Kinetic study of fluid gel formation and viscoelastic response with kappa-carrageenan

We describe the production of fluid gels from kappa-carrageenan using well-defined geometries, flow patterns and cooling rates. Narrow size distributions are achieved by inducing spinodal decomposition under temperature quench and controlled sheared conditions. The polymer concentration effect on the mechanism of decomposition is provided, as is a mathematical description of the relationship between the increase in viscosity, due to the particle formation, and the concentration of the kappa-carrageenan. For all of the studies with kappa-carrageenan a mean diameter of <5 mu m was obtained and the fluid gels produced showed strong and highly recoverable particle bridging. A model is presented for the kinetics of aggregation of these particles, providing information on the mechanisms involved. (C) 2009 Elsevier Ltd. All rights reserved.