DYSPROSIUM COLLOIDS PREPARED IN POLAR ORGANIC SOLVENTS

Abstract

Dysprosium colloids in organic solvents (2-methoxyethanol, 2-propanol and 1,2-dimethoxyethane) have been obtained by the CLD method al 77 K. These colloids were characterized by zeta potentials, UV-Vis, TEM, electron diffraction and EDX measurements. Colloid stability depends on both solvent and metal concentration. The highest stability was obtained in 2-methoxyethanol, which is in agreement with previous results for other lanthanide colloids already reported. Zeta Potential (ξ) of the colloids ranges between 0.1430 and 1.945 mV. UV-Vis spectra exhibit bands in the UV región. 2-methoxyethanol shows bands at 211 and 283 nm, which is very similar to 1, 2-dimethoxyethane colloids (222 and 273 nm). However, the 2-propanol exhibits a band at 207 nm for a 2.5E-4 M concentration. At the TEM particle size distribution, 2-methoxyethanol colloid exhibits ranges from 2.5 to 11.6 nm, but the 2-propanol shows ranges from 2.5 to 4.3 nm, depending on the polarity of the solvent. The electron diffraction gives the most common phases, corresponding to Dy (002) and Dy(2)0(3) (110). EDX confirms the metal presence in the colloids. Luminescence measurements for Dy-2-methoxyethanol at 280 nm exhibit a higher quantum yield at 2.0E-3 and 5.0E-4 which indicates a higher transfer from the metal ion to the solvent.