Adsorptive removal of sunset yellow dye by biopolymers functionalized with (3-aminopropyltriethoxysilane): Analytical investigation via advanced model

The adsorption of dye sunset yellow (SY) on both raw and functionalized chitosan (CTN and CTN-F) was investigated using statistical physics theory. Adsorption data of SY dye on (TN and CTN-F were experimentally obtained at 298-328 K. Statistical physics modeling analysis demonstrated that the adsorption capacities at 298-328 K of both systems were similar. This theoretical evidence explained that the functionalization of the raw chitosan via 3-aminopropyltriethoxysilane did not improve the adsorbent performance. It was also concluded that the SY dye interacted via the same orientation on CTN and CTN-F. The effect of the temperature on the adsorption capacity was studied and results indicated that the SY dye adsorption on CTN and ON-F adsorbents was endothermic. Dye adsorption capacities were due to the similarity in the number of the attracted SY dye molecules per adsorption site and the density of this receptor site. The interactions between SY dye and adsorbents (CTN and CTN-F) and also between SY dye molecules were understood via the calculation of adsorption energies. Physical interactions were the responsible of the dye adsorption mechanism using adsorbents CTN and ON-F. (C) 2020 Elsevier B.V. All rights reserved.