Dispersion and Dissolution of Hydrocolloids

淀粉、羧甲基纤维素、瓜尔豆胶、果胶和卡拉胶等亲水胶体具有多种工业应用，包括纺织和地毯印刷、造纸、食品、个人护理、家庭护理、制药和生物医药产品。它们被广泛用于改善制剂的流变性和质地、稳定微观结构和增强感官性能，并越来越多地被用作高价值和高功能应用的递送系统中的试剂，如制药、营养食品、食品、动物饲料、农用化学品、家居护理和化妆品行业的胶囊和控释。通常，它们必须与水混合才能发生溶胀/溶解。然而，颗粒或包裹体的表面在与水接触时会变得粘性，这通常会导致聚集，从而防止完全膨胀/溶解。目前提议的目的是开发能够确定最佳分散条件的通用数值模型。水与羟基磷灰石的相互作用极其复杂，外部凝胶层的快速形成会导致聚集，从而阻止水的内部毛细管流进入孔隙，因此溶胀/溶解必须依赖于慢得多的扩散过程。为了确定最佳的混合条件，该项目将从分子到工业规模对这些过程进行建模。这一所谓的多物理多尺度战略将涉及分子动力学、有限元分析、与计算流体动力学相结合的离散元模型和种群平衡模型。它将包括一个实验方案，以测量亲水胶体的物理和机械性能，并进行混合测量，以验证模型的有效性。

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.