This study targets betaine type polymers (polycarbobetaines - PCBets) as complexing agent of metal ions. As PCBets are pH-sensitive due to the presence of amine and carboxylic groups, the complexation of copper was followed at various pH (from 3 to 6). Usual methods such as IR, RMN, DSC were used to characterize PCBets, while the complexation of metal ions was followed by uv-vis spectroscopy and/or electrochemical measurements.
The results obtained for the complexation of copper were greatly enhanced with pH increase and reached 250 ± 10 mg/g at pH=6. Such maximal adsorption capacities compete with recent results obtained for molecules of environmental interest such as chitosan, for example. The selectivity of PCBets to copper was pointed out in the presence of nickel and/or cobalt and is part of the main interest of these materials. In addition, PCBets were shown to be regenerable under acidic conditions and became reusable for further complexation of metal ions.
The aim of this research is to develop waste and wastewater treatment processes (using PCBets to precipitate or adsorb metals) ensuring metals recovery and their valorization to the chemical industry. This project is defined as a gateway between the mining industry of yesterday and tomorrow, drawing its resources in wastes rather than into the earth. This way a circular management of metallic material flow is attainable.
