Synthesis of silver nanoparticles in reverse micelles stabilized by natural biosurfactant

The natural "green" biosur-factant, rhamnolipid, is employed to stabilize silver nanoparticles in the liquid phase. The particles are initially synthesized using NaBH4 as reducing agent in rhamnolipid reverse micelles and are extracted from the micellar solution to disperse in heptane. The UV-vis absorption spectra propose that silver nanoparticles could be formed in the reverse micelles and relatively stabilized for at least 2 months without passivator addition. The TEM and AFM show that the silver nanoparticles are of spheric and relatively uniform. (c) 2006 Elsevier B.V. All rights reserved.