We were a bit stuck last week in terms of finding a suitable current collector to use with our electrodes, so we reached out to Dr. Tom Davis, who we knew had extensive experience with electrodialysis systems and could most likely provide a few helpful tips. From our research, we knew that a titanium plate would serve as the best current collector, but faced the challenged of finding one that met our stack dimensions and could be delivered in a reasonable time frame. With Dr. Davis’s help, we stumbled upon an El Paso metal company that had a single titanium plate just big enough to be cut to fit our stack. Just needing a way to connect the power supply to the current collector, we went to several places looking for titanium screws to avoid unnecessary corrosion between the metals, but they’re apparently pretty uncommon. Fortunately, we found a company in Nevada that could deliver the screws by Wednesday of this week, so once those arrive all that’s left is to weld the screws to the plates and then we can start testing the system. Cheers to progress

This fifth week has been very eventful to say the least. I have continued to make samples in preparation for the desired characterization tests. A graduate student ran the characterization tests for me and sent the data files. I used excel to make the plots and interpret the data. I used ChemDraw, a drawing toolkit, to create a schematic for an overview of my research project.

The figure shows how we will transform our starting material into reduced graphene oxide functionalized with nanoparticles. I am currently on the last step where magnetite nanoparticles are mixed with rGO for functionalization. Once this is done, several characterization tests will be run to assess the successfulness of the experiments. In my Friday presentation, I summarized most of what I have been working on and also included characterization data for graphene oxide and the magnetite nanoparticles. I have IR data for both samples, indicating which functional groups are found in the sample. For the nanoparticles, I also have Brunauer-Emmett-Teller (BET) data, which gives the surface area per gram of material. Below, thermo gravimetric analysis (TGA) shows how the mass of the sample changes at various temperatures. We are interested in the potential application of magnetite nanoparticles in extremely hot environments and this data shows the temperatures at which the sample begins to decompose.

My parents drove to El Paso to visit for part of the weekend. It was really nice to catch up with them and tell them about all of my experiences here during the internship. We went shopping and ate at the Mesa Street Grill afterwards. The place was pretty nice and they prepared one of my favorite deserts, bananas foster, table side.

We also enjoyed a few beverages at the Hilton Garden Inn minibar. The bartender recommended that we try this cucumber drink that is apparently popular in the El Paso area. It comes with this spicy chile powder on the rim, called Tajín.

After my parents left Saturday morning, I had the chance to finally put my passport to use. I went to Juarez for the first time with some of my coworkers and had the chance to test out a couple Spanish phrases I learned. Although the people, places, and atmosphere were all very different, I thoroughly enjoyed the experience.

Does it ever end? Research seems to be never ending, even after you publish a paper. There always seems to be something you can test more, expand further, push to no end, but I guess that’s science. How will I put an end to my research here at Yale? Two weeks left and I’m still learning so much. Not only to do with my research but life in general. My month on the East Coast has been more than rewarding and I’d like to think that I’ve grown and matured in many ways. The past two weeks have been eventful and hectic (in the best way possible). Membrane modifications coincided with travels to New York. Hours of contact measurements preceded a trip to Boston. And now we’re working on testing a modified membrane in the RO system just before I make my way to New York for the last time before my time on the East comes to a end.

The week before last was mainly filled by contact angle measurements and calculations of the interfacial energies between the gypsum crystals, water, and surface. Last week I was introduced to ATRP or atom transfer radical polymerization, which is the versatile synthetic tool we will be utilizing to modify the commercial membranes. This process enables the preparation of new (co)polymers with precisely controlled molecular weights, relatively low disparities, composition, and diverse functionalities. We worked with Chanhee, who is working on creating an omniphobic surface that is permeable to only water vapor (so cool, right?). The first step was in preparation for polymer and consisted of applying a PDA coating to the membranes in order for the desired polymers to be attached later on. Then after 20 minutes of PDA, the membrane was coated with an initiator that allows the ATRP to take place. The initiator polymerizes the surface, on which the desired zwitterionic polymers actually attach to. We allowed ATRP to take place for an hour, while Chanhee left one of his membranes for two. It is important to know that modification of the membranes varies as the amount of time for each coating varies.

The point of attaching the zwitterionic polymers or modifying the membrane at all is to make the membranes more hydrophilic. This lab is really pioneering the use of ATRP for non-biofouling purposes, so a lot of uncertainty exists with testing the modified membranes, which we will begin today. Our hopes are that a more hydrophilic surface will cause more water molecules rather than gypsum crystals to gravitate towards the surface of the membrane and attach. Just like if you want to sit in a full classroom, you would have to displace someone from their seat, if water molecules cover the entire surface then there would be no room for gypsum crystals to position themselves.

I’m learning a lot and am realizing, not only how important chemistry is, but how often unpredictable obstacles can occur in research. Recently, in a meeting, Elimelech was explaining how unexpected events can lead to schedule changes and, as result, everything ends up taking a lot longer than initially planned. (The following Tuesday, the chiller used to control the RO system temperature wasn’t running properly so we had to postpone our experiment). All of these new chemical processes and life lessons were complimented by experiences of new lifestyles and city cultures. My first trip out of New Haven was to Boston where I met up with my roommates from Rice. Then I traveled to New York the following weekend to see my best friend from high school. I must say that I do prefer New York over Boston, but the city was rich in history, which was prevalent from its charming architecture and urban design.

Another aspect of Ph.D life that I was not familiar with is conferences. There is a conference at a university in New Hampshire that Humberto is attending at the end of this month, where he will be presenting his research along with other graduate students. It’s just another aspect of being a research student, and provides him with the opportunity to share his ideas with experts in his field and receive feedback on his project. This event, however, has added an extra time constraint to his current work because he wants to be more than prepared with data and analyses for questions and considerations from his colleagues. It must be stressful preparing for a conference, but it’s reassuring to have a community of scholars to support your efforts.

These five weeks have flown by and I’m excited to see how things come to an end with regards to my research. I hope I come away with conclusive results and a wealth of knowledge. Look out for more updates on how our modified membrane compares to the commercial grade. Below are some pictures I took throughout my adventures in the big cities (includes some artwork from the MoMA).

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Another week has passed and we still haven’t run any real tests on the CDI. All of the electrodes finally arrived, but we now face the challenge of connecting them to the power supply. We might have to purchase titanium plates but I’d like to find another conductive, non-corrosive material we don’t have to order and wait for. The creative juices are definitely flowing freely with this project, that’s for sure. Also, a new power supply should arrive soon that will allow us to automize the system, which will be an interesting challenge since I have no experience with labview. Hopefully, all goes well. Honestly, it is a bit frustrating not being able to run the system and I think we underestimated the amount of time acquiring all of the materials would take, but I’m remaining optimistic.

Sorry I am a little late with my weekly blog but this past week has been really busy especially with the holiday weekend. Last Wednesday I started two online classes that I enrolled in through ASU. I’m taking a basic calculus III class, as well as a Beatles class (the musicians). So far Calc III has taken up a good chunk of my free time and a bit of my weekend, however, because of this 3 day weekend I am actually ahead of the class so I’m making sure I don’t fall behind.

As far as my work and projects go the mechanical project fabrication portion is taking a bit longer than should be to get done. This is mainly because of getting our hands on some tools to actual getting the work done. None the less, one of our group member brought some tools from home so we should be finish up this week. Everything is coming a long nicely, even though we don’t have everything on the skid yet we have been comissioning everything as it came in. The solar panel took some time to understand but with a little time and a call to customer service we understand our electrical source really well.

My computational modeling work has also been really rewarding, so far I have been just computing different numbers to see the change in flux and temperature throughout the system. It is taking a good amount of my time, mainly because once I started testing some longer module lengths, the longer it is taking for the program to run. For example I am running a geometry length of 0.5 cm with the permeate temperature at 45 C and flowing in at 4 cm/s, it is going to take about 25-30 min to run the program. As to a smaller length like 0.02 with the same parameter which can take about 8-10 min. I have learned that once the program has runned a few times it take the time is shorter by a few minutes. The beauty of technology, what takes me 30 min to crunch a few number would probably take a few days to run actual number on a full scale system.

Till next time,

Hazel nut (Evelyn)

The first month of our time at Rice is over, and it does not seems like a month has pass. I have been working so hard in learning all the techniques and developing my project that time has just flyby. I have learned about the use of different instruments, different techniques when platting, ways to analyze DNA, and how to prepare agar. This week I started discussing with my mentor, the analyzes that my project was missing. Next week we will further discuss the topic, and start the writing of my report.

In the weekend, I had the chance to get to know my friends from the NEWT program better. Tensae, Evelyn and I, decided to take the metro and go to explore the city. I am glad to say that I will not only get an amazing learning experience out of this program, but also awesome friends.

 

Unfortunately, this week has been a little slower compared to the previous two weeks. The isolation of graphene oxide is challenging and this compound is not very cooperative. I went through several rounds of heating and drying, but graphene oxide retains moisture really well regardless of the solvent making it difficult to work with and manipulate. After heating and drying the sample overnight, GO was dry and stuck to the walls of the container. I had to spend quite a bit of time scraping the walls of the container with a spatula. The good news is that enough GO was produced for several uses and that I should not have to repeat the synthesis.

After this is accomplished, GO will be reduced using hydrazine and ammonia. This will remove oxygen-containing functional groups from the surface of GO. With a quick search on the web, I found that hydrazine is known for being a strong reducing agent and is also a common component of rocket fuel. Hydrazine is highly toxic and will react in the presence of metals, releasing heat up to 1,000 degrees Celsius.

It is crazy that the program is almost half over. Each day here in El Paso seems to go by faster than the day prior. I also paid for a membership to the recreation center so that I can workout a couple times a week. I have been hanging out with my coworkers and the other intern, Sophia, quite a bit in my free time. I had the opportunity to take a ride on scenic drive over the weekend (pictured below). Not having a car limits my exploration, but I am thankful that all of the essentials are within walking distance. Since I have been here, my use of the Uber app has reached unprecedented heights.

I know some other bloggers have mentioned it, but I definitely recommend taking in as many experiences as possible during the internship (both in and out of the lab). I have realized that this internship offers so much more than raw knowledge from another lab. This internship has given us all the opportunity to travel to a new place alone and essentially fend for ourselves. While it is vital to have minds that are well versed in science, I think it is equally important to be able to adapt to new environments. I encourage my fellow NEWT interns to step out of their comfort zone and embrace everything that this summer program has to offer.

We had some time to mess with the CDI setup this week, so we cut out a new rubber gasket to place between the two plates and sealed the stack up without the electrode. Then we connected the stack to the filter system with new tubing and ran water through it to see if we had any leaks while also measuring the differential pressure flowing through the stack and whether the system’s flow rate was accurate.

Also, we finally placed an order for the carbon electrodes. Seems like forever since we began looking for them and we still weren’t able to find a company willing to sell us a larger electrode. Thankfully, the small company that we bought the thinner electrodes from suggested a couple of other contacts that might be able to help us out, one contact being a professor at Case Western University that might already have electrodes that meet our specifications. So, we contacted him and he responded not even 3 hours later, saying that he had 8 electrodes that met our specifications and could send them that same day, no charge. What luck, eh? Anyway, our week ended on a high note and all the electrodes should be here by Tuesday 🙂

P.S. Here’s another beautiful pic of El Paso:

 

 

Midway through last week featured the beginning of the next stage of cleaning the GO. The dialysis. Dialysis has begun for a few of the Hoffman samples, and by the middle of this week, the rest of the Hoffman samples will go through the process. Near the end of the week, dialysis for the Staudenmaier will begin. There is a lot of material for Staudenmaier, so I expect it to take a little more than a week, unless I obtain additional clamps to do more than one dialysis at a time. Also, after dialysis will come lyophilization (freeze drying).

Last week, I was instructed on how to measure contact angles, so once we coat our membranes with GO we can measure how hydrophilic or hydrophobic the membrane is.

During the course of a lot of working and reading, I found time to have a little fun. I played piano in the cafeteria. When I play piano I don’t mind people being around, it is only when they walk up to me and stand over my shoulder that I start to get nervous. I also went to the pool and hung out with some fellow REU students. In addition, I was fortunate to hang out with my mentors and fellow REU students again for a brown bag lunch. Finally, I played basketball. My knees and ankles feel like they went through more than a game of 21 though.

Thank you for reading, more updates coming so 🙂

 

This internship has moved way to fast, it is hard to believe that we only have about 4 more week left until we leave. Its even harder to believe that we have to finish our research in that time as well. So far both of my projects have come a long way since I have been here and they just keep building. So far as part of my Mechanical Project we are almost done with the fabrication of the skid. I think we could have been done since last week but parts have been getting here very slowly. As of today everything is sitting in our lab and is waiting to be screwed, zip-tied, and drilled on to the framework of our product. The only thing that I am dreading at this point is figuring out the configuration of the solar module and connecting everything correctly. I have been reading the manual as closely as I can and so far I feel like once I start connecting the solar panel I feel like I will  know what to do. We should be done with the fabrication by today or tomorrow, and the rest of the week will involve us commissioning the whole system. Commissioning, will help us see if all the part are working so when we start testing next week nothing goes wrong. 

As for my Computational project, my program is processing data. I have only recorded one set of data points, and I hope to run more this week. So far the changeable parameter in this project are the the flow of water coming in from the permeate and the feed side of the MD module, the feed temperature, and the length of the module. The purpose of the computational model is to test certain geometries of MD modules, and which ever geometry that works the best will be built. In doing this it allows to build one or two good real models than building several through trial and error.

Like each of my projects I have been trying to take the most out of this trip as possible. This weekend a group of us went to NASA-Johnson Space Center, as well as the Holocaust Museum, and the Museum of Fine Arts. And the weekend before that we went to the Houston Ballet where we saw Giselle, and went to the Galleria mall. Every stop we have made in Houston has been very memorable and fun, these next couple of week we want to go to the beach as well as the Natural Science Museum.  Four weeks left and i’m planning every second of it, can’t wait till next week to tell you about my progress.

Chao,

Evelyn