Manon L'Estimé

Coalescence : from the merging of complex fluid droplets to thin film instability

Coalescence processes play a key role in many practical systems, from biological processes to industrial applications like inkjet printing. In this seminar, I will explore two situations of coalescence. In the first part,  the coalescence of two freely suspended droplets of a jammed yield-stress fluid is investigated. We analyze the temporal evolution and the shape of the neck formed between merging droplets to better understand the influence of rheology on the coalescence process. The second part focuses on the coalescence of two thin films of a viscous Newtonian liquid. Under certain conditions, the merging of the films leads to the destabilization of the interface, resulting in the formation of finger-like patterns. We 

investigate the mechanisms driving this instability and describe its geometrical features through scaling laws.