A facile and sustainable method for integrating bio-based quercetin into cotton structures to impart multifunctionality: a thorough study on the effects of treatment conditions†

The worsening climate crisis has prompted a call to reduce the use of hazardous chemicals and promote eco-friendly finishing agents for value-added textiles. Therefore, exploring the right biomolecule-based finish with excellent multifunctional properties and wash durability is essential in today's world. Through a sustainable approach, quercetin (a flavonoid) is proposed as a finishing agent on cotton substrates at three different treatment temperatures, i.e., 80 °C, 100 °C, and 120 °C. All treated fabrics show excellent antioxidant and ultra-violet resistance properties. The cotton fabric treated at 120 °C shows antioxidant activity of ∼85% and an ultra-violet protection factor (UPF mean value) of ∼150 with a 50+ rating after 8 laundering cycles. The best antibacterial performance (∼90% against E. coli and ∼92% against S. aureus) is observed when treated at 80 °C. However, there is a decrement in the antibacterial properties against both bacteria with an increase in the treatment temperature. This study provides a detailed analysis of the multi-functional properties of quercetin on cotton fabrics and also systematically presents the variation of functional properties with changes in the treatment conditions. This systematic study is highly focused, as the fragmented and oxidative quercetin by-products formed at different conditions play major roles in the wash durability and multi-functional properties. This novel and simple eco-friendly textile finishing method can certainly facilitate the adoption of biomolecule-based materials to imbue multiple functionalities to cotton fabric with reasonable wash durability.