Entrapment and Removal of Carbon Nanotubes and Fullerenes by Coprecipitation with Calcium Carbonate Beads

Production, growth, and obvious health and environmental concerns about engineered nanomaterials (ENM) require development of methods for their entrapping/removal. Here, we propose a facile method for removal of carbon nanomaterials from water solutions based on coprecipitation with vaterite (CaCO₃) beads. CaCO₃ beads are formed by an aggregation of initially formed amorphous CaCO₃ nanoparticles that efficiently incorporate nanomaterials in solution into the growing beads so that can be finally removed by settling. We show that by using this approach, a high percentage of fullerenes and carbon nanotubes (typically over 95%) can be removed in a broad range of ENM concentrations. We also discuss potential applications of the method for treatment of contaminated water