Shear rheology of viscous interfaces coupled to bulk flow

Abstract

We present a novel interfacial constitutive equation for the material at inter- faces that takes a Newtonian functional form but allows shear viscosity to be a function of the local shear rate. We show excellent agreement between measured interfacial non-Newtonian responses and flows predicted at interface. We highlight that DPPC behaves as a shear-thinning material across physiologically relevant shear rates and surface packings, introducing material properties that include consistency and shear-thinning indices. The results and theory introduced in this thesis make significant strides towards unifying the disparate rheological behavior of DPPC films reported in the literature.