Paper Number
SC7 

Session
Suspensions, Colloids and Granular Systems

Title
Effect of roughness on concentrated colloidal suspensions under flow

Presentation Date and Time
October 9, 2017 (Monday) 1:55

Track / Room
Track 3 / Crystal C

Authors (Click on name to view author profile)

1. Jacob, Alan R. (North Carolina State Univeristy, Department of Chemical and Biomolecular Engineering)
2. Hsiao, Lilian C. (North Carolina State University, Department of Chemical and Biomolecular Engineering)

Author and Affiliation Lines (in printed abstract book)
Alan R. Jacob and Lilian C. Hsiao
Department of Chemical and Biomolecular Engineering, North Carolina State University, Raleigh, NC 27606

Speaker / Presenter 
Jacob, Alan R.

Text of Abstract
Nearly hard sphere colloids are used as model systems in suspension rheology. Concentrated colloidal suspensions under flow have been investigated in detail using scattering, confocal microscopy, rheology, simulations and theory. Despite the presence of microscale roughness on nearly all types of colloidal particles, there is a lack of fundamental understanding of how particle roughness affects suspension rheology. Recently, our group developed rheological state diagram for particles with asperities that connects the steady state viscosity and first normal stresses to lubrication and friction-like interactions. Here, we further investigate the effects of asperities in concentrated colloidal suspensions on the mircroscopic dynamics and bulk flow properties. In this work, we follow shear stress, elastic and viscous moduli providing fundamental insights into yielding and relaxation of concentrated rough sphere suspensions and contrast with smooth sphere suspensions. Our goal is to use particle roughness as a means to control flow properties relevant to applications such as concentrated slurries, soft robots, and liquid body armor.