Surface modification of titanium oxide nanoparticles with chelating molecules: New recognition devices for controlling the selectivity towards lanthanides ionic separation

A series of hybrid TiO2 nanoparticles containing chelating molecules based on diethylenetriaminepentaacetic acid (DTPA) moiety have been synthesized and thoroughly characterized by TEM, SEM, powder XRD, FT-IR, 13C solid-state MAS NMR, CHN elemental analysis, and BET. The surface modification of these nano-materials was established by coupling accessible amino group functions of TiO2/PABA supports (para-amino benzoic acid, PABA) with either modified-monoanhydride or -carboxylic acid compounds. The extraction percentages, distribution coefficients (KdGd), capacities (CGd) and ionic selectivities (SGd/La) of these surface-functionalized nano-structured materials between lanthanum and gadolinium in acidic range of pH were investigated.