(92i) Probe Rheology Simulation Technique for Determination of Viscoelasticity of Complex Fluids

The viscoelastic properties of complex fluids are governed by the interplay of specific interactions and microscopic structure. The structural and dynamic heterogeneities in these systems lead to a local variation in their rheological properties. Over the last two decades, probe microrheology has emerged as an experimental technique that has the potential for determining local viscoelasticity of complex fluids. Recently, inspired by the experimental probe microrheology technique, we have developed an approach that combines molecular dynamics (MD) simulations with inertial generalized Stokes-Einstein relation (IGSER) to extract the viscoelastic properties of a complex medium. In our previous work, we showed that this method can be applied in both passive and active modes to polymer melt systems. The probe rheology simulation results for viscoelastic moduli so obtained were in good agreement with those obtained from nonequlibrium MD (NEMD) simulations and the Green-Kubo formalism. In order to test the generality of the approach, the probe rheology simulation technique is applied to other soft matter systems in this work. Specifically, results will be presented for the application of probe rheology technique to polymer solutions and colloidal suspensions. Probe rheology results for viscoelastic moduli will be compared with those obtained from the NEMD simulation.