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UV–Visible spectra of polyaniline emeraldine salts and base in DMSO. (a) PANIPI, (b) PANIDN, (c) PANICl and (d) PANIEB.
Source publication
Polyaniline (PANI) doped with nitro compounds such as 2,4,6-trinitrophenol i.e., picric acid, 3,5-dinitrobenzoic acid and hydrochloric acid in the emeraldine salt form was synthesized by chemical oxidative polymerization. Polyaniline emeraldine base (PANIEB) was prepared by dedoping polyaniline chloride (PANICl). The as-synthesized PANIs were chara...
Contexts in source publication
Context 1
... UV-Visible absorption spectra of PANIs ( Fig. 4a-d) gen- erally depend on the level of doping, extent of conjugation, nature of the polymer and solvent (Roy et al., 2002). PANIEB exhibits two bands around 330-360 nm and 600 nm character- istic of two chromophores, representing emeraldine oxidation and Gupta, 1995). When PANI is doped with acids, the qui- noid bands exhibit hypochromism ...Context 2
... gen- erally depend on the level of doping, extent of conjugation, nature of the polymer and solvent (Roy et al., 2002). PANIEB exhibits two bands around 330-360 nm and 600 nm character- istic of two chromophores, representing emeraldine oxidation and Gupta, 1995). When PANI is doped with acids, the qui- noid bands exhibit hypochromism as shown in Fig. 4a-c indi- cating the presence of random coil configuration in PANI salts. The characteristic low wavelength polaron bands around 400-440 nm due to the conductive form of PANIs are observed only with PANI salts. In all the PANI salts, besides these peaks a small free electron absorption tail is observed in the region of 800-1100 ...Similar publications
In this work, polyaniline (PANI) in emeraldine-base form, synthesized by chemical oxidation polymerization, was protonated with hydrochloric acid (HCl). Composites based on high-density polyethylene (HDPE) and linear-low density polyethylene (LLDPE) blends with PANI were prepared in molten condition using a torque rheometer. The effect of compatibi...
Citations
... The FTIR spectra of PANI, GNP and PANI-GNP (figure 4) confirmed the composite formation of PANI and GNP. FTIR spectrum of PANI exhibited bands at 3018 cm −1 ,1580 cm −1 , 1496 cm −1 , 1370 cm −1 , 1210 cm −1 and 819 cm −1 indicating C-H, C=N, C=C, C=H , C-N, in plane and out of plane aromatic C-H stretching vibrations respectively [43][44][45][46][47][48]. In the FTIR spectrum of the PANI-GNP composite, the bands at 3416 cm −1 , 3237 cm −1 , 2921 cm −1 , 1674 cm −1 , 1280 cm −1 , 1171 cm −1 , and 820 cm −1 indicated the stretching vibrations of the O-H bond, C=C bonds, C-O bonds, and C-H bending vibrations [49,50]. ...
Polyaniline (PANI) and its graphene-doped composite (PANI-GNP) were subjected to open-aperture (OA) z-scan studies to investigate their nonlinear optical (NLO) properties and optical limiting (OL) behavior. The z-scan experiments were carried out using a nanosecond pulsed Nd:YAG laser at a wavelength of 532 nm. The z-scan studies revealed that PANI and PANI-GNP composites exhibited a reverse saturable absorption (RSA), and graphene doping modified the NLO behaviour and improved the OL property. The nonlinear absorption coefficient (β), OL threshold, and imaginary part of nonlinear susceptibility ( χi(3) ) of PANI and PANI-GNP were calculated for three different laser input pulse energies and found to be in the order of 10⁻⁹ cm W⁻¹, 10⁶ W cm⁻², and 10⁻¹⁰ esu, respectively. These results qualify the PANI-GNP composite as having potential applications in OL and optoelectronic devices. The successful incorporation of graphene into PANI in PANI-GNP composite was confirmed by scanning electron microscopy (SEM), transmission electron microscopy (TEM) and Fourier transform infrared spectroscopy (FTIR). Linear optical properties were analysed using UV–visible absorption spectroscopy. To the best of our knowledge, the present work is the first attempt to explore the intensity-dependent NLO properties, OL behaviour and the calculation of their related NLO parameters of PANI-GNP composites.
... 10 Dhivya et al. discovered that protonated PANI exhibited a remarkable 2-fold increase in antibacterial efficacy compared to that of its deprotonated counterpart when tested against an array of Gram-positive bacterial species and fungi. 11 Omar et al. showed that PANI, with an optimal concentration of 30% ...
... BV0.5D showed bands around 256 nm and 530 nm which resulted from two characteristic chromophores found in the EB form of PANI [73]. They correspond to ππ * transition of aromatic rings and intramolecular electronic transitions between quinoid and benzenoid units, respectively [74]. During doping of PANI with acidic dopants, there is a hypochromism in quinoid bands and random coil configuration [74]. ...
... They correspond to ππ * transition of aromatic rings and intramolecular electronic transitions between quinoid and benzenoid units, respectively [74]. During doping of PANI with acidic dopants, there is a hypochromism in quinoid bands and random coil configuration [74]. The low wavelength polaron band around 400-440 nm is seen only in the conductive form of PANI [75]. ...
Polyaniline (PANI) was in-situ polymerized on nanofibrous polycaprolactone mats as cell-free antioxidant cardiac patches (CPs), providing electrical conductivity and antioxidant properties. The fabricated CPs took advantage of intrinsic and additive antioxidant properties in the presence of PANI backbone and ascorbic acid as a biocompatible dopant of PANI. The antioxidant nature of CPs may reduce the serious repercussions of oxidative stress, produced during the ischemia-reperfusion (I/R) process following myocardial infarction. The polymerization parameters were considered as Aniline (60 mM, 90 mM, and 120 mM), ascorbic acid concentrations ([aniline]:[ascorbic acid]=3:0, 3:0.5, 3:1, 3:3), and polymerization time (1h and 3h). Mainly, the more aniline concentrations and polymerization time, the less sheet resistance was obtained. 1,1 diphenyl-2-picrylhydrazyl (DPPH) assay confirmed the dual antioxidant properties of prepared samples. The advantage of the employed in-situ polymerization was confirmed by the de-doping/re-doping process. Non-desirable groups were excluded based on their electrical conductivity, antioxidant properties, and biocompatibility. The remained groups protected H9c2 cells against oxidative stress and hypoxia conditions. Selected CPs reduced the intracellular ROS content and mRNA level of caspase-3 while the bcl-2 mRNA level was improved. Also, the selected cardiac patch could attenuate the hypertrophic impact of hydrogen peroxide on H9c2 cells. The in vivo results of the skin flap model confirmed the CP potency to attenuate the harmful impact of I/R.
... The characteristic absorption peak at 3430 cm − 1 due to -N-H stretching vibration appears as a broad band because of the electronic transition from the valance band to the conduction band in PAni, an absorption peak at 2922 cm − 1 showing the presence of -C-H aromatic stretching bands. The weaker peak appears at 833 cm − 1 and could be referred to as -CH-in-plane deformation on the aniline ring (1, 4-disubstituted aromatic rings), the -C-C ring deformation peak appears at 613 cm − 1 [19][20][21][22][23][24]. The FT-IR spectrum of the PAni-QUA composite, as shown in Fig. 1(c), also exhibits the typical absorption peaks at 3468, 3055, 1644, 1578, 1493, 1304, 1134, 829, 718 and 507 cm − 1 . ...
... The FTIR spectral analysis of PANI has revealed that the vibration peaks at 3196 cm -1 and 1647 cm -1 correspond to N-H stretching [26,29] and N-H bending vibrations band respectively, due to amines. The characteristic vibration at 1566 cm -1 indicates the signature of the PANI back bone, arising due to the C=C stretching modes of the quinoid ring [26][27][28]. The C=C stretch was also present at 1488 cm -1 due to the benzenoid rings [28]. ...
... FTIR result of PANI/PU composite coatings using coconut-based/PPG blend polyols at different amounts of polyaniline nanoparticles revealed that -NH-stretching absorption were observed due to urethane linkages. A carbonyl group C=O peak was detected at 1737 cm -1 due to non-bonded urethane as varied polyaniline nanoparticles content were incorporated in the PU matrix.Vibration peaks at 1568-1564 cm -1 are C=C stretching band due to the quinoid ring (N=Q=N) in the PANI backbone [26][27][28]. Due to the aromatic amine of PANI, the C-N stretching band was observed at 1293 cm -1 in PANI/PU composite coatings, which is absent in PU-based coating, suggesting a successful incorporation of polyaniline nanoparticles in PU matrix. Hence, PANI/PU composite coatings have been successfully fabricated. ...
Polyurethane coating has been widely used as a protective coating due to its wide range of mechanical strength, excellent abrasion resistance, toughness, low-temperature flexibility, and chemical resistance, simplicity in production and application, and superior protection on corrosion to mild steel. No studies have been reported utilizing coconut-based/PPG blend polyols to produce polyurethane-based protective coatings on mild steel. Therefore, in this work, we fabricated polyurethane-based protective coating using coconut-based/PPG blend polyols for anti-corrosion application. Due to low adhesion strength of Polyurethane-based protective coating, the incorporation of nano-fillers into the polymer matrix improved the adhesion strength of the coating due to its functional benefits and its effects gave rise to increased intermolecular bonding, hydrogen bonding, van der waals, magnetism, and surface energy. Therefore, we fabricated PANI/PU composite coatings with varied amounts of polyaniline nanoparticles on mild steel using coconut-based/PPG blend polyols exposed in 3.5 wt% NaCl aqueous solution for anti-corrosion application. Characterizations like Fourier Transform Infrared Spectroscopy (FTIR), Potentiodynamic Polarization (Tafel plot), contact angle, adhesion test, FESEM, XRD, and UV-VIS were used in this study. Tafel plot revealed that PU-based and PANI/PU composite coatings exhibited a significant reduction in corrosion current density (Icorr), perhaps due to the adsorption of inhibitor in the surface of the mild steel which reduced corrosion rate of the metal by retarding the anodic process and impeding the corrosive species from the surroundings. Among all fabricated coatings, 0.5-PANI/PU composite coating was the best, having a less corrosion rate of 5.66x10-5 mmpy compared to others. In addition, its surface was more compact, smooth, rigid, and no voids present at the interface according to the result of FESEM, suggesting better corrosion protection to mild steel. Hence, PU-based protective coating and PANI/PU composite coatings using coconut-based/PPG blend polyols inhibited the penetration of the corrosive species and served as an adequate barrier protection against corrosion for mild steel.
... The peaks at 1117 cm 1 and 1132 cm 1 are due to aromatic C-H in-plane and the transmission band at 795 cm 1 exhibits C-H out-o-plane bending vibration that is related to the deormation pattern [34]. The presence o C--N + sites with dopant ions on PANI is indicated by the peak in the range o 2300-2800 cm 1 [36]. In doped PANI, a strong transmission peak at 2349 cm 1 was observed, indicating the existence o such sites. ...
... Additionally, the stretching and bending vibrations between 1600 and 500 cm 1 were shited, indicating that NH 4 OH has removed the chloride ions rom doped PANI (Fig. 2 (b)). The obtained spectra show closely comparable values that were stated in the previous study [23,[35][36][37]. Slight variations in the band stretching may be due to the alteration in the method o polyaniline synthesis. ...
We developed a cost-effective, user-friendly smartphone-based sensor equipped with a polyaniline (PANI) label along with optical components and monitored the freshness of three different varieties of fish fillets i.e., Rohu (Labeo rohita), Mullet (Mugil cephalus), and Common Carp (Cyprinus carpio) during storage. We designed an optical cradle as an accessory for a smartphone using ZW3D software and a 3D printer. The cradle with the smartphone was used to observe the spectrum of developed polyaniline deposited labels for ascertaining fish freshness. The sensor was calibrated using a standard ammonia solution (0–400 ppm) and the method was validated with a spectrophotometer and existing conventional techniques like TVB-N (total volatile basic nitrogen), TVC (total visible count), pH, and TPA (Texture Profile Analysis). The limit of detection (LOD), the limit of quantification (LOQ), %Bias, and %RSD of the sensor were 3.83 ppm, 12.96 ppm, 0.14 %, and 1.87 % respectively. The developed smartphone-based sensor used about 1139 pixels for wavelengths between 391.84 and 633.54 nm. A strong correlation could be established between TVB-N, TVC, and pH with the findings of the developed sensor. Application of PANI made the sensor specific for the detection of spoilage of fish therefore can be utilized as a platform for monitoring the freshness of fish. We successfully developed a web application using the present findings to evaluate fish fillet quality.
... The C-H symmetric stretching vibrations are responsible for the band at 2898 cm − 1 [57]. The band at 1731 cm − 1 is attributed due to the C= 0 stretching [58,59]. Furthermore, the band at 1557 cm − 1 is caused by the C--N stretching vibrations of quinoid rings (N = Q=N), while the band at 1455 cm − 1 is due to the C--C stretching mode of vibrations of benzenoid rings (N = B--N). ...
... This could be related to the presence of Fe 3 O 4 /CuO and PACPD in the bionanocomposite. It seems that PACPD with a polycationic backbone disrupts the microbial cell membrane [50,51]. ...
Nowadays, nanocomposites based on carbohydrate polymers owing to good physicochemical and biological properties have found promising applications in various fields especially biomedical applications. In the current study, a bioactive nanocomposite based on carboxymethyl dextrin-grafted-poly(aniline-co-meta-phenylenediamine) and iron oxide/copper oxide (CMD-g-PACPD@Fe3O4/CuO) was prepared by an in-situ copolymerization method. Several analyses such as FT-IR, NMR, EDX, BET, XRD, UV–vis, FE-SEM, TGA, VSM, and DLS were employed for the characterization of prepared materials. The NMR spectroscopy confirmed the preparation of carboxymethyl dextrin. The FTIR and EDX analysis showed that the CMD-g-PACPD@Fe3O4/CuO nanocomposite was prepared successfully. The specific surface area of about 11.30 m2/g was obtained for CMD-g-PACPD@Fe3O4/CuO nanocomposite by using BET analysis. The specific conductivity values of CMD-g-PACPD@Fe3O4/CuO were obtained in a range of 0.3 to 102 µS/cm in various solvents. The solubility test showed that the best solvent for the dispersion of the CMD-g-PACPD@Fe3O4/CuO was dimethyl sulfoxide. A superparamagnetic property of the CMD-g-PACPD@Fe3O4/CuO with saturation magnetism (MS) of 16.49 emu/g was obtained by VSM analysis. The CMD-g-PACPD@Fe3O4/CuO nanocomposite had good antioxidant (54 %) and antibacterial (against Escherichia coli and Staphylococcus aureus) activities and low toxicity at high concentrations (500 mg/mL). The current work may shed light on the potential applications of CMD-g-PACPD@Fe3O4/CuO in biomedical applications.
... Legend for IR spectra in Fig. 8. stretching vibrations rGO 13 1740 C=O 14 2300-2800 Free charge absorption 15 3200-3300 N-H stretching vibrations of quinoid and benzenoid rings peak at 793.15 cm − 1 assigned to the out-of-plane bending vibrations of C-H in 1,4-disubstituted AN on benzene ring [74]. Noteworthy that rGO-PANI H2SO4 was also composed of ortho-coupled AN units due to the presence of the shoulder peak left to 793.15 cm − 1 . ...
... In contrast, the peak signalling para-coupled AN units disappear for rGO-PANI CH3COOH and rGO-PANI DW indicating the dominance of ortho-coupled AN units and thus suggesting their poorer conductive property. The expulsion of dopant ions from the rGO-PANI matrix was also noted going from rGO-PANI H2SO4 to rGO-PA-NI CH3COOH and rGO-PANI DW due to the progressive disappearance (levelling off) of the broad band 2300-2800 cm − 1 [74]. In a nutshell, FTIR analysis complemented the results from SEM analysis that PANI have been successfully grown on rGO nanosheet and fastened at the interface through covalent bonding, hydrogen bonding, and π − π stacking interactions between PANI's quinoid/benzenoid ring and π-bonded rGO surface. ...
Background
Reduced graphene oxide (rGO), polyaniline (PANI), and their composites are advanced nanomaterials widely used in flexible sensor fabrication. However, the interfacial interactions between graphene and PANI of different shapes/dimensionalities have been unknown. This study aimed to close this gap by hypothesizing that the stacking of PANI on rGO relies on its shape and is relatable to the composite's electrical properties.
Methods
rGO was acted as a substrate for the in situ polymerization of aniline. Acidity of the polymerization medium was manipulated using H2SO4, CH3COOH, and distilled water (DW) to yield globule (0-D), tube (1-D), and plate (2-D) PANIs, respectively.
Significant findings
Unique rGO-PANI nanocomposites with various stacking orientations were successfully produced. The distribution of PANIH2SO4 on rGO is more pronounced than PANICH3COOH and PANIDW, suggesting that the 0-D PANIs have better interfacial interaction with rGO than 1-D and 2-D PANIs. Only few 3-D PANIs were found to grow on rGO. The electrical conductance of rGO-PANIH2SO4 (3.34 × 10−4 S) was a thousand times greater than rGO-PANICH3COOH (6.52 × 10−7 S) and ten million times greater than rGO-PANIDW (6.89 × 10−11 S), attributed to both interfacial interaction and oxidation state of PANIs. The results were further verified and justified with FTIR and XRD analyses.
... The band at the range of 295-320 nm is attributed to Π-Π* transitions [3]. The broad band in the range of 600-700 nm [26,30] may be attributed to the doping of PANI with mixed ions (Ni/Zn) and the formation of a polaron lattice [31]. ...
Polyaniline (PANI) nanocomposite with Zn and Ni has been prepared by in situ polymerization of aniline monomer in presence of Ni+2 and Zn+2 ions. The prepared nanocomposite (Ncomp) (PANI/Zn/Ni) has been characterized by spectrophotometric analysis via Fourier-transform infrared spectroscopy (FTIR) and ultraviolet–visible absorption spectra (UV–Vis). Morphological studies via scanning electron microscope SEM, particle size distribution PSD, as well as thermo-gravimetric analysis (TGA), have been investigated. Besides, the prepared (Ncomp) of different weight percentages wt% has been incorporated into water-based paint formulations for carbon steel protection. PSD analysis revealed that the particle size of the formed composite is on the nano-scale ranging between 60 and 160 nm. SEM analysis revealed that the Zn and Ni nanoparticles are quite dispersed into the polymer matrix as they appear in the form of bright spots and have been confirmed by energy dispersive X-ray (EDX) analysis. TGA analysis for the Ncomp showed enhanced thermal stability than that of pure PANI. The corrosion inhibition performance of the painted films has been investigated by potentiodynamic polarization and electrochemical impedance spectroscopy as well. The maximum average inhibition efficiency was found to be ranged from 92.8 to 99.4% for the paint of 9% wt% of Ncomp with fair mechanical properties. All measurements have been repeated three times for confirmation.
