Supramolecular Self-assembly of Galactose-Based Reversed N-Nucleosides for Removal of Disperse Dyes from Aqueous Solutions

This paper describes the design and synthesis of an efficient galactose-triazole based reversed N-nucleoside as a thermoreversible, low molecular weight organogelator (8a). The gelator 8a showed a phase-selective behavior toward ethyl acetate with respect to water. XRD, SEM, FTIR, and UV results showed that the xerogel has a multilamellar structure due to supramolecular forces identified as H-bonding, van der Waals interactions and stacking. The viscoelastic behavior of 8a was examined through rheology experiments, suggesting a dominant viscoelastic structure. The dye adsorption studies and desorption characteristics of 8a were explored against disperse dyes, including Foron Red RD-RBLS, Foron Blue SE-2R and Foron Black S-2B2S via UV and FTIR and SEM. The data revealed that H-bonding between dye molecules and 8a is the main force responsible for dye adsorption. Adsorption kinetics studies showed that physisorption resulted in dye adsorption. Dye removal efficiency was found to be in the range of 80%-90% in 1 h without agitation. The dyes and 8a could be recycled in excellent yields (98% and 92 %, respectively) in their pure forms.