Conducting Polymer Nanofibers Research Articles

Conducting Polymer Nanofibers and Nanotubes as a Potential Nanotechnology: Current Status and Future Directions

Conducting Polymer Nanofibers and Nanotubes as a Potential Nanotechnology: Current Status and Future Directions

Benefits of increasing surface to volume ratio for improving electrochemical performance of poly(3‐hexylthiophene): Electrospun fibers vs. films

AbstractWe report on successful preparation of conducting polymer nanofibers from regiorandom poly(3‐hexylthiophene). It is shown that the electrochemical properties of obtained structures are significantly improved in course of electrochemical doping process performed in the aqueous phase, moreover this process is accompanied with change of optical properties and water contact angle. These effects are not observed for polymer films. Moreover, doping of nanofibers results in pronounced, irreversible changes in the polymer structure – increased crystallinity due to incorporation of doping ions is confirmed by optical and X‐ray crystallographic studies. Ultimately, these changes lead to decreased resistance and improved electrochemical performance of nanofibers mat. As this effect is solely observed for nanofibers of conducting polymer, it can be ascribed to high surface to volume ratio of electrospun fibers mat. Therefore, it is shown for the first time that polythiophene electrochemical doping process effect is dependent on the format of the polymer applied, for nanofibers it can be regarded as attractive method of improving electrochemical properties of polymers.

Self-healing electrical bioadhesive interface for electrophysiology recording

Electrical bioadhesive interfaces (EBIs) are standing out in various applications, including medical diagnostics, prosthetic devices, rehabilitation, and human–machine interactions. Nonetheless, crafting a reliable and advanced EBI with comprehensive properties spanning electrochemical, electrical, mechanical, and self-healing capabilities remains a formidable challenge. Herein, we develop a self-healing EBI by thoughtfully integrating conducting polymer nanofibers and a typical bioadhesive within a robust hydrogel matrix. The accomplished EBI demonstrates extraordinary adhesion (lap shear strength of 197 kPa), exceptional electrical conductivity (2.18 S m−1), and outstanding self-healing performance. Taking advantage of these attributes, we integrated the EBI into flexible skin electrodes for surface electromyography (sEMG) signal recording from forearm muscles. The engineered skin electrodes exhibit robust adhesion to the skin even when sweating, rapid self-healing from damage, and seamless real-time signal recording with a higher signal-to-noise ratio (39 dB). Our EBI, along with its skin electrodes, offers a promising platform for tissue-device integration, health monitoring, and an array of bioelectronic applications.

Progress in Conducting Polymer‐Based Electrospun fibers for Supercapacitor Applications: A Review

AbstractThe ever‐growing need for energy storage has been at the forefront of research for the past few decades. A supercapacitor is an attractive candidate for storage needs with widespread applications in electronic gadgets, electric vehicles and hybrid vehicles, especially in space and the military. The significant role of electrodes in the performance of supercapacitors has led to the development of materials endowed with exceptional electrochemical performance and mechanical stability. Conducting polymers with intriguing properties like tuneable electronic conductivity, broad voltage window, tuneable redox activity etc., are excellent candidates as electrode materials for electrochemical capacitors with superior performance parameters. Electrospun conducting polymer nanofibers exhibit unique characteristics and favourable morphologies that have the potential to enhance the performance of supercapacitors. The review covers the fundamentals of electrochemical capacitors and introduces electrospinning as a versatile method to fabricate nanofibers using conducting polymers and their composites. The application of these nanofibers as electrodes in supercapacitors is discussed in detail and the performance parameters are compared. The article also discusses the challenges and prospects in using these electrospun nanofibers as effective supercapacitor electrodes.

Conducting Polymer Nanofiber for Application to Flexible/Energy Devices

Conducting Polymer Nanofiber for Application to Flexible/Energy Devices

Engineering electrospun of in-situ plasmonic AgNPs onto PANI@PVDF nanofibrous scaffold as back surface support for enhancing silicon solar cells efficiency with the electrical model assessment

Fabrication of polymeric nanofibrous structures with superior electronic properties is a big challenge for producing durable and renewable energy. The influence of conducting polymer nanofibers embedded metal nanoparticles is essential for improving the performance of Silicon Solar Cell (SSC). Herein, rapid in-situ silver nanoparticles (AgNPs) were entrapped during polymerized pure polyaniline (PANI) to exhibit PANI/AgNPs nanocomposites. Then, PANI and/or PANI/AgNPs electrospun with Polyvinylidene Fluoride (PVDF) and deposited on the rear surface of SSCs by electrospinning technique. The surface texture was tested with SEM, and the diameter of nanofibers onto solar cells is below 150 ± 23 nm for all nanocomposites. Owing to the ultrathin diameter of nanofibers, the doped constituent of Ag 3% possesses elevation in the performance of SSCs at a light intensity of 100 mW/cm2 concerning cell temperature 25–27°C. At specific content of coated nanofibrous PANI/AgNPs (3 wt%) @PVDF, the SSCs power conversion efficiency (PCE) attains 15.75% rather than the uncoated solar cell (14.03%). Besides, the series resistance decreased by 12.62%, consequently increasing efficiency and maximum power by 12.25% and 12.71%, respectively. The bandgap of PANI/AgNPs (3 wt%) @PVDF was 3.15 eV, which highly affected the performance of SSCs. This facile plasmonic nanofibrous combination offers homogenous distribution onto SSCs with a favorable conductivity path for the photoelectrons based on the nanofibers' surface-to-volume ratio, enabling excellent candidates in energy applications. An optimized single diode model is considered to assess the electrical performance of the controlled and modified SSCs.

Interface-engineered reduced graphene oxide assembly on nanofiber surface for high performance strain and temperature sensing

Conductive polymer nanofiber composites (CPNCs) based wearable sensing electronics have aroused great attention of scientists in recent years. However, it is still difficult to obtain CPNCs with good water proof, excellent durability, and multiple sensing performance. Herein, we develop a multifunctional CPNC with a wrinkled reduced graphene oxide (RGO) shell and polymer nanofiber core, which is prepared by ultrasonication induced decoration of RGO onto the pre-stretched polyurethane (PU) nanofibers, followed by the release of the strain. The RGO assembly with a wrinkled structure not only greatly increases the surface roughness and thus the hydrophobicity but also enhances the strain sensing sensitivity (with a gauge factor of 154.8 in the strain range of 85%–100%) of the nanofibrous membrane. The obtained CPNC strain sensor also shows excellent sensing durability (over 1000 cycles) and can be used for body motion monitoring. The CPNC shows a negative temperature coefficient effect, which holds promising applications in high performance temperature sensors.

Flexible, Mechanically Robust, Solid-State Electrolyte Membrane with Conducting Oxide-Enhanced 3D Nanofiber Networks for Lithium Batteries.

Using a three-dimensional (3D) Li-ion conducting ceramic network, such as Li7La3Zr2O12 (LLZO) garnet-type oxide conductor, has proved to be a promising strategy to form continuous Li ion transfer paths in a polymer-based composite. However, the 3D network produced by brittle ceramic conductor nanofibers fails to provide sufficient mechanical adaptability. In this manuscript, we reported a new 3D ion-conducting network, which is synthesized from highly loaded LLZO nanoparticles reinforced conducting polymer nanofibers, by creating a lightweight continuous and interconnected LLZO-enhanced 3D network to outperform conducting heavy and brittle ceramic nanofibers to offer a new design principle of composite electrolyte membrane featuring all-round properties in mechanical robustness, structural flexibility, high ionic conductivity, lightweight, and high surface area. This composite-nanofiber design overcomes the issues of using ceramic-only nanoparticles, nanowires, or nanofibers in polymer composite electrolyte, and our work can be considered as a new generation of composite electrolyte membrane in composite electrolyte development.

Polyvinylidene Fluoride Core-Shell Nanofiber Membranes with Highly Conductive Shells for Electromagnetic Interference Shielding.

As the demand for wireless sensors and equipment is unprecedentedly increasing, the interest in electromagnetic interference (EMI)-shielding materials that can effectively block accompanying electromagnetic interference is also constantly increasing. In particular, flexible and lightweight EMI-shielding materials that exhibit high EMI-shielding effectiveness (SE) have been more actively investigated as they are applicable to various applications. In this work, we reported the fabrication and performance of conducting polymer nanofiber EMI-shielding material, which was realized using electrospun polyvinylidene fluoride (PVDF) core-shell nanofiber membranes with highly conductive shells. Using the chemical polymerization method, core-shell nanofibers with highly conductive shells were employed without compositing with conductive fillers, resulting in shell-conductive lightweight EMI-shielding material without impairing the original properties of the nanofiber. In particular, thanks to the nanofiber structure, the EMI-shielding material exhibits superb flexibility, and the EMI SE was also improved through the enhanced absorption of EM waves and multireflections by the porous nanofiber film structure. Specifically, the developed EMI-shielding material in this work exhibited a SE of ∼40 dB in the X-band, which corresponds to an absolute shielding effectiveness (SSEt) of 16,230 dB·cm2/g at a thickness of 14 μm. Moreover, the high durability and hydrophobicity of the PVDF nanofibers with poly (3,4-ethylenedioxythiophene) (PEDOT)-polymerized shell can also be useful in practical applications.

Kirigami electrodes of conducting polymer nanofibers for wearable humidity dosimeters and stretchable supercapacitors

Nanofibrillar Kirigami electrodes enable superior sensitivity in humidity sensors and state-of-the-art energy density in supercapacitors.

Conjugated polymer nanostructures displaying highly photoactivated antimicrobial and antibiofilm functionalities.

This work reports the use of conjugated polymer nanostructures (CPNs) as photoactivated antimicrobial compounds against Gram-positive and Gram-negative microorganisms. Two representative CPNs of polythiophene (PEDOT) and polyaniline (PANI) were prepared as nanofibres with an average diameter of 40 nm and length in the micrometer range. Both CPNs exhibited strong antimicrobial activity under UVA irradiation with the same fluence rate as the UVA component of the solar spectrum. The effect was tested using the Gram-positive bacteria Staphylococcus aureus and the Gram-negative bacteria Escherichia coli. The reduction of colony forming units (CFUs) reached >6 log for PEDOT concentrations as low as 33 ng mL-1. For PEDOT nanofibers, a complete inhibition of S. aureus and E. coli growth was reached at 883 ng mL-1 and 333 ng mL-1 respectively. The photoactivation effect of PANI nanofibres on S. aureus and E. coli was also high, with a CFU reduction of about 7 log and 4 log respectively for an exposure concentration of 33 ng mL-1. The antimicrobial activity was only high under light irradiation and was almost negligible for bulk PEDOT and PANI. The effect of polymeric nanofibers could be attributed to the photoinduced generation of reactive oxygen species, which may induce cell membrane damage, eventually leading to bacterial impairment and inhibition of their biofilm forming capacity. CPN PEDOT and PANI coatings were able to keep surfaces free of bacterial attachment and growth even after 20 h of previous contact with exponentially growing cultures in the dark. PEDOT and PANI CPNs demonstrated good cytocompatibility with human fibroblasts and the absence of hemolytic activity. The materials demonstrated advantages in terms of broad antibacterial spectrum, biofilm inhibition, and the absence of acute toxicity for biomedical applications.

Electrical Double Percolation of Polybutadiene/Polyethylene Glycol Blends Loaded with Conducting Polymer Nanofibers.

The critical phenomena of double percolation on polybutadiene (PB)/polyethylene glycol (PEG) blends loaded with poly-3-hexylthiophene (P3HT) nanofibers is investigated. P3HT nanofibers are selectively localized in the PB phase of the PB/PEG blend, as observed by scanning force microscopy (SFM). Moreover, double percolation is observed, i.e., the percolation of the PB phase in PB/PEG blends and that of the P3HT nanofibers in the PB phase. The percolation threshold (φcI) and critical exponent (tI) of the percolation of the PB phase in PB/PEG blends are estimated to be 0.57 and 1.3, respectively, indicating that the percolation exhibits two-dimensional properties. For the percolation of P3HT nanofibers in the PB phase, the percolation threshold (φcII) and critical exponent (tII) are estimated to be 0.02 and 1.7, respectively. In this case, the percolation exhibits properties in between two and three dimensions. In addition, we investigated the dimensionality with respect to the carrier transport in the P3HT nanofiber network. From the temperature dependence of the field-effect mobility estimated by field-effect transistor (FET) measurements, the carrier transport was explained by a three-dimensional variable range hopping (VRH) model.

Energy-storing brick walls

Brick walls might someday power your lights and laptop, thanks to a new technique that converts the building blocks into battery-like devices ( 2020, DOI: ). By packing bricks’ tiny pores with conductive polymer nanofibers, researchers have made supercapacitors that can power an LED light for up to 15 min. “Bricks have been around for thousands of years, but we’ve added value and new functionality to them,” says , a chemist at Washington University in St. Louis. The proof-of-concept brick supercapacitor takes 13 min to charge fully and can be recharged 10,000 times. Integrated into walls and coupled with solar panels, the devices could provide emergency power and lighting. Supercapacitors, like batteries, have two electrodes with an electrolyte in between. D’Arcy makes supercapacitor electrodes from conductive polymer nanofibers, whose high surface area can store a relatively large amount of charge. He was inspired when he spotted bricks at the hardware

A universal strategy: Rational construction of noble metal nanoparticle-shell/conducting polymer nanofiber-core electrodes with enhanced electrochemical performances

To address a challenge for decoration of noble metal nanoparticles (NMNPs)-shell on conducting polymer nanofiber (CPNF) electrodes (i.e. NMNP-shell/CPNF-core electrodes) for boosting electrochemical performances, a two-step strategy comprising chemical pre-deposition and electrochemical deposition is designed. The strategy shows a high universality in terms of the diversity of NMNP-shell elements (single-element: AgNP-shell, AuNP-shell, PtNP-shell, PdNP-shell; multi-element: Au/Pt/PdNP-shell) and the independence of conductive substrates of electrodes. The shells are composed of high-density NMNPs and have strong adhesion to CPNF-cores. It is demonstrated that in response to a specific applied electrical stimulus, the resulting low doping level of CPNFs facilitates the generation of high-density nucleation sites (small NMNPs) by chemical pre-deposition (as high capability of electron transfer and low resistance to electron transfer from CP chains to NM ions), which is indispensable for the formation of NMNP-shells on CPNF-cores by electrochemical deposition. The decoration of NMNP-shells can significantly enhance the electrochemical performances of CPNF electrodes. Moreover, the great practicality and reliability of NMNP-shell/CPNF-core electrodes in use as an electrocatalytic platform are confirmed. This universal strategy opens up a new avenue to construct high-dimension shell/core-nanostructured electrodes.

Flexible PDA@ACNTs decorated polymer nanofiber composite with superhydrophilicity and underwater superoleophobicity for efficient separation of oil-in-water emulsion

Nanofibrous membranes with superwetting performance have promising applications in oil adsorption or oil/water separation. However, the development of superwettable, stretchable and durable nanofiber composite for efficient separation of oil-in-water emulsion is still a challenge. Herein, a simple and versatile method was proposed to prepare flexible, superhydrophilic and electrically conductive polymer nanofiber composite with a core/shell structure by acidified carbon nanotubes (ACNTs) decoration onto polyurethane (PU) nanofibers and subsequent polydopamine (PDA) modification. Multiple interfacial hydrogen bonding among ACNTs, PDA and PU nanofibers results in the enhancement of both the tensile strength and Young's modulus of the PU nanofibrous membrane and also ensures the excellent stretchability, surface stability and durability of the nanofiber composite. The obtained superhydrophilic/underwater superoleophobic nanofiber composite exhibits superior anti-fouling property and can be used for high efficiency separation of oil-in-water (even corrosive) emulsion with outstanding recyclability. The flexible and multifunctional nanofiber composite with a unique PDA/ACNTs shell and polymer nanofiber core structure shows great potentials in practical oily wastewater purification.

Morphological Evolvement of Carbon Nanotubes Synthesized by Using Conducting Polymer Nanofibers

Carbon nanotubes were synthesized by using a nanostructured conducting polymer—the polypyrrole nanofiber via microwave radiation. The radiation time was set to be 30, 60, and 90 seconds, respectively. The morphological evolvements of the as-synthesized carbon nanotubes with increased radiation time (e.g., shape, diameter, wall structure, and catalyst size) were carefully investigated, and the possible growth mode was discussed in detail. It was found that the growth mode of the carbon nanotubes synthesized from the conducting polymer substrate under microwave radiation was complex and cannot be simply interpreted by either a “tip” or “base” growth model. A new growth mode of the “liquifying cascade growth” was observed for the as-synthesized carbon nanotubes, as their growth was directed by a series of liquified iron nanoparticles with sequentially decreasing sizes, similar to the cascade of liquid droplets. And it could provide useful insights for the morphological and structural designs of the carbon nanotubes prepared by related microwave-based methods.

A highly stretchable, super-hydrophobic strain sensor based on polydopamine and graphene reinforced nanofiber composite for human motion monitoring

Much attention has been given to flexible electronic devices in recent years. Conductive polymer composites (CPCs) have been utilized to fabricate strain sensors owing to their lightweight and high flexibility. It is a great challenge to develop flexible and wearable strain sensors with light weight, good skin affinity and gas permeability, high sensitivity and excellent corrosion resistance. In this work, electrospun thermoplastic polyurethane (TPU) nanofibers were first decorated by graphene through ultra-sonication, followed by polydopamine (PDA) modification and then hydrophobic treatment with 1H, 1H, 2H, 2H-perfluorodecanethiol (PFDT). The obtained electrical conductive polymer nanofiber composites (CPNCs) have a hierarchical polymer core/graphene shell structure and exhibit super-hydrophobicity even under harsh environments. The introduction of PDA not only improves the interfacial interaction between individual graphene sheets but also the interaction between graphene and the TPU nanofibers. Their mechanical properties including Young's modulus, tensile strength and elongation at break are significantly improved, compared to those of TPU nano-fibrous membranes. When CPNC is used as a strain sensor, it displays high stretchability, controllable sensitivity, excellent cyclical stability and durability. Hence, the nanofiber composite based strain sensor can be attached on the skin for precise monitoring of different human motions, such as tiny and large body movements and thus has promising applications in wearable devices.

Flexible, superhydrophobic, and electrically conductive polymer nanofiber composite for multifunctional sensing applications

Sensor materials that can detect chemical vapors or mechanical deformation have wide applications in the field of healthcare, flexible electronics, environmental protection, etc. However, it is still challenging to prepare stretchable and multifunctional sensors that can be served as both chemical vapor and strain sensors. Here, a superhydrophobic and stretchable nanofiber composite is prepared by acid modified carbon nanotubes (ACNTs) decoration onto the polyurethane (PU)/ polystyrene-block-poly(ethylene-co-butylene)-block-polystyrene (SEBS) nanofibers, followed by the hydrolysis of methyltrichlorosilane (MTS) on the ACNT surface. The introduction of ACNTs and hydrolysate of MTS, namely the polysiloxane, significantly improves the mechanical properties of the blend nanofibrous membrane including the Young’s modulus, tensile strength and elongation at break. The superhydrophobicity can be maintained even under corrosive conditions. When served as the chemical vapor sensor, the nanofiber composite displays good selectivity, high sensitivity and low detection limit (1 ppm for the toluene vapor). Also, the nanofiber composite can be used as wearable strain sensors that can detect various body motions. The multifunctional nanofiber composite has potential applications in wearable electronic, electrical nose for gas leakage and smart textile.

Improved Electrical and Mechanical Properties for the Reduced Graphene Oxide-Decorated Polymer Nanofiber Composite with a Core–Shell Structure

Conductive polymer nanofiber composites (CPNCs) have promising applications in many fields. However, preparation of the CPNC with excellent mechanical and electrical properties is still challenging...

Development of all-solid-state battery based on lithium ion conductive polymer nanofiber framework

A thin, flexible, and safe composite polymer electrolyte membrane composed of lithium ion conductive nanofiber framework and polymer electrolyte matrix is demonstrated as an innovative solid-state electrolyte for potential use in high-performance rechargeable all-solid-state lithium ion battery. Due to this unique structural integrity, the composite solid polymer electrolyte indicates excellent mechanical stability, remarkable improvements in the ion conductivity (approximately 10−4 S cm−1 at room temperature) and the lithium ion transference number (approximately 0.5), and the significant battery performance in terms of good charge-discharge cycling behavior and moderate rate capability. Finally, a high-voltage multi-stacked battery with the solid polymer composite electrolytes is developed and can readily produce a doubled cell potential of 6.8 V, promising future batteries operated at high-voltage with high energy densities.