Research Seminars @ Illinois

Abstract 

Over the last century, electro-viscoelasticity has been studied extensively through experimental research into manufacturing techniques such as electrospinning, electrowetting, and electrospraying. However, continuum modeling of this phenomenon remains incomplete, particularly regarding the mechanisms required to capture specific experimentally observed behaviors. To address this gap, we propose a constitutive model termed the upper-convected electro-Maxwell (UCEM) model. This model is derived from a Rouse-based formulation of a linear polymer chain under shear, featuring a characteristic oscillatory charge sequence. To validate the continuum response, coarse-grained molecular dynamics (MD) simulations of Kremer-Grest chains are conducted under Couette flows with fixed charge sequences. Furthermore, a novel flow/field orientation phenomenon is identified, predicting an anisotropic apparent viscosity response of the melt dependent on both the strain rate and the electric field orientation.

About the Speaker 

Zachary Wolfgram is a TAM doctoral student in the Department of Mechanical Science and Engineering at the University of Illinois Urbana-Champaign, working under the supervision of Prof. Martin Ostoja-Starzewski. His research interests include the study of odd/non-reciprocal matter, negative entropy production under granular flows, and electro-viscoelasticity. For the last two summers, he has been working with researchers (Matthew Grasinger and Jeffrey Ethier) at the Air Force Research Laboratory (AFRL) at Wright-Patterson AFB, studying electro-viscoelasticity through the High Performance Computing Modernization Program (HPCMP) summer internship program. His doctoral work focuses on the mechanics of odd linear solids and how to properly characterize this new class of materials.

Host: Professor Martin Starzewski