Effect of anionic groups in cellulose on the adsorption of reactive dyes on cellulose

Abstract The adsorption of CI Reactive Red 120 and CI Direct Blue 1 on cellulose which was reactively-dyed with reactive dyes having six and eight sulfonate groups was examined at 80°C. Above a certain concentration of sodium sulfate, the same saturated adsorption on the dyed cellulose as that of undyed cellulose was observed. When all the dissociated groups were taken into consideration, the values of − Δμ 0 for the dyed cellulose were equal to that for the undyed cellulose within experimental errors. Thus, it was shown that only the anionic groups on cellulose had effect on the adsorption of anionic dyes on cellulose, whether it was dyed or not. How the adsorption of anionic dyes on cellulose on which the hydroxyl groups of cellulose and the dyes dissociated depended upon pH was examined by simulation.