Polyaniline Derivatives Research Articles

Artificially Intelligent Olfaction for Fast and Noninvasive Diagnosis of Bladder Cancer from Urine.

Globally, bladder cancer (BLC) is one of the most common cancers and has a high recurrence and mortality rate. Current clinical diagnostic approaches are either invasive or inaccurate. Here, we report on a cost-efficient, artificially intelligent chemiresistive sensor array made of polyaniline (PANI) derivatives that can noninvasively diagnose BLC at an early stage and maintain postoperative surveillance through ″smelling″ clinical urine samples at room temperature. In clinical trials, 18 healthy controls and 76 BLC patients (60 and 16 at early and advanced stages, respectively) are assessed by the artificial olfactory system. With the assistance of a support vector machine (SVM), very high sensitivity and accuracy from healthy controls are achieved, exceeding those obtained by the current techniques in practice. In addition, the recurrences of both early and advanced stages are diagnosed well, with the effect of confounding factors on the performance of the artificial olfactory system found to have a negligible influence on the diagnostic performance. Overall, this study contributes a novel, noninvasive, easy-to-use, inexpensive, real-time, accurate method for urine disease diagnosis, which can be useful for personalized care/diagnosis and postoperative surveillance, resulting in saving more lives.

Homologous Series of Polyaniline Derivatives Block Copolymers with Amphiphilic and Semiconducting Properties.

Semiconducting polymers with amphiphilic properties can play an increasing role in future organic and unimolecular electronic devices, especially due to their excellent processability and ease of self-assembly into thin films, but they could also be used as intermediate layers to improve electron transport in metal-organic junctions. In this work, we synthesized a homologous series of amphiphiles by copolymerization of aniline with aniline-N-propanesulfonic acid. The polymerization was first initiated with aniline, and the latter monomer was added at different time intervals: 2, 10, 20, 30, 40, and 60 min, spaced from the time of initiation. Thus, the poly(aniline-co-aniline-N-propanesulfonic acid) (PANi-co-PANs) homologous series of copolymers obtained had the same length of the water soluble PANs chain, and a variable length of the water insoluble PANi chain. We demonstrated that there is a strong structure–activity relationship in the homologous series of PANi-co-PANs copolymers, evidenced in the tensiometry and wettability studies, as well as in-depth conductivity with frequency and temperature investigations. We observed a gradual change in solubility, interfacial activity, and conductivity in the homologous series of amphiphiles within the boundaries set by the electrically insulating, hydrophilic PANs chain and the semiconducting, hydrophobic PANi chains; representing a viable platform toward designing polymers with tunable conductivity.

Conjugated polyaniline derivative membranes enable ultrafast nanofiltration and organic-solvent nanofiltration

The separation and recovery of small molecules from aqueous or organic solvents via engineered membranes are facing huge challenge. Herein, conjugated polyaniline derivative membranes were designed through the polymerization of ammonia-rich monomers and post-crosslinking treatment, exhibiting superior performance for ultrafast nanofiltration (NF) and organic-solvent nanofiltration (OSNF). Specifically, p -phenylenediamine (pPD), as one of aniline derivative with conjugate structure was in-situ growth onto porous substrate to fabricate PpPD/HPAN NF membrane, showing ultrahigh water permeance of 297 L m −2 h −1 bar −1 , congo red (CR) and direct red 23 (DR23) rejections above 98.5%. The separation mechanisms of PpPD/HPAN NF membrane were controlled by the co-effects of size sieving and charge repulsion, which had potential application prospects for dye removal and desalination. Subsequently, the chain-like polymer PpPD was post-crosslinking treated by trimesoyl chloride (TMC) to generate (PpPD-TMC)/HPAN OSNF membrane with rigid interconnected network structure, which displayed excellent permeance to organic solvent with ethanol permeance up to 242 L m −2 h −1 bar −1 , and CR rejection of ∼90%. The solvent's permeance was inversely proportional to solvent's viscosity, and the separation mechanism was mainly controlled by size sieving effect. Furthermore, a two-stage OSNF process was designed and operated with simulated industrial waste liquid, successfully achieving 75% solute recovery and 60% solvent recovery after the 1 st and 2 nd stage treatments. • Ultrafast conjugated NF membrane fabricated by in-situ growth of aniline derivative. • Post-crosslinking treatment of poly- p -phenylenediamine being capable for OSNF process. • Two-staged OSNF process achieving 75% solute recovery and 60% solvent recovery.

The structural factors affecting the sensory properties of polyaniline derivatives

This study is the first report that includes the experimental data on the use of a wide range of new substituted polyaniline (PANI) derivatives as a sensitive material in sensors.

Polyaniline-based gas sensors: DFT study on the effect of side groups

Polyaniline (PANI) derivatives are promising compounds for chemical sensor applications due to their low relative cost and high versatility of synthesis. However, at the same time that the great chemical versatility of these compounds allows the design of a number of derivatives, it is difficult to identify optimized materials only via trial and error. Here we present a theoretical study on the opto-electronic responses of PANI derivatives in relation to a series of gaseous compounds. Distinct branched PANI-based compounds were designed considering specific side groups, rationalized by Hammett indexes, and investigated via density functional theory (DFT). The results indicate that the presence of side groups can modulate the local reactivity and electronic properties of the compounds, tuning their capability to detect chemical species. In particular, higher reactivity on accessible side groups are obtained for the derivatives PANI-CCH, PANI-CN and PANI-NO2, facilitating their interaction with analytes.

Multi-stimuli Responsive Natural Fibers Immobilized with Silver Nanoparticles via Plasma-activated Generation of Polyaniline

Functionalization of natural fibers with electroactive polymeric materials can create conductive surfaces with multifunctional properties. Herein, we develop smart fibers using plasma supported coating of wool fabrics with various polyaniline derivatives (PANi) in the presence/absence of in-situ prepared silver nanoparticles (AgNPs). Nanostructural thin film of PANi was synthesized in-situ employing plasma-pretreatment to assess the polymerization process. AgNPs were immobilized in-situ during the formation of PANi starting from silver nitrate (AgNO3) by taking benefit of the reducing ability from the electroconductive polymer derivatives. Some selected electroactive polymers were applied starting from aromatic amines, including m-anisidine, o-phenylenediamine and p-nitroaniline. The morphological characteristics of the produced fabrics were studied by scan electron microscope (SEM). The chemical analysis was studied by energy-dispersive X-ray analyzer and Fourier transform infrared (FTIR) spectra. As monitored by CIE Lab colorimetric measurements, instant reversible color variations were monitored by recording the colorimetric measurements of the produced sensor fabrics. By changing the sort of the electroactive polymer and the inclusion of silver nanoparticles, the imparted characteristics of the developed wool fabrics, including antimicrobial, electroactivity and stimuli-responsive effects were explored for a diversity of promising medical applications.

Antibacterial properties of polyaniline derivatives

AbstractThis work presents a detailed study on the effect of various functional groups both at the ortho position of the aromatic ring and in the amino group of PANI on the antibacterial properties of polymers against gram‐positive (Bacillus subtilis) and gram‐negative (Pseudomonas aureofaciens) microorganisms. It was found that incorporation of methyl, methoxy, or pentyl groups into the ortho‐position of PANI did not increase the antibacterial activity but in most cases causes a significant decrease in the antibacterial properties of functionally substituted polyanilines. At the same time, PANI derivatives modified by incorporation of pentyl groups into the amino group were found to be more efficient antibacterial compounds against both gram‐positive and gram‐negative microorganisms than the original polymer. It was also found that N‐substituted PANI derivatives manifest not only bactericidal but also bacteriostatic properties toward the test microorganisms. Varying the nature and position of the substituent allowed us to conclude that the synthesis of various N‐substituted PANI derivatives with a high degree of doping is the most promising approach to PANI modification for application in bacterial growth inhibition.

Phenoxazine-Containing Polyaniline Derivatives with Improved Electrochemical Stability and Processability

Phenoxazine-Containing Polyaniline Derivatives with Improved Electrochemical Stability and Processability

Solid phase mechanochemical synthesis of Poly(o-anisidine) protected Silver nanoparticles for electrochemical dopamine sensor

Among the π-conjugate conducting polymers, polyaniline derivatives have much attention and attraction due to their efficient applications in many fields in the past three decade. In this work, we have reported the in-situ synthesis of Poly(o-anisidine) (POA) and POA protected Silver nanoparticles (POA@Ag) nanocomposites by green approach like solid phase mechanochemical method using sulfate salt of o-anisidine (o-Anisidine hydrogen sulfate or anisidinium sulfate) as a monomer and AgNO3 is play a vital role as a metal precursor as well as oxidant. The structure, morphology, composition, size, crystallinity and thermal stability of POA@Ag were analyzed using various instruments techniques. The transformation of emeraldine salt to emeraldine base form in its polymeric backbone is monitored by UV–vis and FT-IR studies in detail. The electrochemical performances of newly fabricated POA@Ag/GCE obtained more stability over the detection of dopamine (DA) and high sensitivity in trace level by the methods of Differential Pulse Voltammetry (DPV) and chronoamperometry. The working linear ranges of the electrode by DPV and chronoamperometry was 10–130 μM, 5–45 μM and its detection limits 2.8 and 0.83 μM, respectively. Furthermore, POA@Ag/GCE sensor has excellent selectively towards the detection of DA in presence of additional electroactive agent.

Synthesis and physicochemical properties of poly[2-(cyclohex-2-en-1-yl)aniline] as a new polyaniline derivative

A new polyaniline derivative, poly[2-(cyclohex-2-en-1-yl)aniline], was synthesized using different synthetic parameters.

Polymerization of new aniline derivatives: synthesis, characterization and application as sensors.

This work is focused on modifying aniline monomers with various characteristics that allows one to study the effect of the substituent on the respective polymer. A series of new polyaniline (PANI) derivatives based on an ortho-substituted aniline derivative, 2-(1-methylbut-2-en-1-yl)aniline, were synthesized and characterized. The structures and composition of the polymers that we synthesized were confirmed by elemental analysis, proton nuclear magnetic resonance (1H NMR) spectroscopy, carbon nuclear magnetic resonance (13C NMR) spectroscopy, Fourier-transform infrared spectroscopy (FT-IR), and ultraviolet-visible spectroscopy (UV). Characterization by FT-IR and UV-visible spectroscopy techniques indicated that the polymers exist in protonated emeraldine forms. Scanning electron microscope (SEM) results revealed that the surface morphology of the resulting polymers changed from a heterogeneous hierarchical to spherical structure upon changing the substituent in the aniline monomers. The polymers are soluble in common organic solvents, so they can be used to make films. The electrical properties of the polymers were studied and their high sensitivity to moisture and ammonia was demonstrated. The results of the studies showed the prospects of using thin polymer films in the design of chemical sensors. The impact of the substituent on the polymer characteristics is rationalized in terms of steric and electronic effects.

Nanocomposites based on the cellulose extracted from the Amazon Peperomia pellucida and polyaniline derivatives: structural and thermal properties

POMA/Cellulose and POEA/Cellulose nanocomposites were successfully synthesized based on interfacial polymerization over cellulose fibers extracted from the Amazon P. pellucida. The triclinic structure of poly(o-methoxyaniline) (POMA) and poly(o-ethoxyaniline) (POEA) was maintained after polymerization over cellulose fibers. However, possible chemical interactions between polymers and cellulose chains resulted in the increase of the average crystallite size, suggesting an oriented polymerization as well as the cellulose surface modification. The average crystallite size of POMA changed from (32 ± 2) A (for pure POMA) to (41 ± 2) A (for POMA in the nanocomposite form). The average crystallite size of POEA changed from (32 ± 2) A (for pure POEA) to (44 ± 2) A (for POEA in the nanocomposite form). Initially, the extracted cellulose presented average crystallite size of (29 ± 2) A, while the cellulose crystallites in the nanocomposites were found around (59 ± 2) A (POMA/Cellulose) and (92 ± 2) A (POEA/Cellulose). The morphology of POMA/Cellulose was significantly different from that observed in the pure as-synthesized POMA: globular vesicular shape was formed during the polymerization over the cellulose surface. In the POEA/Cellulose nanocomposite, the cellulose nanofibrils were also completely recovered by POEA consisting of well-defined nanometric spheres. These results were correlated with the thermal stability of the developed nanocomposites by Thermogravimetric Analysis (TG/dTG). Thus, the interfacial synthesis of POMA and POEA over a cellulose matrix was reported here, contributing to a better understanding of the thermal, structural and morphological properties of these resulting nanocomposites.

Synthesis and Physicochemical Properties of Poly(2-ethyl-3-methylindole)

Intramolecular acid-catalyzed cyclization was suggested for the first time for a polyaniline derivative, namely, poly[2-(2-chloro-1-methylbut-2-en-1-yl)aniline] (PClPA), to give hitherto unknown po...

Combined experimental and theoretical investigation of optical and structural properties of poly aniline derivatives

The structure of poly aniline (PANI), poly para phenylenediamine (PpPDA), and poly benzidine (PBz) is strongly dependent on the synthesis conditions and procedure. For this reason there is an ambiguity in the proposed structure of the polymers in the literature. A density functional theory (DFT) calculation were performed to establish the structure of synthesized PANI, PpPDA, and PBz. Different structures were considered for each polymer and fully optimized. Then their electrical and optical properties were calculated. Experimental band gaps of studied polymers were obtained using cyclic voltammetry technique and compared with those calculated by DFT. Optical band gap was also obtained from UV–visible spectrum of each polymer dissolved in DMSO solvent. Optical band gap value obtained for aniline is 1.90 eV which is close to the experimental band gap value reported for emeraldine form of poly aniline. Comparing calculated and experimental HOMO–LUMO gaps decline the formation of benzoid (PPDA-a) and phenenzine (PPDA-b) structures during synthesis of PpPDA. However, the exact structure of PpPDA was recognized through comparing experimental and simulated optical properties. Calculated electronic and optical band gaps of phenanzine structure of synthesized benzidine (PBz-c) are close to those of experimental ones and are confirmed by the spectroscopic results. Obtained results show that theoretical calculations play an important role in the detection of complex polymer structures.

Improvement of the adhesion of conductive poly(m-toluidine) onto chemically reduced-wool fabrics.

Wool has disulphide bonds containing-hydrophobic external keratin layers, which act as a barrier for the modification through coating with hydrophilic materials. For that reason, in this work, to ensure a dense and homogenous conductive polymer coating onto the wool, the fabrics were subjected to the reduction process in the aqueous alkaline medium containing agents that can attack these disulphide bonds. Then, one of the polyaniline derivatives, poly(mtoluidine) (PMT), was coated onto wool by in situ polymerization of m-toluidine sulphate using ammonium persulfate (APS) as an oxidant. The effects of conditions, such as the composition of reduction-bath and types of dopants were investigated, on the mass increase (%) and surface resistivity of the composite. The reduction pretreatment of wool with sodium hydrosulphide significantly improved the coating density, conductivity, and colour shade of PMT on the surface, compared to an untreated one. The coating stability of PMT/wool composite was examined by rubbing test and detergent washing, through surface resistivity measurements. The changes in structural and surface properties of wool fabrics were determined with ATR-FTIR, contact angle, and optical microscopic techniques, respectively. The performance of PMT/wool composite was also examined in the electromagnetic shielding effectiveness (EMSE) measurements within 30 MHz-3 GHz.

Synthesis and Characterization of Hollow-Sphered Poly(N-methyaniline) for Enhanced Electrical Conductivity Based on the Anionic Surfactant Templates and Doping.

Poly(N-methylaniline) (PNMA) is a polyaniline derivative with a methyl substituent on the nitrogen atom. PNMA is of interest owing to its higher solubility in organic solvents when compared to the unsubstituted polyaniline. However, the electrical conductivity of polyaniline derivatives suffers from chemical substitution. PNMA was synthesized via emulsion polymerization using three different anionic surfactants, namely sodium dodecylsulfate (SDS), sodium dodecylbenzenesulfonate (SDBS), and dioctyl sodium sulfosuccinate (AOT). The effects of surfactant structures and concentrations on electrical conductivity, doping level, crystallinity, morphology, and thermal stability were investigated. The re-doping step using perchloric acid (HClO4) as a dopant was sequentially proceeded to enhance electrical conductivity. PNMA synthesized in SDBS at five times its critical micelle concentration (CMC) demonstrated the highest electrical conductivity, doping level, and thermal stability among all surfactants at identical concentrations. Scanning electron microscopy (SEM) images revealed that the PNMA particle shapes and sizes critically depended on the surfactant types and concentrations, and the doping mole ratios in the re-doping step. The highest electrical conductivity of 109.84 ± 20.44 S cm−1 and a doping level of 52.45% were attained at the doping mole ratio of 50:1.

Synthesis and physicochemical properties of poly[2‐(2‐chloro‐1‐methylbut‐2‐en‐1‐yl)aniline] obtained with various dopants

AbstractHighly soluble polyaniline was synthesized from a newly designed aniline derivative, namely 2‐[2‐chloro‐1‐methylbut‐2‐en‐1‐yl]aniline. The corresponding polyanilines, PClPA‐HA, PClPA‐SA, PClPA‐NA and PClPA‐PA, were characterized by means of 1H NMR, 13C NMR, high resolution mass spectroscopy, Fourier transform infrared spectroscopy, ultraviolet–visible spectroscopy and SEM images. The elemental analysis and electrical conductivity of the polymers are also presented. It is shown that the molecular weight of the polymers obtained depends on the method of synthesis. Spectroscopic studies confirmed the emeraldine form of the polyaniline derivatives. In the work, the dependence of the current passing through resistive structures based on thin poly[2‐(2‐chloro‐1‐methylbut‐2‐en‐1‐yl)aniline] films on the relative humidity of air was studied. The results of the studies showed the prospects of using thin polymer films in the design of chemical sensors. © 2020 Society of Chemical Industry

Plasma activation toward multi-stimuli responsive cotton fabric via in situ development of polyaniline derivatives and silver nanoparticles

Cotton fabrics have been known as one of the most common fibers due to its high absorption ability to chemicals, cheapness and high strength. The functionalization of natural fabrics with conductive polymers can produce conductive surfaces of high-performance textile with multifunctional properties. In the current work, conductive natural high-performance fabric was prepared by plasma assisted coating of cotton fabrics with different conductive polymers in presence or absence of silver nanoparticles. Nanostructured thin layer of polyaniline derivative was prepared in situ after plasma activation technique. Silver nanoparticles were deposited from silver nitrate solution by taking advantage of reduction capability of the conductive polymers. By changing the type of conductive polymer and the incorporation of silver nanoparticles, high-performance fabrics with altered or improved multifunctional properties were obtained including antibacterial, electrical conductivity, thermochromism, acid sensitivity and responsiveness to metal ions for a variety of potential purposes, such as biomedical, geo-textile and antistatic applications.

Development of highly efficient chemosensors for Cu2+ and N2H4 detection based on 2D polyaniline derivatives by template-free chemical polymerization method

Chemosensors play an important role in environmental protection, medical diagnosis and energy conservation. Although polyaniline and its derivatives and two-dimensional (2D) materials have been applied as chemosensors in many reports, the concept of two-dimensional (2D) polyaniline derivatives has not been achieved in chemosensors. Here, two kinds of two-dimensional (2D) polyaniline derivatives are designed and synthesized by template-free chemical polymerization. It can be found that these two two-dimensional (2D) chemosensors exhibit high selectivity and sensitivity to Cu2+ and N2H4. Moreover, it is noteworthy that one of the two-dimensional materials can achieve the limit of detection (LOD) of 45 nM and 8 nM for Cu2+ and N2H4, respectively. Especially, these results imply that this two-dimensional polyaniline derivative is promising as the chemosensor in sensing field.

Pauli Paramagnetism of Stable Analogues of Pernigraniline Salt Featuring Ladder-Type Constitution.

Polyaniline derivatives represent one of the most widely used classes of conductive polymers. The fundamentally important electronic properties of pernigraniline salts, the fully oxidized and acid-doped derivatives of polyanilines, however, are still not well-understood due to their poor stability and configurational uncertainty. To address these issues and to synthetically access stable analogues of pernigraniline salts, ladder-type constitution was imparted into a series of model oligomer analogues with rigid backbones constituted by up to 27 fused rings. The syntheses were achieved through iterative cross-coupling reactions followed by cyclization and oxidation. In contrast to their unstable non-ladder-type counterparts, these ladder-type pernigraniline-like molecules all adopt a well-defined all-trans configuration and demonstrate an excellent chemical stability after protonation, rendering it possible to reveal the intrinsic electronic and magnetic properties of molecules resembling pernigraniline. Protonated salts of these oligomers feature a significant diradicaloid open-shell resonance contribution. A dominant temperature-independent Pauli paramagnetism was observed in the solid state, an indication of the delocalization nature of the polarons in ladder-type analogues of pernigraniline salt.