Controlling Shapes and Sizes of Synthesis Silver Nanowires by Polyol Method using Polyvinyl Alcohol and Polyvinyl Pyrrolidone

Abstract

Background/Objectives: To synthesis silver nanowires with Polyvinyl Alcohol (PVA) and Polyvinyl Pyrrolidone (PVP) as a capping agent by the polyol method. Methods/Statistical Analysis: Synthesis of silver nanowires was done by adding PVA and PVP for controlling of Multi-Twinned Particles seeds (MTPs) before grown to silver nanowires. The silver nanowires were characterized by UV-vis, SEM and XRD techniques. PVA and PVP is to be absorbed on the surface of the Ag seeds through Ag-O bond to form silver nanowires. Reaction time and temperature, as well as the kind of capping agent, affected the morphologies and sizes of the silver nanowires. Findings: The UV-vis spectra of silver nanowires show that the absorbance peaks at a wavelength of 350 to 390 nm. SEM images showed the selective absorption of PVA and PVP on the side surfaces of {100} and {111} facets plays an important role in the growth of anisotropic silver nanostructures. The diameter and length of silver nanowires of PVA were (190 ± 10) nm and (80 ± 10) µm. The addition of PVP as a capping agent can decrease the diameter and length of silver nanowires about 100 nm and 10 to 20 µm, resfectively. XRD pattern of silver nanowires represented that the final product was highly crystallized. The crystal structurecan be identified as a face-centered cubic (fcc) with lattice constant according to the spacing distance between the {111} planes was 4.1454 Å for PVA and 4.0756 Å for PVP. Applications/Improvements: PVA can be used as a capping agent for the synthesis of silver nanowires with high aspect ratio. The silver nanowires are synthesized with PVA longer than PVP