Transient forces and non-equilibrium states in sheared polymer networks

¹ Department of Physics, Harvard University - 9 Oxford Street, Cambridge, 02138 MA, USA
² Institut de la Matière Condensée et des Nanosciences, Université Catholique de Louvain Croix du Sud 1, 1348 Louvain-la-Neuve, Belgium, EU
³ Computational Biophysics, University of Twente - PO Box 217, 7500 AE, Enschede, The Netherlands, EU
⁴ Institute for Physical Sciences and Technology, University of Maryland - College Park, 20742-2431 MD, USA

^a joris.sprakel@gmail.com

Received: 27 October 2010
Accepted: 9 February 2011

Abstract

The response of many soft materials to external fields is dominated by transient forces, which arise from memory of the configurations the system has undergone in the past. Using large-scale particle-based simulations we show that these transient forces lead to a rich non-equilibrium behavior in networks of soft polymeric particles or polymer-engrafted colloids. We compute the diagram of states for an experimental system of network-forming associative polymers and show viscoelastic instabilities such as shear banding, melt fracture and a shear-induced disorder-order transition.