Natural dyes extracted from Cassia fistula and onion peels are used to dye wool that is pretreated with chitosan by using tannic acid as a mordant. The effect of the mordant concentration on the color strength (K/S) is discussed. The results obtained indicated that K/S increases after treatment with chitosan. It is also noticed that K/S increases with an increasing concentration of chitosan. K/S also increases with an increase of mordant concentration until 4% and then decreases. The effect of the dye bath pH, dyeing temperature and dyeing time are also studied. The K/S and dye uptake exhibit high values. Good fastness properties of the dyed fabric are achieved. The antimicrobial activity of chitosan-treated wool fabric is tested in accordance to diffusion agents. Test organisms, such as Escherichia coli, Bacillus subitilus Pseudomons aeruginosa and Staphylococcus aureus are used and the results indicate that the samples treated with a lower concentration of chitosan exhibit a smaller inhibition zone.
Antimicrobial activity of natural dyes obtained from Pterocarpus indicus Willd barks
