Papers by Keyword: Polyaniline

Abstract: Ultraviolet (UV) photodetectors have garnered considerable attention because of their critical roles in diverse technological applications. This study reports the fabrication and characterization of single-walled carbon nanotube (SWCNT)/polyaniline (PANI) nanocomposite films prepared via the spin-coating technique on Indium Tin Oxide (ITO) substrates for ultraviolet (UV) photodetector applications. Two weight concentrations of SWCNTs (0.04 g and 0.06 g) were investigated to assess their influence on the optical and structural properties of the films. Structural consistency was confirmed using scanning electron microscopy (SEM), while UV–visible spectroscopy revealed optical band gaps of 1.60–2.08 eV. Electrical characterization demonstrated that an increased SWCNT content led to an enhanced current response. The device with 0.04 g SWCNT achieved a detectivity of 1.12 × 10¹⁶ Jones and a photoresponsivity of 11.361 μA/mW, with response and recovery times of 0.36 s and 0.34 s, respectively. The 0.06 g SWCNT device showed improved performance, reaching a photoresponsivity of 12.1414 μA/W and detectivity of 1.43 × 10¹⁶ Jones, with response and recovery times of 0.36 s and 0.38 s, respectively. These findings demonstrate the potential of SWCNT/PANI composites for high-performance UV photodetector applications.

Abstract: This study provides accounts of the bonding character, electronic structure, and optical properties of the cellulose–polyaniline hybrid complex using principles of quantum mechanics. The calculations revealed cellulose and polyaniline binding energy per unit ranged from -0.52 eV to -0.68 eV. The electron localization function of the complex revealed that there was no value at the interface but deformed basins, indicating a physisorption type of interaction. The highest occupied molecular orbitals and lowest molecular orbitals are mainly dominated by the polyaniline, with minor hybridization of the orbitals of the cellulose in all configurations. These results indicate that the bonding between cellulose and polyaniline is characterized as an unshared electron interaction. Generally, the density of states of the cellulose and polyaniline complex can be considered a superposition of the states of isolated subsystems—the bandgap of the complex ranges from 2.30 eV to 2.87 eV. The lowest bandgap is observed when the prototype polyaniline is placed near the cellulose hydroxy and hydroxymethyl group. Further, the optical absorption spectra are calculated using time-dependent density functional theory. The results indicate that the prominent peak of the prototype polyaniline at 3.59 eV (345.36 nm) is suppressed at the complex. Meanwhile, in the higher energy region, the optical absorption spectra can be considered a superposition of the absorption spectra of the isolated constituents. The results presented here provide new information on the cellulose–polyaniline complex's bonding mechanism and give the resulting electronic–optical properties. The results will be helpful in the development of innovative biomaterials, fibers, and multifunctional composites based on cellulose and polyaniline.

Abstract: In this study, we used green tea extract to prepare Silver-PANI nanocomposites and incorporated varying percentages of platinum oxide through in-situ chemical polymerization. The synthesized Ag-PANI/PtO₂ conducting polymer nanocomposites were characterized using FT-IR, XRD, and SEM analysis, which showed uniform incorporation of PtO₂ in the nanocomposites. EMI shielding effectiveness results demonstrated that the Ag-PANI/PtO₂ (10%) composite effectively shields electromagnetic interference. The EMI SE results showed that PtO₂ exhibited good absorption in the range of 2-3 GHz, indicating its conducting behaviour. Additionally, the Ag-PANI/PtO₂ (6%) and Ag-PANI/PtO₂ (10%) composites demonstrated good absorption in this range, likely due to the proper mixing of platinum oxide and silver-decorated polyaniline within the polymer matrix. Therefore, silver polyaniline decorated conducting polymer composites are a promising material for effectively shielding electromagnetic radiation in electronic devices.

Abstract: This paper attempts to evaluate the use of composite of polyaniline (PANI)/palm kernel shell-derived porous carbon (C-PKS) as alternative materials for supercapacitor electrodes. The preparation of PANI/C-PKS composites was carried out using an in-situ polymerization method. After the composite was formed, the structures and morphologies were characterized using an N2-sorption analyzer, SEM - EDX, and TGA. As for the performance of supercapacitor electrodes, the composite was tested using a three-electrode system. Structural and morphological characterization results showed that PANI was successfully deposited in C-PKS. The amount of PANI deposited in C-PKS was ca. 7.5%, obtained from TGA analysis. Meanwhile, the capacitance performance test results showed that the PANI/C-PKS composite featured a specific capacitance of ca. 116 F/g. There was an increase in specific capacitance compared to the blank material (C-PKS only) which showed only 94 F/g.

Abstract: This study employed the template-free chemical oxidative polymerisation method to synthesise polyaniline (PANI) and polyaniline/tin-doped titania (PANI/Sn-doped TiO₂) nanocomposite as corrosion inhibitors. FTIR and XRD were employed to characterise the chemical composition of the prepared samples. TEM and FESEM microscopy validated the presence of the PANI and that the Sn-doped TiO₂ nanoparticle were successfully incorporated into PANI to form the nanocomposite. The synthesised materials were mixed in the polyvinyl butyral (PVB) binder, coated onto mild steel substrates, and exposed to 3.5 wt.% NaCl solution for 30 days. Altogether, three coating systems were tested, i.e., pure PVB, PVB + PANI, and PVB + PANI/Sn-doped TiO_2. The corrosion parameters were measured via EIS and Tafel polarisation techniques. Overall, the PANI/Sn-doped TiO₂ nanocomposite as a corrosion inhibitor effectively inhibited the corrosion of the mild steel, and its corrosion rate was 3.484 x 10^-7 mm/year.

Abstract: Mesoporous silica nanoparticles and polyaniline (PANI) are widely used in many potential applications. This work establishes a new formulation that functionalizes the surface of mesoporous silica MCM-41 nanoparticles with a brush polymer of polyaniline to synergistically combine their properties. The new formulation is designed to fit in many applications due to its high surface area and good electrical conductivity. Results showed the successful preparation of MCM-41 with a spherical porous structure. The polyaniline functionalization on MCM-41 was confirmed by FTIR.

Abstract: In this study, polyaniline (PANI) was synthesized through oxidative polymerization assisted by sodium dodecylbenzene sulfonate (SDBS) in hydrochloric acid (HCl) concentration solution to investigate the effect of dopants in the electrical conductivity of polyaniline. The polyaniline obtained from the oxidative polymerization was confirmed with FTIR. The x-ray diffraction pattern showed that polyaniline is semi-crystalline. SDBS does not only act as a template for oxidative polymerization but also acts as a dopant. The dielectric constant, the dielectric loss, and the ac conductivity increase as polyaniline is doped with SDBS, HCl, or with both SDBS and HCl.

Abstract: Composite of polyaniline-MgCl has been synthesized using oxidative polymerization method. Synthesized samples were characterized for structural analysis using FTIR and XRD. Morphological studies were carried by SEM micrographs. Current-Voltage (I-V) properties are obtained through Kiethly source meter. FTIR spectrum of polyaniline-MgCl composite indicates all the characteristic peaks of polyaniline. X-ray diffraction patterns represented the amorphous nature of polyaniline-MgCl composite. SEM micrographs confirmed the presence of MgCl particles in polyaniline matrix. I-V characteristics have shown the ohmic type behavior of polyaniline and polyaniline-MgCl composite.

Abstract: Atomic force microscopy techniques (conductive-AFM, I-V spectroscopy and PFM) were used for characterisation of the local electrical properties of bilayer polyaniline-polystyrene/P(VDF-TrFE) polymer nanocomposite. Observed hysteresis of current-voltage characteristics confirms its memristive properties. It was caused by the influence of the ferroelectric polarization of P(VDF-TrFE) layer, the domain structure of which was visualised by piezoelectric force microscopy on the transport of charge carriers at the interface.

Abstract: In this study, facile preparation using a new solvent – lactic acid and physical properties of PAni-Cs films are observed. The main goal of the study is to easily synthesize PAni-Cs films using lactic acid as solvent through the solvent casting method and investigate if producing PAni-Cs with lactic acid will enhance its properties. The presence of PAni-Cs was confirmed by observing its structure using Fourier transform infrared (FTIR) spectroscopy. The wettability of the films showed that films produced with lactic acid are less hydrophobic than those produced with acetic acid. Consequently, the computed surface energies revealed PAni-Cs films produced using lactic acid were higher. Water uptake of the films showed deviations when PAni and the solvents (lactic acid and acetic acid) were introduced. Furthermore, films produced with lactic acid were observed to be more flexible. These characterizations revealed that PAni-Cs produced with lactic acid are comparable to the properties of those produced with acetic acid showing that lactic acid helps in the improvement of PAni-Cs surface properties.