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

A series of hybrid TiO 2 nanoparticles containing chelating molecules based on diethylenetriaminepentaacetic acid (DTPA) moiety have been synthesized and thoroughly characterized by TEM, SEM, powder XRD, FT-IR, 13 C 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 TiO 2 /PABA supports ( para -amino benzoic acid, PABA) with either modified-monoanhydride or -carboxylic acid compounds. The extraction percentages, distribution coefficients ( K d Gd ), capacities ( C Gd ) and ionic selectivities ( S Gd/La ) of these surface-functionalized nano-structured materials between lanthanum and gadolinium in acidic range of pH were investigated. [ABSTRACT FROM AUTHOR]