Functionalization of conducting polymers and their applications in optoelectronics

Stimuli-Responsive Multiacceptor Conjugated Polymers: Recent Trend and Future Direction

Apart from the visual effects, geometric shapes of materials play an important role in their engineering and biomedical applications. Responsive materials-based patient-specific anatomical models provide better insights into the structure and pathology. Polymers are by far the most utilized class of materials for advanced science and technology. Because of these properties, these polymers have been used as functional coatings, thermoplastics, biomedical materials, separators, and binders for Li-ion batteries, fuel cell membranes, piezoelectric devices, high-quality wires and cables, and so on. Reactive to stimuli because of their unusual electrical characteristics and adaptability, stimuli-responsive multiacceptor conjugated polymers have been a prominent focus of materials science study. These polymers combine several electron-accepting units inside their conjugated backbone, resulting in increased functionality and responsiveness to a variety of stimuli. The production, workings, and wide range of applications of stimuli-responsive multiacceptor conjugated polymers are the focus of this review.

Tuning the Optical Properties of Electrospun Poly(methyl methacrylate) Nanofibres via Montmorillonite and Magnetite Ratios

Poly(methyl methacrylate) (PMMA) polymer has unlocked new frontiers in the field of nanotechnology and is suitable for a wide range of applications. However, its optical band gap limits its use in optoelectronics. This study aims to ascertain the influence of varying montmorillonite and magnetite ratios on the optical properties of electrospun PMMA nanofibres produced from solution. The nanofibres were characterised using Fourier-transform infrared spectroscopy (FTIR), atomic force microscopy (AFM), scanning electron microscopy (SEM), X-ray diffractometry (XRD), energy-dispersive X-ray spectroscopy (EDX), spectroscopic ellipsometry, and UV-Vis spectroscopy (UV-Vis). XRD analysis revealed the successful incorporation of magnetite and montmorillonite within the PMMA matrix, with diameters ranging from 203 to 328 nm. The incorporation of magnetite and montmorillonite altered the light absorption characteristics of PMMA, resulting in increased absorption in the ultraviolet and visible light regions compared to pristine PMMA and a reduction in the optical band gap from 4.9 eV to 2.5 eV. These findings suggest that PMMA is a suitable host matrix for montmorillonite and magnetite. The observed properties also indicate the suitability of the produced materials for optoelectronic applications, including chemical sensors and protective UV coatings.

Smart conducting polymer innovations for sustainable and safe food packaging technologies

Biofilm formation on food packaging surfaces is a major issue in the industry, as it leads to contamination, reduces shelf life, and poses risks to human health. To mitigate these effects, developing smart coatings that can actively sense and combat microbial growth has become a critical research focus. This study is motivated by the need for intelligent packaging solutions that integrate antimicrobial agents and sensors for real-time contamination detection. It is hypothesized that combining conducting polymers (CPs) with nanomaterials can enhance antimicrobial efficacy while maintaining the mechanical integrity and environmental stability required for food packaging applications. Through the application of numerous technologies like surface modification, CP-nanoparticle integration, and multilayered coating, the antimicrobial performance and sensor capabilities of these materials were analyzed. Case studies showed a 90% inhibition of bacterial growth and a tenfold decrease in viable bacterial counts with AgNPs incorporation, extending strawberries' shelf life by 40% and maintaining fish freshness for an additional 5 days. Moreover, multilayered CP coatings in complex systems have been shown to reduce oxidative spoilage in nuts and dried fruits by up to 85%, while maintaining the quality of leafy greens for up to 3 weeks under suboptimal conditions. Environmental assessments indicated a 30% reduction in carbon footprint when CP coatings were combined with biodegradable polymers, contributing to a more transparent and reliable food supply chain. CP-based films integrated with intelligent sensors exhibit high sensitivity, detecting ammonia concentrations below 500 ppb, and offer significant selectivity for sensing hazardous gases. These findings indicate that CP-based smart coatings markedly enhance food safety and sustainability in packaging applications.

Recent Developments in the Adsorption of Heavy Metal Ions from Aqueous Solutions Using Various Nanomaterials

Water pollution is caused by heavy metals, minerals, and dyes. It has become a global environmental problem. There are numerous methods for removing different types of pollutants from wastewater. Adsorption is viewed as the most promising and financially viable option. Nanostructured materials are used as effective materials for adsorption techniques to extract metal ions from wastewater. Many types of nanomaterials, such as zero-valent metals, metal oxides, carbon nanomaterials, and magnetic nanocomposites, are used as adsorbents. Magnetic nanocomposites as adsorbents have magnetic properties and abundant active functional groups, and unique nanomaterials endow them with better properties than nonmagnetic materials (classic adsorbents). Nonmagnetic materials (classic adsorbents) typically have limitations such as limited adsorption capacity, adsorbent recovery, poor selective adsorption, and secondary treatment. Magnetic nanocomposites are easy to recover, have strong selectivity and high adsorption capacity, are safe and economical, and have always been a hotspot for research. A large amount of data has been collected in this review, which is based on an extensive study of the synthesis, characterization, and adsorption capacity for the elimination of ions from wastewater and their separation from water. The effects of several experimental parameters on metal ion removal, including contact duration, temperature, adsorbent dose, pH, starting ion concentration, and ionic strength, have also been investigated. In addition, a variety of illustrations are used to describe the various adsorption kinetics and adsorption isotherm models, providing insight into the adsorption process.

Mixed Conducting Polymers Alter Electron Transfer Thermodynamics to Boost Current Generation from Electroactive Microbes

Electroactive microbes that can release or take up electrons are essential components of nearly every ecological niche and are powerful tools for the development of alternative energy technologies. Small-molecule mediators are critical for this electron transfer but remain difficult to study and engineer because they perform concerted two-electron transfer in native systems but only individual, one-electron transfers in electrochemical studies. Here, we report that electrode modification with ion- and electron-conductive polymers yields biosimilar, concerted two-electron transfer from Shewanella oneidensis via flavin mediators. S. oneidensis biofilms on these polymers show significantly improved per-microbe current generation and morphologies that more closely resemble native systems, setting a new paradigm for the study and optimization of these electron transfer processes. The unprecedented concerted electron transfer was found to be due to altered mediator electron transfer thermodynamics, enabling biologically relevant studies of electroactive biofilms in the lab for the first time. These important findings pave the way for a complete understanding of the ecological role of electroactive microbes and their broad application in sustainable technologies.

Carbon-Based Nanomaterials Decorated Electrospun Nanofibers in Biosensors: A Review

Nanomaterials have revolutionized scientific research due to their exceptional physical and chemical capabilities. Carbon-based nanomaterials such as graphene and its derivates have excellent electrical, optical, thermal, physical, and chemical properties that have made them indispensable in several industries worldwide, including medicine, electronics, and energy. By incorporating carbon-based nanomaterials as nanofillers in electrospun nanofibers (ESNFs), smoother and highly conductive nanofibers can be achieved that possess a large surface area and porosity. This approach provides a superior alternative to traditional materials in the development of improved biosensors. Carbon-based ESNFs, among the most exciting new-generation materials, have many applications, including filtration, pharmaceuticals, biosensors, and membranes. The electrospinning technique is a highly efficient and cost-effective method for producing desired nanofibers compared to other methods. Various types of natural and synthetic organic polymers have been successfully utilized in solution electrospinning to produce nanofibers directly. To create diagnostics devices, various biomolecules like antibodies, enzymes, aptamers, ligands, and even cells can be bound to the surface of nanofibers. Electrospun nanofibers can serve as an immobilization matrix to create a biofunctional surface. Thus, biosensors with desired features can be produced in this way. This study comprehensively reviews biosensors that integrate nanodiamonds, fullerenes, carbon nanotubes, graphene oxide, and carbon dots into electrospun nanofibers.

Ultrathin Mixed Ionic-Electronic Conducting Interlayer via the Solution Shearing Technique for High-Performance Lithium-Sulfur Batteries

The commercialization of lithium-sulfur (Li-S) batteries has been hampered by diverse challenges, including the shuttle phenomenon and low electrical/ionic conductivity of lithium sulfide and sulfur. To address these issues, extensive research has been devoted to developing multifunctional interlayers. However, interlayers capable of simultaneously suppressing the polysulfide (PS) shuttle and ensuring stable electrical and ionic conductivity are relatively uncommon. Moreover, the use of thick and heavy interlayers results in an unavoidable decline in the energy density of Li-S batteries. We developed an ultrathin (750 nm), lightweight (0.182 mg cm-2) interlayer that facilitates mixed ionic-electronic conduction using the solution shearing technique. The interlayer, composed of carbon nanotube (CNT)/Nafion/poly-3,4-ethylenedioxythiophene:tetracyanoborate (PEDOT:TCB), effectively suppresses the shuttle phenomenon through the synergistic segregation and adsorption effects on PSs by Nafion and CNT/PEDOT, respectively. Furthermore, the electrical/ionic conductivity of the interlayer can be improved via counterion exchange and homogeneous Li+ ion flux/good wettability from SO3- functional group of Nafion, respectively. Enhanced sulfur utilization and reaction kinetics through polysulfide shuttle inhibition and facilitated electron/ion transfer by interlayer enable a high discharge capacity of 1029 mA h g-1 in the Li-S pouch cell under a high sulfur loading of 5.3 mg cm-2 and low electrolyte/sulfur ratio of 5 μL mg-1.

Piezoresistive Behavior of Polypyrrole:Carboxymethyl Cellulose Composites

The unique properties of conducting polymers make them ideally suited for applications in organic electronics, photovoltaics, and energy storage systems. Depending on the specific application, they can outperform metal-based electronics by cost, mechanical flexibility, molecular design opportunities, and environmental impact. Many composites of conducting polymers with polyanions can be processed in water. However, the facile processing of such composites comes at a cost of reduced conductivity. In this manuscript, electronic conductivity dependence on composition for a composite of polypyrrole (PPy) with carboxymethyl cellulose (CMC) has been studied. Secondary ion mass spectrometry and electron energy loss spectroscopy mapping indicate the formation of a nanostructure forming PPy-rich nanospheres with a CMC-rich surface coverage. This structure requires inter-particle electron conduction to occur via quantum tunneling. Variations in the tunneling distance are dependent on the applied pressure, giving rise to a pressure-dependent electronic conductivity and thus piezoresistance. This behavior opens new applications of conducting polymer composites in pressure-sensitive electronic devices, providing metal-free alternatives to quantum tunneling composites.

Conducting polymers/zinc oxide-based photocatalysts for environmental remediation: a review

The accessibility to clean water is essential for humans, yet nearly 250 million people die yearly due to contamination by cholera, dysentery, arsenicosis, hepatitis A, polio, typhoid fever, schistosomiasis, malaria, and lead poisoning, according to the World Health Organization. Therefore, advanced materials and techniques are needed to remove contaminants. Here, we review nanohybrids combining conducting polymers and zinc oxide for the photocatalytic purification of waters, with focus on in situ polymerization, template synthesis, sol-gel method, and mixing of semiconductors. Advantages include less corrosion of zinc oxide, less charge recombination and more visible light absorption, up to 53%.

Advances in Nanomaterial-based Biosensors for Determination of Glycated Hemoglobin

Diabetes is a major public health burden whose prevalence has been steadily increasing over the past decades. Glycated hemoglobin (HbA1c) is currently the gold standard for diagnostics and monitoring of glycemic control in diabetes patients. HbA1c biosensors are often considered to be cost-effective alternatives for smaller testing laboratories or clinics unable to access other reference methods. Many of these sensors deploy nanomaterials as recognition elements, detection labels, and/or transducers for achieving sensitive and selective detection of HbA1c. Nanomaterials have emerged as important sensor components due to their excellent optical and electrical properties, tunable morphologies, and easy integration into multiple sensing platforms. In this review, we discuss the advantages of using nanomaterials to construct HbA1c sensors and various sensing strategies for HbA1c measurements. Key gaps between the current technologies with what is needed moving forward are also summarized.

Recent Advances in Functional Polymer Materials for Energy, Water, and Biomedical Applications: A Review

Academic research regarding polymeric materials has been of great interest. Likewise, polymer industries are considered as the most familiar petrochemical industries. Despite the valuable and continuous advancements in various polymeric material technologies over the last century, many varieties and advances related to the field of polymer science and engineering still promise a great potential for exciting new applications. Research, development, and industrial support have been the key factors behind the great progress in the field of polymer applications. This work provides insight into the recent energy applications of polymers, including energy storage and production. The study of polymeric materials in the field of enhanced oil recovery and water treatment technologies will be presented and evaluated. In addition, in this review, we wish to emphasize the great importance of various functional polymers as effective adsorbents of organic pollutants from industrial wastewater. Furthermore, recent advances in biomedical applications are reviewed and discussed.

Recent Developments in Flexible Transparent Electrode

With the rapid development of flexible electronic devices (especially flexible LCD/OLED), flexible transparent electrodes (FTEs) with high light transmittance, high electrical conductivity, and excellent stretchability have attracted extensive attention from researchers and businesses. FTEs serve as an important part of display devices (touch screen and display), energy storage devices (solar cells and super capacitors), and wearable medical devices (electronic skin). In this paper, we review the recent progress in the field of FTEs, with special emphasis on metal materials, carbon-based materials, conductive polymers (CPs), and composite materials, which are good alternatives to the traditional commercial transparent electrode (i.e., indium tin oxide, ITO). With respect to production methods, this article provides a detailed discussion on the performance differences and practical applications of different materials. Furthermore, major challenges and future developments of FTEs are also discussed.

Acid Treatment Enhances the Antioxidant Activity of Enzymatically Synthesized Phenolic Polymers

Phenolic polymers produced by enzymatic oxidation under biomimetic and eco-friendly reaction conditions are usually endowed with potent antioxidant properties. These properties, coupled with the higher biocompatibility, stability and processability compared to low-molecular weight phenolic compounds, open important perspectives for various applications. Herein, we report the marked boosting effect of acid treatment on the antioxidant properties of a series of polymers obtained by peroxidase-catalyzed oxidation of natural phenolic compounds. Both 2,2-diphenyl-1-picrylhydrazyl (DPPH) and ferric reducing/antioxidant power (FRAP) assays indicated a remarkable increase in the antioxidant properties for most phenolic polymers further to the acid treatment. In particular, up to a ca. 60% decrease in the EC50 value in the DPPH assay and a 5-fold increase in the Trolox equivalents were observed. Nitric oxide- and superoxide-scavenging assays also indicated highly specific boosting effects of the acid treatment. Spectroscopic evidence suggested, in most cases, that the occurrence of structural modifications induced by the acid treatment led to more extended π-electron-conjugated species endowed with more efficient electron transfer properties. These results open new perspectives toward the design of new bioinspired antioxidants for application in food, biomedicine and material sciences.