Construction of polycationic film coated cotton and new inductive effect to remove water-soluble dyes in water

Abstract

In order to realize the high efficient purification of dyeing waste-water, we designed the construction of the polycationic film coated on cotton. We firstly detected that the crystallization spaces of natural cotton could be decreased by triethanolamine pretreatment, so that the cationic reagent:3-chloro-2-hydroxypropylmethyldiallylammonium chloride (CMDA) could be grafted more efficiently, in turn forming the higher cationic degrees of grafting cotton (G-cotton). Subsequently, a copolymerization of another cationic monomer: dimethyldiallylammonium chloride (DMAC) with the cationic CMDA units in G-cotton was carried out, to obtain the polycationic film coated cotton (PF-cotton). Under equal conditions, the G-cotton adsorption capacity of anionic dyes was 15.70 times of that of activated carbon, while the PF-cotton adsorption capacity was near to that of G-cotton, but the average adsorption rate of PF-cotton was 2.8 times of that of G-cotton, indicating that the obtained PF-cotton was very suitable to purify the dyeing waste-water. Moreover, the PF-cotton had a wide range of application universal, e.g., enlarged use, adsorbing different dye solutions and simulated dyeing waste-water, being a filtering filler, and recycling utilization. In addition, we also detected that a new inductive effect occurred in the process of PF-cotton adsorption, playing an important role in speeding up the adsorption.