Submitted by: Rukmava Chatterjee
Program: Mechanical Engineering
Division: Engineering, Mathematics, and Physical Sciences
Come winter and the environment is draped in a snowy blanket, immensely diverse yet infinitely monotonous. But there’s more to this icy monochromatic beauty, with the ubiquitous menace of ice engendering slippery roads. Rock salts are the common choice of chemical deicers, used to steer clear of icy sidewalks and roadways. These salts work by lowering the freezing point of water, precluding ice formation. And it is this working mechanism of salt which the current image (captured as a part of my ongoing doctoral research on anti-icing systems) intends to convey. To demonstrate this, I carried out an experiment with a single sodium chloride salt crystal subjecting it to an extremely humid and frigid atmosphere; conditions favorable for icing. The central salty drop remains unfrozen, untouched by virtue of an annular region of inhibited condensation which occurs due to a variation of water vapor concentration above the salty drop and neighboring population of super-cooled water droplets. And this is how salts prevent ice formation for extended periods of time.