This study presents an innovative approach to the recovery of nickel from industrial wastewater using cost-effective carbon fiber electrodes, aiming to provide a sustainable and scalable solution for industrial effluent management. Carbon fibers offer unique benefits in electrochemical recovery processes due to their high surface area, excellent conductivity, mechanical durability, and compatibility with low-cost production. The optimized conditions, including a deposition potential of 4 V, pH 3.5, and temperature of 60 degrees C, achieved a high nickel recovery efficiency of 90%, with minimal energy consumption at 3 kW h per kilogram of nickel. This efficiency was verified through Scanning Electron Microscopy (SEM) and Energy Dispersive X-ray (EDX) analyses, which revealed uniform and dense nickel coatings on the carbon fibers, even under continuous operation. Fourier Transform Infrared Spectroscopy (FTIR) and X-ray diffraction (XRD) confirmed successful nickel deposition and modifications to the carbon fiber surface chemistry, enhancing the adsorption and reduction of nickel ions. Using carbon fiber electrodes in this process addresses several limitations in traditional electrode materials by reducing costs, improving scalability, and supporting continuous, large-scale nickel recovery. This method offers a viable alternative to conventional electrochemical metal recovery and contributes to circular resource utilization by recycling valuable metals from wastewater. With regulatory pressures increasing around heavy metal discharge limits, this carbon fiber-based electrodeposition process presents a highly promising solution for industrial wastewater treatment, combining environmental sustainability with economic feasibility.

The study demonstrates a scalable and reproducible method for synthesising graphene oxide (GO) nanosheets from commercial carbon fibres derived from carbonised polyacrylonitrile (PAN) polymer. An exfoliation route with nitric acid allows for the preparation of monolayer GO nanosheets with a consistent thickness of 0.9 ± 0.2 nm, identical to the commercially available GO from mined graphite. The GO nanosheets exhibit distinct circular and elliptical shapes, in contrast to the polygonal and sharp-edged morphology of commercial GO. An extensive evaluation of acidic solutions and electrical potentials identified a narrow processing window critical for obtaining GO nanosheets sized 0.1–1 µm. An unexpectedly low 5% acid concentration was found to be the most effective, providing a balance between efficient exfoliation through synergistic acidic and electrochemical oxidation. The process provides a high yield of 200 mg of GO per gram of carbon fibre. Advanced characterisation using high-resolution electron and atomic force microscopy (HR-TEM/SEM/AFM), Raman spectroscopy, X-ray photoelectron spectroscopy (XPS), and infrared spectroscopy (FTIR) provided detailed insights into the morphology, thickness, surface functionalisation, and chemical composition of the nanosheets. With its high yield, environmentally sound production, and versatility, the synthesised GO offers transformative potential for large-scale applications, including energy storage, advanced coatings, high-performance composites, water purification, and electronic devices.

Mycelium derived from Ganoderma lucidum was employed as a template for synthesising silicon oxide (SiOx) nanofibers. The intricate structures of mycelial hyphae fibrils were replicated with high precision using an inexpensive commercial silane (3-aminopropyl)-triethoxysilane (APTES). Following the removal of the organic mycelium template phase at 600 degrees C, APTES was successfully converted to SiOx. The resulting SiOx fibres retained the morphology of the mycelium template, with a nearly identical fibre density to the original fibrous network. A fibril diameter reduction of approximately 43% was observed from 603 to 344 nm. All synthesised materials exhibited coherent structural integrity, sufficient for handling without breakage, although they were notably less mechanically flexible than the original mycelium template. The novel hybrid mycelium-3-aminopropyl-silsesquioxane fibre network and the thermally converted SiOx network displayed notable liquid absorption properties. These materials allowed for the preferential absorption of oil or water, depending on the presence of the amino group functionality. Remarkably, the SiOx network rapidly absorbed methylene blue-dyed water within 400 ms, demonstrating behaviour opposite to the virgin mycelium network. Additionally, the materials exhibited high thermal stability, withstanding flame exposure at approximately 1400 degrees C while maintaining their nano/micromorphology. This innovative approach of using "living" templates expands the range of morphologies that can be replicated in inorganic materials, enabling the creation of genetically and environmentally tuneable structures. The SiOx nanofibers produced through this method have potential applications in various fields, including water purification, biosensors, catalytic support, and insulation.

Biomass-derived materials are increasingly being incorporated into plastics to create biocomposites that reduce reliance on fossil-based feedstocks and lower carbon footprints. Maximizing the sustainability potential of these bio-based materials requires increasing their content within polymer matrices. However, a significant challenge arises: as bio-based content increases, performance trade-offs often arise. This study addresses this issue by examining the combined use of multiple bio-based components, specifically lignin and biochar, in acrylonitrilebutadiene-styrene (ABS) biocomposites. The bio-based content reached up to 44 wt%, while retaining adequate processability for extrusion and vacuum forming, as demonstrated by producing a miniature roof box sample. With this biocomposite composition, greenhouse gas emissions could be reduced by up to 40 %. Moreover, the fire performance was slightly improved by adding either lignin or biochar alone, while the combination of both fillers improved the fire performance significantly (a peak heat-release rate being half of that of ABS) due to a synergistic barrier-forming effect, limiting the transport of oxygen and fuel to the heat source and reducing heat transfer. The inclusion of both biochar and lignin influenced the mechanical properties of the composite, leading to an increase (33 %) in stiffness but a slight reduction (22 %) in strength. This study suggests that combining biochar and lignin can maximize bio-based content while improving critical performance characteristics, offering a viable pathway for more sustainable plastics.

This review focuses on the use of polyolefins in high-voltage direct-current (HVDC) cables and capacitors. A short description of the latest evolution and current use of HVDC cables and capacitors is first provided, followed by the basics of electric insulation and capacitor functions. Methods to determine dielectric properties are described, including charge transport, space charges, resistivity, dielectric loss, and breakdown strength. The semicrystalline structure of polyethylene and isotactic polypropylene is described, and the way it relates to the dielectric properties is discussed. A significant part of the review is devoted to describing the state of art of the modeling and prediction of electric or dielectric properties of polyolefins with consideration of both atomistic and continuum approaches. Furthermore, the effects of the purity of the materials and the presence of nanoparticles are presented, and the review ends with the sustainability aspects of these materials. In summary, the effective use of modeling in combination with experimental work is described as an important route toward understanding and designing the next generations of materials for electrical insulation in high-voltage transmission.

The majority of plastics used today are produced from nonrenewable resources, and, depending on the end-of-life management, they may end up in landfills or in nature, giving rise to microplastic pollution. A potential way of minimizing this is to use proteins, preferentially recovered from organic waste and residues, to make plastics. In line with this, we explored here the potential of protein-based bioplastics sourced from single-cell protein (SCP). Films of glycerol-plasticized SCPs (grown by recovering carbon from cheese whey and nitrogen from anaerobic digestate) were produced by compression molding. Electron microscopy revealed a structure of intact cells and the presence of cracks/voids, and the mechanical properties indicated a rather poor cohesion between the cells, despite the high-temperature treatment in the pressing stage. The resulting structure yielded a material that could absorb a sizable amount of both nonpolar (rapid capillary uptake) and polar liquids. The anaerobic biodegradation of the SCP films demonstrated that full biodegradability (100%) and high specific biomethane productions (471 ± 8 mL/gram of volatile solids) could be attained within operating conditions that are typical of anaerobic digestion processes in the treatment of food waste. Overall, this study highlights the potential and also the challenge of using SCP as an alternative bioplastic material in food packaging and edible coatings.