Suspensions of non-Brownian fibers in liquids are utilized for variety of applications, and above a certain fiber concentration, fiber suspensions are shear thinning, thixotropic and viscoplastic in both Newtonian and non-Newtonian suspending fluids. This is owed to the fiber networks and entanglements formed while flowing. The measurement of the changes in suspension microstructure to relate the macroscopic rheological changes are performed. We understand the properties for high solids concentrations of fiber suspensions.
Rheology of biomass fiber suspensions
We perform rheological measurements of high solids concentrations (above 20 wt. % solids) of lignocellulosic biomass fibers at high temperature, high pressure and low acid concentrations using a novel rheometer, designed in our lab called Lignocellulosic Biomass Rheometer (LCBR). This consists of an insert, an impeller-blade system and a weight placed together in a Parr reactor which can be used to measure steady state shear torques at constant impeller rotations. (Shown in right)
Rheology of monodisperse fiber suspensions
We perform rheological measurements of synthetic fiber suspensions of high aspect ratio (above 50) in the designed LCBR equipment to understand dependence of yield stresses of this solid-like material over temperature. We also perform experiments using rheological modifiers.