Insights on drying and precipitation dynamics of respiratory droplets in the perspective of Covid-19

摘要: We isolate a nano-colloidal droplet of surrogate mucosalivary fluid to gain fundamental insights into the infectivity air borne nuclei during Covid-19 pandemic. Evaporation experiments are performed with salt-water solutions seeded viral load inactive nanoparticles in an acoustic levitator. seek emulate drying, flow and precipitation dynamics such droplets. Observations validated by similar actual samples from healthy subject. A unique feature emerges regards final crystallite dimension; it is always 20-30% initial diameter for different sizes ambient conditions. The preserved precipitates levitated droplets show that 15% total virion population remain dispersed on outer surface air-desiccated nuclei. This fraction increases ~90% if respiratory (of larger size) settle then evaporate sessile mode.