|Research at R. Castillo's Group|
We are interested in several physical systems, which at first sight they do not seem quite related. However, using the new way of thinking developed in the field of complex fluids or more generally, in the field of soft condensed matter, they are very close. Examples of the systems we are interested in are:
We are interested in understanding the structure in these systems and how the molecules interact and organize into supramolecular structures, most of the time along interfaces. These interfaces can be of two types. The first type we call macroscopic interfaces, because they are of macroscopic dimensions, where molecules organize in very well defined and interesting forms. Examples in this case are the Lagmuir monolayers at the interface of water and air, and films on solid substrates named Langmuir-Blodgett films . In our group, we study systems such as monolayers of fatty acids, of fatty amines, and of proteins with amphiphilic α-helixes, phospholipids etc.
The second type of interfaces is what we call microscopic interfaces; because they have microscopic dimensions. These interfaces appear in ternary systems, which are formed by a surfactant, some kind of oil, and water. In these kinds of systems, the addition of surfactant apparently makes the macroscopic illusion that water and oil are soluble. However, the system organizes (microscopically) in such a way creating microscopic surfaces made of surfactant molecules, separating the water and the oil. These surfaces have different shapes forming very peculiar supramolecular structures named micelles, lamellae, bicontinuous structure, etc. Here, we study phase diagrams of ternary mixtures (microemulsions or lyotropic liquid crystals) with ionic surfactants and their supramolecular structures and how these supramolecular structures are modified when a shear stress is induced in the system
Our group is also interested in colloids, mainly embedded in polymeric nets and how they scatter light, as well as in proteins and the way they interact between them.