Isolation of colour components from flowers of Tabebuia argentea : kinetic and adsorption studies on silk yarn

The colour components from the flowers of Tabebuia argentea have been isolated and characterised as rutin and epigallocatechin gallate using spectral techniques. Adsorption kinetic and thermodynamic studies of these colour components on silk yarn have been investigated. It is noted that the adsorption is an endothermic process. The dyeing studies have been carried out at pH 4. The mordanting studies revealed that the post-mordanting technique could only increase the dye performance marginally. The fastness properties of the dyed silk were determined. The adsorption isotherm studies showed that the Langmuir model fitted the experimental data very well with a high regression coefficient.