title: Fluid dynamics of evolving foams.
abstract: The physical properties of many multiphase systems are determined by coarsening phenomena. From raindrops to polycrystal grains and foams, the formation and stability of these systems continuously evolve towards lower-energy configurations through events such as coalescence, Ostwald ripening and drainage. Here we propose a procedure to identify and characterise key topological transformations of coarsening phenomena using a physically-based fluid dynamic framework. In situ, real-time foaming processes of a polymeric matrix reinforced with two morphologically different nanofillers, carbon nanotubes and graphene sheets were observed by synchrotron X-ray radioscopy. We obtained detailed information on the evolution of the growth patterns and coarsening events. Filled samples showed differences in both trend and speed compared with the unfilled sample. Furthermore, we found different dominating coarsening phenomena due to the wetting nature of carbon nanoparticles. Our procedure can be extended to sequences of any type of 2D projection or 3D images and to other multiphase systems.
authors.affiliation: Institute of Polymer Science and Technology, (CSIC), Juan de la Cierva, 3, 28006 Madrid, Spain. rverdejo@ictp.csic.es
authors.forename: Raquel
authors.initials: R
authors.lastname: Verdejo
authors.forename: Francisco J
authors.initials: FJ
authors.lastname: Tapiador
authors.forename: Lukas
authors.initials: L
authors.lastname: Helfen
authors.forename: M Mar
authors.initials: MM
authors.lastname: Bernal
authors.forename: Natacha
authors.initials: N
authors.lastname: Bitinis
authors.forename: Miguel A
authors.initials: MA
authors.lastname: Lopez-Manchado