Enhanced Nanocellulose Production from Cotton and Textile Waste Using Binary and Ternary Natural Deep Eutectic Solvents

Abstract

The growing accumulation of textile waste poses significant environmental challenges, as only a small percentage of materials is currently recycled. However, cotton waste offers a valuable feedstock for the regeneration of cellulose and nanocellulose (NC). This study presents a sustainable and efficient method for producing NC from textile waste using both binary and ternary natural deep eutectic solvents (NADESs). By treating cotton wool, pre-consumer standard cotton fabrics, and post-consumer denim textiles, with NADESs, NC generation is achieved in high yields (up to ≈90%) in all cases. The most promising NADESs, composed of choline chloride and gallic acid (and tartaric acid), effectively dissolve cotton-based materials when subjected to heating and sonication, producing cellulose nanocrystals with length ranging from 100 to 300 nm and crystallinity level up to ≈80%. The NADESs are characterized by thermogravimetric analysis (TGA), fourier transform infrared spectroscopy (FT-IR), as well as modeled by density functional theory (DFT), to investigate their hydrogen bond network. Eventually, their recyclability is also investigated. This approach opens promising applications in the fields of sustainable nanomaterial production and textile recycling, providing a greener alternative for waste valorization and promoting circular economy practices.