A sonochemical synthesis method for silver nanoparticles coated with chitosan was designed and evaluated. In this approach, chitosan was previously treated with sodium hydroxide in order to neutralize its charge and facilitate binding and reduction of silver ions. UV-Vis and Atomic Force Microscopy (AFM) characterization showed that spherical nanoparticles were obtained of approximately 10 nm in diameter. Dynamic Light Scattering (DLS) analysis for size dispersion shows a polydispersion index of 0.532 indicating the presence of several nanoparticle groups of different sizes. The DLS results show that (98 ± 1) % of the nanoparticles have a diameter ≤ 20 nm and that these particles represent the (87 ± 5) % of the total volume of particles in the solution. We conclude that, despite the relatively large size dispersion obtained, the evaluated method corresponds to a simple and feasible to optimize way for the obtaining of silver nanoparticles through a quick and inexpensive synthesis.
