2017/10/09 by Guilherme Oliveira, Oliveira, Guilherme H., A. Honorato +3
Biochemistry, Genetics and Molecular Biology · Chemistry · Materials Science · #Diffusion and Search Dynamics #Electrostatics and Colloid Interactions #Gold and Silver Nanoparticles Synthesis and Applications
paper · pdf · doi:10.48550/arxiv.1710.03175
We use a simple model of particle shape to investigate how particle asymmetry\naffects particle-surface interaction, orientation, and stochastic dynamics over\na planar surface. With this geometric model, we construct potential energy\ncurves as a function of particle orientation relative to the surface, and\nidentify the potential energy minimum for particles of various shapes ranging\nfrom symmetric (sphere) to asymmetric (oval-shaped). The calculated difference\nbetween particle centroid position and potential energy minimum location is\nused to define an offset, which is useful for comparison with experimental\nparticle trajectories. For asymmetric particles the potential energy minimum\nlocation is decoupled from the center of the particle long-axis. Based on these\nobservations, we construct a Brownian motion model of a rigid rotor with one\nend fixed to the planar surface. In the case of asymmetric particles, the\nresulting stochastic trajectories exhibit passive circular Brownian motion,\nthus providing one possible microscopic mechanism for the stochastic dynamics\nof fluorescence upconversion nanoparticles near a surface previously reported\nby us.\n