Time-resolved structure-property relations in model soft gel networks under large amplitude oscillatory shear

Soft particulate gels are incredibly useful due to their ability to reversibly yield, i.e. transition between solid-like and fluid-like behavior, when sufficient deformation is applied. While the microscopic dynamics and constitutive flow behavior of these systems have been studied separately in detail, the development of direct connections between the two has been difficult, particularly with regard to the non-linear rheology. To bridge this gap, we use molecular dynamics simulations to perform a series of numerical large amplitude oscillatory shear (LAOS) measurements on a model soft particulate gel. Our system consists of particles that interact with a combination of a two-body short-range attraction and a three-body bending stiffness term, which spontaneously self-assemble into disordered network of soft gels at relatively low volume fractions (Φ < 20%). We track the nonlinear constitutive physics of the gels using the analytical sequence of physical processes (SPP) framework to define time-resolved dynamic moduli within a period of oscillation, and compare their changes to the evolving orientation and deformation of the gel network microstructure to develop structure property relations.