Due to the rapid development of the textile industry and increased consumption of various textiles composed of both synthetic and natural fibers, large amounts of textile waste are produced, leading to environmental and economic problems on a global scale. Turning textile waste into carbon materials that can be used in a broad range of applications has become a viable solution to address this challenge in terms of sustainability and value generation. Natural and synthetic textile fibers have distinctive molecular structures with relatively high carbon content and variable chemical functionality; therefore, they have been identified as highly promising precursors for fabricating carbon materials with various electrochemical and environmental applications. At the same time, the properties of carbonized and activated textile fibers are strongly dependent on the molecular transformations taking place during thermal treatment and functionalization of textile fibers. This review will provide a comprehensive overview of the molecular evolution of natural and synthetic textile fibers during carbonization and activation processes in terms of dehydration, depolymerization, aromatization, heteroatom preservation, and graphitization mechanisms. The effect of precursor chemical composition, pyrolysis conditions, activation process, and heteroatom incorporation on the structure of carbonized and activated textile fibers and their physical and electrochemical properties will be analyzed. Particular emphasis is placed on electrochemical applications, including capacitive deionization, supercapacitors, electrocatalysis, and emerging smart electrochemical textile systems, highlighting how molecular transformation, pore engineering, and surface chemistry govern charge storage, ion adsorption, and catalytic behavior. In addition, major characterization techniques such as Raman spectroscopy, X-ray diffraction, X-ray photoelectron spectroscopy, and Brunauer–Emmett–Teller surface area analysis will be reviewed and discussed in relation to understanding the interdependence between molecular structure and material properties. Finally, recent issues related to feedstock heterogeneity, scalability, energy efficiency, and sustainability of processing are highlighted, and future perspectives on multifunctional carbon structures and circular utilization of textile waste are discussed.

Cotton dyeing and printing requires a number of preparatory processes involved the use of various chemicals and eventually creates massive pollution load on effluent which disposed in the environment directly or partially treated consequently increases the health hazard. In this work cotton knitted fabric was scoured and bleached by naturally occurring clay ‘Bentonite’ as an alternative of auxiliaries. The wetting power, detergency, sequestering power and stabilizing action of bentonite clay was tested thoroughly. The scouring and bleaching efficiency and dyeability with a bi-functional reactive dye were evaluated on differently pretreated samples. The residual pretreated liquors were analyzed for ecological parameters including pH, Total dissolved solids, chemical oxygen demand, and biological oxygen demand (BOD₅). In comparison with conventional auxiliaries, bentonite clay showed acceptable results. The scouring and bleaching performances of all pretreated fabrics was satisfactory. All samples were evenly dyed and there was no noticeable color difference. It also observed that bentonite clay treated liquors create less pollution when compared to the conventional treated liquors. Finally, cost of bentonite process was calculated and compared with conventional.

The increasing demand for cleaner coloration of synthetic textiles has renewed interest in plant-based dyes; however, limited dye–fiber affinity and shade durability remain major challenges in nylon dyeing. This study developed a mordant-free dyeing process for nylon fabric using Terminalia catappa leaf extract by optimizing extraction pH, dyebath pH, dyeing time, and temperature. Mature T. catappa leaves were aqueously extracted under acidic, neutral, and alkaline conditions, followed by systematic dyeing optimization. The dyed fabrics were evaluated using color strength (K/S), CIELAB color coordinates, standard fastness tests, FTIR spectroscopy, and FE-SEM analysis. Alkaline extraction followed by acidic dyeing produced the highest dye uptake. The optimum condition was extraction pH 11, dyebath pH 3, 120 °C, and 60 min, yielding a maximum K/S value of 21.94 with ΔL, Δa, and Δb values of −54.25, 8.03, and 24.92, respectively. FTIR and SEM results supported possible dye–fiber interaction through hydrogen bonding, electrostatic attraction, and surface/inter-filament dye deposition without obvious fiber damage. The optimized fabric showed very good washing, dry rubbing, perspiration, and saliva fastness, good light fastness, excellent ultraviolet protection, and slightly lower wet rubbing fastness. Overall, T. catappa leaf extract offers a promising mordant-free route for durable nylon coloration.