Sustainable Materials and Methods for Functional Finishing of Textiles: Current Trends, Challenges, and Future Directions

The textile industry is rapidly shifting toward sustainability due to increasing environmental concerns, regulatory pressures, and consumer demand for eco-friendly products. The global functional textile market reached approximately USD 4.72 billion by 2020, with a compound annual growth rate of 30-3.58%. However, conventional functional finishing relies on over 8,000 chemicals, including formaldehyde-based resins, per fluorinated compounds (PFCs), and heavy metals, many of which pose serious environmental and health risks. This review, based on the analysis of 172 references, presents a comprehensive overview of sustainable materials and methods for textile functionalization. It highlights bio-based, animal-derived, hybrid, and green-synthesized nanomaterials that range from 1-100nm, used to impart functional properties such as antimicrobial activity, UV protection, self-cleaning, and flame retardancy. Sustainable application techniques, including coating, sol-gel processing, layer-by-layer assembly, encapsulation, and enzymatic treatments, are critically discussed. Further, key challenges related to durability, scalability, material compatibility, and regulatory compliance are examined. Emerging trends, including multifunctional bio-nanocomposites, circular textile systems, and digitalized green manufacturing, are also explored. This review provides a concise roadmap for developing high-performance, sustainable functional textiles with reduced environmental and health impacts.