| Authors |
Ivanovska, A; Gajic, IS; Mravik, Z; Reljic, M; Ilic-Tomic, T; Savic, I; Luxbacher, T; Ladarevic, J |
| Abstract |
This study takes a new look at a circular economy concept for discarded walnut green husks. Their ethanol extract was prepared and characterized using RP-HPLC, then diluted with water and employed for dyeing and/or functionalizing different fabrics. A diluted extract can dye wool (WO), cotton (CO), cellulose acetate (CA), and polyamide (PA) at pH 4.5. Extract:water ratio of 10:40, 65 degrees C and 75 min and extract:water ratio of 15:35, 45 degrees C, and 60 min were found suitable for dyeing WO and CA, respectively. Dyed WO and CA exhibited color strength values of 29.0 and 9.2, and excellent antioxidant activity (>97 %) before and after washing, and a significant level of efficacy against S. aureus. CA possessed excellent (5) and very good (4) color fastness to rubbing in a dry and wet state, respectively. WO showed very good (4) and good to very good (3-4) color fastness to rubbing in a dry and wet state, respectively. CO and PA displayed excellent antioxidant activity, with CO also exhibiting significant antibacterial activity against S. aureus even after washing. Moreover, the same dyebath can be reused for up to four dyeing cycles, enabling obtaining bioactive WO and CA fabrics in various brown shades suitable for different applications. Cytotoxicity assay confirmed the non-cytotoxic nature of dyed and washed CA, PA, and CO fabrics. Bioactive WO, CO, CA, and PA fabrics can be considered for the production of wound dressing, performance clothes, and tights for people with sensitive skin. Finally, this paper sheds new light on a novel circular economy concept since collected husks' solid parts that remained after extraction were converted into activated carbon, which was then used for the preparation of supercapacitor having a specific capacitance of 144-275 F/g at current densities 0.1-2.0 A/g. |
