Dear Diary
If you recall last week, I wrote about how OCT (Optical Coherence Tomography microscope) could possibly steal my heart from FoMD (Fouling of Membrane Distillation). Well…it was almost so. I spent even more time with OCT and everything was going swimmingly when I had the opportunity to use a new scientific toy. And let me tell you, Diary, it had me all in a flutter.
The new toy is SEM, or the scanning electron microscope, and the images it took for me were absolutely stunning. SEM and I spent two hours together getting to know one another and it was wonderful. SEM likes spectrometry, photography, Fifty Shades of Gray, and chillin’ in nice cool rooms. I guess I should explain those interests a little bit more to you, Diary. SEM can do spectrometry of samples which is scanning them to determine what elements are present and roughly the quantity; this is useful to help determine the type of minerals that are precipitating out of the salty water in FoMD (see the first time I wrote to you, Diary, for more details about FoMD). SEM can take images that are magnified over 10,000x meaning one micrometer (10-6 meters) appears to be one-centimeter in length. To put it another way, imagine taking a picture of your foot and enlarging it so that your foot is nearly two miles long so now you can see each individual skin cell on your foot since they will be about the length of your arm…Well not your foot and arm, Diary, because you’re a diary; you don’t have feet or arms. The photographs are amazing but they are all in gray-scale; see what I did there in listing SEM’s interests (don’t worry, I’ll pat myself on the back). The room that SEM lives in is nice and cool, around 70oF which feels awesome after walking a quarter mile in the 110oF+ heat we have.
Here’s some samples of images that SEM and I took together. The magnification is shown in the bottom left and the white bar in the bottom center shows you the scale of the image. SEM and I didn’t take any 10,000x magnified images; only up to 5,000x magnification. The first one, 300x magnification, shows what appears to be two different crystals forming. There are long and thin crystals near the top of the image and short and thick crystals near the center.
The next image, about 1000x magnification shows that a short and thick crystal is actually thin in the 3rd direction, noticeable in the bottom of the image. This means that the short crystals could actually be the same crystals as the long ones but oriented differently and shorter.
The 5000x magnified image shows that there are even smaller crystals that were still forming when the FoMD experiment was stopped.
The spectrometry shows that there was carbon, oxygen, sulfur, and calcium present which is what I was expecting. It also showed chlorine present and no magnesium present which I was not expecting. This means that my previous models might be wrong but I’m not going to make such a claim based off of only one sample.
SEM likes to take things slow, a little too slow for me. After two hours together we only analyzed two samples. I was hoping to get to four samples but SEM said we were out of time. As I was leaving, another person was coming in to use SEM. I was hurt so I told SEM that it had to choose either this other “engineer” or me. Luckily for me, SEM said it would see me again on Monday. I hate to brag, Diary, but no scientific equipment can resist my charm.
I’ll write to you again next week, Diary. – Chay