Optics and Spectroscopy, 2024 Volume 132, Issue 3,Pages 230–237(Mi os1162)
Proceedings of the International Conference The XXVII Annual International Conferences Saratov Fall Meeting 2023, September 25 - 29, 2023, Saratov, Russia Nanophotonics
Modeling of extinction spectra of silver nanoparticles in colloidal solutions and flexible substrates
Abstract:
The full realization of the biomedical and technological potential of silver nanoparticles requires reliable methods of their synthesis with precisely controlled size, structure, and morphology. The use of mathematical modeling allows us to obtain a more detailed understanding of the interaction of silver nanoparticles with electromagnetic radiation and determine the optimal parameters to achieve the desired optical properties. This paper presents the results of modeling the effect of silver nanoparticle parameters on extinction spectra in colloidal solutions and on substrates. Calculations were performed in the PyGDM software product based on the dyadic Green method and the volumetric sampling method. The diameter of silver nanoparticles in the simulation of extinction spectra, the positions of the extinction peak were considered in the range 1–85 nm, the refractive indices of the medium varied in the range 1.0–2.4, nonwovens of polycaprolactone ($n$ = 1.1) and polyacrylonitrile ($n$ = 2.4) were considered as substrates. The simulation was carried out both for single nanoparticles in a colloidal solution and on the surface of a non-woven material, and for a pair of nanoparticles on the surface of a non-woven material with specified gaps between the nanoparticles. In addition to modeling extinction spectra, calculations were carried out for the dependence of the maximum value of the electric field strength caused by laser radiation with a wavelength of 532 nm for silver nanoparticles on a substrate on the gap between particles at different particle diameters (10, 20, 30 nm). It is shown that the resonant extinction peak corresponding to spherical silver nanoparticles increases and shifts towards high wavelengths with increasing diameter. However, the refractive index of the substrate (if any) and the refractive index of the medium have a greater influence on the position of the extinction peak.
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