Removal of bromophenol blue dye from aqueous solutions through the synthesis and characterization of a polymer-clay composite

In this study, the synthesis of a clay-polymer composite was carried out by the in-situ polymerization method of two biopolymers, Alginate-Chitosan (Alg-Chit), with the intercalation of an organo-modified clay, for the removal of bromophenol blue dye (BP-Dye). For this purpose, a natural Montmorillonite clay from Mexico was modified with a cationic surfactant, in order to exchange the cations of the clay galleries with those of the surfactant, and to change its nature from hydrophilic to hydrophobic. Moreover, the synthesis of the copolymer was carried out using different ratios between both biopolymers. Once the copolymer was obtained, it was characterized through FTIR technique. On the other hand, the modified clay was used to obtain the polymer-clay composites using a ratio of 2%-wt of the homopolymer, and the obtained material was characterized with the same technique. Finally, a contact test was carried out by preparing a solution of BP-Dye at a concentration of 5 mg/L, with and without initial pH adjustment, for 1 h, in a bath at controlled room temperature and constant stirring (100 rpm). After this time, phases were separated, and the quantification of the dye was carried out by UV-Vis spectroscopy.