Studies of silver nanoparticles by laser ablation method

The laser ablation technique has been employed to study silver colloidal fo rmation. Laser intensities, irradiation wavelengths (1064 nm and 532 nm), a nd solvents (water, methanol, and isopropanol) were all considered. Changes of the maximum UV-Visible absorbance of the solutions with laser intensiti es exhibited nonlinear behavior for 1064 nm and 532 nm and displayed better ablation efficiency at 532 nm. Larger mean sizes were observed at 532 nm o r at higher guise energy. For solvent effect, the bigger particle sizes wer e generated in H2O. As to colloidal stability, isopropanol, which has a low er dielectric constant than water, was found to stabilize Ag nanoparticles without protecting reagents over six months. Preliminary results in 2-butan ol suggested that the viscosity of solvent may need to be considered in add ition to the dielectric constant.