Sean Friedowitz (Materials Science & Engineering) | Dielectric properties of aqueous polyelectrolyte solutions (Freie Universität Berlin)

Image

With the support provided to me through the GRIP, I spent the past three months, from early July to late September of 2019, working as a research assistant under the supervision of Prof. Roland Netz at the Freie University (FU) in Berlin, Germany. As a whole, I found the experience incredibly rewarding, both in terms of academic growth and cultural exploration. Not only did I make good progress on outstanding research questions from my PhD work back home, but I also was able to travel to a large handful of cities across Europe, meeting many lasting friends along the way. A summary of these experiences are detailed below.

Although I am doing my PhD in materials science here at Stanford, my actual research topics could be more adequately described as soft matter theoretical physics. I study predominantly the physics of charged polyelectrolyte systems, focusing both on their thermodynamics and materials properties. My research is performed entirely theoretically and computationally, and all I need to complete my work is an adequate computer. Thus, it was entirely fitting to join the scientific team of Prof. Netz at FU Berlin, as his group's research is described as (from their web page) "the theoretical description of bio soft matter physics." After hearing about my research background and financial support from the GRIP, Prof. Netz was happy to take me aboard for the summer, and the question of visiting his group was met with the eager response of "Sure, why not!".

One of the first tasks to take care of after accepting the visitation offer from Roland was deciding on a suitable summer project. Like most other topics in the physical research sciences, it is difficult in my field to perform an entire project from start to finish in a matter of just three months. Fortunately, since my research background group's focus shared so much common ground, I proposed a topic of interest that I had been meaning to begin working on for years at Stanford, that also seemed relevant to his scientific focuses. My goal for the summer would be to study the dielectric properties of aqueous polyelectrolyte solutions, focusing on aspects such as the role of chain length and polymer concentration on dielectric relaxation behavior. For those familiar with molecular simulation and statistical physics, this type of system property can readily be measured by examining polarization time correlation functions in molecular dynamics simulations. However, the application of these methods is complicated for charged (ionic) systems. Fortunately, students in Roland's group had studied the dielectric properties of simple salt solutions in the past, which offered a knowledge base for extending these calculations to polymeric systems. In the end, after much coding and many jobs posted to a computational cluster, I was able to leave the internship with a strong understanding of dielectric relaxation theory, and a handful of promising initial results for the dielectric behavior of aqueous poly-(styrene)-sulfonate chains. This project is still ongoing, and is something I am continuously working on since my return back to Stanford.

Image

Naturally, beyond my research goals for the summer, I also wanted to experience and explore the city of Berlin. One of my initial concerns when heading out there was the fact that I knew nobody in the city, not a single person. Coupled with the fact that my German was (is) still quite bad, I was naturally worried about being in such a foreign place alone. Quickly though after arriving, all these fears went away. Part of this was because of how easy it was to meet people and settle into such a young and active city like Berlin. And part of this as well was that I was very fortunate that the other graduate students and post-docs in Roland's group were very welcoming to me. Having lived in California my whole life prior, it was a very novel experience being the most "foreign" person in the group, and my new labmates were all excited to hear about life back on the west coast. We often went out as a group for drinks, dinner, sight-seeing around the city, and even sometimes to some of the ridiculous techno clubs in Berlin.

Another very helpful part of settling into life in Berlin was meeting some very cool people outside of my research group. During my first weekend in Berlin, still not knowing many people or having friends, I attended an international student trip put on by the university to a neighboring city Spreewald. On this day trip, I was fortunate to become friends with a pharmacology masters student at the university named Lucy. She happened to be interning for the summer at Bayer Pharmaceuticals in Berlin, which also hosted a large cohort of visiting interns from across Europe. Through these connections, I ended up settling into a large group of visiting friends for the summer, with whom I was often out exploring the city and going out with. Many of these friends and colleagues I am still in regular touch with, and I view it was an incredibly valuable part of my summer experience to have made these connections. Again, whether it be a matter of luck, or something about the culture in Berlin, it was just shockingly easy to settle in and feel comfortable in town. For that reason, I highly recommend Berlin for any other students exploring this summer internship opportunity. There's endless things to do, endless history to see, amazing green spaces around the city, and a young and welcoming culture -- I am not disappointed here.

Image

Looking back at my summer, it still feels pretty crazy to have experienced everything that I did. With all the connections I made and all the places around Europe I was able to explore, I feel like this summer will stick with me for a long time. I can't think of many expectations I had that I did not meet, and overall I strongly enjoyed my experience in Germany. I would strongly recommend this fellowship to any future students who may be reading this. My advice to them would be that, when embarking on this journey, to really force yourself to be out there and explore and try as many new things as possible. The people I met and connections I made along the way were as valuable, or more valuable and experience than any amount of research I accomplished working with Prof. Netz, and are aspects of my summer that I hope to keep with me for the rest of my life.