Synthesis of silver/montmorillonite nanocomposites using γ-irradiation

Abstract

Silver nanoparticles (Ag-NPs) were synthesized into the interlamellar space of montmorillonite (MMT) by using the γ-irradiation technique in the absence of any reducing agent or heat treatment. Silver nitrate and γ-irradiation were used as the silver precursor and physical reducing agent in MMT as a solid support. The MMT was suspended in the aqueous AgNO 3 solution, and after the absorption of silver ions, Ag + was reduced using the γ-irradiation technique. The properties of Ag/MMT nanocomposites and the diameters of Ag-NPs were studied as a function of γ-irradiation doses. The interlamellar space limited particle growth (d-spacing [d s ] = 1.24-1.42 nm); powder X-ray diffraction and transmission electron microscopy (TEM) measurements showed the production of face-centered cubic Ag-NPs with a mean diameter of about 21.57-30.63 nm. Scanning electron microscopy images indicated that there were structure changes between the initial MMT and Ag/MMT nanocomposites under the increased doses of γ-irradiation. Furthermore, energy dispersive X-ray fluorescence spectra for the MMT and Ag/ MMT nanocomposites confirmed the presence of elemental compounds in MMT and Ag-NPs. The results from ultraviolet-visible spectroscopy and TEM demonstrated that increasing the γ-irradiation dose enhanced the concentration of Ag-NPs. In addition, the particle size of the Ag-NPs gradually increased from 1 to 20 kGy. When the γ-irradiation dose increased from 20 to 40 kGy, the particle diameters decreased suddenly as a result of the induced fragmentation of Ag-NPs. Thus, Fourier transform infrared spectroscopy suggested that the interactions between Ag-NPs with the surface of MMT were weak due to the presence of van der Waals interactions. The synthesized Ag/MMT suspension was found to be stable over a long period of time (ie, more than 3 months) without any sign of precipitation.

Synthesis of Silver-Chitosan Nanocomposites Colloidal by Glucose as Reducing Agent

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Investigation of the Role of Reductant on the Size Control of Fe3O4 Nanoparticles on Rice Straw

“…Studies on talc/Fe 3 O 4 -NCs (Kalantari et al 2013a,b), rice straw/Fe 3 O 4 -NCs , zeolite/Fe 3 O 4 -NCs (Jahangirian et al 2013), and other nanoparticles such as silver in talc (Shameli et al 2010a), montmorillonite (Shameli et al 2010b, Ahmad et al 2009a, Ahmad et al 2009b, zeolite , montmorillonite/starch (Ahmad et al 2010), chitosan (Ahmad et al 2009cShameli et al 2011b), polyethylene glycol (Shameli et al 2012a,b), plant extract (Shameli et al 2012c,d), and polymeric substrate (Shameli et al 2011c), have been previously reported.…”

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