific electrical applications.

Enhancing electron transfer in anaerobic process by supercapacitor materials: Polyaniline functionated activated carbon

Strengthening the direct interspecies electron transfer (DIET) is an effective strategy to improve the performance of anaerobic digestion (AD) process. In this study, the polyaniline functionated activated carbon (AC-PANi) was prepared by chemical oxidative polymerization. This material possessed pseudo-capacitance properties as well as excellent charge transfer capability. The experimental results demonstrated that the incorporation of AC-PANi in AD process could efficiently increase the chemical oxygen demand (COD) removal (18.6 %) and daily methane production rate (35.3 %). The AC-PANi can also act as an extracellular acceptor to promote the synthesis of adenosine triphosphate (ATP) and secretion of extracellular enzymes as well as cytochrome C (Cyt-C). The content of coenzyme F420 on methanogens was also shown to be increased by 60.9 % with the addition of AC-PANi in AD reactor. Overall, this work provides an easy but feasible way to enhance AD performance by promoting DIET between acetate-producing bacteria and methanogens.

Synthesis, characterization and microwave absorption properties of BaFe12O19/Ni0.5Mn0.5Fe2O4@ polyaniline nanocomposites with different ferrite percentages

AbstractIn this paper, BaFe12O19/Ni0.5Mn0.5Fe2O4@PANI core‐shell nanocomposites were synthesized with different ferrite/PANI ratios. The Ferrite nanoparticles were prepared by the auto‐combustion sol–gel method. Chemical oxidative polymerization of aniline in acidic solution along with adding ferrite nanoparticles to the composition was used for the synthesis of nanocomposites. The product then was studied by X‐ray diffractometer)XRD(, field emission scanning electron microscope (FE‐SEM), transmission electron microscope (TEM), and Fourier transform infrared spectroscopy (FTIR) analyses. The magnetic properties of samples were investigated with vibrating sample magnetometer (VSM). Also, nanocomposite samples were examined in terms of the ability to absorb microwaves. Using Vector Network Analyzer (VNA). the reflection loss (RL) of nanocomposites was measured at frequencies between 2 and 18 GHz. The minimum reflection loss (RLmin) was obtained at −36.98 dB at the frequency of 13.8 GHz with an effective absorption bandwidth of 4.87 GHz for the sample with the equal ratio of ferrite/PANI. Synthesized nanocomposite as an effective compound has very high reflection loss in a wide frequency range.Highlights Thermal stability is improved by adding ferrite nanoparticles to polyaniline. The polymer shell reduces the magnetic properties of ferrite nanoparticles. There is a strong exchange coupling between hard and soft ferrite. Ferrite/polymer ratio of 1:1 has the lowest amount of reflection loss. In the X and Ku band, magnetic loss is mainly caused by eddy currents.

EMI shielding study of PVC-PT-Ag/ZnS nanocomposites in microwave region

Chemical oxidative polymerization and hydrothermal methods were employed to synthesize polythiophene (PT) and silver-doped zinc sulfide (Ag/ZnS) nanoparticles for electromagnetic interference (EMI) shielding applications. Composite films based on PVC were fabricated by incorporating these nanoparticles, both Ag/ZnS and PT-Ag/ZnS. Initially, X-ray diffraction and zetasizer technology were utilized to analyze the crystal structure and particle size of these nanoparticles. Subsequently, the nanocomposite films were assessed for various properties, including electrical conductivity and transmittance in the near-infrared wavelength range of 200–800 nm, as well as their effectiveness in shielding electromagnetic interference in the microwave frequency range of 0.1–20 GHz. The aforementioned features were investigated using DC conductivity, vector network analysis, and NIR spectroscopy. It was discovered that both conductance and shielding effectiveness increased to 0.029 S/cm and 54 dB, respectively, as the nanoparticle density increased. At 20 wt% PT-Ag/ZnS, the maximum attenuation value within the 0.1–20 GHz frequency band reached 54 dB, with transmittance below 0.5 %.

Polyaniline/hollow glass beads/carbon fiber powder composite film for multifunctional military tarpaulins

In this paper, a composite film with a thickness of 0.25 mm was prepared, which has the functions of infrared stealth, ultraviolet protection, sound absorption, and thermal insulation. Firstly, polyaniline was synthesized through chemical oxidative polymerization using aniline as a monomer, acetic acid as a dopant, and ammonium persulfate as an oxidant. Then, the synthesized polyaniline (PANI), hollow glass beads (HGB), and carbon fiber powder (CFP) were sequentially added to waterborne polyurethane, and a film coating machine was used to prepare a multifunctional composite film of PANI/HGB/CFP. Finally, the composite film's infrared properties, ultraviolet protection properties, sound absorption properties, thermal constants, resistance to water penetration properties, bending properties, tensile properties, chemical corrosion resistance, and aging resistance were tested. The results show that the prepared PANI/HGB/CFP composite film has an infrared emissivity of 0.668 and an ultraviolet protection factor (UPF) of 1072, indicating that it can block more than 99 % of ultraviolet rays. Additionally, it has an acoustic absorption coefficient of 0.386. At the same time, the thermal conductivity is 0.04629 W/mK, making it a highly efficient material for heat preservation and thermal insulation. The prepared PANI/HGB/CFP composite film is expected to be a new multifunctional military tarpaulin.

Investigation of TiO2/PPy nanocomposite for photocatalytic applications; synthesis, characterization, and combination with various substrates: a review.

The use of photocatalysis technology, specifically visible light photocatalysis that relies on sustainable solar energy, is the most promising for the degradation of contaminants. The interaction of conducting polymer and titanium dioxide (TiO2) leads to the exchange that enhances the alteration of the semiconductor's surface and subsequently decreases the bandgap energy. Polypyrrole (PPy) and TiO2 nanocomposites have promising potential for photocatalytic degradation. Chemically and electrochemical polymerization are two predominant methods for adding inorganic nanoparticles to a conducting polymer host matrix. The most commonly utilized method for producing PPy/TiO2 nanocomposites is the in-situ chemical oxidative polymerization technique. Immobilizing PPy/TiO2 on substrates causes more charge carriers (electron/hole pairs) to be produced on the surface of TiO2 and enhances the rate of photocatalytic degradation compared to pure TiO2. The increased surface charge affects how electron/hole pairs are formed when visible light is used. This study provides a comprehensive investigation into the synthesis, characterization, application, efficiency, and mechanism of PPy/TiO2 nanocomposites in the photocatalytic degradation process of various pollutants. Furthermore, the effect of stabilizing the TiO2/PPy nanocomposite on various substrates will be investigated. In conclusion, the review outlines the ongoing challenges in utilizing these photocatalysts and highlights the essential concerns that require attention in future research. Its objective is to help researchers better understand photocatalysts and encourage their use in wastewater treatment.