Scientist at Work: Amy Chu on Green Chemistry, National Support for Groundbreaking Research with SMC Students, and ‘Thinking Cyclically’

“At Work” is a series that highlights Saint Mary’s faculty and staff at work in the world. Artists, writers, scholars, scientists—we sit down and dive deep into their latest projects.

For humans, “green chemistry”—as a field, as a phrase—emerged in the 1990s. Following centuries of industrial pollution, chemists sought a new direction, one that reduced waste and hazardous materials. For nonhumans, however, chemistry was always green, or at least greener. 

Consider, for instance, a much-beloved chemical reaction: fall foliage. On the November day I meet Amy Chu in her Brousseau Hall office, campus maples and sycamores are going off like firecrackers. Their red and orange plumes are incredibly Instagrammable; they’re also, fundamentally, changing matter. As temperatures drop and days shorten, the leaves’ chlorophyll begins to break down, revealing other pigments usually hidden behind chlorophyll’s green. Soon, those leaves will drop, decompose, and feed the trees. In other words, not much goes to waste. 

It’s a level of circularity Chu is striving to bring to inorganic chemistry. Originally from Taiwan, Chu earned her BS in Chemistry from the National Taiwan University and went on to pursue a PhD in Chemistry from the University of Illinois. After completing postdoctoral research, she taught at Mills College before joining the School of Science faculty in 2022. 

In August, Chu learned she was awarded a grant from the National Science Foundation (NSF) after applying for their new initiative, Launching Early-Career Academic Pathways in the Mathematical and Physical Sciences. The award, totalling $188,625, is part of the NSF’s effort to support early-career faculty at minority-serving institutions. Chu fits that bill, as does Saint Mary's; the College has been a designated Hispanic-Serving Institution since 2015 and recently welcomed one of its most diverse incoming classes ever.

With the grant’s support, Chu, alongside her student researchers, will work to develop molecules that can extract excess phosphates from waterways. From there, she hopes, the phosphate can be put back to use in fertilizers. It’s cutting-edge work—but as Chu explains, her favorite part is that SMC undergraduates are helping her do it. 

What initially drew you to inorganic chemistry?

I kind of happened upon chemistry, actually. In Taiwan, where I grew up, we have to take standardized tests in different subjects to get into college. I tested into chemistry, and I was one of the lucky ones in my class, because it turned out that I really liked it.

I did a little bit of chemistry research as an undergraduate and then decided to pursue graduate school in the US. After earning my PhD, I did postdoctoral work with Karen Goldberg at the University of Washington, who later moved to the University of Pennsylvania. That’s when I really understood my passions: working with younger students and mentoring them in the lab, specifically with a focus on environmental issues. 

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Your research seems to have two prongs: uncovering the environmental impact of industrial processes as well as exploring how we can do things better. How do you see those two aspects of your research? 

Well, we can be doing pretty much everything better. For centuries, chemistry—and industry in general—was mostly about what materials were the cheapest and easiest to get. But that mentality has gotten us into a difficult place; the climate is rapidly changing, and extreme weather is increasingly more common. We've only recently started thinking about greener industrial practices!

As scientists, because there’s so much opportunity to do better, the hardest thing can be to just focus on one issue. Sometimes, our research subjects sneak up on us. For instance, one day I was listening to a podcast episode about phosphates and nitrates—both important ingredients in fertilizer. The episode explained that, in the 1800s, as populations skyrocketed, fertilizers became very, very valuable. But then, in the early 1900s, scientists developed methods to make artificial fertilizers, which is when we started using them on a massive scale. 

On one hand, it was good: It supported the growth of the population. But there's the other side, too, because only about 20% of the fertilizer we put in the ground gets absorbed by plants. The rest of it ends up in our waterways. Whenever you see algae blooms, they're often because of excess nitrates and phosphates in the water that came, originally, from agricultural sites. 

All of these problems we're thinking about always have multiple sides to them. I try to communicate this tension to my students—as well as the opportunities.

"One of the things I really love about the School of Science at Saint Mary's is we do so much research with students... I really do see myself not just as a researcher, but as a teacher-scholar."

Talk a bit more about the research the NSF grant is supporting. 

With this particular project, we're thinking about how we can make an improvement and remediate water quality. There are a lot of nitrates and phosphates in our waterways. We’re mostly interested in phosphates, because we think we have a good idea of how to capture them in water. 

So the grant is helping my students and me design these small molecules, the shape of which acts as a nice little claw that grabs onto the phosphate and extracts it from the water. That’s science, essentially: Here’s a big overarching issue, and here’s a very small, specific thing we’re trying to do to help.

It’s exciting that students get to be so involved in research like this. 

One of the things I really love about the School of Science at Saint Mary's is we do so much research with students. This NSF-supported project and all my other projects are always designed with the skills and techniques I think will benefit a student-in-training. For me and all my colleagues, we never design a project that we envision ourselves doing with multi-million dollar instrumentation, even if some of us might have the ability to get access to it on our own. We are thinking about how our students can benefit. 

I really do see myself not just as a researcher, but as a teacher-scholar. It’s one of the reasons why I was drawn to Saint Mary’s, and it’s why I applied for this NSF grant. With the project, I currently have three students supporting my research. And all three of them, because of the NSF support, will be traveling to a conference in San Diego in March to present their work. 

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Down the road, if the research does pan out, what could the impact of this molecule be?

The benefit of this molecule, we envision, is that it will be incredibly portable. Right now, the only way to remediate phosphates from water is at very large water treatment sites, and the capital cost to build those sites is very expensive. But at all of these surface lake sites, it'll be very easy for us to drop a few molecules in and capture those phosphates, quickly diminishing the algae blooms and improving the overall water quality. 

We’re very ambitious, too, because we even think about reusing the phosphates we capture. Phosphorus is actually what we chemists call an endangered resource; some scientists people think that in the next 100 years, we're going to run out of phosphate rocks. So, eventually, that will become a problem, too. 

It strikes me that this shift toward green chemistry and green industry is really an effort to think cyclically, as opposed to just using and throwing away.  

Most chemists, even when I was trained, all we often thought about was the material in front of us and, at most, what went into the waste bin. But we didn’t talk about what happened to the waste bin. We didn’t even think about where we got our materials from, because many of them were obtained through very intensive mining processes. In recent years, though, we’ve begun to talk more about the life cycles of chemicals like phosphorous. Where do we get it? Where does it go? How do we get it back? 

The promise of research like yours is inspiring, and yet there are so many obstacles ahead. What gives you hope, and what hope do you offer your students? 

My students give me hope. When I see them give a presentation about their motivation for a project, for instance, I see just how passionate they are about topics like the one we’ve been discussing. Obviously, there are a lot of challenges. It’s a big world, and we’re just a small research lab at Saint Mary’s.

Ultimately, though, the larger impact of this NSF grant will be what my student researchers do next. It will be them going forward in their careers, continuing to think about problems cyclically and consider the entire life cycle of all materials. That makes me very hopeful. 

(This interview was edited and condensed for clarity.)

Hayden Royster is Staff Writer at the Office of Marketing and Communications for Saint Mary's College. Write him.