Natural Flavonoid-Functionalized Silk Fiber Presenting Antibacterial, Antioxidant, and UV Protection Performance

Abstract

Natural bioactive compounds as promising alternatives to synthetic finishing agents have recently gained increasing attention in the textile industry due to their eco-friendliness, low irritation, and biocompatibility. The present study reports a sustainable approach for preparing antibacterial, antioxidant, and UV-protective silk fiber using two natural flavonoids (quercetin and rutin) by an adsorption technique. The adsorption kinetics and isotherms of the two flavonoids were investigated, and their functionalities and the washing durability of their functionalities were discussed. The equilibrium adsorption isotherms fitted well to the Langmuir and Freundlich adsorption models, demonstrating that ion–ion interactions, hydrogen bonding, and van der Waals forces play major roles in the adsorption of quercetin and rutin on silk. The adsorption isotherm parameters of quercetin and rutin had a decisive effect on their adsorption kinetics, which fit well to the pseudo-second-order kinetic equation. Quercetin exhibited higher initial adsorption rate, shorter half adsorption time, and higher adsorption capability than those of rutin due to its higher affinity constant. Quercetin also imparted better antioxidant, antibacterial, and UV protection performance to silk than rutin at the same initial application concentration and provided better washing durability of functionalities. This study demonstrates that quercetin and rutin can be employed as promising multifunctional agents for the chemical processing of silk materials.

Facile and Eco-Friendly Fabrication of Colored and Bioactive Silk Materials Using Silver Nanoparticles Synthesized by Two Flavonoids

“…This result indicates that the AgNPs prepared by flavonoids can improve the antioxidant activity of silk. However, the silk samples treated with the flavonoid prepared AgNPs displayed much lower antioxidant activity than those directly treated with the equivalent concentration of flavonoids according to our previous work [21]. This is due to the fact that the phenolic hydroxyl groups of catechol moiety in the B ring of the flavonoids are mainly responsible for radical scavenging [48], but they are oxidized and converted into the quinine form during the AgNPs synthesis.…”

Onion (Allium cepa L.) Skin: A Rich Resource of Biomolecules for the Sustainable Production of Colored Biofunctional Textiles

“…In recent years, innovative ‘biofunctional’ applications have been receiving attention in the field of cosmetotextile technology, mostly to meet the needs of people with highly sensitive skin. These kinds of material are indeed becoming diffusely appreciated as an innovative vehicle for the local treatment of skin diseases caused by microbial agents [6,7] or sunlight induced photooxidation [5,8].…”

“…Flavonoids and phenolic acids are among the most important chemical classes exhibiting antioxidant activity, mostly via radical-scavenging mechanisms [8,11]. This evidence along with the their strong interactions with fiber material has fueled the interest by scientists towards the functionalization of textiles by these molecules [8,12,13]. In this context, natural dyes, extracted from various species of wild plants or crops, are particularly appreciated because, in addition to the aforementioned beneficial biofunctional properties, they are also able to confer peculiar soft colors with a unique shade.…”

Functional Properties of Natural Dyed Textiles

“…The basic structural feature of flavonoid compounds is the 2-phenyl-benzo pyrane or flavan nucleus, which consists of two benzene rings linked through a heterocyclic pyrane ring (Figure 4 It has been reported that quercetin, a flavonoid, imparted better antioxidant, antibacterial and UV protection performance to silk fabric [81]. Flavonoids and anthocyanin from red onion skin (Allium cepa L.) are natural dyes with antibacterial activity and UV protection after application on wool and cotton fabric [82].…”