Diffusion coefficient analysis by dynamic light scattering enables determination of critical micelle concentration

Abstract

The critical micelle concentration is an important property of supramolecular detergents. Two dynamic light scattering approaches have been developed for critical micelle concentration analysis, i. e., concentration-dependent light scattering intensity analysis and diffusion coefficient analysis. Their utility as complementary tools for a reproducible determination of critical micelle concentration remains to be clarified. Herein, we address the question which of the two approaches is more suitable for obtaining reproducible critical micelle concentration values. We systematically compare both approaches in context with common detergent classes and benchmark utility by means of literature values. Our results show that the diffusion coefficient analysis delivers reproducible critical micelle concentration values in aqueous solutions. Our findings outline a roadmap to guide the critical micelle concentration analysis of detergents by dynamic light scattering in the future.