Dispersion and Dissolution of Hydrocolloids

Hydrocolloids such as starch, carboxymethyl cellulose, guar gum, pectin and carrageenan have many industrial applications including textile and carpet printing, paper production, foods, personal care, home care, pharmaceutical and biomedical products. They are widely used for modifying the rheology and texture of formulations, stabilising microstructures and enhancing organoleptic properties and are increasingly being investigated as agents in delivery systems for high value and high functional applications, such as encapsulation and controlled release in pharmaceutical, nutraceutical, food, animal feed, agrochemical, household care and cosmetics industries. Invariably, they have to be mixed with water in order to allow swelling/dissolution to occur. However, the surfaces of the granules or encapsulates become sticky when in contact with water and this can often lead to aggregation that prevents complete swelling/dissolution. The aim of the current proposal is to develop generic numerical models that will be able to identify the optimal dispersion conditions. The interaction of water with HCs is extremely complex with the rapid formation of an outer gel layer, which causes aggregation that inhibits internal capillary flow of water into the pores so that swelling/dissolution has to rely on the much slower process of diffusion. In order to determine the optimal mixing conditions, the project will model these processes from the molecular to the industrial scale. This so-called multiphysics multiscale strategy will involve molecular dynamics, finite element analysis, discrete element modelling coupled with computational fluid dynamics and population balance modelling. It will include an experimental programme to measure the physical and mechanical properties of the hydrocolloids and also mixing measurements to validate the modelling.