Structure of colloidal gels during microchannel flow.
We investigate the structure and flow behavior of colloidal gels in microchannels using confocal microscopy. Silica particles are first coated with a cationic polyelectrolyte and then flocculated by the addition of an anionic polyelectrolyte. In the quiescent state, the suspension is an isotropic and homogeneous gel. Under shear flow, the suspension contains dense clusters that yield at intercluster boundaries, resulting in network breakup at high shear rates. These structural changes coincide with a transition from pluglike flow at low pressures to fluidlike flow at high pressures.
Conrad
Jacinta C
JC
Frederick Seitz Materials Research Laboratory, Materials Science and Engineering Department, University of Illinois, Urbana, Illinois 61801, USA.
Lewis
Jennifer A
JA