Characterization of anisotropic nano-particles by using depolarized dynamic light scattering in the near field

TL;DR

This paper introduces a novel near field dynamic light scattering technique for characterizing anisotropic nano-particles, providing advantages over traditional methods and accurately measuring diffusion coefficients.

Contribution

The study presents the first application of a near field scattering method to measure polarized and depolarized light scattering, improving data quality and statistical sampling.

Findings

Accurate measurement of translational and rotational diffusion coefficients.

Good agreement with traditional light scattering results.

Enhanced immunity to stray light and rapid data acquisition.

Abstract

Light scattering techniques are widely used in many fields of condensed and sof t matter physics. Usually these methods are based on the study of the scattered light in the far field. Recently, a new family of near field detection schemes has been developed, mainly for the study of small angle light scattering. These techniques are based on the detection of the light intensity near to the sample, where light scattered at different directions overlaps but can be distinguished by Fourier transform analysis. Here we report for the first time data obtained with a dynamic near field scattering instrument, measuring both polarized and depolarized scattered light. Advantages of this procedure over the traditional far field detection include the immunity to stray light problems and the possibility to obtain a large number of statistical samples for many different wave vectors in a single instantaneous measurement. By using the proposed technique we have measured the translational and rotational diffusion coefficients of rod-like colloidal particles. The obtained data are in very good agreement with the data acquired with a traditional light scattering apparatus.