Parameters for predicting the composition of nanocrystalline triglycerides under different processing conditions

这项研究计划源于工业的必要性，通过热机械加工，在对配方施加限制(营养、健康、可获得性、价格)的情况下，定制脂类材料的物理功能。对于这些中等大小分子的材料科学，必须发展有价值的基础和一般知识，以显著提高我们控制其结晶的能力。 因此，这项研究计划的长期目标是开发预测模型，以确定在加工过程中施加的场下脂质多组分材料的自组装。 所需的概念模型和数学模型包括晶体成核和生长(成分和速率)以及动量、热量和质量传递机制。外加磁场主要包括温度分布和剪切/伸展流动，在这些流动下，这些材料自发形成纳米片。 性能和性能测量工具的开发是研究计划的另一个重要部分。通过将模型的预测与受控过程的测量结果进行比较，模型的优化周期将继续下去。这可能看起来很明显，但这些模型的大多数重要参数都无法直接测量。要确定它们，需要收集大量数据，并且模型参数需要与数据相适应。实施并不是微不足道的，这一点在本提案中将变得明显。 这一建议的具体目标旨在获得最近提出的线性动力学分离(LKS)结晶模型的关键参数的值。在这个过程中，模型本身将受到测试。我们进行的初步工作既显示了这一方法的前景，也表明了预期中的许多困难。参数为过剩能或固溶体和吸附动力学比。它们依赖于纳米晶体的多晶型，但被认为与结晶条件无关。

This research program arises from industry's necessity to tailor, by thermo-mechanical processing, the physical functionality of lipid materials, given restrictions (nutrition, health, availability, price) imposed on the formulation. A valuable fundamental and general knowledge on the materials science of these medium sized molecules must be developed to contribute significantly to our ability to control their crystallization. The long term objective of this research program is thus the development of predictive models that determine the self-assembly of lipid multicomponent materials under the fields imposed during processing. The conceptual and mathematical models needed include crystalline nucleation and growth (composition and rate) along with momentum, heat and mass transfer mechanisms. The imposed fields include chiefly temperature profiles and shear/extensional flow under which these materials spontaneously form nanoplatelets. The development of measuring tools for the properties and performance is another essential part of the research program. The cycle of optimization of the models will be continued by comparing its predictions with the measured outcomes of controlled process. This may seem obvious, but most of the important parameters for these models cannot be directly measured. To determine them a large collection of data is necessary, and the model parameters need to be fit to correspond to the data. The implementation is not trivial, as will become apparent in this proposal. The specific objectives for this proposal aim at obtaining values for key parameters of the recently proposed linear kinetic segregation (LKS) crystallization model. In the process, the model itself will be tested. Preliminary work conducted by us has showed both the promising value of this approach, as well as many of the difficulties that are expected. The parameters are the excess energies or the solid solution and the kinetic ratio of adsorption. They depend on the polymorphic form of the nanocrystals, but are thought to be independent of the crystallization conditions.