Formation of Colloidal Silver Nanoparticles:  Capping Action of Citrate - [scite report] (2024)

“…chemical [10][11][12][13], electrochemical [14] and photochemical reduction [15], ultrasound [16], microwave [17] gamma and electron irradiation [18][19][20][21][22][23][24]) for the synthesis of silver nanoparticles with different stabilisers have been developed.…”

confidence: 99%

Section: Introductionmentioning

et al. 2008

Colloidal silver nanoparticles were prepared by -irradiating Ag þ in aqueous solution in the presence of 2% polyvinyl pyrrolidone (PVP) as stabilising agent and ethyl alcohol as free radical (OH . ) scavenger. The saturated conversion dose of Ag þ into Ag was determined by UV-Vis spectroscopy and the silver nanoparticles size was characterised by transmission electron microscopy. The influence of Ag þ concentration (1-50 mM) on the saturated conversion dose and average diameter of silver nanoparticles was investigated. Results showed that the saturated conversion dose was from 8 to 48 kGy and the silver particles size was in the range of 6-21 nm for Ag þ concentration from 1 to 50 mM. The effect of PVP molecular weight on silver particles size was studied as well.

A simple method to embed noble metal (Ag, Au) nanoparticles in organic-inorganic nanocomposite films by single step method is described. This is accomplished by the assistance of Keggin ions present in the composite film. The photochemically reduced composite film has served both as a reducing agent and host for the metal nanoparticles in a single process. The embedded metal nanoparticles in composites film have been characterized by UV-Visible, TEM, EDAX, XPS techniques. Particles of less than 20 nm were readily embedded using the described approach, and monodisperse nanoparticles were obtained under optimized conditions. The fluorescence experiments showed that embedded Ag and Au nanoparticles are responsible for fluorescence emissions. The described method is facile and simple, and provides a simple potential route to fabricate self-standing noble metal embedded composite films.

A novel colloidal method is presented to synthesize silver nanoparticles on aluminosilicate nanotubes. The technique involves decomposition of AgNO 3 solution to Ag nanoparticles in the presence of aluminosilicate nanotubes at room temperature without utilizing of reducing agents or any organic additives. Aluminosilicate nanotubes are shown to be capable of providing a unique chemical environment, not only for in situ conversion of Ag ? into Ag 0 , but also for stabilization and immobilization of Ag nanoparticles. The synthesis strategy described here could be implemented to obtain self-assembled nanoparticles on other single-walled metal oxide nanotubes for unique applications. Finally, we demonstrated that nanotube/nanoparticle hybrid show strong antibacterial activity toward Gram-positive Staphylococcus epidermidis and Gram-negative Escherichia coli.