The LPSI has developed broad expertise in simulation techniques and their experimental validation. This has yielded detailed understanding of interfacial phenomena at the molecular level.
Simulations can provide tremendous savings in the experimental effort required to understand a wide range of phenomena. Once validated by experiment, the codes can be used to study related phenomena that are experimentally inaccessible. At present we work with a cluster of 200 processors, which provides excellent capacity and flexibility.
Studies are based classically on the three complementary techniques of molecular dynamics (MD), Monte-Carlo simulations, and genetic algorithms. Dedicated codes and software developed within the LPSI provide access to all types of interaction potentials and very large systems of >1.000.000 particles. Specific modules address collective properties such as viscosity, surface tension, and static and dynamic contact angles.
These techniques have been used intensively to study the dynamics of wetting on solid surfaces of varied geometry : flat surfaces, capillaries, and fibres. For example, we now have a better understanding of the influence of substrate wettability on the maximum speeds at which a liquid will wet a surface before air entrainment occurs in coating (see reference below). The results are already being used by industry.
We are now building on our successes in studying the microscopic details of dewetting and slip length. The corresponding possible applications can be found in wear studies, flotation, lubrication, …
Recently, we have also developed new simulations to get a better understanding of the spreading of liquid metals on other metals at high temperature. We have in mind to study how we can optimize soldering.
We are also working on adhesion between polymers and fibres, using very realistic potentials. We have in mind the reinforcement of thermosets for the aircraft industry.