Effect of size and shape of particulate inclusions on the rheology of guargalactomannan solutions

In our earlier work, the effects of particulate inclusions on the rheologic al properties of a guar galactomannan entanglement solution were studied. F iller materials varying in size and shape were investigated including a ric e starch sample, chosen for its homogeneity and spherical nature. In the pr esent paper, the work has been extended to include microcrystalline cellulo se selected for its rod-like appearance and heterogeneous nature. The effec ts of particulate and composite properties on the apparent zero-shear visco sity and yield stress of the system were determined, and compared with prev ious results obtained using the more isotropic rice starch filler. (C) 2000 Elsevier Science Ltd. All rights reserved.