Grups de recerca
06
oct
Seminari FMC: Carla Fernandez-Rico
El proper 6 d'octubre reprenem els seminaris del departament i tindrem el plaer de comptar amb la Dra Carla Fernandez-Rico del Dept of Materials de l'ETH, i ens presentarà el seu treball: "From Colloidal Self-Assembly to Phase Separated Materials". Us esperem a tots!
Dates:
06-10-2023
Horari:
12:45
Lloc:
Seminar room 320, 3rd floor of the Faculty of Physics, UB
Afegeix-ho a l'agenda (iCal)
From Colloidal Self-Assembly to Phase Separated Materials
Carla Fernandez-Rico (carla.fernandezrico@mat.ethz.ch)
Department of Materials, ETH Zurich, Switzerland.
Phase separation is a fascinating physical process that is not only responsible for the internal organization of living cells but also a promising tool for structuring materials. The central challenge in making meso-structured materials via phase separation is the lack of structural control at length scales beyond the macromolecular scale.
In this talk, I will first briefly introduce a colloidal system of banana-shaped particles and their exotic self-assembly (see Fig.1A), and then focus on describing Elastic MicroPhase Separation (EMPS) as a route to create highly correlated and bi-continuous structures in the scale of hundreds of nanometers (see Fig.1B). The essential idea of our EMPS approach is simple; we counter the thermodynamic forces that drive phase separation with elastic stresses in the host matrix. In this way, we can tune the size and morphology of the structures by changing the mechanical properties of the matrix. Analysis of the microstructure, phase equilibria, and kinetics suggests that these systems emerge through a unique thermodynamic pathway, featuring aspects of both nucleation and growth and spinodal decomposition. We demonstrate the potential our approach by toughening polymeric materials, and making bicontinuous structures with controlled structural and anisotropic gradients.
Figure 1. (A) Confocal microscopy image of the splay-bend nematic phase formed by colloidal bananas, where the particles are colored according to their long axes orientation. (B) Schematic of the phase separation process which produces elastomer-rich and liquid-rich bicontinuous phases.
