Confinement and Complex Viscosity: Experiments
Coombs, Steacy J.
Giacomin, A. Jeffrey
Macromolecular confinement , Thin-film rheology , Macromolecular orientation , Complex viscosity , Rigid dumbbell suspension , Microfluidics
Whereas much is known about the complex viscosity of polymeric liquids, far less is understood about the behaviour of this material function when macromolecules are confined. By confined, we mean that the gap along the velocity gradient is small enough to reorient the polymers. We examine classical analytical solutions [Park and Fuller, JNNFM, 18, 111 (1985)] for a confined rigid dumbbell suspension in small-amplitude oscillatory shear flow. We test these analytical solutions against the measured effects of confinement on both parts of the complex viscosity of a carbopol suspension and three polystyrene solutions.