Abstract:
Woven cotton and silk fabric samples have been dyed with Racinus communis extract at optimized conditions of extract
concentration, temperature, material - to - liquor ratio (MLR), alum concentration and treatment time, and then evaluated for
their fastness properties following ISO standards, antimicrobial activity quantitatively against Staphylococcus aureus and
Pseudomonas aeruginosa bacterial strains and wash durability. Central composite design and single-factor design have been
used in the optimization process, and based on the lowest number of colony-forming units per milliliter, optimized values
are selected. The results indicate that optimized extract concentration of 39%, dyeing temperature of 70ºC, alum
concentration of 3g/L, MLR of 1:30 (silk) and 1:40 (cotton), and treatment time of 30min (silk) and 40min (cotton) lead to
99.84% and 99.78% bacterial count reduction against Staphylococcus aureus and Pseudomonas aeruginosa respectively for
dyed cotton fabrics. However, for dyed silk fabrics, a more improved percentage reduction in the bacterial count of
99.88% and 99.83% respectively is realized against both bacterial strains. Retention of the antimicrobial activity of dyed
fabrics is found to be more significant even after 5 washes. The fastness properties of rubbing, washing, light, and
perspiration for both fabrics range from moderate to excellent.