Synthesis of nano-Ag with different morphologies by extraction of garlic (allium sativum) and onion (allium cebae); sol-gel via acrylamide and microwaves; and in solution of acetone, distilled water and ammonium hydroxide.*

Silver nano-crystals have exceptional optical, electrical, thermal and antibacterial properties. The purpose of studying three different methods of nano-Ag synthesis is to compare their morphologies. The first one uses two different solvents, nitrate and water, in garlic (allium sativum) and onion (allium cebae). The second one was sol-gel method, using polyacrylamide with microwaves. Finally, the third one studied the synthesis based on three different solutions of acetone, distilled water and ammonium hydroxide; via stirrer and an ultrasound obtained the nano-crystals solutions.

Results of thermal analysis determined the dehydration and decomposition of organic material (250- 700 C). By X-ray powder diffraction (XRD), we obtained cubic structures. Through optical electronic microscopy, we noticed a porous nano-Ag sponge with acetone solution in ultrasound equipment (4- 5 h); with scanning electronic microscopy, SEM, we detected symmetrical cubes in onion, fibbers in garlic and spherical shape with sol-gel; and through high resolution of transmission electronic microscopy, HRTEM, the crystals size (3- 10 nm) and diameter (20- 50 nm).

Also we report, complementary studies on the nano-Ag with computer simulation, along the manufacturing process.