Hybrid gels of Bis(benzimidazole)-base ligand with perchlorate salts driven by squaric acid: synthesis, characterization and dye adsorption

摘要

2,6-bis(2-benzimidazyl)pyridine ligand (L) with or without squaric acid in the presence of Zn(II) or Ni(II) has been found to form gel-like materials (GLs). The GLs have been characterized by infrared spectroscopy, optical microscopy, scanning electron microscope (SEM) and transmission electron microscope (TEM). The results show that the mixture of L, squaric acid and Zn(II) or Ni(II) was found to gelate N,N-dimethylformamide to generate hybrid gels. The synergetic effect of the coordination and hydrogen bonding in the mixture is the key factor to form gels. Needle shaped samples observed in optical microscopy turned out to be different morphologies in SEM and TEM measurements. Network structures formed by strands and fibers have better dye absorption properties than those of networks formed by fibers and nanospheres. Dye absorption monitored by UV-Vis has been done to investigate the properties of the gels. The dye absorption amounts are in the range of 12.15-15.38 mg.g(-1). Moreover, the model for self-aggregation of the sample has been proposed.