UNS: Dynamics and Rheology of Concentrated Suspensions of Rigid Rods: Effects of Confinement

University Of Florida, Gainesville FL

Investigators

Abstract

CBET - 1511787 PI: Jason Butler Fibers often are added to materials to provide extra strength and improve lifetime. However, adding fibers to a material complicates processing, because the fibers cause changes in the physical properties of the material during flow. This project will conduct experiments and computer simulations of the flow behavior of suspensions of rigid rods in a viscous liquid. The project will examine concentrated suspensions where the rods interact with each other during flow. Furthermore, the project will focus on the effects of nearby bounding walls on the structure and physical properties of the suspension. Results of the project will provide information that engineers who process fibrous materials can use in process design to enhance material properties. The project will provide research training for graduate students, research involvement for interested undergraduates, and opportunities to enhance international collaborations through established initiatives at the University of Florida. The rheology of concentrated fiber suspensions will be studied experimentally in a series of devices. To examine effects of confinement, the distance between bounding walls in the devices will be varied. The effects of nearby walls on the microstructure of the suspension will be determined by imaging the rods. Changes in the microstructure due to confinement will be correlated with changes in fluid rheology. Experimental measurements will be compared to simulations with periodic boundary condition or with bounding walls to examine connections between microstructure, confinement, and rheology. In addition to clarifying the influence of confinement, the project will identify the physical mechanisms that control structure and dynamics of concentrated suspensions of rods.