Synthetic Routes for the Preparation of Silver Nanoparticles

NATALIA L. PACIONI; CLAUDIO D. BORSARELLI; VALENITNA REY; ALICIA V. VEGLIA

Silver Nanoparticle Applications

Springer

Año: 2015;

Silver nanoparticles (AgNP) are already part of our daily life, being present in clothes (eg. in socks); household and personal care products, mainly due to their antimicrobial properties [1], for further details see Chapters 5 and 6. Furthermore, as discussed in the previous chapter, their unique physical/electronic properties have converted them in excellent candidates for different applications e.g., Surface. Enhanced Raman Spectroscopy (SERS)[2-4], see Chapter 3. AgNP?s optical properties depend on characteristics such as size, shape and capping-coating. Synthetic approaches for the preparation of AgNP continue to grow as evidenced from the quasi-exponential increment in the number of articles published in the last two decades (Fig. 1). Generally, the methods used for the preparation of metal nanoparticles can be grouped into two different categories ?Top-down? or ?Bottom-up.? Breaking a wall down up to get its minimum component ?the brick? represents the Top-down approach, Fig. 2. While building up ?the brick? from clay-bearing soil, sand, lime and water corresponds to Bottom-up, Fig. 2. Thus, in nanosciences Top-down involves the use of bulk materials and reduce them into nanoparticles by way of physical, chemical or mechanical processes whereas Bottom-up requires starting from molecules or atoms to obtain nanoparticles Top-down fabrication of nanomaterials usually comprise mechanical-energy, high energy lasers, thermal and lithographic methods. Examples of these categories include, but are not limited to, Atomization, Annealing, Arc discharge, Laser ablation, Electron beam evaporation, Radio Frequency (RF) sputtering and Focused ion beam lithography [5]. Bottom-up production of nanomaterials is divided into the following categories: gaseous phase, liquid phase, solid phase, and biological methods. Among others, chemical vapor deposition and atomic layer deposition belong to the gas-phase methods whereas reduction of metal salts, sol-gel processes, templated synthesis, and electrodeposition correspond to liquid-phase methods