An experimental and interdisciplinary approach to physics teaching: determination of critical micellar concentration by light scattering

In the field of supramolecular fluids, one of the fundamental concepts is the critical micelle concentration (CMC), defined as the concentration threshold above which surfactant molecules begin to self-assemble into supramolecular aggregates with distinct geometries. The morphology of these structures depends on various factors, including the nature and amount of the surfactants present, as well as thermodynamic variables such as temperature. Among these structures, micelles stand out for their simplicity and relevance. Micellar systems play a crucial role in the solubilization of hydrophobic compounds and are widely used, for instance, in drug delivery. In this work, we propose an introductory activity for a Physical Chemistry course aimed at the experimental determination of the CMC of sodium dodecyl sulfate (SDS) through light scattering measurements.

Keywords:
Critical micelle concentration; light scattering; sodium dodecyl sulfate