Ultrasonic extraction of onion (Allium cepa) peel dye, its applications on silk fabric with bio-mordants and its antibacterial activity

Ecofriendly natural dye was extracted ultrasonically from the red onion peel (Allium cepa). It is applied on silk fabric with and without bio-mordants. Bio-mordants used were tea leaves, tamarind, aloe vera and acacia bark ash. Colorfastness, color measurement and antibacterial properties were studied. Among colourfastness properties colourfastness to washing, light, heat, rubbing, seawater and dry-cleaning were studied. Dyed fabrics were also subjected to colour measurement values i.e Tristimulus properties (XYZ), Labs values and Munsell renotations (Hue,Vivideness and Chroma). Antibacterial properties against three strains of bacteria i.e escherichia coli, staphylococeus aureus and pseudomonas aeruginosa were also performed.