Skip to main content
Vai all'homepage della Commissione europea (si apre in una nuova finestra)
italiano it
CORDIS - Risultati della ricerca dell’UE
CORDIS

Colloidal Yielding: tunable glasses to explore plasticity from macroscopic to microscopic length-scales.

Descrizione del progetto

Studio del cedimento nei solidi amorfi tramite nuovi vetri colloidali

Quando si applicano forze esterne a solidi privi di una struttura interna ordinata, questi si deformano elasticamente. Se la sollecitazione applicata è sufficientemente grande, possono «cedere», fratturandosi o deformandosi. Alcuni lo fanno bruscamente, mentre altri gradualmente. I meccanismi di queste transizioni sono sconosciuti. Con il sostegno del programma di azioni Marie Skłodowska-Curie, il progetto COLLY mira a studiare questo fenomeno in nuovi vetri colloidali regolabili controllati dalla loro «frazione volumetrica». COLLY utilizzerà una miscela di nanoparticelle e mesogel di polimeri non colloidali, con questi ultimi che si restringono o si gonfiano in funzione della temperatura, per controllare il volume libero disponibile per le nanoparticelle insensibili alla temperatura.

Obiettivo

Upon external mechanical loading, amorphous solids initially deform elastically, but for large enough applied stress they may fracture or flow as a plastic fluid. This transition, known as yielding, is one of the most fascinating open problems in condensed matter statistical physics. In fact, the exact nature of the transition is still unclear: some systems show abrupt (brittle) yielding (e.g. in oxide glasses) while others, such soft gels or foams, display ductility with a smooth and gradual increase of plastic deformation. A unique picture of the processes at play is yet missing and recent models and theories claim experimental support.
Here I will use a use a novel colloidal glass to explore the yielding transition and its properties. Colloidal glasses are controlled through their volume fraction: it plays the same role of temperature in molecular ones, but it is much more difficult to precisely tune. I will overcome this difficulty exploiting a mixture of nanoparticles and non-colloidal polymer mesogels. The mesogels swell/shrink as a function of temperature, controlling the available ‘free’ volume for the (temperature-insensitive) nanoparticles. This approach allows for an unprecedented precise control of the volume fraction in a colloidal glass without changing particle-particle interaction or their size (e.g. in microgels). The versatility of the system will be exploited to investigate plastic activity for different level of glass equilibration and external applied stresses thanks to cutting-edge experiments involving rheology, time- and space- resolved visible scattering and synchrotron-based X-ray photon correlation. These approaches will be combined to obtain a comprehensive picture of the processes at play, allowing for a ground-breaking study from inter-particle distances up to macroscopic sizes. The yielding transition will then be tackled from a new point of view, potentially elucidating its nature and confronting emerging theories.

Campo scientifico (EuroSciVoc)

Parole chiave

Programma(i)

Argomento(i)

Meccanismo di finanziamento

HORIZON-TMA-MSCA-PF-EF - HORIZON TMA MSCA Postdoctoral Fellowships - European Fellowships

Vedi tutti i progetti finanziati nell’ambito di questo schema di finanziamento

Invito a presentare proposte

(si apre in una nuova finestra) HORIZON-MSCA-2024-PF-01

Vedi tutti i progetti finanziati nell’ambito del bando

Coordinatore

UNIVERSITE DE MONTPELLIER
Contributo netto dell'UE
€ 226 420,56
Indirizzo
163 RUE AUGUSTE BROUSSONNET
34090 Montpellier
Francia
Regione
Occitanie Languedoc-Roussillon Hérault
Tipo di attività
Higher or Secondary Education Establishments
Collegamenti
Costo totale
Nessun dato

Partner (1)