A microfocus time-resolved mapping study of levitated model respiratory droplets during water loss: diffusion and surface effects to underst

We will study mm-scale droplets of a model respiratory aerosols containing the lung surfactants DPPC and POPC , using microfocus SAXS in a controlled humidity acoustic levitation cell. Temporal and spatial changes in orientation and lattice parameter of the self-assembled surfactant phases throughout the droplet will give insights into water diffusion through and out of the droplet. These are large unknowns in understanding the behaviour of respiratory aerosols after exhalation, key to understanding persistence and spread of airborne pathogens, but the role of the surfactant components and their self-assembly has not been considered. The experimental and modelling methodology is similar to our previous published work on self-assembly of droplets of model lipids and fatty acids from cooking emissions, from a technique development and environmental perspective.