Stochastic Simulation of Mass Transport under Arbitrary Illumination Conditions: The Influence of the Nanoparticle Localized Surface Plasmon Resonance

Mass migration is induced in some azopolymers by illumination with a spatial distribution of intensity, phase, or polarization. In particular, illumination with an interference pattern results in the formation of a surface relief grating (SRG). The addition of metallic nanoparticles to the azopolymer has shown an improvement in diffraction efficiency and modulation ( Opt. Mater. 2021, 115, 111015; Nanomaterials 2023, 13, 2946). Several hypotheses have been proposed to heuristically explain this phenomenon ( Nanophotonics 2024, 13, 229–238; J. Chem. Phys. 2023, 158, 104905); however, none have offered a definitive explanation. In this work, we present a Monte Carlo model based on the two-dimensional (2D) Self-Avoiding Walk (SAW) method to describe the mass transport in polymer chains surrounding metallic nanoparticles. We propose that under certain conditions, the increased modulation may result from the nanoparticle acting as a mass propeller, driving material away from its surface along the direction of the incoming electric field polarization.