From Graphic to Reality to Magnetic Resonance Imaging
Emma Thompson
PhD student in the group of Dr Melanie Britton
Phase separation is a phenomenon which can affect any material consisting of particles suspended in a fluid. It causes problems in formulation and processing of many everyday products such as consumer products and pharmaceuticals. This process must be understood in order to make fabrication processes more efficient and, in the case of pharmaceuticals, ensure the correct dosage.
Materials phase separate due to density differences between particles and fluid. These density differences become unpredictable when the product changes over time. For example, in cell or vesicle dispersions the particles can aggregate (far left of image) and become larger, changing their density and making the dispersion phase unstable. These dispersions can be used in consumer products, such as fabric conditioner and cosmetics, which have shelf lives and need to be phase stable for a certain amount of time. Phase separation on the shelf leads to unattractive and less efficient products (centre of image). However, during formulation it is not practical to wait the entire length of the shelf life to see if a new product is viable. This is why MRI (magnetic resonance imaging) is being used to image the phase separation in these dispersions to see if instability is predictable (far right of image).