This interview is with Dr. Somentha Mitra, a Distinguished Professor in the Chemistry and Environmental Science departments at NJIT. His research focuses primarily on the absorbing property of carbon nanotubes and other real-world applications.
During this interview. Dr. Mitra was happy to explain his field of research, what he has worked on in the past and looks forward to in the future, and what it means to be a researcher. We are excited to share his expertise and hope you enjoy!
Q: Just in simpler terms for our viewers, can you give an overview of your research with carbon nanotubes and what that importance is for real-world applications in society?
A: Carbon nanotubes are made of carbon, as the name suggests. If you take a sheet of interconnected carbon called graphene, and if you roll it up, it becomes a nanotube. The dimensions of the hairlike nanotubes range from a few (typically 0.5 to 4) nanometers in diameter to a few microns in length. It’s a very interesting material because it can be 100 times stronger than steel, conducts electricity better than copper and has very high thermal conductivity. You can also make transistors out of them and different kinds of composites such as epoxy. It has a huge number of important properties for many different applications.
Besides all this, we were interested in looking at absorbing materials called absorbents. And that has been our angle for using carbon nanotubes in many different applications. Carbon nanotubes do not have pores, so they absorb chemicals on the surface and release them very easily. This process is called rapid mass transfer.
Q: So considering this angle that you’ve taken with your research, what is it that you want to achieve? What is your end goal?
A: Another thing that we came up with is how to put different chemical entities on this tube. It’s called functionalization. By themselves, nanotubes do not dissolve in water, but we can put functional groups on the surface which attract water. Then we can take it and put it in a drug crystal. For example, if you take blood thinners like Eliquis or antibiotics like Sulfamethoxazole or, which is a very common blood thinner. So Sulfamethoxazole does not dissolve very well in water, but we can make a crystal of Sulfamethoxazole with some nanotubes sticking out: functional groups on the nanotube surface trap water. Now the water will come into the crystal and break it so that the drug dissolves quickly. The effectiveness of the drug goes up dramatically. That’s our application in drug delivery.
We can apply a similar concept, for example, in batteries, the nanotubes conduct electrons but don’t conduct ions. If you put some functional groups that will conduct ions, now they will conduct ions in a battery. We not only have electrical conductivity but also ionic conductivity. You can mix it with polymers and make electrodes for batteries, which is what we’ve been working on. Now all of a sudden, the battery electrodes are more effective than they would be without the nanotubes.
The other big application that we are working on now is that you can take nanotubes and put them in membranes for water desalination. We bring hot salt water to one side of the membrane and the water vapor absorbs on the nanotube. Then it moves to the other side while rejecting the salt water, resulting in pure water on the other side. We are also using this technique, for recovering biofuels, for recycling solvents, and many other applications, including taking viruses out of water. We’ve worked on all kinds of applications in the area of water purification. This currently is our major thrust.
Q: What innovations led to the current stage of your research?
A: It’s very difficult to put a functional group on the surface. One of our major breakthroughs was when we figured out that the nanotubes picked up microwaves. We can take this tube, put it in an acid, for example, and do a microwave reaction. In three minutes, we put functional groups on the surface. That allows us to change the chemical functionality of the tube for a huge variety of applications
This helped us develop flexible batteries. So you take a sheet of plastic and you put a coating of things on it to do the electrochemistry. We added carbon nanotubes to the coating because they have very high electrical conductivity. They interact with ions and things like that. That’s the battery application. Functionalization is also used in our work for desalination and drug delivery.
Functionalization can open many doors. For example, the same technology is used for making sensors. What you have is you have two electrodes and let’s say you want to measure something. Let’s say you want to measure blood sugar, for example. You take the electrode and you put a molecule on the nanotube that selectively responds to the blood sugar. So changing the functional group on the nanotubes can allow us to make glucose monitors.
Now, let’s delve into what it means to be a researcher. According to Dr. Mitra, this takes a few key qualities, and extends beyond the lab.
A: Being a researcher is not easy. You have to run your lab. This is at a human level. For that, you have to get funds. You have to recruit students. Students have to do PhD, so they need to publish papers. You have to wear many hats. There’s challenges at each level. But what helped in my case is that I had a bachelor’s and master’s degree in engineering and a PhD in Chemistry. So I understood engineering and chemistry. That helped me get a broad vision of things.
For research you must have a vision and then you have to know how to make it work.. At some level, you look at the sky for a vision, but then you work at ground level to make sure it works. For example, you try to make a battery. A battery has many criteria. For example, the battery has to generate a certain voltage. It has to have a certain life. It should not discharge by itself. So all these things, right? You can come up with a very fancy idea, but the device has to meet all these criterias. So you have to have a vision and at the same time, you have to be very pragmatic to make it work. You can’t be just a dreamer or just a worker – you need both.
But you also should be able to see an experiment, how it will work. Some of it is in the literature, and some of it you have to figure out in your head. You must have the ability to plan out experiments to the smallest details, and be able to adapt when things are not going as well. Just like sports are a skill, research is a skill. 80% of it is done in your head, the other 20% you do in the lab.
But Dr. Mitra acknowledges that beyond the lab, there are difficulties that may exceed the actual research. We delved into a conversation on commercialization, and how researchers trying to disseminate their work through products have a difficult time because of lack of capital and exposure of the product. But Dr. Mitra is still making it work with his own start-up.
In fact, Dr. Mitra informed us about the commercial success that carbon nanotube innovation already has.
A: It’s being used in many places and they don’t tell you that they have used carbon nanotubes. A lot of applications, like for example, paints, coatings, polymers, and battery storage use nanotubes, but they don’t necessarily tell you that there are nanotubes in the product.
But with every innovation, there can be negatives.
A: You take a product like a plastic water bottle. Then you throw the plastic and over the years the plastic degrades and forms microplastics. Now, based on a recent study, I think 77% of the population have microplastic in their blood. So carbon nanotubes have the same shortcomings, I would say. There’s a lot of industrial-type applications. Nanotubes will eventually end up in your water. If you burn the plastic with nanotubes, it’ll end up in the air.
One of our big accomplishments was making water-soluble nanotubes. That nanotube is water soluble and it could stay soluble in water. So now it can get into rivers and lakes. It’ll get into fish and enter the food chain. Our lab created a new potential water pollutant.
Dr. Mitra is working hard to find solutions to this. But as a researcher, he also believes he has a duty to foster the next generation in his field.
My lab mainly employs PhD students. Typically, when they come in they have solid education, but they have very few skills. They learn laboratory skills, how to make membranes, how to functionalize a nanotube. Then they learned characterization techniques like electron microscopy. Every time we do something with nanotubes, we characterize them with a variety of instruments: different electron microscopes, different spectroscopic techniques, and so on and so forth. Students learn all that. Then they learn to put a project together. Then they learned how to publish a paper. Typically, a PhD student would publish 3-5 papers. They learn how to start a project, do the project, finish the project, and publish the project. Then, of course, they’re also learning how to think like a scientist.
For my course, the learning outcomes are very obvious because I teach analytical chemistry, which is how to measure things. Especially nowadays, there are so many measurement tools. So unless you’re very skilled in these measurement tools, you can’t really do good research. There are typically eight or ten big instruments that people in my lab use: microscopes, spectroscopes, HPLC, and different types of chemical analysis. Basically, I teach these techniques. I have a couple of books also on these techniques. People learn these techniques and use it in whatever research they’re doing. Like the microscope that we used to look at carbon nanotubes, you can also use them to look at cells, for example.
I end up teaching students from the Masters level to the PhD level in a variety of fields. I have students in chemistry, environmental science, pharmaceutical chemistry, biology, biochemistry, electrical engineering, mechanical engineering, materials science, and civil engineering.
Tech Talks Insight:
Unlike the previous interview, Dr. Mitra’s work has applications in countless fields. Additionally, it is much more accepted by the industry and easier to disseminate into society. The most interesting point that was brought up was the implications on the environment. Dr. Mitra said that he unknowingly created a water pollutant, and that carbon nanotubes are so tiny that they could end up being like microplastics. While he is working on solutions for this, the industry has already started to use carbon nanotubes without advertising them. It is not widely known what effects they could have, and needs to be advertised.
Dr. Mitra brings up the point that research is a skill. And while it may seem difficult and some may pick up on it easier than others, it is always something that can be practiced and improved. We here at Tech Talks hope that students see that many professors are more than willing to help you learn this process. While it may take dozens of emails, we urge you to reach out to professors and researchers and ask them to mentor you. It is one step towards your future and becoming an innovator.