Investigating the Metal-Binding Properties of Chitosan and Bisphosphonate Functionalized Chitosan
Abstract
Functionalized polymers can be used as chelating agents to remove heavy metal contaminants from water. Chitosan is a biologically derived and commercially available polymer with a wide variety of clinical and industrial applications. The primary amine pendant group on the repeat unit of chitosan has the potential to act as a metal binding site due to the presence of a lone pair on the nitrogen atom. The purpose of this study was to functionalize deacetylated chitosan with a tridentate group to enhance its metal binding potential through the addition of more ligand binding sites. Specifically, a multicomponent Moedritzer-Irani reaction was utilized to transform the primary amine into an aminobisphosphonate group, which serves as a tridentate ligand. Functionalization reactions were conducted with deacetylated chitosan, phosphoric acid, hydrochloric acid, and paraformaldehyde under reflux or microwave irradiation. The degree of functionalization was varied by controlling the reaction stoichiometry and reaction time and measured through infrared spectroscopy (IR) and nuclear magnetic resonance spectroscopy (NMR). Functionalization ranged from 10% to over 90%, depending on the chosen conditions. The metal binding properties of the functionalized chitosan derivatives with varying degrees of functionalization will be compared to determine the effect of adding a tridentate bisphosphonate group on binding efficiency.
Faculty Sponsors
Dr. Patricia Calvo
Project Type
Event
Location
Alvin Sherman Library
Start Date
4-5-2023 12:00 PM
End Date
4-6-2023 4:00 PM
Investigating the Metal-Binding Properties of Chitosan and Bisphosphonate Functionalized Chitosan
Alvin Sherman Library
Functionalized polymers can be used as chelating agents to remove heavy metal contaminants from water. Chitosan is a biologically derived and commercially available polymer with a wide variety of clinical and industrial applications. The primary amine pendant group on the repeat unit of chitosan has the potential to act as a metal binding site due to the presence of a lone pair on the nitrogen atom. The purpose of this study was to functionalize deacetylated chitosan with a tridentate group to enhance its metal binding potential through the addition of more ligand binding sites. Specifically, a multicomponent Moedritzer-Irani reaction was utilized to transform the primary amine into an aminobisphosphonate group, which serves as a tridentate ligand. Functionalization reactions were conducted with deacetylated chitosan, phosphoric acid, hydrochloric acid, and paraformaldehyde under reflux or microwave irradiation. The degree of functionalization was varied by controlling the reaction stoichiometry and reaction time and measured through infrared spectroscopy (IR) and nuclear magnetic resonance spectroscopy (NMR). Functionalization ranged from 10% to over 90%, depending on the chosen conditions. The metal binding properties of the functionalized chitosan derivatives with varying degrees of functionalization will be compared to determine the effect of adding a tridentate bisphosphonate group on binding efficiency.
