A Multilamellar, Thermoreversible, Phase-Selective Galactose-Triazole Organogelator: Role of Noncovalent Interactions and Porous Nanostructure in Environmental Remediation

Abstract

This article 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 shows a phase-selective behavior toward ethyl acetate with respect to water. Powder X-ray diffraction, scanning electron microscope (SEM), Fourier transform infrared spectroscopy (FTIR), and UV results show that the xerogel has a multilamellar structure due to supramolecular forces identified as H-bonding, van der Waals interactions, and pi-pi stacking. The viscoelastic behavior of 8a is examined through rheology experiments, suggesting a dominant viscoelastic structure. The dye adsorption studies and desorption characteristics of 8a are explored against disperse dyes, including Foron Red RD-RBLS, Foron Blue SE-2R, and Foron Black S-2B2S via UV, 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 show that physisorption results in dye adsorption. Dye removal efficiency is found to be in the range of 80%-90% in 1 hr without agitation. Thermodynamic studies reveal that dye adsorption is spontaneous. The dyes and 8a can be recycled in excellent yields (98% and 92%, respectively) in their pure forms.