Polymer Day 2023 showcases interdisciplinary innovation

Chemical “recycling,” or turning plastics into high-value products, left. Materials that repair the damage and restore it to the right. Straight forward: fibers that can be woven into fabric and used as microphones or loudspeakers.

Such was the variety of innovation gathered in MIT’s Morse Hall at Polymer Day 2023. Sixty-four teams from schools across the North East and beyond presented their research ahead of the poster competition – the most since the event began in 2013.

“We almost ran out of room in Morse Hall,” says Eric Lee, a graduate student in MIT’s Materials Science and Engineering and Polymers and Soft Materials Program (PPSM), who hosted the event. Lee along with graduate students Yelin Cho, Emily Crooker-Velasquez, and Camilla Kunin, who chaired the Polymer Day organizing committee. “We’ve never had this problem before because we’ve never had this many participants.”

Polymers are a large class of materials made of long, repeating chains of molecules. Polymers can be used in everything from food products to pharmaceuticals – from polyethylene in packaging to polyester in clothing, for example.

The MIT event included seminars, student workshops, and an alumni career panel. There were also industry booths with 10 sponsors including Cabot, Dow and Saint Gobain. The goal of the annual event is to provide students with opportunities to network and share their research with people in their field, Lee said. It is also a demonstration of the great diversity of polymer research.

“That makes it really special,” says Lee. “The great thing about PPSM and polymer science in general is its interdisciplinary nature. PPSM integrates chemical engineering, chemistry, materials science, mechanical engineering and biological engineering. So five different units.”

Slime models

This diversity was reflected in the research presented during the afternoon poster session. Nadia Zaragoza spoke about her work creating synthetic vaginal mucus from the polymers of bottle brushes, which look like long brushes for cleaning glassware under a microscope.

“I love slime,” says Zaragoza, a graduate student at DMSE and PPSM. “This is very interesting material.”

Its ultimate goal is to better study infections such as bacterial vaginosis, a vaginal inflammation caused by an overgrowth of bacteria. This is a commonly misunderstood diagnosis.

“We don’t understand how it happened,” says Zaragoza. “We know mucus plays a role. If we can make better samples of vaginal mucus, can we better study those diseases?”

From polymers to proteins

Another speaker with an interest in polymers and health science was Kayla Koch, a graduate student in the Department of Polymer Science and Engineering at the University of Massachusetts Amherst. Koch uses polymers to mimic protein transduction domains, called cell-penetrating peptides, that can transport antibodies or proteins across the cell membrane into the cell, such as an mRNA vaccine against Covid-19. The vaccine works by delivering mRNA into the body’s cells.

“The advantage of using polymers is that you can easily tune them. “If you want to change the structure of a peptide, it’s a very difficult and painful process,” says Koch. “With polymer chemistry, you put everything together and away you go.”

Koch and his team are now trying to optimize polymers to efficiently transport proteins across cell membranes in order to deliver therapeutic agents such as drugs. The work presented at Polymer Day showed what happens when different types of alcohol are added to polymers.

“We can see that it affects protein delivery. In some cases, it improves protein delivery,” he said.

Long-lasting blisters

Saurabh Nath, a postdoctoral fellow in the Varanasi research group at the Massachusetts Institute of Technology’s Faculty of Mechanical Engineering, presented his work on bubbles, specifically how to make them last. Try to blow bubbles into the water, he said, and they appear in milliseconds.

“The only way to stabilize them is to add soap or additives. But when you add soap to water, it’s not water anymore, it’s soapy water,” says Nath.

So his research asked a simple question: How does an air bubble remain a bubble without changing its purity? They tried to answer this question by placing silicon oil in a glass and the glass on a hot plate. A bite of the oil produced bubbles that lasted for 10 milliseconds. Heat the oil to 68 degrees Celsius (154 degrees Fahrenheit), bubbles will remain for about an hour.

Reason: Heat pushes liquid flow to the top of the bubble; the coolant flows down. “The bubble survives because gravity is counteracted by the upward flow,” says Nat.

One application that can lead to such knowledge is foam. Foams—used in insulation, packaging, and safety, among other applications—rely on additives or polymers to give them their structure. Nath described a new type of foam consisting of long-lasting bubbles stabilized without any additives. Also, such a material can solve the problem of “defoaming” or removing foam when it is not needed.

“It’s a radical step in making and breaking foam,” says Nat. “You turn off the heat, the bubbles are gone.”

The first place winner of the poster competition was Joon Ho Park, a postdoctoral fellow in the Department of Chemical Engineering at MIT, for his presentation, “Development of a Cartilage Penetrating Dendrimer for the Treatment of Osteoarthritis.” Second- and third-place winning topics included materials design inspired by nature, data-driven predictions of materials properties, and using DNA as a building block for biomaterials.