14 Jun Cricket Kees, U of Houston Chemistry, Week 2

I have just completed my second week at the University of Houston! I have spent most of my time in the lab working on locating and sealing any leaks in the evaporator and getting more experience with the machine under professor Baldelli’s supervision. A leak in the evaporator machine (which I use to make metal films) appeared, so I started the week off by learning the long process that goes into installing a leak-proof “fitting” that connects to a vacuum to set a chamber pressure to an extremely low level (approx. 10^-7 torr). Since Baldelli had returned, he helped correct any mistakes and taught me some important facts that I missed my first time learning about the evaporator. Outside of my lab, I have gotten to hang out with friends, watch a little bit of the world cup on tv (some games are being played in Houston!), and have a blast with my friends.

The part that I replaced

On the evaporator, there are multiple gauges for different pressure readings, which are used in order to get a more accurate idea of the pressure in the chamber. This is necessary since the readings done by these gauges aren’t the most accurate, so for a more accurate understanding, it can help. I had a lot of trouble with this, since I was working in the under section of the evaporator, trying to fit different pieces in place. The main piece that was experiencing a leak was a right angle 1/8 inch-27 thread fitting that we couldn’t find a replica of, and ordering a new one took some time, so instead Baldelli had me help find a replacement. I searched for similar fittings online for purchase, and then looked for ones we could use in the lab. Once I finally found a good one, I reassembled the tube to the vacuum. Sadly, this first attempt didn’t lead to a very good pressure, which meant the leak hadn’t been fixed. So, I modified the fittings using the machinery around the lab, with the help of professor Baldelli, to create tighter links. After my trial and error with getting the fitting to properly seal, I was able to make some of my first films!

Using nitrogen gas to further lower the pressure!

For the practice round, Baldelli watched and made sure I followed the steps of cleaning the substrates properly, turning on the machines, and measuring the thickness of the metal. For the experiments Baldelli is running, he requires a thickness of 100 nm of different metals such as copper, silver, and other metals with a vapor pressure of less than 1000 degrees celsius. After the practice run, I was able to do my own copper film. Then, Baldelli had me work with a substrate instead of glass, which was the usual material we worked with. I used silicone, and washed the substrates before placing it in the chamber with the copper which I would use for the metal. Since this whole process took me a week, I was only able to just begin working with silicone, so all I did was turn the vacuum on, which lowers the pressure of the chamber. I am now letting it run over Sunday.

Me shopping for the piece!

My working days are Monday – Saturday, so with not a lot of free time, we spent Sunday going out to the Houston “post” and watching a movie! Wesaw backrooms, and I am a super big horror fan so this was great! Seeing the city of Houston was so much fun, and visiting the “post” (which is a food court/mall/museum area located in the city) was a blast. We got to watch a couple World cup games on the television, and got to eat some yummy food too.  Throughout the week, I got sickwhich was definitely a down side, so I highly recommend any future interns to bring medicine to their internship! Other than that, some eventful things had happened, but in general I have had a great week fitting in and getting used to the work and my schedule. Even though I struggled with the physical labor over this week in order to fix the machine, it taught me more about the process and effort it takes to design parts for an experiment. Hopefully, I will get to continue on my side projects during my free time in the lab, and get to see how my films can help with Baldelli’s work.