Microscopic energy dissipation mechanisms in composite materials – MEDICO

Polymer composites are versatile materials characterized by a complex, hierarchical microstructure entailing a wide variety of energy dissipation mechanisms, which can be tailored to meet the most demanding applications. However, the connection between their microstructure and their mechanical properties is not well understood. This knowledge gap hinders the development of novel materials with specific properties.
This project aims at elucidating the relationship between the microscopic structure of composite materials and their mechanical properties, especially nonlinear.
We aim to achieve this goal using an innovative experimental platform that integrates shear rheology, light scattering and microscopy. It allows us to measure at the same time the microscopic structure of the sample, how it evolves under shear, and the underlying distribution of local stresses, probed thanks to mechanophore molecules integrated in the polymer matrix.
To fully exploit the potential of this experimental platform, this project will primarily focus on model polymer composites with well-defined structural and mechanical properties. To this end, we will explore novel approaches to the preparation of polymer composites, in which the matrix and the filler networks are assembled sequentially, in solution. This will enable a consistent study of the whole spectrum of reinforcements, including the limiting cases of pure polymer or particle networks, which will help highlighting the peculiarities of composite materials over simpler, single-component systems.
Our study will provide guidelines for the formulation of materials with specific mechanical properties. To test the generality of these results, this project will also entail the study of a wider class of industrially-relevant composite materials.