Measurement of special nanoparticle structures by light scattering

The characterization of nanoparticle size and structure by means of classical light scattering measurements from monodisperse suspensions is examined from both the Rayleigh-Gans (R-G) approximation as well as (for various spherical structures) the exact Lorenz-Mie theory. A means by which the traditional limits of the R-G theory may be extended and simplified is shown by a detailed discussion of the characteristic mean-square radius. This becomes particularly important for irregular particle shapes, where scattering depends on the orientation of such particles with respect to the direction of the incident illumination. A variety of particle structures are addressed, including rods, tubes, ellipsoids, rings, and superellipsoids.