Monday, July 6, 2020
By:
Shorter blog post this time. It is hard to believe this has been my fifth week of interning at NASA! I have had a great time so far with all of my other interns, and my tests have been going well. I did some research into the coffee-stain effect, which is what I am trying to minimalize when I spray solvents onto a surface. It turns out that it is caused because liquid near the edge of the droplet evaporates faster and liquid near the center, causing a flow of solute to the edge. One solution I am testing is using liquid with less of a contact angle, so that all parts evaporate more evenly. I also used rhodamine, and bought a UV light bulb to see residue a bit better (see the picture at the end).
My next steps include renting a thermal imaging camera to see if airbrushing a sample plate on a hot plate will significantly cool it off. I will also be testing the rate at which a liquid evaporates vs. the coffee stain effect.
Alex Mikulich