Recycling

Biography

Biography: Stephane Daniele

Abstract

Rare earth (RE) elements are used in an ever-increasing variety of applications in new green and low-carbon technologies such as catalysis, permanent magnet, rechargeable NiMH batteries, lamp phosphors and biomedical applications among others. Their recovery needs contributions of chemistry and physical chemistry of selective extractive systems since the separation of the RE mixtures into individual elements is usually a complex and expensive process. (Mesoporous) silica-based nanocomposites prepared by sol-gel hydrolysis and containing amido, imido, polyamine, and CMPO ligands or self-assembled monolayers of lanthanide-selective ligand (SAMMSTM) were studied for the recovery of RE. Non silicate systems are rare and require the need of a reliable and reproducible functionalization route as we previously reported. However, new hybrid metal oxide-based nanosorbents as a potential system to develop new separation techniques are of significant relevance. Herein, we present the results on the preparation and use of a series of novel modified DTPA-based ligands grafted onto TiO2 nanoparticles in order to provide a better understanding of the requirements in hybrid nanomaterial design as selective ionic separation devices. We demonstrate that DTPA-functionalized nano-titania devices for efficient lanthanide ionic separation (La/Gd) with excellent selectivity (SGd/La around 150) can be reached through the right balance between the ligand affinity towards the metal (in relation to the nature and flexibility of the ligand) and the self-agglomeration (trough supramolecular interactions) of the nanocrystals. These results will be addressed in detail in order to provide useful guidelines for design of future nano-structured ionic recognition device in the separation of strategic metals for recycling economy.