SMSD Seminar - Impact of drops and beads of complex fluids and gels
Wednesday, December 11, 2019 at 4:00pm
Professor Laurence Ramos, Université de Montpellier
Spray and drop impact are ubiquitous processes in industry, agriculture and every-day life. In all cases, complex fluids are involved, rendering crucial the understanding of the behavior of complex materials upon impact on a surface.
To disentangle the role of capillary, viscous and elastic forces in the dynamics of drops upon impact on a repulsive surface, we have investigated several classes of materials, whose rheological characteristics are tuned over several orders of magnitude: viscous liquids, ultrasoft solids with elastic modulus as low as 10 Pa, viscoelastic Maxwell fluids characterized by an elastic modulus, G0, a relaxation time, t, spanning three orders of magnitude, and shear-thinning fluids.
Overall, our study allows a quantitative rationalization of the spreading of drops for viscous, viscoelastic and elastic materials by taking into account surface tension, elastic deformation and elongational viscous dissipation.