Grant: Research Tools and Instruments - Category 1 (<$150,000)

This application is to fund the modification of an existing pulsed nuclear magnetic resonance equipment (pNMR) to be able to perform Rheo-NMR experiments on crystallizing lipid systems. We need this to model the effects of shear flow on crystallization of controlled multicomponent lipid systems. The main parameter in the study of kinetics of crystallization is the increase in solid fraction (known as solid fat content, SFC) as a function of time and temperature. The rheological characteristics of the processed material change as the crystallization progresses under flow.  The only direct non-destructive method to obtain SFC in these materials is pNMR, whereas the rheological characteristics require using a rheometer capable of measuring the stress applied to the sample as it is sheared. The changes happen continuously and relatively fast, therefore manual data acquisition is not reliable. The combined measurements are needed because using separate instruments would result in different temperature conditions and interfacial conditions, thus precluding real combination of the data generated. The combined information will allow us to test hypotheses formulated for these systems regarding effects of shear such as acceleration of nucleation and growth, polymorphic transformations, variation of polymorphism paths, and formation of anisotropic structures. Our fundamental scientific insights and models will improve the design of processes and equipment, currently done rather empirically. Fundamental studies will be carried by preparing controlled systems made up of a few single components that can still mimic natural systems. The impact of the multicomponent nature of these systems under shear will therefore be better understood. Applied projects will include common natural materials which contain thousands of components. This unique instrument will allow graduate students to be trained in several essential disciplines such as physical chemistry, rheology, transport phenomena, and soft materials science.