The Influence of Silver Nanoparticles on Absorption Spectra and Structure of thin Poly(ortho-toluidine) Films

Abstract

Poly(ortho-toluidine) (PoTI) films of different thicknesses were obtained by electrochemical polymerization on the SnO₂ surface and doped with silver nanoparticles, synthesized by citrate method. It was established that doping by nanosilver causes significant changes in optical absorption of films in the wavelength range λ = 310- 450 nm and λ = 550 - 1000 nm. In comparison with the undoped PoTI there is decrease in the intensity and halfwidth strip of π-π * transition with maximum at λ = 370 nm, the appearance of the absorption band with a maximum at λ = 612 nm and leveling broad bipolaron band at λ = 800 - 950 nm. The observed changes can be explained by the interaction of silver nanoparticles with conjugated polymer chain which is confirmed by research of structure of PoTI films doped with nanosilver.Keywords: optical absorption, plasmon resonance, electron microscopy, energy dispersive analysis, poly(ortho-toluidine), silver nanoparticles, doping.