"Characterization by Optical Extinction Spectroscopy of Ag NPs synthesized by fs laser ablation using different stabilizers"

MUÑETÓN ARBOLEDA, DAVID; SANTILLÁN, JESICA MARÍA JOSÉ; ARCE, VALERIA BEATRÍZ; SCAFFARDI, LUCÍA BEATRÍZ; SCHINCA, DANIEL CARLOS

Ciudad Autónoma de Buenos Aires

Otro; XVII GIAMBIAGI WINTER SCHOOL: "LIGHT AND LIGHT BASED TECHNOLOGIES"; 2015

Departamento de Física "J. J. Giambiagi" de la Facultad de Ciencias Exactas y Naturales (FCEyN) de la Universidad Nacional de Buenos Aires (UBA)

Strong research efforts have been devoted in the last decay to develop synthesis of noble metal nanoparticles (NPs) due to their applications in many areas of science and technologies. Silver NPs show unique chemical, physical and optoelectronic properties [1, 2] with good potential foruse in medical therapeutics, high density optical recording. However, the synthesis of stable colloids still remains as a big challenge. In this presentation, we study the characteristics of size stabilization of Ag colloids NPs fabricated by fs laser ablation in aqueous solutions using trisodium citrate (Na3C6H5O7) and starch as stabilizing agents at different concentrations. Colloidal suspensions were obtained using a 100 fs amplified Ti:Sa laser system, working at l = 800 nm and a repetition frequency of 1 kHz. The laser was focused on a solid silver target immersed in the liquid media at different pulse energies (100 μJ y 500 μJ).  The colloids were experimentally characterized through Transmission Electron Microscopy (TEM) and Optical Extinction Spectroscopy (OES). Experimental extinction spectra were fitted using Mie theory [3] considering a suitable size modification of the bulk experimental complex dielectric function and leaving size as the fitting parameter [4, 5]. The stabilizers modify Ag NPs surface through functional group in their chemical structure. This fitting procedure yielded broader size distribution for water, intermediate for starch and narrower for citrate. References:  [1] Blanco-Andujar C., Tung L. D. and Thanh N. T. K., 2010, Synthesis of nanoparticles for biomedical applications, Ann. Rep. Prog. Chem.  A106, 553-568. [2] Zhang G. R. and Xu B. Q., 2010, Superprisingly strong effect of stabilizer on the properties of Au nanoparticles and Pt^Au nanostructures in electrocatalysis, Nanoscale 2, 2798-2804. [3] Bohren C. F. and Huffmanm D. R., 1998, Absorption and Scattering of Light by Small Particles; Wiley: New York. [4] Scaffardi L. B. and Tocho J. O., 2006, Size dependence of refractive index of gold nanoparticles, Nanotechnology, 17, 1309-1315. [5] Muñetón Arboleda D., Santillán J. M. J., Mendoza Herrera L. J., Fernández van Raap M. B., Mendoza Zélis P., Muraca D., Schinca D. C. and Scaffardi L. B., 2015, Synthesis of Ni nanoparticles by fs laser ablation in liquids: structure and sizing, Journal of Phys. Chem. C, 119 (23), 13184-13193.