Synthesis of novel dyes based on curcumin for the creation of antibacterial silk fabrics

Purpose - The study reported in this paper aims to synthesize some new curcumin containing sulphadiazine and sulphathiazole dyestuffs and study their application in dyeing silk fabrics rendering the dyed fabric antibacterial. Design/methodology/approach - Simultaneous dyeing and antibacterial finishing for silk fabric using a new antibacterial acid dye having a modified chemical structure to curcumin were conducted. This modification of curcumin dye was carried out by introducing sulphonamide containing heterocyclic rings sulphadiazine and sulfathiazole through coupling with curcumin. All newly synthesized dyes were characterized by elemental analyses and spectral data (IR, 1H-NMR and MS). The dyeing characteristics of these dyestuffs were evaluated at optimum conditions. Antibacterial activities of the dyed samples at different concentrations of both dyes were studied against gram-positive (Staphylococcus aureus) and gram-negative (Salmonella typhimurium) bacteria. Findings - The synthesized curcumin-containing sulphonamide dyes were applied on silk fabrics. The modified dyes exhibited good fastness properties compared to curcumin dye at optimum conditions. It was found that synthesized dyes exhibit good fastness and antibacterial properties efficient against gram-positive and gram-negative bacteria. The dyed silk fabrics showed higher antibacterial efficacy after many times of washing. Originality/value - Curcumin, a common natural dye used for fabric and food colouration, was used as an antimicrobial finish due to its bactericidal properties on dyed textiles. A common dyeing process could provide textiles with colour as well as antimicrobial properties. Novel antibacterial dyestuff containing curcumin moieties with sulphonamide coupler components were shown to be an interesting natural colorant for silk with high antimicrobial ability of the dyed silk fabrics. This work has afforded a new acid dye that can be used in medical textile.