THE CITY COLLEGE OF NEW YORK
CHEMICAL ENGINEERING DEPARTMENT
Graduate Student Symposium
City College of New York
Monday, March 5, 2018
Seminar will be held in MR-1307 (Marshak Building) at 2:00 PM
Reception will be held in Steinman Hall, Exhibit Room – 1st Floor
From 3:00 – 3:30 PM
Simulations of Active Microrheology of Dense Suspensions
Active microrheology is an emerging alternative to conventional rheology for characterizing the non-linear response of colloidal suspensions, especially when the amount of the material of interest is too small to perform rheological measurements. It remains an open question how the bulk rheological properties and active microrheological response of these materials are related, since the deformation of the material induced by the probe particle is not purely viscometric. Here, we study the constant-force active microrheology of very dense colloidal suspensions by performing particle scale simulations. These simulations allow transition from a lubricated hydrodynamic interaction to an un-lubricated frictional contact between the particles and have been successful in quantitatively reproducing the non-Newtonian shear behavior of thickening suspensions including discontinuous shear thickening. The focus will mainly be on the kinematics of the suspension along with the changes in the microstructure within the material in response to the motion of the probe. In addition, we investigate how the stresses generated within the material are related to the frictional contact networks generated by the probe particle.
Omer Sedes obtained his undergraduate degree in Chemical Engineering and in Economics from the Johns Hopkins University. He’s currently nearing the completion of his Ph.D. at CCNY under the guidance of Professor Jeff Morris.