Silver nanodisks: size selection via centrifugation and optical properties

Area of Science:

• Nanotechnology and Materials Science
• Plasmonics and Optical Properties of Nanomaterials
• Computational Physics and Chemistry

Background:

• Soft chemistry offers versatile routes for nanoparticle synthesis.
• Understanding the optical properties of nanoparticles is crucial for applications.
• Discrete Dipole Approximation (DDA) is a powerful simulation tool for nanoparticles.

Purpose of the Study:

• To synthesize silver nanodisks and spherical particles.
• To investigate the influence of size and shape on the optical properties of silver nanodisks.
• To compare experimental absorption spectra with DDA simulations.

Main Methods:

• Synthesis of silver nanoparticles using soft chemistry.
• Separation of nanodisks using centrifugation.
• Measurement of experimental absorption spectra.
• Simulation of optical properties using the Discrete Dipole Approximation (DDA) method.

Main Results:

• Silver nanodisks of two different sizes and spherical particles were successfully synthesized.
• Experimental absorption spectra of nanodisks were compared with DDA simulations.
• For small nanodisks, assuming a spheroidal shape in simulations yielded good agreement.
• For larger nanodisks, precise geometry, including 'snip' and aspect ratio, was necessary for accurate simulations.

Conclusions:

• The optical properties of silver nanodisks are strongly dependent on their precise geometry and size.
• Accurate simulation of plasmonic properties requires detailed geometric information for larger nanostructures.
• The study highlights the importance of shape fidelity in correlating experimental and simulated optical spectra of nanoparticles.