A two-flux model of the optical properties of gold nanoparticles on a porous polymer substrate

The diffuse reflectance of films formed by the deposition of gold nanoparticles on a porous polymer substrate is investigated. Measured reflectances are compared with those calculated using a two-flux model of radiative transfer, modified to take into account the optically-rough surface. The required scattering and absorption coefficients of the nanoparticles are calculated using a standard Mie scattering method for optically-isolated particles, and the generalized-multiparticle-Mie method for clusters of particles. The calculated reflectances show good agreement with measurements for the films containing optically-isolated particles. Progress is described for the films containing clusters of particles.