The adsorption of dyes used in the textile industry on mesoporous materials

An adsorbent material made with a silica lamellar mesoporous material treated with chitosan has been proved to be useful to adsorb both anionic and cationic dyes used in the textile industry. The two tested dyes Tectilon Blue (anionic) and Rhodamine B (cationic) have different adsorption kinetics reflecting a complex mechanism of the phenomenon. Furthermore, the adsorption capacity and interaction strength of Tectilon Blue is higher than those of Rhodamine B. Tectilon Blue molecules are situated with the molecular plane perpendicular to the adsorbent surface, whilst that of the Rhodamine B molecule is flat and parallel to the surface. The differences may be attributed to the different regions of the adsorbent surface on which the dyes are adsorbed because of their different electric charge.