Following the people and events that make up the research community at Duke

Tag: chemistry

For Undergraduate Student Tiffany Yen, Sustainability is More Than Just a Buzzword

Tiffany Yen, a Duke junior majoring in chemistry, grew up in the sunny suburbs of Los Angeles, never too far from the coastline. She’s always loved being outside, especially in California where there is no shortage of trails to hike and beaches to go to. Friends know her as a Patagonia aficionado, going so far as to buy her a book profiling the company’s business model for her birthday. In fact, from Yen, I learned that every Patagonia store gives out city-specific stickers, so if you feel so inclined, you can collect them (as Yen obviously does). All this is to say: Tiffany Yen has always been interested in sustainability.

“I never understood why what we do has to come at the cost of the planet,” Yen said, in discussing how her years in school learning about climate change fueled her passion for sustainable science. “The environment is so important. Without it, we wouldn’t be here.”

Tiffany Yen

Unsure of what she wanted to study at Duke and where she wanted to go post-graduation, she decided to take her two interests – sustainability and chemistry, particularly polymer chemistry – and see what she could do to combine them. She knew coming into college that she wanted to do research, so that landed her at the Becker Lab for Functional Materials.

The Becker Lab is a multidisciplinary organic materials lab focused on biomedical applications – specifically, things like adhesives and drug delivery. Yen works on improvements to intercranial pressure sensors. Traditionally, after head trauma, doctors need to measure the intercranial space to see if the brain is damaged. The sensor that is used is wired and tends to be a very invasive procedure – the probe is connected to a machine outside, and there’s a high risk of infection.

Collaborators at Northwestern developed a biodegradable wireless device that, after implantation, doesn’t require a secondary procedure to take out. The problem is that it degrades a little too fast – and so measurements can’t be taken. Yen, with her mentor, is working on building a film encapsulation to make it possible for the device to take good measurements.

Right now, they’re trying out azelaic acid instead of succinic acid. Azelaic acid has favorable anti-inflammatory properties and is commonly used in acne medications. It could also potentially increase the bioresorbability of the polymer. Their hope is that the film not only helps the body metabolize more of the polymer, but actually helps in healing.

Snapshots from Yen’s life at the lab

So why medical research? Yen explains that while her work may not seem obviously linked to sustainability, the push for finding materials that can degrade is extremely relevant. And while she’s not all that interested in medicine specifically, she likes things that are practical and applicable.

“When I did research in the past,” Yen said, “there wasn’t always an application. It sometimes was about synthesizing something, just for the sake of science.” And while there’s certainly value in strengthening science fundamentals, she admits that research in that vein doesn’t really appeal to her. “I want to work on things that I directly see adding value to society.”

After college, Yen sees herself going to graduate school and working towards a PhD in “some physical science related to chemistry.”  Ultimately, her goal is to work at the interface of venture capital and scientific research, using her science background to find and fund promising innovations in sustainability. “There are so many incredible things being researched out there,” Yen says, “but the biggest problem in research is funding and commercializing.” She continues, “I think there are other people out there who can do better research than I can, so I want to go out there, find the stuff, and fund it.”

Yen has come to believe that just because she dedicated her time at Duke to science, it doesn’t mean she needs to stay in science forever. There’s value in scientific knowledge no matter where you go. And as businesses realize that public interest in sustainability is growing, she’s crossing her fingers that her skillset will poise her to be a valuable asset in seeking out new innovations. 

Snapshots from Yen’s life at the lab

She said that when she came into college, she felt a pressure to pursue a more traditional path, like being pre-med. “I value stability, and I’m very risk-averse,” she laughs.

But when she asked herself what she’d be happiest doing, she knew it would be trying to save the planet in some way. But she clarifies: “At this point, I can’t save the planet. I think that’s a very far-fetched thing for one person to do.” Instead, “I’d rather try and maybe fail than not try at all.”

Post by Meghna Datta, Class of 2023

Tracking Tiny Moving Targets

This squiggly line shows the path taken by a snippet of DNA as it might move around within the soupy interior of a cell. Duke’s Kevin Welsher and colleagues have developed a technique that turns a microscope into a ‘flight tracker’ for molecules, making it possible to follow the paths of viruses and other particles thousands of times smaller than the period at the end of this sentence. Until now, such techniques have required particles to be tethered to make sure they stay within the field of view. But the Welsher lab has developed a way to lock on to freely moving targets and track them for minutes at a time.

Researchers created a tiny circuit through a single water molecule, and here’s what they found

Graphic by Limin Xiang, Arizona State University

Many university labs may have gone quiet amid coronavirus shutdowns, but faculty continue to analyze data, publish papers and write grants. In this guest post from Duke chemistry professor David Beratan and colleagues, the researchers describe a new study showing how water’s ability to shepherd electrons can change with subtle shifts in a water molecule’s 3-D structure:

Water, the humble combination of hydrogen and oxygen, is essential for life. Despite its central place in nature, relatively little is known about the role that single water molecules play in biology.

Researchers at Duke University, in collaboration with Arizona State University, Pennsylvania State University and University of California-Davis have studied how electrons flow though water molecules, a process crucial for the energy-generating machinery of living systems. The team discovered that the way that water molecules cluster on solid surfaces enables the molecules to be either strong or weak mediators of electron transfer, depending on their orientation. The team’s experiments show that water is able to adopt a higher- or a lower-conducting form, much like the electrical switch on your wall. They were able to shift between the two structures using large electric fields.

In a previous paper published fifteen years ago in the journal Science, Duke chemistry professor David Beratan predicted that water’s mediation properties in living systems would depend on how the water molecules are oriented.

Water assemblies and chains occur throughout biological systems. “If you know the conducting properties of the two forms for a single water molecule, then you can predict the conducting properties of a water chain,” said Limin Xiang, a postdoctoral scholar at University of California, Berkeley, and the first author of the paper.

“Just like the piling up of Lego bricks, you could also pile up a water chain with the two forms of water as the building blocks,” Xiang said.

In addition to discovering the two forms of water, the authors also found that water can change its structure at high voltages. Indeed, when the voltage is large, water switches from a high- to a low-conductive form. In fact, it is may be possible that this switching could gate the flow of electron charge in living systems.

This study marks an important first step in establishing water synthetic structures that could assist in making electrical contact between biomolecules and electrodes. In addition, the research may help reveal nature’s strategies for maintaining appropriate electron transport through water molecules and could shed light on diseases linked to oxidative damage processes.

The researchers dedicate this study to the memory of Prof. Nongjian (NJ) Tao.

CITATION: “Conductance and Configuration of Molecular Gold-Water-Gold Junctions Under Electric Fields,” Limin Xiang, Peng Zhang, Chaoren Liu, Xin He, Haipeng B. Li, Yueqi Li, Zixiao Wang, Joshua Hihath, Seong H. Kim, David N. Beratan and Nongjian Tao. Matter, April 20, 2020. DOI: 10.1016/j.matt.2020.03.023

Guest post by David Beratan and Limin Xiang

New Course Offers Lessons from Lasering Priceless Art

Duke graduate student Tana Villafana and chief conservator at the NC Museum of Art William Brown stand over The Crucifixion (inset). (Photo: Martin Fischer)

Duke graduate student Tana Villafana and chief conservator at the NC Museum of Art William Brown stand over The Crucifixion (inset). (Photo: Martin Fischer)

By Erin Weeks

A group of chemists at Duke University has gained recognition in recent years for shooting lasers at medieval artwork — technology that allows a harmless peek at the many layers and materials in a painting and offers insight into long gone eras and artists. Now, Duke students will have the chance to learn from this pioneering work at the intersection of chemistry and art history in a new course on the science of color.

The course coincides with the publication of the first scientific measurements from the laser work, reported Jan. 20 in the Proceedings of the National Academy of Sciences.

“The images we have now are enormously better than a year ago,” said Warren S. Warren, head of the lab performing the imaging and the James B. Duke professor of chemistry. He and fellow Duke authors, grad student Tana Villafana and associate research professor Martin Fischer, have not only demonstrated the technology works — they’ve shown it works at an incredible level of detail, telling the difference, for example, between nearly identical pigments.

But lasering The Crucifixion by Puccio Cappano was just the start, as the team envisions countless more cultural applications of the technology. Given enough funding and manpower, they could visualize ancient scrolls of text too fragile to unroll, reveal the bright colors that once adorned Greek statues, learn the secrets of China’s terracotta warriors, and even detect the beginnings of pigment degradation in aging artwork.

There are talented people in art conservation, Warren said, whose work could benefit from more advanced technology, and there are talented people at the cutting-edge of laser science looking for meaningful ways to apply their inventions. For the past several years, Warren’s lab has brought these people together.

Now, he hopes to accomplish something similar with students at Duke. Warren, Fischer, and another chemistry instructor, Adele DeCruz, are teaming up to teach “The Molecular, Physical, and Artistic Bases of Color” in the second half of spring semester.

The class will visit the Nasher Museum of Art, the North Carolina Museum of Art in Raleigh, and possibly even the National Gallery of Art in Washington, D.C, to learn first-hand from art conservators and working artists. Students can expect to learn about how humans have used and made pigments over the millennia; how color works at a molecular level; and the basics of how human vision, microscopes, cameras, and lasers all see or image color.

Students can register for the half course, CHM 590, until the add/drop deadline for classes on January 22. “Students should not be scared off by the course number,” Warren said. “The prerequisite is one college-level science course, and the intent is to make both the science and artistic components accessible to a broad audience.”

Funding for the research was provided by National Science Foundation grant CHE-1309017.

CITATION: “Femtosecond pump-probe microscopy generates virtual cross-sections in historic artwork.” Tana E. Villafana, William P. Brown, et al. Proceedings of the National Academy of Sciences, Jan. 20, 2014. Doi: 10.1071/pnas.1317230111

Powered by WordPress & Theme by Anders Norén