Current recycling strategies and high-value utilization of waste cotton

Flame-retardant innovations in bio-based treatments for lignocellulosic natural fibers: A review

The growing environmental concerns tied to synthetic materials have sparked interest in renewable, biodegradable, and sustainable alternatives like lignocellulosic fibers (LFs) from plants and agricultural waste. While advantageous, the inherent flammability of LFs limits their use in safety-critical applications, necessitating effective flame-retardant treatments. Traditional flame retardants (FRs) involve harmful chemicals, which pose environmental and health risks. Consequently, research is increasingly focusing on bio-based FRs derived from natural compounds such as polysaccharides, proteins, and phytic acid. These materials have shown promise in enhancing the fire resistance of natural fiber through mechanisms that improve thermal stability and char formation. This review provides a comprehensive analysis of recent advancements in bio-based flame retardant solutions alongside the physical, mechanical, thermal, and flammability properties of LFs. It also examines recent techniques for applying bio-based coatings to fibers and explores the latest fiber applications. By evaluating the interactions between these FRs and fiber structures, the review highlights the potential for developing effective, sustainable solutions that can facilitate the safe and environmentally friendly use of LFs across various applications. Ultimately, this review aims to contribute to a transformative shift toward safer and more sustainable materials in the face of growing environmental challenges.

High-Efficiency Dry-Jet Wet Spinning of Ultratoughness Regenerated Wool Keratin Fibers

Regenerated wool keratin fibers (RWKFs) featuring their ecofriendliness, ample resources, and intrinsic biocompatibility have attracted significant interest, while their high-value-added applications are still severely limited by inadequate mechanical properties and complex fabrication processes. Herein, a straightforward dry-jet wet spinning technique without post-treatment processes is proposed to prepare ultratoughness RWKFs. The as-spun fibers achieve a macroscale hierarchical structure due to the preorientation of nanoscale α-keratin protofibrils in air-gap drawing of dry-jet wet spinning, while α-keratins are preserved in large quantities because of no additional post-treatment stretching. As a result, the fabricated RWKFs achieve a tensile strength of ∼142.7 MPa, an outstanding elongation of ∼171.7%, and a record high toughness of ∼176.3 MJ m-3, outperforming natural wool and previously reported regenerated keratin fibers. Moreover, the reported RWKFs' dyeability, moisture-induced shape-memory capacity, and electric generation performance remarkably expand their applications in textiles or even smart apparel.

Chemical Valorization of Textile Waste: Advancing Sustainable Recycling for a Circular Economy

As textile production continues to grow worldwide, managing the mounting waste generated by this industry is becoming an urgent environmental concern. Globally, over 92 million tons of textile waste are produced annually, much of which is incinerated or disposed of in landfills, contributing to greenhouse gas emissions, soil and water contamination, and ecosystem harm. This review explores how chemical and biotechnological methods, such as acid hydrolysis (achieving up to 70% glucose recovery) and enzymatic recycling (reducing energy consumption by approximately 20% compared to conventional methods), can transform textile waste into valuable resources, fostering a shift toward a circular economy that minimizes reliance on virgin materials. However, the diverse nature of textile waste-particularly in mixed fibers and materials treated with various finishes and additives-adds complexity to recycling processes, often necessitating specific pretreatment steps to ensure both efficiency and economic viability. Scalable solutions such as advanced solvent recovery systems, optimized pretreatment techniques, and fluidized-bed pyrolysis (which can increase bio-oil yields by up to 25% compared to fixed-bed reactors) play crucial roles in making textile recycling more sustainable and adaptable at an industrial scale. By addressing these technical and financial challenges, the industry can improve the efficiency and sustainability of textile recycling practices, reducing waste and contributing to environmental resilience. This review also suggests several future directions to enhance scalability and compatibility with environmental goals, highlighting the potential for these technologies to create valuable secondary materials and support greener practices in textile waste management. Through continued innovation and a commitment to sustainable practices, the textile industry can better balance resource recovery with economic feasibility, unlocking substantial opportunities to mitigate environmental impact and support a more resource-efficient, sustainable future.

Novel millimeter-sized honeycomb-like Fe/Fe3C@HBC from waste cotton textiles towards rapid degradation of ofloxacin via activation of H2O2

Although multiphase catalysts with large sizes exhibit excellent recyclability and low toxicity in heterogeneous Fenton reactions, their reactivity, reusability and storage stability for degradation of organic contaminants still need improvement, which is essential for treating complex wastewater and ensuring environmental sustainability. In this study, the waste cotton textiles were firstly used as the carbon source to generate a novel millimeter-sized catalyst (Fe/Fe3C@HBC) with a honeycomb-like structure, which could effectively activate H2O2 to realize rapid removal of ofloxacin (OFL) (100% in 10 min). It achieved remarkable removal performance across a broad temperature range (4-40 °C) and high-concentration OFL. It even demonstrated excellent removal towards other typical contaminants (Tetracycline, Ciprofloxacin, Methylene Blue, Rhodamine B, Malachite Green), showing outstanding storage stability, physical structural stability, reusability and separation characteristics. Whereafter, its removal mechanism was also explored, showing that it was entirely dependent on the degradation by the reactive oxygen species (ROS), including •OH, O2•- and 1O2, as well as the persistent free radicals from the catalyst. Moreover, the honeycomb-like structure promoted the effective utilization of H2O2, facilitated the generation of •OH and expedited the accumulation of OFL on the catalyst surface. Fe/Fe3C (inside of the catalytic instead of in the reaction solution) was essential for the degradation. Finally, the OFL degradation pathways and toxicity predictions were also proposed. Overall, this innovation supports cleaner water resources and enhances public health, demonstrating a significant step forward in environmental remediation technologies.

Advanced Bioinspired Personal Thermoregulation Textiles for Outdoor Radiative Cooling

Radiative cooling textiles designed to reflect incoming sunlight and enhance mid-infrared (MIR) emissivity show great potential for ensuring personal thermal comfort. Thus, these textiles are gaining prominence as a means of combating the heat stress induced by global warming. Nonetheless, integrating radiative cooling effects into scalable textile materials for personal thermoregulation remains a formidable challenge. To achieve optimal cooling performance, textiles must exhibit finely tuned optical properties and spectral selectivity. In this study, a radiative cooling smart textile was devised by drawing inspiration from the structure of greater flamingo (Phoenicopterus roseus) feathers, which have effective thermoregulatory properties. Specifically, a nanoporous nonwoven material was fabricated from polyacrylonitrile and alumina particles and integrated with a cellulosic cotton knit fabric through an efficient electrospinning and hot pressing process to produce smart textile metafabric (PAC@T) with superior optical properties and wearer comfort. PAC@T exhibited an average fiber diameter of 501.6 nm and pore size of 857.6 nm, resulting in a solar reflectance of 95 ± 1.2% and an MIR emissivity of 91.8 ± 0.98%. It also demonstrated an enhanced water vapor transmission rate (5.5 kg/m2/24 h), water vapor evaporation rate (334 ± 2.2 mg/h), and significant radiative cooling performance, leading to temperatures 6.1 °C cooler than those achieved by a traditional knitted textile. Thus, PAC@T offers several distinct advantages, namely superior cooling efficiency, long-term durability, and energy-free operation. In addition, it is formed from accessible raw materials via a potentially scalable process that is likely to have substantial applications in industrial generation of smart textiles for personal thermoregulation.

Enhanced removal of tetracycline in light-dark tandem by FeCu-doped carbon composites derived from waste cotton fabrics

It is of great significance to develop an energy-efficient and external oxidant-free strategy for antibiotics removal. In this study, the novel light-dark tandem strategy was established to enhance tetracycline (TC) removal by bifunctional FeCu-doped carbon composites (FeCu@BC) derived from waste cotton fabrics. Interestingly, over 95 % TC was removed by FeCu@BC under light alone and dark alone in 10 min, with the same preferred conditions of pH 7.50 and 0.04 g/L catalyst dosage. Surprisingly, the enhanced mineralization efficiency of TC was achieved by the light-dark tandem without adjusting the parameters as 86.65 %, which was 1.13, 1.46 and 2.12 times higher than those of the dark-light tandem, light alone and dark alone, respectively. The mechanisms were elucidated as that 83.28 % direct degradation and 4.37 % indirect degradation under light while 47.63 % direct degradation and 24.16 % indirect degradation under darkness contributed for TC removal. The synergetic effects of persistent free radicals (PFRs) and FeCu interactions enabled FeCu@BC to work efficiently under both light and darkness, and light enhanced electron transfer between PFRs and FeCu interactions. Furthermore, energetic electrons stored in these active sites under light could be extracted to enhance electron transfer under subsequent darkness and the strongly catalytically active species initiated under light remained in action after cessation of light. Finally, high molecular TC was easily decomposed by energetic photo-catalysis and low molecular intermediates were mineralized under subsequent enhanced dark-catalysis to increase the mineralization efficiency. In general, this study provided an eco-friendly organics removal strategy and mechanisms insights based on the natural day-night cycle.

Study on Fenton-based discoloration of reactive-dyed waste cotton prior to textile recycling

The aim of this study is to investigate the feasibility of an alternative Fenton-based advanced oxidation process for the discoloration of reactive-dyed waste cotton as a pre-treatment for textile recycling. For that, pre-wetted dark-colored (black and blue) knitted samples of 300 cm2 are treated in 1200mL Fenton-solution containing 14 mM Fe2+ and 280mM H2O2 at 40 °C. Characterization of the textiles before and after the treatments are performed by UV VIS-spectrophotometry measuring color strength, microscopy, FTIR spectroscopy, thermal analysis and tensile testing measuring tenacity and elongation. Afterwards, the cotton is mechanically shredded for qualitative analysis of the recyclability. The color-strength measurements of the black and blue cotton led to discoloration-efficiencies of respectively 61.5 and 72.9%. Microscopic analysis of discolored textile fabric also showed significant fading of the colored textiles. Mechanical analysis resulted in reduced tensile strength after treatment, indicating oxidation of the cellulosic structure besides the degradation of the dye-molecules, also confirmed by reductions in thermal stability found after thermal analysis. Shredding of the fabric resulted in enhanced opening, but shorter remaining fibers after treatment. The findings of this study provide a proof-of-concept for an alternative color-stripping treatment concerning a Fenton-based advanced oxidation process as a pre-treatment for textile recycling.

Development of strontium aluminate-printed nonwoven fabric from recycled cotton cellulose for smart wearable photochromic applications

Smart photochromic and fluorescent textile refers to garments that alter their colorimetric properties in response to external light stimulus. Cotton fibers have been reported as a main resource for many textile and non-textile industries, such as automobiles, medical devices, and furniture applications. Cotton is a natural fiber that is distinguished with breathability, softness, cheapness, and highly absorbent. However, there have been growing demands to find other resources for cotton textiles at high quality and low cost for various applications, such as sensor for harmful ultraviolet radiation. Herein, we present a novel method toward luminescent and photochromic nonwoven textiles from recycled cotton waste. Using the screen-printing technology, a cotton fabric that is both photochromic and fluorescent was developed using aqueous inorganic phosphor nanoparticles (10-18 nm)-containing printing paste. Both CIE Lab color coordinates and photoluminescence spectra showed that the transparent film printed on the nonwoven fabric develops a reversible green emission (519 nm) under ultraviolet light (365 nm), even at low pigment concentration (2%) in the printing paste. Colorfastness of printed fabrics showed high durability and photostability.

Design, characterizations, and antimicrobial activity of sustainable home furnishing-based waste fabric treated using biobased nanocomposite

Clothing and textile industries are major contributors to environmental pollution including textile manufacturing through garment production, spinning, weaving, and dyeing. In this context, the sustainability textile industry is a big challenge and contributes to serving a large segment of society. Also, textile wastes could be used as a raw material for added-value products. Herein, in this study, recycling of residues fabric was treated with antimicrobial nanocomposite to reach the best use of exhausts and obtain multifunction products of aesthetic via the technical design of the waste raw materials. Besides, solving the unemployment problem by opening fields for small industry projects capable of producing high-value textile artifacts, especially when treated against microbes, can be applied to home furnishings. The waste fabric was treated via green synthesis nanocomposite based on chitosan and in situ prepared ZnONPs and cross-linked with tannic acid. The prepared nanocomposite was characterized using physicochemical analysis including attenuated total reflectance Fourier transform infrared spectroscopy (ATR-FTIR) and X-ray diffraction (XRD). Additionally, the nanocomposite and treated fabric topographical behavior were studied using scanning electron microscopy (SEM) attachment with energy dispersive X-ray analysis (EDX), and images were processed to evaluate the roughness structure. Additionally, high-resolution transmission electron microscopy (HR-TEM) and dynamic light scattering (DLS) were performed to ensure the size and stability of the nanocomposite. The obtained results affirmed the green synthesis of nanocomposite with a size around 130 nm, as well as the doped ZnONPs average size of 26 nm and treated waste fabric, performed a promising attraction between nanocomposite and fabric fibers. Moreover, the antimicrobial study observed excellent activity of nanocomposite against bacteria and unicellular fungi as well.

Biofuel production for circular bioeconomy: Present scenario and future scope

In recent years, biofuel production has attracted considerable attention, especially given the increasing worldwide demand for energy and emissions of greenhouse gases that threaten this planet. In this case, one possible solution is to convert biomass into green and sustainable biofuel, which can enhance the bioeconomy and contribute to sustainable economic development goals. Due to being in large quantities and containing high organic content, various biomass sources such as food waste, textile waste, microalgal waste, agricultural waste and sewage sludge have gained significant attention for biofuel production. Also, biofuel production technologies, including thermochemical processing, anaerobic digestion, fermentation and bioelectrochemical systems, have been extensively reported, which can achieve waste valorization through producing biofuels and re-utilizing wastes. Nevertheless, the commercial feasibility of biofuel production is still being determined, and it is unclear whether biofuel can compete equally with other existing fuels in the market. The concept of a circular economy in biofuel production can promote the environmentally friendly and sustainable valorization of biomass waste. This review comprehensively discusses the state-of-the-art production of biofuel from various biomass sources and the bioeconomy perspectives associated with it. Biofuel production is evaluated within the framework of the bioeconomy. Further perspectives on possible integration approaches to maximizing waste utilization for biofuel production are discussed, and what this could mean for the circular economy. More research related to pretreatment and machine learning of biofuel production should be conducted to optimize the biofuel production process, increase the biofuel yield and make the biofuel prices competitive.

Internal water circulation mediated synergistic co-hydrolysis of PET/cotton textile blends in gamma-valerolactone

Recycling strategies for mixed plastics and textile blends currently aim for recycling only one of the components. Here, we demonstrate a water coupling strategy to co-hydrolyze polyester/cotton textile blends into polymer monomers and platform chemicals in gamma-valerolactone. The blends display a proclivity for achieving an augmented 5-hydroxymethylfurfural yield relative to the degradation of cotton alone. Controlled experiments and preliminary mechanistic studies underscore that the primary driver behind this heightened conversion rate lies in the internal water circulation. The swelling and dissolving effect of gamma-valerolactone on polyester enables a fast hydrolysis of polyester at much lower concentration of acid than the one in the traditional hydrolysis methods, effectively mitigating the excessive degradation of cotton-derived product and undesirable product formation. In addition, the system is also applicable to different kinds of blends and PET mixed plastics. This strategy develops an attractive path for managing end-of-life textiles in a sustainable and efficient way.

Green, chemical-free, and high-yielding extraction of nanocellulose from waste cotton fabric enabled by electron beam irradiation

Recycling and high-value reutilization of waste cotton fabrics (WCFs) has attracted a widespread concern. One potential solution is to extract nanocellulose. Sulfuric acid hydrolysis is a conventional method for the production of nanocellulose with high negative charge from WCFs. However, the recycling and disposal of chemicals in nanocellulose production, along with low yields, remain significant challenges. Consequently, there is a pressing need for a sustainable method to produce nanocellulose at higher yield without the use of chemicals. Herein, we propose a green, sustainable and chemical-free method to extract nanocellulose from WCFs. The nanocellulose displayed a rod-like shape with a length of 50-300 nm, a large aspect ratio of 18.4 ± 2 and the highest yield of up to 89.9 %. The combined short-time and efficient two-step process, involving electron beam irradiation (EBI) and high-pressure homogenization (HPH), offers a simple and efficient alternative approach with a low environmental impact, to extract nanocellulose. EBI induced a noticeable degradation in WCFs and HPH exfoliated cellulose to nano-size with high uniformity via mechanical forces. The as-prepared nanocellulose exhibits excellent emulsifying ability as the Pickering emulsion emulsifier. This work provides a facile and efficient approach for nanocellulose fabrication as well as a sustainable way for recycle and reutilization of the waste cotton fabrics.

Effects of Alkali Activation of the Cotton Straw Biochar on the Adsorption Performance for Cd2

In this study, a single factor exploration method was adopted to optimize the cotton shell-based activated carbon adsorption reaction time, temperature, pH value, initial concentration of cadmium ion, and other conditions. The experimental results showed that under the conditions of Cd2+ solution pH = 8, initial concentration of 100 mg/L, adsorption reaction time of 180 min, adsorption temperature of 45 °C, cotton shell-based activated carbon dosage of about 0.1 g, the removal rate of Cd2+ was 94.03%, the adsorption capacity was 51.95 mg/g, and the error was only 0.05%. The adsorption kinetic analysis of this study conforms to the quasi-second-order kinetic model, the adsorption isotherm analysis conforms to the Langmuir adsorption isothermal model, and the Gibbs free energy of the adsorption process is negative; the above simulation analysis also proves the spontaneity and feasibility of the adsorption process.

Valorisation of cotton post-industrial textile waste into lactic acid: chemo-mechanical pretreatment, separate hydrolysis and fermentation using engineered yeast

BACKGROUND

The textile industry has several negative impacts, mainly because it is based on a linear business model that depletes natural resources and produces excessive amounts of waste. Globally, about 75% of textile waste is disposed of in landfills and only 25% is reused or recycled, while less than 1% is recycled back into new garments. In this study, we explored the valorisation of cotton fabric waste from an apparel textile manufacturing company as valuable biomass to produce lactic acid, a versatile chemical building block.

RESULTS

Post-industrial cotton patches were pre-treated with the aim of developing a methodology applicable to the industrial site involved. First, a mechanical shredding machine reduced the fabric into individual fibres of maximum 35 mm in length. Afterwards, an alkaline treatment was performed, using NaOH at different concentrations, including a 16% (w/v) NaOH enriched waste stream from the mercerisation of cotton fabrics. The combination of chemo-mechanical pre-treatment and enzymatic hydrolysis led to the maximum recovery yield of 90.46 ± 3.46%, corresponding to 74.96 ± 2.76 g/L of glucose released, which represents a novel valorisation of two different side products (NaOH enriched wastewater and cotton textile waste) of the textile industry. The Saccharomyces cerevisiae strain CEN.PK m850, engineered for redirecting the natural alcoholic fermentation towards a homolactic fermentation, was then used to valorise the glucose-enriched hydrolysate into lactic acid. Overall, the process produced 53.04 g/L ± 0.34 of L-lactic acid, with a yield of 82.7%, being the first example of second-generation biomass valorised with this yeast strain, to the best of our knowledge. Remarkably, the fermentation performances were comparable with the ones obtained in the control medium.

CONCLUSION

This study validates the exploitation of cotton post-industrial waste as a possible feedstock for the production of commodity chemicals in microbial cell-based biorefineries. The presented strategy demonstrates the possibility of implementing a circular bioeconomy approach in manufacturing textile industries.

Recent advances in liquid fuel production from plastic waste via pyrolysis: Emphasis on polyolefins and polystyrene

The management of plastic waste (PW) has become an indispensable worldwide issue because of the enhanced accumulation and environmental impacts of these waste materials. Thermo-catalytic pyrolysis has been proposed as an emerging technology for the valorization of PW into value-added liquid fuels. This review provides a comprehensive investigation of the latest advances in thermo-catalytic pyrolysis of PW for liquid fuel generation, by emphasizing polyethylene, polypropylene, and polystyrene. To this end, the current strategies of PW management are summarized. The various parameters affecting the thermal pyrolysis of PW (e.g., temperature, residence time, heating rate, pyrolysis medium, and plastic type) are discussed, highlighting their significant influence on feed reactivity, product yield, and carbon number distribution of the pyrolysis process. Optimizing these parameters in the pyrolysis process can ensure highly efficient energy recovery from PW. In comparison with non-catalytic PW pyrolysis, catalytic pyrolysis of PW is considered by discussing mechanisms, reaction pathways, and the performance of various catalysts. It is established that the introduction of either acid or base catalysts shifts PW pyrolysis from the conventional free radical mechanism towards the carbonium ion mechanism, altering its kinetics and pathways. This review also provides an overview of PW pyrolysis practicality for scaling up by describing techno-economic challenges and opportunities, environmental considerations, and presenting future outlooks in this field. Overall, via investigation of the recent research findings, this paper offers valuable insights into the potential of thermo-catalytic pyrolysis as an emerging strategy for PW management and the production of liquid fuels, while also highlighting avenues for further exploration and development.

Mobilisation of textile waste to recover high added value products and energy for the transition to circular economy

The textile industry is a major contributor to global waste, with millions of tons of textiles being discarded annually. Material and energy recovery within circular economy offer sustainable solutions to this problem by extending the life cycle of textiles through repurposing, recycling, and upcycling. These initiatives not only reduce waste but also contribute to the reduction of the demand for virgin materials (i.e. cotton, wool), ultimately benefiting the environment and society. The circular economy approach, which aims to recreate environmental, economic, and societal value, is based on three key principles: waste reduction, material circulation, and ecological restoration. Given these difficulties, circularity incorporates the material recovery approach, which is focused on the conversion of waste into secondary raw resources. The goal of this notion is to extract more value from resources by prolonging final disposal as long as feasible. When a textile has outlived its functional life, material recovery is critical for returning the included materials or energy into the manufacturing cycle. The aim of this paper is to examine the material and energy recovery options of main raw materials used in the fashion industry while highlighting the need of close observation of the relation between circularity and material recovery, including the investigation of barriers to the transition towards a truly circular fashion industry. The final results refer to the main barriers of circular economy transition within the industry and a framework is proposed. These insights are useful for academia, engineers, policy makers and other key stakeholders for the clear understanding of the industry from within and highlight beyond circular economy targets, SDGs interactions with energy and material recovery of textile waste (SDG 7, SDG 11, SDG 12 etc.).

An efficient interfacial solar evaporator featuring a hierarchical porous structure entirely derived from waste cotton

Interfacial solar evaporators are widely used to purify water. However, photothermal materials commonly constituting most interfacial solar evaporators remain expensive; additionally, the inherent structure of the evaporators limits their performance. Furthermore, the large amount of waste cotton produced by the textile industry is an environmental threat. To address these issues, we propose an interfacial solar evaporator, H-CA-CS, with a hierarchical porous structure. This evaporator is made entirely of waste cotton and uses carbon microspheres (CMS) and cellulose aerogel (CA) as photothermal and substrate materials, respectively. Additionally, its photothermal layer (CS layer) has large pores and a high porosity, which promote light absorption and timely vapor escape. In contrast, the water transport layer (CA layer) has small pores, providing a robust capillary effect for water transport. Combined with the outstanding light absorption properties of CMS, H-CA-CS exhibited superior overall performance. We found that H-CA-CS has an excellent evaporation rate (1.68 kg m-2 h-1) and an efficiency of 90.6 % under one solar illumination (1 kW m-2), which are superior to those of many waste-based solar evaporators. Moreover, H-CA-CS maintained a mean evaporation rate of 1.61 kg m-2 h-1, ensuring sustainable evaporation performance under long-term scenarios. Additionally, H-CA-CS can be used to purify seawater and various types of wastewater with removal efficiencies exceeding 99 %. In conclusion, this study proposes a method for efficiently using waste cotton to purify water and provides novel ideas for the high-value use of other waste fibers to further mitigate ongoing environmental degradation.

MXene Enhanced 3D Needled Waste Denim Felt for High-Performance Flexible Supercapacitors

MXene, a transition metal carbide/nitride, has been prominent as an ideal electrochemical active material for supercapacitors. However, the low MXene load limits its practical applications. As environmental concerns and sustainable development become more widely recognized, it is necessary to explore a greener and cleaner technology to recycle textile by-products such as cotton. The present study proposes an effective 3D fabrication method that uses MXene to fabricate waste denim felt into ultralight and flexible supercapacitors through needling and carbonization. The 3D structure provided more sites for loading MXene onto Z-directional fiber bundles, resulting in more efficient ion exchange between the electrolyte and electrodes. Furthermore, the carbonization process removed the specific adverse groups in MXenes, further improving the specific capacitance, energy density, power density and electrical conductivity of supercapacitors. The electrodes achieve a maximum specific capacitance of 1748.5 mF cm-2 and demonstrate remarkable cycling stability maintaining more than 94% after 15,000 galvanostatic charge/discharge cycles. Besides, the obtained supercapacitors present a maximum specific capacitance of 577.5 mF cm-2, energy density of 80.2 μWh cm-2 and power density of 3 mW cm-2, respectively. The resulting supercapacitors can be used to develop smart wearable power devices such as smartwatches, laying the foundation for a novel strategy of utilizing waste cotton in a high-quality manner.

Sustainable conversion of cottonseed hulls to valuable proanthocyanidins through ultrasound-assisted deep eutectic solvent extraction

This study presents a novel approach for converting cottonseed hulls (CSHs) into valuable proanthocyanidins (PAs) through deep eutectic solvent (DES)-based ultrasound-assisted extraction (UAE-DES). Response surface methodology (RSM) was applied to optimize and model this process, resulting in maximum yields of 78.58 mg/g. The ideal PA extraction conditions were determined to be a liquid-to-material ratio of 36.25 mL/g, a water content of 33.21%, and an extraction period of 7.4 min. Molecular dynamic simulations (MDS) were performed to study the interactions between the solvent and target chemicals. Increased van der Waals forces and stronger interactions between DES and the target chemical catechin (CA) compared to those observed with methanol or water were observed. Furthermore, the optimized extract exhibited a higher PA content than can be obtained with conventional extraction methods and demonstrated antioxidant activity in vitro. The cottonseed hulls residues (CSRs) remaining after the extraction process can be used to produce activated carbon (ACCSR), which has some capacity to adsorb methylene blue (MB) contaminants. This study offers a reference for the fruitful transformation of waste biomass into high-value products.

A Three-Dimensional Fiber-Network-Reinforced Composite Solid-State Electrolyte from Waste Acrylic Fibers for Flexible All-Solid-State Lithium Metal Batteries

The large amount of waste chemical fiber textiles that exists has posed pressure on the sustainable development of the natural environment and of society. Therefore, it is of great importance to increase the added value of waste chemical fiber textiles and expand their applications in other fields. Herein, acrylic yarn from waste clothing is used as the raw material to construct a three-dimensional (3D) acrylic-based ceramic composite nanofiber solid electrolyte. The electrochemical properties of batteries based on this solid electrolyte are also investigated. We found that the fabricated composite electrolyte has good performance in lithium ion conduction and electrochemical stability because of its 3D acrylic-based ceramic composite fiber framework. The introduction of this composite electrolyte to a lithium symmetric battery enabled the battery to circulate stably for 2350 h at 50 °C without short-circuiting. In addition, all-solid-state batteries using a LiFePO4 cathode exhibited high reversible capacity. Lastly, a flexible lithium metal pouch battery was able to operate safely and stably under extreme conditions. This work demonstrates a strategy for upcycling waste textiles into ion-conducting polymers for energy storage applications.

Chemical recycling of waste clothes: a smarter approach to sustainable development

Amount of fabric waste has increased many folds in the past few years due to increasing population and rapidly changing fashiosn trends. Its larger portion being dumped in the landfills is creating a lot of problem in its management. This is causing problems to environmental components of earth, viz., air, water, and land. Chemically, cotton-based fabrics are made up of mainly cellulose with small components of other chemicals and contribute to a big segment of overall textiles. Along with donating the cloths for various purposes, scientific solutions are also feasible for valorizing waste fabrics to value-added products. This review article focuses on important strategies for addressing fabric waste for their possible conversion to significant products of varied applications. It emphasizes on chemical routes suitable for this purpose for producing cellulose, sugar, composites, etc. This will provide an insight to the readers for understanding the chemical significance of waste fabric and exploring the best possible ways for its efficient management, ensuring a step ahead towards sustainable development.