Antibacterial and Antifungal Cotton Fabrics Functionalized with Plant Extracts for Sustainable Textile Applications

This study reports the development of multifunctional cotton fabrics finished with bioactive extract from Terminalia catappa leaves, with a focus on sustained release kinetics as a novel contribution. A Box-Behnken design was employed to optimize extract concentration (1 - 5 %w/v), bath pH (4 - 8), and treatment time (10 - 60 min). Under the optimized finishing condition (5.0 %w/v extract, pH 6.0, 60 min), the treated cotton exhibited antibacterial efficiency of 96.1% against E. coli, antifungal inhibition of 94.1% against Candida albicans, and washing durability of 90.2%. Phytochemical profiling via GC-MS confirmed the presence of dominant flavonoids (quercetin 2.29 ± 0.10 mg/g DW; kaempferol 1.96 ± 0.09 mg/g DW), phenolic acids (gallic acid 2.85 ± 0.12 mg/g DW; ellagic acid 2.05 ± 0.09 mg/g DW), and triterpenoids (β-sitosterol 5.39 ± 0.21 mg/g DW). Release studies monitored by UV-Vis spectroscopy demonstrated cumulative polyphenol release of 73% (pH 5), 84% (pH 7), and 93% (pH 9) after 96 h. Higuchi fitting (R² = 0.981 - 0.992; kH = 4.82 - 6.38 %·h−1/2) and Korsmeyer-Peppas modeling (n = 0.82 - 0.91) confirmed anomalous transport involving both Fickian diffusion and polymer matrix relaxation. SEM images showed uniform nanoscale deposition on fibers, supporting the controlled release mechanism. These findings demonstrate that T. catappa extract provides a green and effective strategy for sustainable cotton finishing, with the novelty of integrating release kinetics as a critical parameter for durability and functionality. HIGHLIGHTS Polyphenol-rich Terminalia catappa extract functionalized cotton 1% antibacterial and 94.1% antifungal efficiency achieved Sustained release (73%-93%) over 96 h following Higuchi kinetics Strong immobilization with minimal leaching (< 2%) Potential low-cost, eco-friendly antimicrobial textile for screening use GRAPHICAL ABSTRACT