Nanotechnology at Northwestern

Meet Julie Fenton, a postdoctoral fellow in the Dichtel Research Group

By Mark Heiden

June 30, 2021

Julie Fenton is a postdoctoral fellow in the Dichtel Research Group, which uses the tools of synthetic and supramolecular chemistry to address fundamental challenges in the assembly and integration of nanostructured materials.


Where are you originally from?

I grew up in Lancaster County, Pennsylvania.

Where did you complete your undergraduate degree?

A small, private, liberal arts college in Pennsylvania – Messiah College (Grantham, PA).

When did you first become interested in chemistry?

I have always had an interest in puzzles, problem solving, and learning new things, but my specific interest in science and chemistry didn’t click until high school, when I took my first course in chemistry with a phenomenal teacher. He presented the discipline like a complex, intriguing problem to be solved – I found it challenging and exciting. I guess the rest is history.

How do you explain what you study to non-scientists?

Every substance we interact with is comprised of atoms. The behavior and properties of everything is defined by both the elements that comprise it, and the arrangement of these elements and atoms with respect to each other. I am a synthetic materials chemist, which means that I am principally interested in making known materials in new ways and discovering entirely new types of materials. I develop routes to manipulate the ways in which atoms arrange themselves in solids, and work to understand how these arrangements of atoms impact the properties of the resultant materials.

You’ve been working to develop new routes to covalent organic framework thin films and membranes. What inspired you to focus on that, and what are you finding that you’re excited about?

Covalent Organic Frameworks (COFs) are an extraordinarily interesting class of materials to a materials chemist – you take rigid, geometrically constrained monomers that can react and perfectly tile together to form a framework with an extended structure of precisely defined pores, all connected with stable, covalent bonds.

In a very intuitive way, these structures can be modulated to change the pore size/shape, material topology, and chemical bonding features, or to incorporate targeted functionality – and in principle, do it all with a high degree of predictability. Reality ends up being considerably more complex than this idealized picture, so methods to access these useful materials in device-compatible architectures (like films or membranes) are in high demand.

During our efforts to generate improved synthetic methods, we were investigating the use of COFs as size-selective membranes for molecular separation applications. Previous reports suggested that COF films are capable of molecular separations by size-sieving but as we began to critically re-evaluate these prior claims, we found an alternative mechanism that could better explain the observed phenomena. Instead, we found that these materials more likely behave as adsorbents, and the separations observed were due to differences in adsorption affinity for various molecular probes.

What has been a highlight of your time at Northwestern?

There are too many to name – my time at Northwestern has been rewarding professionally and personally. I have grown and improved as a scientist, had an opportunity to work with some incredible colleagues and collaborators, and tackled challenges in a new (to me) field. Personally, I have loved living in and exploring the Chicago area.

What has been the most challenging aspect of your work or your time at Northwestern?

I viewed the postdoc as an opportunity (perhaps my last major opportunity) to immerse myself in something truly new and to learn something different. As a grad student, I worked to develop synthetic methods for inorganic nanosolids, and wanted to diversify my skill set as a materials chemist and solve some new problems as a postdoc. I was excited by materials synthesis, so I joined the Dichtel group and joined their efforts to synthesize and characterize organic solids.

It was a challenge to switch fields and the first six months were a real adjustment, requiring me to change my thinking, read papers in a new field, and ask a lot of (likely simple) questions. This was humbling and challenging, and at the time, I had moments where I questioned my choice to go quite so far outside my area of expertise. In retrospect, being uncomfortable and pushing myself outside of my scientific comfort zone was critical to my growth and professional development (but it certainly did not feel that way at the time).

Who are some of the mentors that have meant the most to you? And what made you decide to join the ACS Material Letters Early Career Advisory Board?

I have been fortunate enough to benefit from many fantastic scientific mentors and role models. (Too many to specifically name here!) Most significantly for me, though, have been my research advisors throughout the years: my undergraduate advisor at Messiah College, Prof. Rick Schaeffer, my graduate research advisor, Prof. Ray Schaak, and my current postdoctoral advisor, Prof. Will Dichtel.

Each of these scientists have been phenomenally encouraging to me, helping me to develop and to think creatively as a scientist, while giving me the space to work independently on projects that I have cared about. Each in their own way and with their unique styles, they have modeled how one can balance the demands of a career in chemistry with other priorities and goals in life.

They have championed my career, encouraged me to go after every possible opportunity, and pushed me to think broadly about my place in the scientific community and in the world more broadly. All three have gone well beyond my expectations for a research or academic advisor. If I can be even a fraction of the mentor they have been to me to my future students, I will have succeeded.

I joined the ACS Materials Letters early career advisory board for a variety of reasons – most of all, it was a great opportunity to contribute to the broader materials community and to help steer a new journal towards emerging areas in materials synthesis and materials chemistry.

What are your hobbies outside of the lab?

Outside of lab, I enjoy cross-training, travel (during non-COVID times, of course), cooking, trivia, and spending time with my family.