PANI) And Polypyrrole Research Articles

The Use of Low‐Quality Cotton‐Derived Cellulose Films as Templates for In Situ Conductive Polymer Synthesis as Promising Biomaterials in Biomedical Applications

AbstractHere, the use of cellulose films (CFs) produced from low‐quality cotton is reported as a template for in situ synthesis of well‐known conductive polymers, e.g., polyaniline (PANI) and polypyrrole (PPY) via oxidative polymerization. Three successive monomer loading/polymerization cycles of aniline (ANI) and pyrrole (PY) within CFs as PANI@CF or PPY@CF are carried out to increase the amount of conductive polymer content. The contact angle (CA) for three times ANI and PPY loaded and polymerized CFs as 3PANI@CF and 3PPY@CF are determined as 26.3±2.8 and 42.3±0.6 degrees, respectively. As the electrical conductivity is increased with increased number of conductive polymer synthesis within CF, the higher conductivity values, 3×10−4±8.1×10−5 S.cm−1 and 2.1×10−3±5.8×10−4 S.cm−1, respectively are measured for 3PANI@CF and 3PPY@CF composites. It is found that PANI@CF composites are hemolytic, whereas PPY@CF composites are not at 1 mg mL−1 concentrations. All PPY@CF composites exhibit better biocompatibility than PANI@CF composites on L929 fibroblast cells with more than 70±8% viability at 1 mg of CF‐based conductive polymer composites. Moreover, MIC and MBC values of 3PPY@CF composites for Escherichia coli (ATCC8739) and Staphylococcus aureus (ATCC6538) are determined as 2.5 and 5.0 mg.mL−1, whereas these values are estimated as 5 and 10 mg.mL−1 for Candida albicans (ATCC10231).

Synthesis and characterisation of carbon nanofiber-wrapped polyaniline and polypyrrole sensory films in polyester resin for strain sensing

ABSTRACT Nanomaterials hold promise as flexible sensor elements due to their enhanced flexibility and efficiency compared to conventional sensors. This study explores Carbon Nanofibers (CNF) in strain-sensing applications, synthesised with Polyaniline (PANI) and Polypyrrole (PPy) via a chemical oxidative technique. These composites form sensory layers on flexible Polyester resin substrates using a layer-by-layer technique. Characterisation through Fourier-Transform Infrared (FTIR) Spectroscopy and Powder X-ray Diffraction (PXRD) reveals strong interactions within CNF/PANI/Polyester and CNF/PPy/Polyester configurations, with heightened crystallinity in CNF/PANI, indicating enhanced electrical conductivity. Stress-strain analysis shows a significant 25% elongation with a corresponding 15% change in resistance across all samples. Calculated gauge factors exhibit substantial improvements: Polyester/PPy (12.96), Polyester/PANI (13.54), Polyester/CNF wrapped PPy (58.62), and Polyester/CNF wrapped PANI (95.8). Notably, CNF-wrapped PPy and CNF-wrapped PANI demonstrate superior gauge factors compared to conventional strain sensors, with Polyester/CNF-wrapped PANI displaying the highest sensitivity at 95.8%. This research underscores the potential of CNF-based composites, particularly CNF-wrapped PANI within a Polyester matrix, for advanced strain-sensing applications.

Tailoring interlayer spacing of Ti3C2Tx MXene with organic acid doped polyaniline and polypyrrole for more stable supercapacitors

Polyaniline (PANI) and polypyrrole (PPy) are promising for use as spacers materials to prevent re-stacking of MXene layers and to increase their electrochemical properties. However, these conducting polymers (CPs) may undergo hydrolysis during long charge-discharge cycles. The use of organic acids to dope CPs may lead to better polymer cyclic stability. However, PANI and PPy used as spacers in MXene are mainly doped with inorganic acids. Herein, we applied dodecylbenzenesulfonic acid (DBSA) doped PANI and PPy as effective spacers and additional pseudocapacitance agents for Ti3C2Tx MXene. Taking advantage of the favored dispersibility of the functional inks in water, we easily prepared the electrodes by drop casting. X-ray diffractograms confirmed that the CPs are effectively allocated among MXenes sheets. Spectroscopic analyses showed that the functional groups of Ti3C2Tx may work as effective dopants for PANI and PPy. The enhanced interlayer spacing of MXenes and increased high conductivity of CPs boosted capacitance from 175 F g−1 (Ti3C2Tx) to 255 F g−1 and 270 F g−1 at 1 A g−1 after addition of 10 wt% of PANI and PPy, respectively, at a three-electrode setup. The Dunn’s and Trasatti’s methods showed greater pseudocapacitive contribution after addition of PPy and greater double layer capacitance contribution after addition of PANI. Similarly, symmetric solid-state SCs exhibited enhancement of 72 % in specific capacitance for Ti3C2Tx/PANI and 208 % for Ti3C2Tx/PPy, when compared to pristine Ti3C2Tx. SCs based on Ti3C2Tx/CPs also yielded outstanding capacitance retentions (>98 %) after 5000 cycles against only 88 % of the Ti3C2Tx pristine device. These results indicate that the organic doped-CPs modulated interlayer spacing of MXene sheets, preventing their re-stacking during the charge and discharge cycles. Finally, the aqueous Ti3C2Tx/CPs based inks is an eco-friendly and low-cost alternative to fabricate SCs with enhanced capacitance and stability.

Design of Phytic Acid Crosslinked Xerogels as Organic Photocatalysts for Visible Light‐Assisted Degradation of Dyes

AbstractExtensive research is being carried out on the degradation of water pollutants using various strategies to overcome the global water crisis. In the present study, xerogels as a better alternative is utilized to metal oxides for the photocatalytic degradation of toxic water pollutants such as dyes. Xerogels of polyaniline (PANI) and polypyrrole (PPy) are synthesized using phytic acid as a dopant as well as cross‐linker in the weight ratios of 1:1, 1:2, and 2:1 via simple chemical oxidative polymerization. The synthesized xerogels are analyzed for their spectral, morphological, thermal, and optical properties using FTIR, UV–vis, XRD, SEM, and TGA techniques. The xerogels are also tested for their photocatalytic activity against textile dyes – Methylene Blue (MB), Alizarin Red S, (ARS), Rhodamine B (RhB), and Methyl Orange (MO). Among all the composite xerogels, PANI/PPy‐2/1 showed excellent degradation efficiency of 91% for MB dye, 88% for RhB dye, 96% for ARS dye, and 92% for MO dye respectively. The composite PANI/PPy xerogels showed better degradation efficiency than their pristine counterparts. The fragments of the degraded dyes are examined using the LCMS technique and a tentative dye degradation mechanism is proposed.

Recent Advances and Developments in Injectable Conductive Polymer Gels for Bioelectronics.

Soft matter bioelectronics represents an emerging and interdisciplinary research frontier aiming to harness the synergy between biology and electronics for advanced diagnostic and healthcare applications. In this context, a whole family of soft gels have been recently developed with self-healing ability and tunable biological mimetic features to act as a tissue-like space bridging the interface between the electronic device and dynamic biological fluids and body tissues. This review article provides a comprehensive overview of electroactive polymer gels, formed by noncovalent intermolecular interactions and dynamic covalent bonds, as injectable electroactive gels, covering their synthesis, characterization, and applications. First, hydrogels crafted from conducting polymers (poly(3,4-ethylene-dioxythiophene) (PEDOT), polyaniline (PANi), and polypyrrole (PPy))-based networks which are connected through physical interactions (e.g., hydrogen bonding, π-π stacking, hydrophobic interactions) or dynamic covalent bonds (e.g., imine bonds, Schiff-base, borate ester bonds) are addressed. Injectable hydrogels involving hybrid networks of polymers with conductive nanomaterials (i.e., graphene oxide, carbon nanotubes, metallic nanoparticles, etc.) are also discussed. Besides, it also delves into recent advancements in injectable ionic liquid-integrated gels (iongels) and deep eutectic solvent-integrated gels (eutectogels), which present promising avenues for future research. Finally, the current applications and future prospects of injectable electroactive polymer gels in cutting-edge bioelectronic applications ranging from tissue engineering to biosensing are outlined.

Impact mechanisms of aggregation state regulation strategies on the microwave absorption properties of flexible polyaniline

In the field of electromagnetic (EM) wave absorption, intrinsic conductive polymers with conjugated long-chain structures, such as polyaniline (PANI) and polypyrrole (PPy), have gained widespread use due to their remarkable electrical conductivity and loss ability. However, current research in this area is limited to macroscopic descriptions of the absorption properties of these materials and the contribution of various components to the absorption effect. There has been insufficient exploration of the impact mechanisms of polymer aggregation states on the material's absorption performance and mechanism. To address this, a series of flexible PANI sponge absorbers with different molecular weights and aggregation states were prepared. By carefully controlling the crystallinity and other aggregation characteristics of PANI through the adjustment of its preparation conditions, we were able to influence its electrical conductivity and electromagnetic parameters, thereby achieving control over the material's absorption properties. The resulting PANI sponge absorbers exhibited an effective absorption bandwidth (EAB) that covered the entire X-band at a thickness of 3.2 mm. This study comprehensively explores the absorption mechanisms of conductive polymer absorbers, starting from the microstructure of PANI, and providing a more complete theoretical support for the research and promotion of polymer absorbers.

Conductive Polymer and Nanoparticle-Promoted Polymer Hybrid Coatings for Metallic Bipolar Plates in Proton Membrane Exchange Water Electrolysis

Proton exchange membrane water electrolysis (PEMWE) is a green hydrogen production technology with great development prospects. As an important part of PEMWE, bipolar plates (BPs) play an important role and put forward special requirements due to the harsh environments on both the anode and cathode. Recently, metal-based BPs, particularly stainless steel and titanium BPs have attracted much attention from researchers all over the world because of their advantages of high corrosion resistance, low resistivity, high thermal conductivity, and low permeability. However, these metallic BPs are still prone to being oxidized and are facing with hydrogen embrittlement problems in the PEMWE working environment, which would result in reduced output power and premature failure of the PEMWE stack. In order to reduce the corrosion rate and maintain low interfacial contact resistance, the surface modification of the metallic BPs with protective coatings, such as precious metals (e.g., Au, Pt, etc.) and metal nitrides/carbides, etc., have been extensively investigated. However, the above-mentioned coating materials are restricted by the high-cost materials, complex equipment, and the complicated operation process. In this review, the surface modification of metallic BPs based on silane treatment, conductive polymers, e.g., polyaniline (PANI) and polypyrrole (PPy) as well as some nanoparticles-promoted polymer hybrid coatings which have been investigated for PEMWE, are summarized and reviewed. As for the silane treatment, the dense silane can not only effectively enhance the corrosion resistance but also improve the adhesion between the substrate and the conductive polymers. As for PANI and PPy, the typical value of corrosion current density of a PANI coating is 5.9 μA cm−2, which is significantly lower than 25.68 μA cm−2 of the bare metal plate. The introduction of nanosized conductive particles in PANI can further reduce the corrosion current density to 0.15 μA cm−2. However, further improvement in the electrical conductivity is still desired to decrease the interface contact resistance (ICR) to be lower than 10 mΩ cm2. In addition, serious peeling off of the coating during long-term operation also needs to be solved. Typically, the conductive polymer reinforced by graphene, noble metals, and their compounds in the form of nanoparticle-promoted polymer hybrid coatings could be a good choice to obtain higher corrosion resistance, durability, and conductivity and to extend the service life of PEMWE. Especially, nanoparticle-promoted polymer hybrid coatings consisting of polymers and conductive noble metals or nitrides/carbides can be controlled to balance the conductivity and mechanical properties. Due to the advantages of a simple preparation process, low cost, and large-scale production, nanoparticle-promoted polymer hybrid coatings have gradually become a research hotspot. This review is believed to enrich the knowledge of the large-scale preparation process and applications of BPs for PEMWE.

Insight into the corrosion inhibition of the iron anode with electro-deposited polyaniline during the electrocoagulation treatment process of electroplating wastewater

In this study, polyaniline (PANI) and polypyrrole (PPy) coatings were applied to modify iron plate anodes to treat electroplating wastewater by electrocoagulation (EC) treatment.

Synthesis and Characterization of Hydroxyethyl Cellulose Grafted with Copolymer of Polyaniline and Polypyrrole Biocomposite for Adsorption of Dyes

The emerging concepts of sustainable textiles and controlled production strategy demands ideally zero emissions of contaminants into the aquatic environment. However, the currently in-practiced conventional processes in textiles dispose of a number of contaminants especially super toxic synthetic dyes as effluents. In recent years, nanomaterials have become attractive choice for eco-friendly removal of organic dyestuff. Accordingly, this article reports synthesis and characterization of biocomposite wherein copolymer of polyaniline (PANI) and Polypyrrole (PPY) was grafted onto hydroxyethyl cellulose (HEC). Further, adsorption properties of as-prepared composite were evaluated using textile dyes Rhodamine B (RhB) and methyl Orange (MO)- as model adsorbate. The characterization of novel biocomposite (HEC/PANI-PPy) was carried out using Fourier Transform Infrared (FT-IR), Brunauer-Emmett-Teller analyzer (BET), Scanning Electron Microscope (SEM), and powder X-ray diffraction (XRD). The operational parameters such as dye initial concentration, adsorbent amount, pH and contact time were also studied to evaluate the efficiency level of the prepared biocomposite. Interestingly, the composite-mediated adsorption of RhB and MO followed pseudo-second order and the Langmuir isotherm. It is found that the adsorption capacity HEC/PANI-PPy is 30.06 and 29.3 for RhB and MO respectively. Thus, HEC/PANI-PPy is an inexpensive and highly efficient adsorbent that could be employed for could be employed for the separation and removal of toxic organic dyes from polluted textile effluents.

Poly (Vinyl Alcohol)/Agar Hydrogel Electrolytes Based Flexible All-in-One Supercapacitors with Conducting Polyaniline/Polypyrrole Electrodes.

The major components of supercapacitor are electrodes and electrolytes which are fabricated using various materials and methods. Hydrogel is one such material that is used in supercapacitors as electrodes and electrolytes or both. Hydrogels are usually described as a soft and porous network of polymer materials that can swell in water because of the hydrophilic nature of its polymer chains, compriseng a 3D structure. It is well known that supercapacitors possess high-power density but low energy density. For enhancing energy density of these electrochemical cells and a boost in its electrochemical performance and specific capacity, binder free conducting polymer hydrogel electrodes have gained immense attention, especially polyaniline (PANI) and polypyrrole (PPy). Therefore, in this work, chemically crosslinked PVA/Agar hydrogel electrolytes have been prepared and employed. Agar has been added in PVA since it is environmentally friendly, biodegradable, and cost-effective natural polymer. Subsequently, the binder free polyaniline/polypyrrole electrodes were grown on the PVA/Agar hydrogel electrolytes to fabricate all-in-one flexible hydrogels. The synthesized hydrogels were characterized using X-ray diffraction (XRD) analysis, Fourier transform infrared (FTIR) analysis, Field emission scanning electron microscope (FESEM) and mechanical studies. Then, the all-in-one flexible supercapacitors were fabricated using the hydrogels. The electrochemical studies such cyclic voltammetry (CV), galvanic charge discharge (GCD), and electrochemical impedance spectroscopy (EIS) studies. The fabricated all-in-one lamination free supercapacitors showed promising results and by comparing all four samples, PAP2 where 5 mL of PVA was used in combination with 3 mL of Agar and 5 mL of PANI and PPy each, exhibited the highest areal capacitance of 750.13 mF/cm2, energy density of 103.02 μWh/cm2, and 497.22 μW/cm2 power density. The cyclic stability study revealed the 149% capacity retention after 15,000 cycles.

Humidity sensing studies on conducting polymers: Polyaniline and polypyrrole

• Polyaniline (PANI) and Polypyrrole (PPy) - synthesized by in-situ polymerization and chemical polymerization method respectively. • The film of the samples prepared by spin deposition technique. • Humidity sensing response for PANI and PPy was experimentally established in the RH range of 10–97 %. • The mechanism for sensing: Grotthus mechanism was discussed thoroughly. The present paper addresses, a comparative canvas on the humidity sensing performance of the conducting polymers: Polyaniline (PANI) and Polypyrrole (PPy). For the purpose, PANI and PPy were synthesized by in-situ polymerization and chemical oxidative polymerization method respectively. The polymer matrix was functionally characterized by FTIR and XRD studies, and phonological characterized by SEM techniques. For the humidity monitoring measurements, the film of the PANI and PPy were made by fixing each sample on the simple substrate using an efficient spin deposition technique. The PANI has depicted a sensing response (S R ) of 41 % in the RH range of 10–97 % with timing behavior of 180 s of 60 s respectively. But PPy depicted a S R of 71 % over the RH 10–97 % with a response and recovery time of 63 s and 60 s respectively. The PPy has shown a better real sensitivity of 0.006 Ώ/% RH, lower limit of detection (LOD) of 11 % RH, best linearity of 0.9818, less humidity-hysteresis of 15 % and maximum stability over a period of two months. Along with these, physical features are also increased in PPy compared to PANI. The sensing operation has thoroughly discussed on the shaping of three layers in accordance with Grotthus mechanism, later followed by condensation.

Conducting polymer based visible light photocatalytic composites for pollutant removal: Progress and prospects

Conducting polymers (CPs) have been proved to be instrumental in enhancing photocatalytic efficacy owing to their unique physicochemical properties and energy levels. In this regard, titanium dioxide (TiO 2 ) has been investigated in transdisciplinary research areas (like catalysis, energy technologies, health, and environment) due to its desirable characteristics. In the process of developing advanced photocatalysts, novel inorganic–organic heterojunction design based materials have been explored and developed in contrast to conventional, inorganic–inorganic type semiconducting photocatalysts (SCPs). In this context, hybrid/composite SCPs comprising CPs and TiO 2 , have received significant attention for enhancing photocatalytic efficacy in terms of activity as well as visible light activation. The synergistic contribution from CPs (here we focus only on polyaniline (PANI) and polypyrrole (PPy)) and TiO 2 have been proved to enhance light-absorption capability in the visible region, photogenerated extraction, and higher stability. Importantly, the published literature (before 2015) on the photocatalysis of TiO 2 -CP composites mainly discusses in terms of the sensitizing aspects of CP for TiO 2 . However, there is a critical need to review the literature (beyond 2015) to explore the state of art progress concerning the mechanism of photocatalytic performances as phenomenal parallel developments and knowledge gaps have been addressed on new kinds of heterojunction formation (like S-Scheme over traditional ones), band tuning and interfacial contact effects between two SCPs. In particular, this topical review aims to capture and highlight the current advancements (2016–2021) in relevance to the visible light photocatalytic performance of CP–TiO 2 functional composites, which include nanostructures and multi-components. The predominantly available literature over the last five years on the application of CPs–TiO 2 functional composites for monitoring or removal of pollutants under visible light activation is reviewed giving importance to revealing the role of CP in concurrent enhancement in both visible light activation and photocatalytic performances. Finally, we elaborate on the challenges and future outlook for advanced research and development in this area. • Captured the recent advances in hybrid conducting polymer functional composites. • Discussed the role of conducting polymer in visible light-mediated photocatalysis. • Reviewed various types of nanocomposites photocatalysts for pollutant removal. • Synergistic contributions and importance of these hybrid composites were elaborated.

Investigation of structural and optical properties of ternary polyaniline–polypyrrole–nickel oxide (PANI‐PPy‐NiO) nanocomposite for optoelectronic devices

AbstractA new ternary nanocomposite comprising nickel oxide (NiO) embedded into a binary polymeric network of polyaniline (PANI) and polypyrrole (PPy), i.e. PANI‐PPy‐NiO, is synthesized using an in situ chemical oxidative method. The infrared spectrum of PANI‐PPy‐NiO exhibits most of the characteristic peaks of unary nanoparticles with slight shift in the frequencies. The shift is due to the synergistic interaction of binary PANI‐PPy with the inorganic NiO nanoparticles. X‐ray diffraction pattern reveals the semicrystalline structure of the PANI‐PPy‐NiO nanocomposite with an average crystallite size of 22 nm. From Williamson–Hall plot, the micro‐strain value of as‐prepared PANI‐PPy‐NiO is found to be −0.16727. Surface morphology of PANI‐PPy‐NiO shows fine grains of NiO‐encapsulated PANI‐PPy that tend to coalesce and form an agglomeration assembly. The elements detected from energy‐dispersive X‐ray analysis indicate the purity of synthesis of the ternary material. Further, the optical constants obtained from UV–visible spectra (absorption coefficient, extinction coefficient, refractive index, optical conductivity and real and imaginary dielectric constants) are found to be higher for PANI‐PPy‐NiO than for the unary PANI, PPy and NiO nanoparticles. Tauc plot and Urbach energy studies indicate the low bandgap energy of PANI‐PPy‐NiO (2.67 eV) compared to unary nanoparticles. Further, the emission intensity peak (492 nm) observed in the photoluminescence spectrum of PANI‐PPy‐NiO corresponds to the blue region of the visible spectrum. Thus, the optical studies clearly indicate the high suitability of the synthesized PANI‐PPy‐NiO in visible‐light‐based device applications. © 2022 Society of Industrial Chemistry.

Progressive Intercalation and Exfoliation of Clay in Polyaniline–Montmorillonite Clay Nanocomposites and Implication to Nanocomposite Impedance

Conducting polymers, such as polyaniline (PANi) and polypyrrole (PPy), and their nanocomposites, are desired in a wide range of applications, including supercapacitors, lithium ion battery, chemical sensors, biosensors, barrier thin films, and coatings, because of their interesting electrical and electrochemical properties. It is well known that the properties of polymer nanocomposites depend on their chemical structure, as well as their microstructure, yet scientists and engineers have not fully understood how to properly control the structure of polymer nanocomposites. In this study, it is shown that the structure of polyaniline–montmorillonite clay nanocomposites (PACN) can be controlled by varying the ammonium persulfate (APS, oxidant) concentration. The structure of polyaniline and Cloisite 20A clay are, therefore, profoundly affected during the synthesis of PACN nanocomposites. The thickness of polyaniline crystal decreased with increasing oxidant concentration. Fourier transform infrared spectroscopy (FTIR) was used to determine the oxidation state of PANi. The structure of the nanocomposites was studied by using scanning electron microscopy (SEM), transmission electron microscopy (TEM), wide-angle X-ray diffraction (WAXD), wide-angle X-ray scattering (WAXS), and small-angle X-ray scattering (SAXS). Electrochemical impedance spectroscopy (EIS) analysis of polyimide nanocomposite coatings containing PACN with varying levels of intercalation and exfoliation indicate that the coating impedance decreased with exposure time for some coating systems. It is shown that polyimide–PACN nanocomposite coating containing highly intercalated clay was more durable and maintained constant impedance after 20 weeks of exposure in a corrosive medium.

Performance comparison of electro-polymerized polypyrrole and polyaniline as cathodes for iodine redox reaction in zinc-iodine batteries

At present, Zinc-iodine (Zn//I) batteries have attracted much attention due to their high safety and capacity. However, how to suppress the shuttling of polyiodide ions generated during charging processes is still a tricky problem. Herein, polyaniline (PANI) and polypyrrole (PPy) are electro-polymerized on carbon felt (CF) by constant current and used as cathodes for zinc-iodine (Zn//I) batteries. Electrochemical tests of the PANI@CF and PPy@CF electrodes prove that the PANI@CF electrode has a higher capacity, a stronger ability to suppress shuttling of polyiodine ions, and more excellent cyclic stability than the PPy@CF electrode. According to the material characterizations, the differences of both electrodes in electrochemical performances are mainly caused by the microstructures of PANI and PPy in both electrodes. The PANI has a micro-nano porous structure while the PPy is very dense. The porous PANI not only has more channels for the infiltration of electrolyte, but also can provide more active adsorption sites to minimize the shuttling of polyiodide ions to anode, ensuring the excellent performances of the PANI@CF. However, dense PPy seriously hinders the electrolyte diffusion and triggers the formation of an insulating dense iodine film, bringing poor performances to the PPy@CF. Ultimately, the PANI@CF electrodes achieves the most specific capacity of 235.9 mAh g−1 at 0.35 A g−1 (∼1.7 C) and performs out long cycle life with high stability (75.7% capacitiy rention after 10,000 cycles) at 3.5 A g−1 (∼17 C) in Zn//I battery, manifesting the porous PANI@CF electrode is a greatly promising candidate as cathode for Zn//I batteries in actual application.

Antimicrobial Activities of Conducting Polymers and Their Composites

Conducting polymers, mainly polyaniline (PANI) and polypyrrole (PPY) with positive charges bind to the negatively charged bacterial membrane to interfere with bacterial activities. After this initial electrostatic adherence, the conducting polymers might partially penetrate the bacterial membrane and interact with other intracellular biomolecules. Conducting polymers can form polymer composites with metal, metal oxides, and nanoscale carbon materials as a new class of antimicrobial agents with enhanced antimicrobial properties. The accumulation of elevated oxygen reactive species (ROS) from composites of polymers-metal nanoparticles has harmful effects and induces cell death. Among such ROS, the hydroxyl radical with one unpaired electron in the structure is most effective as it can oxidize any bacterial biomolecules, leading to cell death. Future endeavors should focus on the combination of conducting polymers and their composites with antibiotics, small peptides, and natural molecules with antimicrobial properties. Such arsenals with low cytotoxicity are expected to eradicate the ESKAPE pathogens: Enterococcus faecium, Staphylococcus aureus, Klebsiella pneumoniae, Acinetobacter baumannii, Pseudomonas aeruginosa, and Enterobacter spp.

EMI Shielding and Absorption of Electroconductive Textiles with PANI and PPy Conductive Polymers and Numerical Model Approach

The paper presents the results and analysis of interdisciplinary research concerning electromagnetic field shielding, conductive polymers printed on textiles and numerical simulation using the finite element method (FEM). The use of conductive, layered textiles for shielding electromagnetic interference (EMI) has been proposed. After establishing the optimal conditions for deposition of polyaniline (PANI) and polypyrrole (PPy) on polyacrylonitrile (PAN) fabric, conductive composites were made by means of reactive inkjet printing. For this purpose, polyacrylonitrile (PAN) fabrics were coated with polyaniline or polypyrrole, obtained by chemical oxidation of aniline hydrochloride and pyrrole by ammonium peroxydisulfate. The morphology of the obtained coatings was observed using a scanning electron microscope (SEM). The conductive properties (surface resistance) of the fabrics were measured using the four-wire method, and the tests of the effectiveness of electromagnetic shielding were carried out using the waveguide method in the frequency range from 2.5 to 18 GHz. The results of experimental shielding effectiveness (SE) tests and numerical simulation showed that the composites of polyacrylonitrile with polyaniline PAN/PANI and polyacrylonitrile with polypyrrole PAN/PPy achieved very good and good EMI shielding efficiency, respectively. Moreover, the obtained measurement results were verified by numerical modeling with the use of FEM–ANSYS HFFS software.

Intrinsically conductive polymers hybrid bilayer films for the fluorescence molecular diagnosis of the Zika virus

In 2016, the Zika virus (ZIKV) infection became a major public health problem, after the discovery that an alarming increase in the number of Brazilian newborns with microcephaly could be associated with the occurrence of this viral disease during the pregnancy of their mothers. The urgent need for simple diagnostic methods that allow rapid screening of suspected cases has stimulated the search for low-cost devices capable of detecting specific sequences of nucleic acids. The present work describes the development of nanostructured films formed by bilayers of conjugated polymers for rapid detection of the presence of Zika virus DNA, via fluorescence methods. For this, we initially deposited alternating layers of polyaniline (PANI) and polypyrrole (PPY) on the surface of polyethylene terephthalate (PET) sheets. The films obtained were then characterized by SEM, UV-Vis, ATR-FTIR, and contact angle measurements. For their use as quenchers for the diagnosis of Zika, a single DNA strand-specific for ZIKV was labeled with a fluorophore (FAM-ssDNA). We determined the time required for the saturation of the interaction between probe FAM-ssDNA and the film (180 min) and the time for the maximal hybridization between FAM-ssDNA and target DNA to occur (60 min). The detection limits were estimated as 345 pM and 278 pM for the PET/PPY-PANI and PET/PANI-PPY hybrid films, respectively. The simplicity of the procedure, coupled with the fact that a positive/negative response can be obtained in less than 60 min, suggests that the proposal of using these polymeric bilayer films is a promising methodology for the development of rapid molecular diagnostic tests.

Ammonia sensors manufactured by plasma enhanced grafting of conducting polymers on nylon-6 fabrics

In this study, two conducting polymers viz. Polyaniline (PANI) and Polypyrrole (PPY) were grafted on nylon 6 fabrics separately using in situ chemical oxidative polymerization method. For better adhesion and deposition, nylon 6 fabrics were treated with low pressure RF oxygen (O2) plasma prior to grafting of conducting polymers. Both PANI and PPY grafted nylon 6 fabrics were characterized by scanning electron microscopy (SEM), ATR-FTIR, XPS (ESCA), contact angle and sheet resistance measurements. Both the fabrics have been tested as ammonia gas sensor. Uniform deposition of PANI and PPY on nylon 6 fabric surfaces have been observed due to oxygen plasma pre-treatment. PANI grafted nylon 6 fabrics are found to be less conductive but more sensitive towards ammonia gas than PPY grafted nylon 6 fabrics.

Specially Designed Polyaniline/Polypyrrole Ink for a Fully Printed Highly Sensitive pH Microsensor.

pH sensing for healthcare applications requires sensors with mechanically stable materials of high sensitivity and high reproducibility combined with low-cost fabrication technologies. This work proposes a fully printed pH sensor based on a specially formulated conducting polymer deposited on a microelectrode in a flexible substrate. A formulation, which combined polyaniline (PANI) and polypyrrole (PPy) with integrated polyelectrolyte poly(sodium 4-styrenesulfonate) (PSS), was specially prepared to be printed by inkjet printing (IJP). The sensor has good sensitivity in the physiological region (pH 7–7.5) key for the healthcare biosensor. This mixture printed over a commercial gold ink, which has a singular chemical functionalization with phthalocyanine (Pc), increased the sensor sensitivity, showing an excellent reproducibility with a linear super-Nernstian response (81.2 ± 0.5 mV/pH unit) in a wide pH range (pH 3–10). This new ink together with the IJP low-cost technique opens new opportunities for pH sensing in the healthcare field with a single device, which is disposable, highly sensitive, and stable in the whole pH range.