ABSTRACT
Silver carbonate and silver nanoparticles (NPs) over of stabilizer montmorillonite (MMT) have been synthesized in aqueous and polyol solvent, respectively. Dispersions of silver nanoparticles have been prepared by the reduction of silver nitrate over of MMT in presence and absence of Na2CO3 compound in ethylene glycol. It was observed that montmorillonite was capable of stabilizing formed Ag nanoparticles through the reduction of Ag(+) ions in ethylene glycol. Na2CO3 was used as carbonate source in synthesis of Ag2CO3 NPs in water solvent and also for controlling of Ag nanoparticles size in ethylene glycol medium. The samples were characterized by X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), transmission electron microscopy (TEM), and ultraviolet-visible diffuse reflectance spectroscopy (DRS). The TEM images showed that Ag NPs size in presence Na2CO3 salts was smaller than without that. The results indicated intercalation of Ag and Ag2CO3 nanoparticles into the montmorillonite clay layers. The diffuse reflectance spectra exhibited a strong surface plasmon resonance (SPR) adsorption peak in the visible region, resulting from Ag nanoparticles. The antibacterial testing results showed that the Ag2CO3-MMT nanocomposite exhibited an antibacterial activity higher than Ag-MMT sample against Escherichia coli.
Subject(s)
Anti-Bacterial Agents , Bentonite/chemistry , Carbonates/chemistry , Metal Nanoparticles , Silver Compounds/chemistry , Silver/chemistry , Anti-Bacterial Agents/chemistry , Anti-Bacterial Agents/pharmacology , Carbonates/pharmacology , Coated Materials, Biocompatible/chemistry , Coated Materials, Biocompatible/pharmacology , Metal Nanoparticles/chemistry , Microbial Sensitivity Tests , Microscopy, Electron, Scanning , Microscopy, Electron, Transmission , Silver/pharmacology , Silver Compounds/pharmacology , Spectroscopy, Fourier Transform Infrared , Surface Plasmon Resonance , X-Ray DiffractionABSTRACT
CuO-montmorillonite (CuO-MMT) nanocomposite was synthesized by thermal decomposition methods and characterized by diffuse reflectance spectroscopy (DRS), X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR) and transmission electron microscopy (TEM). The resultant particles are nearly spherical and particle size is in the range of ~3-5 nm. X-ray diffraction patterns indicate that MMT (1.22 nm) has a d-spacing higher than CuO-MMT nanocomposite (0.97 nm). This result implied that CuO nanoparticles can exist in micropore of MMT. The disappeared of band at 918 cm(-1) and decreasing of intensity of 3630 cm(-1) band in FT-IR spectra confirm substitution of aluminum in octahedral layer by Cu(2+) cations. The diffuse reflectance spectra show that the value of band gap energy for CuO-MMT nanocomposite (2.7 eV) is more than CuO nanoparticles (1.2 eV). It was found that decrease in the particle size of CuO nanoparticles due to quantum size effect. The antibacterial activity of CuO-MMT nanocomposite was tested against Escherichia coli. Nanocomposite showed efficient bactericidal effect.
