The Desorption of a Direct Cotton Dye from Cellulosic Fibres

A study has been made of the desorption of purified Chlorazol Sky Blue FF from dyed bleached cotton and from dyed viscose rayon into water and into solutions of sodium chloride. With cotton a dyeing hysteresis is observed. Unexpected features of the desorption into very dilute solutions of sodium chloride have been explained by assuming that the cotton may contain a small proportion of basic groups.