A novel chelating organosilicone resin bearing long chain imidazolyl ligands: Preparation, characterization, and adsorption properties

The imidazole ring is an important chemical component in nature that plays various critical roles. In this study, the imidazole used as a metal-chelating ligand was combined with a silicone resin structure by a long chain. The preparation, surface properties, thermal stability, complexation and adsorption properties with respect to Cu2+ ions, and multiple use cycles of the synthesized organosilicone resin bearing long chain imidazolyl ligands (ImSR) were studied using Fourier transform infrared spectroscopy (FTIR), 1H, 13C and 29Si nuclear magnetic resonance (NMR), a contact angle goniometer, thermogravimetric analysis (TGA) and UV–visible spectrophotometry methods. ImSR is a hydrophilic material with a water contact angle of 56° on a flat surface. It possesses good thermal stability and exhibits rapid weight loss above 230 °C. ImSR was evaluated as a promising adsorbing material for Cu2+ ions. It exhibited a high affinity for Cu2+ ions, with a maximum adsorption ability of 66.1 mg/g. Langmuir, Freundlich and Dubinin–Radushkevich isotherm models were used to analyze the experimental data. The results showed that the ImSR absorbent exhibited chemisorption and monolayer distribution on homogeneous active sites. The equilibrium adsorption capacity remained relatively constant after 5 use cycles.

Graphical abstractA novel chelating organosilicone resin bearing long chain imidazolyl ligands prepared is a promising candidate material for the removal of Cu2+ ions from aqueous solutions.Figure optionsDownload full-size imageDownload as PowerPoint slideHighlights► A novel chelating organosilicone resin bearing long chain imidazolyl ligands was synthesized. ► It had a high affinity for Cu2+ ions. ► The absorbent exhibited chemisorption and monolayer distribution on homogeneous active sites. ► The equilibrium adsorption capacity remained relatively constant after 5 use cycles.