Polyvinyl Alcohol Films Loaded with Silver Nanostructures with Different Sizes and Shapes with Tuneable Plasmonic and Electric Properties. A Spectroscopic Study

Abstract

To study the effect of the incorporation of silver nanoparticles into polyvinyl alcohol (PVA) films on their optical and conducting properties, silver nanostructures with different sizes covering from spherical to polyhedral shapes were synthesized and embedded into the polymer. The sizes of the obtained silver nanostructures were analyzed by Dynamic Light Scattering (DLS), which exhibited high stability, attributed to their surface potential. Multimodal distributions suggest changes in shape ranging from spheres (~40 nm) to prisms (~100 nm), which was confirmed by Scanning Electron Microscopy (STEM/SEM) analysis. By embedding these nanostructures in polyvinyl alcohol (PVA), AgNPs loaded PVA polymer films were prepared, exhibiting a hypsochromic shift in the surface plasmon resonance band of the nanostructures. For conductivity determination of AgNPs loaded PVA polymer films, Electrochemical Impedance Spectroscopy (EIS) was used. The results indicated that the conductivity of the samples is highly dependent on the size and shape of the AgNPs embedded into the polymer, resulting in higher conductivity for smaller silver nanostructures.

Keywords:
Silver nanostructures; Plasmon bands; Electrochemical Impedance; Nanocomposites