Nanoseminar 15 October - prof. dr. Erik Luijten (Northwestern University)

Speaker: Prof. dr. Erik Luijten (Northwestern University)

Title: Charge Transport and Structure in Polarizable Soft Materials

Abstract: Soft materials in confined geometries, from colloidal systems to polyelectrolyte brushes, exhibit static and dynamic properties that are controlled by electrostatic interactions. Interestingly, the structure of these systems depends not only on parameters like temperature and pressure, but also can be controlled by manipulating the spatial variation in permittivity. Examples include the grafting of polymers onto metallic vs. insulating substrates and variation of the solvent in colloidal suspensions. Incorporation of dielectric effects in theoretical and computational predictions is often intractable due to their many-body nature. I will demonstrate how this limitation can be overcome, leading to discoveries that range from the control over ionic transport in nanochannels to pattern formation in dipolar thin films. As a next step in complexity, I will discuss the consequences of charge regulation, where the variation in polarization charges is augmented by configuration-dependent ionization states of colloids, nanoparticles, and polymers. In toto, these phenomena offer underexplored avenues for the design of functional materials.