Highly Spherical Nanoparticles Probe Gigahertz Viscoelastic Flows of Simple Liquids Without the No-Slip Condition

Simple liquids are conventionally described by Newtonian fluid mechanics, based on the assumption that relaxation processes in flow occur much faster than rate at which is driven. Nanoscale solids, however, have characteristic mechanical response times picosecond scale, comparable to simple liquids; as a result, viscoelastic effects liquid must be considered. These been observed using time-resolved optical measurements of vibrating nanoparticles, but interpretation has often complicated finite velocity slip liquid–solid interface. Here, we use highly spherical gold nanoparticles drive flows theoretically modeled without no-slip boundary condition particle surface. We obtain excellent agreement with this analytical theory considers both compression and shear properties liquid.