This last week I have been working hard in my mentor’s lab to learn the method of nantotube synthesis. The procedure is straight-forward enough, but like everything done in lab it takes much practice to achieve a good result. Since I am more familiar with biological lab procedures such as DNA polymer-chain-reaction (PCR), cell-culturing, and preparation of Western blots I am amazed at how much manual engineering is involved. For instance, the first step of nanotube synthesis involves cutting thin square-sheets a few micrometers in width from a larger circular sheet of SiO2. This is done with a diamond tip pen that must shear through the SiO2 at a perpendicular angle. Furthermore, all the measurements for where to cut are made with a metal ruler; it makes one feel as if they are a mechanic and a scientist at the same time.
Unlike the intricate handiwork involved in the first step, it is the solution that does the labor in the second, where small squares of SiO2 are put in a solution called “piranha” for a few minutes in order to wash away a thin protective layer which coats the surface. Some of you might wonder why they name this solution after a vicious, sharp-toothed fish that resides in the Amazon. If you guessed it’s because it must be handled with care, you’ve guessed right. Since it is composed of 1 part H2O2 and 3 parts H2SO4, the solution is very corrosive; however, great care is taken to make sure the only surface this solution comes in contact with are the SO2 square wafers. This is why administration of the "piranha" solution is done under a hood with acid-resistance gloves stretching to the forearms (so grandparents please you can relax now). After the thin protective layer has been removed, the square pieces of SiO2 are washed with ultra-pure H20 and dried with N2 before a FeO2 catalyst is deposited on them. After these preliminary steps, the silicon wafers are all set for the furnace, which is the key to the whole experiment, much like an oven is key to cooking a good roast after all the ingredients have been added. I will safe the details on what buttons are pushed and which parameters are set to facilitate nanotube synthesis in the furnace, but here's the jest: The furnace is heated to around 900oC and Carbon and Hydrogen are allowed to flow in the furnace at particular time-points to fuel nanotube formation from the catalyst. Theoretically, after 45 minutes or so you should have a linear array of nanotubes on the silicon wafers, but I am still working to meet this objective since all the ones I have done so far show as an entangled network on SEM (scanning electron microscope). By next week, hopefully I’ll get the eureka result I’ve been waiting for.
The person I've been working with to do nanotube synthesis in the lab is Zhang Guoming. He is very helpful and I believe his English vocabulary has improved significantly since the first time I met him. Everyday, he asks me for the English name of some instrument we have in lab. The other day he asked me for the English word that describes little pinchers that grab tiny objects; when I told him that I call them forceps, he was puzzled since he thought they were called tweezers. Then, I told him that they could be called that too and it made me even wonder why there was even a difference. The conclusion I came up with is that forceps is the name given to this instrument in lab, while tweezers is the cosmetic alternative that American consumers reserve for their home-body care use. Therefore, this last week has made me realize just how many words there are in the English language to describe the same thing.
Other members I have met in the lab are very welcoming as well. Last Sunday one of the other grad students in my lab named Zhonghuai invited myself and others from our study abroad group to take part in a soccer match, including Marko, Xu and Spencer. Though I felt like I still had some foot-skills leftover from my AYSO (Am. Youth Soccer Association) days when I was 12, I found out just how much these skills needed improvement. As a result I left most of the offense to Xu and Marko, while I supported our team on defense as the striker (or, in other words, the guy who tries to stop the ball and kick it back down-field). I hope this weekend to try my luck in our lab’s badminton tournament, a sport I used to be decent at as a high-schooler. I’ve been told that apparently Prof. Liu is the best player, so I’m interested to see if this hype turns out to be true or if the lab-members have been instructed to say this.
I continue to enjoy the Chinese food, but some of us (Kelly, Spencer, Justin and I) decided to take a break from the food offered at the University dining center for an All-American burger at “Lush”. On second though, only two of us par-took in eating a juicy, savory, delicious burger, since Kelly and Justin are vegetarians. However, Justin is what I like to call a bandwagon vegetarian since he is easily swayed when there isn’t another vegetarian at the table to encourage him to not eat meat. This was evident as he continued to ask me “How my food was”, which was really code for “If Kelly wasn’t here I’d so devour that burger too.” Anyway, it was a good break from the cafeteria to eat at “Lush”, which is located near the Wu-Dao-Kou subway station above a quaint bookstore. Nevertheless, I believe I’m at the point where I could eat Chinese for the rest of the trip and be content.
In addition to the badminton tournament this weekend, our lab also has a discussion tomorrow at 2pm, which will consist of students presentations of their work. I’ve already attended one of these discussions with Zhang Guoming serving as my Chinese translator, but even with this aid the discussion can be hard to follow at times; my saving grace is that the slides are in English. Honestly, though the feedback given by peers and Prof. Liu is very constructive. The other day, for example, Prof. Liu made a point of telling one student that he needs more than a few data points to verify that a linear relationship exists between film thickness and transparency. I hope in the coming weeks I might also get a chance to present some experimental ideas I’ve come up with. However, I may have to take the reverse approach by presenting my slides in Chinese, since I will need to speak English. (I guess that’s why it’s good to have a roommate like Xu, even if his Chinese reading ability may only be at a freshman level).