Optimization of process conditions of silk fabric dyeing with galinsoga parviflora leaf extract for antibacterial application

Abstract

Silk being one of the organic natural fibers, is susceptible to microorganisms attack thus leading to loss of physical aesthetic and mechanical properties. The present study was focused on optimizing the dyeing process parameters (Extract concentration and dyeing temperature) of dyestuff extracts from the Galinsoga Parviflora plant and analyzing the antibacterial activity of the dyed silk fabric. The Pad-dry method was used for the application of herbal dye extract onto selected silk fabric and the AATCC 100:2019 test method was used in assessing the treated fabric quantitatively against Staphylococcus Aureus and Pseudomonas Aeruginosa bacterial strains. Dyeing conditions obtained using Central Composite Design (CCD) indicated that dye concentration and temperature of 39.14 percent and 70 0 C respectively could be deemed as optimum. Also, the Analysis of Variance (ANOVA) results showed that extract concentration has a statistically significant effect on bacterial count whereas the effect of temperature was not so much influential. Silk fabric dyed with optimized values demonstrated a 99.33% and 99.15% reduction in the bacterial count against Staphylococcus Aureus and Pseudomonas Aeruginosa bacterial strains respectively. Also, its fastness properties to light, washing, and Rubbing ranged from very good to excellent (4-5 to 5). Thus, in general, this research confirmed that Galinsoga Parviflora plant leaves, abundantly available in most parts of Uganda can be used as an antibacterial finish on silk fabric for improved bacterial resistance.