Abstract

Through the illustration of examples of recent work in my group, I try to show the interplay that exists between the macroscopic physical chemistry description and the dynamics of molecules obtained by atomistic simulations. As an example we can consider a drop. We understand very well how it behaves on a windowpane and describe it by continuum equations. As the size of the drop, or the number of molecules in it, decreases, it ceases to be a drop and becomes a molecular cluster. Still, one can try to apply fluidodynamics to describe its behavior. The question I will like to address is when the continuum description breaks down, if ever. In some noteworthy cases, there is no real breakdown, while in others the molecular scale behavior is entirely different. Bubble dynamics, nanotube pipettes, fullerenic ballbearings and other examples will be presented and examined emphasizing the accuracy and the role of the two pictures.