Synthesis of Guar-Gum-Stabilized Nanosized Silver Clusters with γ Radiation

Gamma ray induced synthesis of Ag clusters in the aqueous medium has been carried out using natural polysaccharicle guar gum as a stabilizer. The results showed that guar gum is very effective in binding the Ag clusters and restricts their size in the nano region. The surface plasmon resonance band in the wavelength range of 410-425 nm of visible region has confirmed the formation of Ag clusters. The size of the clusters is governed by the concentration of both, i.e. precursor Ag+ and guar gum. The clusters were characterized by TEM and XRD, which shows that the size of clusters is in the range of 10-30 nm. The results have shown that silver clusters stabilized by guar gum are stable in acid media and alkaline media is not a desired media for the synthesis. From thermogravimetric analysis it has been demonstrated that incorporation of nano sized Ag clusters within guar gum improves the thermal properties of irradiated guar gum. To the best of our knowledge, the use of guar gum as a stabilizer in the gamma ray induced synthesis of Ag nano clusters is being reported first time in the literature. (C) 2009 Wiley Periodicals, Inc. J Appl Polym Sci 114: 2348-2355, 2009