Resumen de Synthesis and characterization of bimetallic auag colloids and films

Galo Cardenas, Elizabeth Salgado

• Bimetallic colloids of AuAg were prepared by simultaneous cocondensation of the metals with organic solvents at 77K. The metals are evaporated to yield atoms at 77K, which produced the alloy and upon warming, relatively stable liquid colloids are formed with a narrow and nanometric particle size depending on the solvent. The bimetallic colloids were characterized by several studies, including the stability at room, temperature, particle size, transmission electron microscopy (TEM) with energy dispersive X-ray (EDAX). The solvents under study were: acetone, 2-butanone, 2-methoxyethanol, 2-ethoxyethanol, 2-propanol and THF. The colloids are negatively charged. The particle size growth was slow and sizes from 100 to 220 nm were obtained. The FT-IR studies of the films prepared by evaporation of the solvents showed the incorporation of the solvents. The EDAX studies showed the presence of Au and Ag metals. The thermogravimetric studies of the AuAg films showed a low stability inacetone but an increase inTHF and 2-propanol with T D = 475°C and 400 °C, respectively