Sustainable and environmentally friendly activated carbon from biomass materials is proposed to produce supercapacitors from banana peels and has the potential to replace the non-sustainable and hazardous process from either graphite or/and fossil fuels. In order to determine the potential of using banana peel for supercapacitor application, raw banana peel, a bio-waste, was activated both mechanically and chemically to observe the real differences. The sample was activated at 700 °C and chemically activated using KOH. Characterization of activated banana peel was performed using FTIR, DLS, TGA and XRD analytical equipment. FTIR analysis revised the presence of hydroxyl, carbonyl and aromatic compounds on a banana peel cellulose-based carbon. The TGA results proved that 700 °C could be sufficient to totally carbonize banana peel. DLS clearly showed a strong difference between the carbonized and KOH-activated material in particle size distribution. Meanwhile, surface area analysis using BET displayed an increase from 553.862 m²/g to 565.024 m²/g BET in surface area (SBET) when carbon was activated using KOH with a nitrogen isotherm at 77.350 K. Specific capacitance was increased from 0.3997 Fg⁻¹ to 0.821 Fg⁻¹, suggesting more than a 100% increase in the specific capacity due to KOH activation, as proved by the cyclic voltammetry (CV) curve. The X-ray diffraction results revealed the patterns of activated carbon. The findings demonstrated the feasibility of using banana peel waste as a low-cost and sustainable material for the preparation of flexible supercapacitor batteries.

Flexible supercapacitors are highly demanding due to their wearability, washability, lightweight property and rollability. In this paper, a comprehensive review on flexible supercapacitors based on conductive polymers such as polypyrrole (PPy), polyaniline (PANI) and poly(3,4-ethylenedioxtthiophne)-polystyrene sulfonate (PEDOT:PSS). Methods of enhancing the conductivity of PEDOT:PSS polymer using various composites and chemical solutions have been reviewed in detail. Furthermore, supercapacitors based on carbonized banana peels and methods of activation have been discussed in point. This review covers the up-to-date progress achieved in conductive polymer-based materials for supercapacitor electrodes. The effect of various composites with PEDOT:PSS have been discussed. The review result indicated that flexible, stretchable, lightweight, washable, and disposable wearable electronics based on banana peel and conductive polymers are highly demanding.

The use of hydrogel in tissue engineering is not entirely new. In the last six decades, researchers have used hydrogel to develop artificial organs and tissue for the diagnosis of real-life problems and research purposes. Trial and error dominated the first forty years of tissue generation. Nowadays, biomaterials research is constantly progressing in the direction of new materials with expanded capabilities to better meet the current needs. Knowing the biological phenomenon at the interaction among materials and the human body has promoted the development of smart bio-inert and bio-active polymeric materials or devices as a result of vigorous and consistent research. Hydrogels can be tailored to contain properties such as softness, porosity, adequate strength, biodegradability, and a suitable surface for adhesion; they are ideal for use as a scaffold to provide support for cellular attachment and control tissue shapes. Perhaps electrical conductivity in hydrogel polymers promotes the interaction of electrical signals among artificial neurons and simulates the physiological microenvironment of electro-active tissues. This paper presents a review of the current state-of-the-art related to the complete process of conductive hydrogel manufacturing for tissue engineering from cellulosic materials. The essential properties required by hydrogel for electro-active-tissue regeneration are explored after a short overview of hydrogel classification and manufacturing methods. To prepare hydrogel from cellulose, the base material, cellulose, is first synthesized from plant fibers or generated from bacteria, fungi, or animals. The natural chemistry of cellulose and its derivatives in the fabrication of hydrogels is briefly discussed. Thereafter, the current scenario and latest developments of cellulose-based conductive hydrogels for tissue engineering are reviewed with an illustration from the literature. Finally, the pro and cons of conductive hydrogels for tissue engineering are indicated.

Skin wound management is a very difficult undertaking in the medical field. There is no information available concerning the wound beneath the bandages. Electrospun nanofibrous wound dressings stand out for their resemblance to extracellular matrix (ECM), increased surface-to-volume ratio, porousness, and capacity to encapsulate or load medications, among other distinctive qualities. Traditional antibacterial loaded electrospun nanofibrous wound dressings do not indicate the state of the wound and constantly release antibacterial chemicals even when there are no bacteria in the wound area. As a result, dressings that can track the condition of the wound and dispense medications as needed are crucial. Self-responsive wound dressings can release medications based on bacterial, oxygen spectra, pH, or infection responsiveness, reducing the need for antibacterial agents. Self-responsive mats, which are wound dressings that can release medications based on response to bacteria, oxygen species, and pH or infections, are required to reduce the overuse of antibacterial agents. Self-responsive electrospun nanofibrous mats can be used to monitor the condition of a wound by altering its color in response to an infection or a change in the pH of the wound. Electrospun nanofibrous wound dressings that are stimulus-responsive (self-responsive) are discussed in this review paper. Self-responsive electrospun nanofibrous wound dressings that are triggered by pH, temperature, light, bacteria, and oxygen species are discussed in detail after self-responsive smart materials or polymers used for electrospun nanofibrous wound dressings are covered in the first section of the review.

The rapid growth of textile industries in Ethiopia plays an important role in economic development. However, the sludge from these wastewater treatment plants, which is not an integral part of the treatment process, is often considered hazardous as it is contaminated with heavy metals of dyestuffs and chemicals. The customary transfer routines such as landfilling and incineration may not be suitable because the leachate from the landfilling destinations and the buildups from the incinerators lead to optional contamination. Moreover, such transfer choices are not financially practical. Therefore, there is a growing need to look for various applications of sludge handling for sustainable development. This study attempts to find out an environmentally friendly solution for the management of the textile sludge by incinerating the sludge and using it for partial replacement of cement in concrete production. Concrete is a composite material formed by the combination of cement, sand, coarse aggregate, and water in a particular proportion so that concrete produced meets the needs regarding its workability, strength, durability, and economy. Typical textile sludge was having high heavy metal contents as per the United States Environmental Protection Agency (USEPA) guideline and should be properly disposed of. The sludge upon incineration at 625°C for four hours gives 78.1% moisture content, 61.2% volatile organic matter, and 59.6% inorganic ash content. The main reactive oxide elements such as SiO₂, Fe₂O₃, CaO, and Al₂O₃ were found to be 18.51, 3.19, 23.87, and 12.73% by weight in the ash. The calorific value determined from the dried sludge were found to be 1973 cal/gm. Concrete block was manufactured by replacement of cement with 10, 20, 30, 40, and 50% incinerated textile sludge ash, and the manufactured block was evaluated in terms of their compressive strengths, leaching behavior, and water absorption. The replacement cement by the ash increases the hydration time reduced, and up to 20%, sludge ash incorporation in the concrete mix design gives the designed compressive strength. Eventhough water absorption increases with increasing content of the incorporation of the ash, for the 20% replacement of cement, the lethal concentration of heavy metals was obtained to be below the permissible limit set by USEPA. Consequently, the experiment work indicates that the potential use of textile sludge ash for cement concrete gives the possibilities of reduction of heavy metal contamination to surroundings upon sludge disposal, reduces the use of raw materials for producing cement and reduces environmental pollution during cement production.

Recycled cellulosic fiber (RCF) composites offer significant potential to reduce environmental burdens associated with virgin fiber production; however, their broader adoption remains limited by feedstock variability, recycling-induced degradation, and uncertainty regarding long-term performance. This review critically synthesizes recent advances in RCF composites using a structure–processing–performance–sustainability framework, treating recycled fibers as secondary materials with distinct morphological, chemical, and mechanical characteristics rather than direct substitutes for virgin reinforcements. Emphasis is placed on the effects of fiber shortening, surface damage, moisture sensitivity, and altered surface chemistry on interfacial adhesion, load transfer efficiency, durability, and failure mechanisms. The analysis reveals that many reported performance discrepancies arise from poorly defined structure–property relationships and the absence of standardized characterization, grading, and durability testing protocols for recycled fibers. Addressing these gaps enables more reliable predictive modeling and application-specific material design. Beyond mechanical behavior, the review evaluates various critical factors for integration into higher-value applications such as durability under realistic service conditions, including environmental aging, fire performance, and long-term stability. Emerging strategies such as hybrid reinforcement, environmentally benign surface functionalization, smart functionalities, and recyclable or bio-based matrices are assessed for their potential to enhance multifunctionality and circularity. Overall, the findings indicate that RCF composites can meaningfully contribute to circular material systems if materials design, performance validation, and life-cycle assessment are integrated systematically. Advancing standardized evaluation and aligning materials innovation with circular economy principles are essential to transition RCF composites from downcycled applications to reliable, performance-oriented components in sustainable engineering systems.