Accurate Retrieval of Bimodal Particle Size Distribution in Dynamic Light Scattering

Dynamic light scattering (DLS) is one of the most popular techniques for the particle size distribution (PSD) determination of particles under Brownian motion. However, the accurate retrieval of PSD from bimodal particles with a peak position ratio less than 2:1 is still an open problem in single-angle DLS measurement. In this letter, we proposed a new weighted constrained regularization (CR) method to improve the accuracy of inversion PSD for single-angle bimodal DLS data. The weighted CR method significantly improves the accuracy of inversion PSD for various bimodal particles, and, for the first time, reasonably resolves bimodal particles with a peak position ratio less than 2:1, such as 1.75:1, 1.50:1, and 1.68:1.