Effects of Surfactant and Polymer on the Morphology of Advanced Nanomaterials in Aqueous Solution

The sculpturing effects of cetyltrimethylammonium bromide and poly(vinyl)alcohol on the shape transformation of silver nano-particles are presented. It is a simple process of recent interest for obtaining silver nano-rods, spherical and hexagonal nano-plates in the thiosulphate reduction of Ag+ ions with or without stabilizers. Formations of silver nanoparticles were observed visually by color change of the reaction mixture from colorless to dark yellow. Interestingly, the reaction mixture remained colorless and no absorption peak due to the Ag-nanoparticles was observed at higher [S2O32-] (≥ 20.0 × 10-4 mol dm-3). UV-vis spectroscopy and transmission electron microscopy (TEM) were used to monitor the growth and morphology of Ag-nanoparticles, which reveal to the nano nature of the particles. These studies infer that the particles are mostly spherical in shape and have an average size of 16 nm in absence of CTAB. Selected area electron diffraction (SAED) results indicate that the Ag- nanoparticles grow along the [111] direction.