Comparative rheological study of A.nilotica subspecies of Sudanese origin

Abstract

Solutions at relatively high concentration (25% - 50%) of Composite samples of subspecies, A. nilotica var. tomentosa, A. nilotica var. nilotica from Sinnar, Blue Nile, and A. nilotica subsp. adistringen from Kordofan state, were subjected to Shear flow viscosity, and Oscillating flaw behaviour. At (50%) concentration, the results show Newtonian flow behaviour in the shear rate range 0.1s-1 to 100 s-1, for subsp. tomentosa, and adistringen, while subsp. nilotica show Newtonian flow behaviour in the shear rate range 10.0 s-1 to 100 s-1, at (25%) concentration the results show subsp. tomentosa, and subsp. adistringen exhibit shear thinning behaviour in the shear rate range 0.1 s-1 to 1 s-1, while subsp. nilotica at 10%, 20%, 30%, 40% concentration exhibit shear thinning behaviour in the shear rate range 0.1 s-1 to 10 s-1. The loss modulus (G″) of the above A.nilotica subspecies was higher than the storage modulus (G′), Energy of deformation is dissipated viscously and the samples exhibits liquid-like behaviour.