LIQUIDS

Author: PENNA TOSSO FLORENCIA.
Year: 2005.
University: AUTÓNOMA DE MADRID [www.uam.es].
Place of defense: FISICA TEORICA DE LA MATERIA CONDENSADA.
Place of preparation: FISICA TEORICA DE LA MATERIA CONDENSADA.

Summary: In recent years there has been an increasing both experimental and theoretical development of what have been called "lab on a chip" devices for the control of liquids in the range of pico-litros seeking to replicate the processes at the molecular level that occur the laboratories of physics, chemistry or biology. The effective design of these devices requires a theory for the dynamics at the molecular level. The Dynamic Density Functional (FDA) is a technique that enables the study at the molecular level of dynamic systems relajativos (those in which the hydrodynamic modes are not relevant), using the only assumption that we can approximate the dynamic correlations by those that exist in an equivalent system (with the same density profile) in balance. Work performed in the Doctoral thesis can be divided into two camps: a) design based devices micro-fluidos by applying theory FDA: 1) micro-bomba particles in narrow channels (set in 1D). 2) system polymers subjected to potential time-dependent external System (2D and 3D). B) Improved theory FDA for the simplest case of system 1D of hard particles. For the selected systems (hard particles in 1D and soft 2D and 3D) from the comparison of results for steady state simulation and by the FDA theory we can say that the FDA theory is a very useful tool for the design of devices based in micro-fluidos. However, there are cases where the FDA theory fails, predicting a temporal evolution very different from that obtained in simulation. For those cases we designed (limited to systems in 1D of hard particles) and tested a new theory can reproduce the decay temporary obtained through simulation of a relationship that we call feature, which endures in the time course and that seems to determine the the system dynamics.