Young Investigators Group Dr. Marisol Ripoll
Young Investigators Group
Thermal diffusion of complex fluids by mesoscopic hydrodynamic simulations
A temperature gradient applied to a fluid system induces not only a current of energy but also a current of mass. This cross-effect is known as thermal diffusion. The purpose of this project is to elucidate the mechanisms of thermal diffusion of concentrated colloidal suspensions. These suspensions are often referred to as complex fluids and consist of small particles (spheres, rods, disks), macromolecules (polymers, proteins) or membranes (vesicles, cells) with sizes in the nanometer to micrometer range which are dispersed in a solvent. In most colloidal systems of biological relevance (membranes, DNA, proteins) or with technological applications (paints, drilling fluids), temperature and concentration effects play an important role.
The research of this young investigators group is performed by means of computer simulations using a special technique called multiparticle collision dynamics. In this novel mesoscopic method, hydrodynamic interactions, thermal fluctuations and non-isothermal conditions are naturally taken into account. We are first investigating the properties of a concentrated solution of spherical colloids in sustained temperature inhomogeneities. In a next stage we study effects induced by the shape and flexibility of the particles for which we will consider other geometries like rod-like or polymeric. An equally important theme for this group is to learn how thermodiffusion is affected by the coupling of a thermal gradient with other external fields like flow fields (capillary, shear), walls, and with inter-particle interactions.