Recently, I have been assigned more chemical reactions and NMR analyses to perform. I have performed a polymerization but am struggling to precipitate the solution. I have also performed the boronic ester synthesis using two methods—ball-milling and co-grounding. Ball-milling involves placing the substance in a metal canister containing different sized metal balls that are vigorously shaken in a mechanical machine. Co-grounding means placing the substance in a mortar and grinding it using a pestle. All resulting products were then placed in the NMR to analyze the molecular structure and purity of the product. The boronic ester synthesis involving co-grounding involved using the Dean Stark distilling trap, as shown in the first picture, which helps remove water and solvent from the reaction until the liquid level is at the level of the sidearm. Once the liquid level reaches the level of the sidearm, the solvent flows back into the reaction flask to ensure the flask does not remain dry. A reflux condenser is attached on the top of the Dean Stark distilling trap to ensure vapors do not leave. The top of the condenser is attached to nitrogen to enable a moisture free environment. Removing water helps push the reaction towards creating products, as indicated by Le Chatelier’s principle. This principle generally means that “any change in status quo prompts an opposing reaction in the responding system.”
I am learning to gain confidence in doing things alone and appreciate my efforts in this internship, although I am still a safety hazard. For example, I was tasked to manipulate the rotary evaporator alone, and was relieved to see that I had notes about how to operate the machine that I could refer to. I definitely took a long time to do a simple task, but I erred on the side of safety. I had trouble using the Schlenk line, as when I tried to remove a flask from the Dean Stark apparatus, I turned off the vacuum, leaving the pipe to momentarily contain a vacuum, thus air at atmospheric pressure invaded the hose connected to the Schlenk line, lifting my sample into the hose. My workplace is very encouraging and honest (will not condone inauthenticity), thus I felt inclined to be honest about my mistake. After this fiasco, Max, my polymer synthesis buddy, helped guide me through the physics of the line, and reminded me to not follow rules but think through about the situation at hand. Kira, while she was teaching me about ionic conductivity and how charged porous polymers enable the charged carriers to increase their transference number, also reminded me to think about the physics of the problem instead of making generalizations. Pete, my supervisor, also pointed out that we should avoid making generalizations when my team discussed about cultures during lunch.
Jon taught me about crosslinking, where the polymer of intrinsic microporosity is linked using an azide which is a compound with three nitrogen atoms as a group. These compounds have a wavelength of light applied on it for crosslinking to occur.
On Monday, 6/26/17, I checked on my polymer reaction that results in a monomer similar to monomers in the desired polymer. The toluene had not reached the Dean Stark trap, thus toluene was not reentering the reaction flask to help the reaction. I increased the heating temperature to 135C and waited for it to heat for 4 hours. In the meantime, I read a journal about “Boronic acids as building blocks for molecular nanostructures and polymeric materials”. Additionally, I attended a talk about “Garnet-based solid-state Li-metal batteries: Interface engineering to improve the wetting between Li metal anode and Garnet solid-state electrolyte” and “wood derived 3D conductive framework toward highly stable Li metal anodes and Na metal anodes”. It was interesting to see scientists incorporate carbonized wood into lithium metal anodes and sodium metal anodes.
On Tuesday, 6/27/17, I listened to a talk about “Tracing Structural Dynamics in Metastable Materials Using Ultrafast Electron Diffraction”. The talk inspired respect for quantum dynamics, but I was quickly lost with understanding the content. I spent most of the day creating a presentation of research updates and analyzing an NMR spectrum. I learned the difference between a pair of doublets and a doublet of doublets.
On Wednesday, 6/28/17, I helped Kira assemble and prepare the ingredients for the battery and read a paper about “Soluble Porous Coordination Polymers by Mechanochemistry: From Metal-Containing Films/Membranes to Active Catalysts for Aerobic Oxidation”. This paper is about the creation of soluble porous coordination polymers.
Outside of the lab, we celebrated my arrival at Tasty Pot one day, and it was fun to see my coworkers try Taiwanese cuisine, although they may have struggled with the spiciness of the dish. They really liked the spicy, fermented tofu!
A funny thing that happened was that a bowl of red vines was placed on the dining table. This is because one of our coworkers couldn’t stop digging his hands into the red vine jar and basically ate all of them, save for around five. He’s trying to quit the habit! Another funny incident is that since the supervisor was gone, my coworkers and I designated a yoga mat topped with a chef hat and an origami crane and a pair of sunglasses to be him.
I had an epiphany recently. In my workplace, I have realized that it is important to have a goal when one is doing something. Working hard is meaningless unless it has a purpose. I guess this comes late at a time when I am a senior and I have chosen a major that doesn’t particularly resonate, but at least I understand the value of purpose to guide hard work.
The final picture is my laboratory note-taking setup that I am very proud of having. I use a tablet to take observations on experiments. The backdrop is a view of greenery and sunlight.