Influence of gelation on particle shape in sheared biopolymer blends

The morphology of biopolymer droplets gelled under shear as the dispersed p hase of a two-phase mixture of biopolymers in aqueous solution (or "biopoly mer blend") was investigated experimentally. The process involves shearing the liquid biopolymer blend either at a steady stress till gelation, for cr eation of ellipsoidal gelled particles. or a stress step-up process for cre ation of high aspect ratio particles. The resulting particle shapes are ana lyzed and compared against models for affine deformation conditions [Jansse n (1997)] and steady shear conditions [Maffetone and Minale (1998)]. Althou gh they are only strictly valid for Newtonian fluid phases, application of these models to a situation where one phase is gelling, has provided insigh t into the morphological changes occurring in the shear-g-elation process. (C) 2001 The Society of Rheology.