We utilize a combination of millifluidic and particle tracking microrheology experiments to study dissolution dynamics in concentrated surfactant systems. Previous work conducted demonstrated the diffusion-limited nature of this process and highlighted the need for a better understanding of mesophase formation and convective effects on dissolution dynamics [1,2]. Our experiments enable us to measure diffusivity in the different meshophases formed during dissolution by combining results obtained with different boundary conditions. The use of millifluidic devices allows us to investigate the role of convection on dissolution dynamics while microrheology provides information on the evolution of local viscoelastic properties.

1 Lim, J. C., Miller, C. A., "Dynamic Behavior and Detergency in Systems Containing Nonionic Surfactants and Mixtures of Polar and Nonpolar Oils," Langmuir, 7, 2021-7 (1991).

2 Chen, B.-H., Miller, C. A., Walsh, J. M., Warren, P. B., Ruddock, J. N., Garrett, P. R., Argoul, F., Leger, C., "Dissolution Rates of Pure Nonionic Surfactants," Langmuir, 16, 5276-83 (2000).