College Life as an Environmental Engineer at UCONN

                Hello everyone, this is Dea! I currently go to UCONN as an environmental engineering major. This is a post on what is going on with me in college, hopefully it'll also give you all some piece of mind by giving some tips that may be able to help you on your college journey.  

                One of the first things that you'll do when you are accepted into a college is to pick your classes. Remember that if you are picking classes early enough, you design your schedule how you want it. One nice idea is to make a schedule for yourself where you won't have classes all of Friday or Monday, with no early morning classes. When I picked my classes, I just enrolled into the ones that were required and was lucky enough to have all of the first half of Monday free, only one class on Friday, and only one 8am class.  

                 Coming to UCONN is a great opportunity for someone who plans on becoming an environmental engineer as it's campus makes use of a lot of environmentally friendly technology, available for you to look into and see for yourself. Because UCONN has plans to continue on improving its sustainability, there are many opportunities to see environmental engineering put into practice right on campus.

                As an engineering major in UCONN, I am required to take a class that introduces you to engineering, ENGR1000. This is a class that is meant to introduce you to all kinds of engineering, but if you are already familiar, you can use it to acquaint yourself with what you are interested in. Near the end of the semester, you are able to attend tours or talks of your choosing that center around various  engineering majors. I was able to get a tour of UCONN's water treatment facility, which allowed for me to get a personal look at what environmental engineers with a focus on water treatment do for a living. This kind of thing is great, as it allows for you to see whether or not you will actually get to like what you claim to want to do as a job.

                 The college life may seem like one that takes a while to settle into, and as a result of that you may not want to involve yourself in extracurricular activities. However, I feel that it is better to dive right in, as the earlier you get involved with something the stronger your connections are with the organization in the long run. Getting involved also adds a nice extracurricular to put on your resume which you will be using to get jobs and internships. As for me, I went to info sessions for around nine extracurriculars, and attempted to stick with seven out of those nine. This sounds like a scheduling nightmare, putting several activities on top of classes, but it helped me find which activities I was willing to stick with. I ended up centering my focus on two organizations: the Environmental Committee in the UCONN Honors Council, and UconnPIRG. The deciding factor being that these were the organizations that could get plans in action on campus, and would allow for me to explore my interests in the environment outside of engineering.

                Now, as for a life outside of classes, if you are ever worried about not being able to find that group of people you fit in with, you don't need to worry. Along with the campus clubs you can join, there are many events you can attend. Go out to the events, and join the clubs that interest you, and you may be able to find the company you want to keep. That's it from me! Hopefully, some of this was helpful, and I wish you all peace of mind in your first steps on your college journey.   

~Dea Acorda

Summer Lab Internship: Image processing of iron sucrose nanoparticles with ImageJ

July 3

I am excited to begin working with images of Iron Sucrose nanoparticles. I know that it is used to treat anemia/iron deficiency, but after reading and doing literary research, I know a lot more about it’s uses and the uses of nanoparticles in general. I am looking forward to learning more and working first hand with the images of nanoparticles. I also look forward to learning about the program ImageJ, I had not heard of it before my time here, but after reading about it I have noticed that it is extremely useful for research purposes.

July 10

Iron Sucrose is an iron oxyhydroxide core surrounded by a sucrose shell used in the treatment of iron deficiency and anemia. Currently, there is one brand dominating the market. The goal is to compare the brand-name iron sucrose to a generic version and look for similarities. We also want to make sure that the generic brand is reproducible by comparing them in batches. This is done by processing images taken with a Transmission Electron Microscope (TEM) in ImageJ, a free and open-source image processing software. We use the particle analysis feature to obtain, accurate and consistent particle sizes, areas, axis, etc.

July 17

We used the following procedure to process our images:

Procedure for Processing Iron Sucrose Nanoparticle Images using ImageJ

1. Starting with the raw grayscale image, apply a pre-processing filter of “Mean” at the intensity of 1.
2. Apply a thresholding algorithm. We used one called “Triangle”.
3. Using the particle analysis feature, select the options to view outlines and results.
4. Save all of the images from steps 1 - 4.
5. Rename and save the results. (They will save as an excel file.)
6. In excel, record the average and standard deviation for the rectangular area, elliptical area, and minor/major axis.

July 24

The most challenging/frustrating part so far has been working with excel. I have never used excel prior to this internship, and in order to complete my tasks I had to learn how to navigate the system. However, I have learned that it is a very handy and useful tool that I will most likely have to use often in the future so I am glad that I have learned to use it.

July 31

So far, I have learned quite a lot about the concept of nanoparticles through primarily literary research. I learned about their uses, functions, and that they hold great importance in the future of medicine. I have also learned about the importance of using computers to analyze images of nanoparticles rather than doing manual measurements. Using computer software/programs instead of manual measurement usually yields better, more accurate, and consistent results.

August 7

The purpose of my project was to determine the best image processing procedure to create images that can be used to determine the size and general shape of each particle. That information could then be used to compare iron sucrose from different sources. Hopefully, my information will assist in proving that one source of iron sucrose is the same as another. This will potentially provide more options of iron sucrose for people. The procedure I have developed could also be used in the future on similar images.

August 14

I did not attend the MAYA conference.

August 21

I enjoyed my time in the lab working with graduate students and professors on a project that, to me, seemed important. I am a lot more interested in the scientific research process now than I was before. It may even be something I want to do in the future. This experience was very valuable for me and my future in the science field. On top of getting familiar with a lab setting, I was able to articulate scientific information in the form of a presentation to people with a lot more knowledge than me. I believe it is a good thing to not always be the smartest person in the room, working with people that had a significantly larger amount of knowledge and experience allowed me to learn something new every day. I am glad this program was a part of my summer and I enjoyed all the time I spent with the funny, friendly, and knowledgeable people in the lab.

Conclusions & Future Implications: Osuji Lab

As my four weeks came dwindling down, my mentor and I were able to conclude our studies and determine what states provided the most optimal results of ZnO nanorod growth. Through the variation of acetone concentration, revolutions per minutes of spin coating, and the growth temperature, we somewhat optimized conditions for unseeded brass substrates. The conditions necessary for the optimal growth on brass would be a 15% acetone concentration and an RPM of 2000 revolutions. We ultimately decided, however, that unseeded substrates do not provide adequate control of array morphology as was shown by the uncorrelated molecular weight nanorod diameter data. During the last week, we seeded brass substrates with the hydrolyzed zinc solution expecting that the layer would fill the scratches on the brass substrates. This method worked, and we achieved more uniform growth. Although this process does not eliminate the time-consuming seeding step, it does provide an alternative set of substrates that are cheaper than silicon.

Two future implications I’ve found are necessary for further optimization of our studies are:

1. A Decrease in Substrate Roughness 
2. ZnO Nanotube Array Formation Through Ethanol Reconstruction

A decrease in substrate roughness (including the absence of micro-scratches) will produce a better quality of arrays. Creating a forest of ZnO nanotubes would be an important expansion for the development in photovoltaic devices. Nanotubes exhibit nearly twice as much surface area as opposed to rod-like structures that are within similar dimensions.

Results: Osuji Lab

We tested the following variables for array optimization: Acetone Concentration in Growth Solution (%), Spin-Coat RPM (1750-2500), Growth Temperature (60-80), & Molecular Weight of Ps-b-P4VP block copolymer. My mentor and I had initial expectations before conducting each variable. We expected that an increase in acetone concentration would give us a larger areal density of rods. This is because the acetone swells the PS coronas, which allows more reactants to come into contact with the cores. We also understood that the micelle cores were made of P4VP polymer chains. The size of the P4VP cores is directly related to the nanorod diameter, meaning that as the molecular weight of the P4VP increases, the diameter will as well.

We attained the following results.

From our investigation, we were able to determine that 15% acetone concentration provided the best uniform growth of the four shown.

We also determined that 2000 RPM was a soundly speed at which the nanorods could be most uniform.

As you can see, there is no adequate growth pattern that is dependent on the molecular weight of the polymer.

As you increase the temperature, the aerial density increases and the rod diameter decreases.

Things Learned & Motivation: Osuji Lab

As with the completion of many tests and trial runs come results. These results helped distinguish which state certain variables should have been set at for optimal results. But, what are these results for? Why should we have an optimal array of nanorod arrays on brass nonetheless?

Inside: Photovoltaic Cell

Over the course of my first two weeks at my internship, I slowly began to understand the worth of our results. By finding stable variants, we could take these optimized arrays and apply them to important devices. One specific device I learned about was “Hybrid Nanocomposite Photovoltaics”. Photovoltaics are devices used to convert sunlight directly into electricity. We want to make these devices more efficient with our research. Photovoltaic efficiency is directly related to the amount of interface contact between the polymer and the semiconductor. When you excite the polymer layer, the first particles from the layer become dipole-induced and expand to about ten nanometers. This length is known as an exciton diffusion length. The semiconductor collects these excitons. By nano-forming these electrodes we can increase the surface area of interface contact. We want to optimize the surface area, keeping in mind that the space between the nanorods cannot be too small. Otherwise, the polymer will not be able to fit in between the rods. For these reasons, I realized that it is important to systematically control the diameter and spacing between the ZnO nanorods for this specific application.

Challenges & Frustrations: Osuji Lab

When you pose a research question and conduct an experiment, you always want to find some sort of result that is in favor of your hypothesis. You’re not always going to find the results you want when you conduct your experiments due to a variety of reasons, however. Human error, substrate wear-and-tear, and chemical inconsistencies are just a few reasons.

The internship I experienced was founded on top of a single research topic, “Optimal Growth of ZnO Nanorods on Brass”. We were given a single procedure that was tailored for silicon substrates, a couple research papers, and the liberty of testing any variable we deemed fit for optimal array growth. With this liberty, however, came good and bad consequences. Valeria and I were able to learn from these consequences—nonetheless being disappointed by bad results. Changing the acetone percentage in the growth solution bore great results! We were able to determine that 15% acetone concentration was the best level for nanorod growth.

Changing the molecular weight of the PS-b-P4VP block copolymer didn’t produce the quality results we assumed would occur. Theoretically, the micelle cores are comprised on P4VP polymer chains. This means that the size of the P4VP cores is directly related to the nanorod diameter. This relation would mean that as the molecular weight of the P4VP increases, the diameter would increase as well. When we characterized our nanorods for each molecular weight state (235K/23, 41K/24K, 15K/7K), we saw no adequate growth pattern that was dependent on the molecular weight of the polymer. Another important frustration was the difference in uniformity between brass and silicon substrates. No matter how optimized we could make unseeded ZnO nanorod arrays on brass look, the arrays were never going to be as uniform as the silicon substrates.

Procedures: Osuji Lab

During the course of my four weeks, we tested the following variables for array optimization: Acetone Concentration in Growth Solution (%), Spin-Coat Rotations Per Minute (1750-2500 RPM), Growth Temperature (60-80 Degrees Celsius), & Molecular Weight of Ps-b-P4VP block copolymer.

© Candice Pelligra, Osuji Lab

In order to prepare for the experimental process, brass substrates were sonicated in a water-soap, ethanol, and acetone solution-each state for 15 minutes. Afterwards, the substrates were UV irradiated for further elimination of organic contaminants.

About 4 mL of micelle solution are coated above the brass substrate by spin coater revolving from ranges 1750 RPM to 2500 RPM. By adjusting the solution concentration and spin speed, we achieve a block copolymer monolayer. The machine used to spin-coat our substrates is called the “WS-650-23 Spin Coater”.

The spin-casted substrate was then placed in a growth solution containing hexamethylenetetramine (HMTA) and zinc acetate dihydrate dissolved in deionized water and acetone. The vial was sealed and then placed in a water bath that was variably heated at 60, 70, 75, and 80 degrees Celsius between 15, 20, and 30-minute increments. The final step before rod characterization was a water and ethanol cleansing, each done for 45 seconds. In order to later characterize our nanorod at high resolutions, we took our substrate samples to the Hitachi SU-70 SEM machine.