We have fabricated and characterised colloidal silver
nanoparticles by the electrical arc discharge method in DI water. Size and
optical properties of the silver nanoparticles were studied versus different
arc currents. Optical absorption indicates a plasmonic peak at 392 nm for
10 A which increases to 398 nm for 20 A arc current. This reveals that by
raising the arc current the size of the nanoparticles increases. Optical
absorption of silver nanoparticles after 3 weeks shows precipitation of them
in a water medium. The effect of different surfactant and stabilizer
concentrations such as cethyl trimethylammonium bromide (CTAB), polyvinyl
pyrrolidone (PVP), sodium citrate, sodium dodecyl sulfate (SDS), sodium
di-2-ethylsulfosuccinate (AOT) and carboxymethyl cellulose (CMC) on the
stability of silver nanoparticles was investigated. The colloidal silver
nanoparticles with 100 μM concentration were stable for more than
3 months at 50 μM CTAB and 6 months at 10 μM sodium citrate
concentration, respectively. SEM images of the sample prepared at 50 μM
CTAB concentration reveal uniform and fine nanoparticles. The mean size from
TEM images is about 14 nm. TEM images of the sample prepared at 10 μM
sodium citrate concentration show a shell of citrate that covers the silver
nanoparticles.