New approach could lead to designed plastics with specific properties

plastic bags
Credit: CC0 Public Domain

Imagine a plastic bag that can carry home your groceries, then quickly degrade, without harming the environment. Or a super-strong, lightweight plastic for airplanes, rockets, and satellites that can replace traditional structural metals in aerospace technologies.


Machine learning and artificial intelligence have accelerated the ability to design materials with specific properties like these. But while scientists have had success designing new metallic alloys, polymers—like the plastic used for bags—have been much more difficult to design.

Researchers at the Pritzker School of Molecular Engineering (PME) at the University of Chicago have found a way forward in designing polymers by combining modeling and machine learning.

By computationally constructing nearly 2,000 hypothetical polymers, they were able to create a large-enough database to train a neural network—a type of machine learning—to understand which polymer properties arise from different molecular sequences.

“We show that the problem is tractable,” said Juan de Pablo, Liew Family Professor of Molecular Engineering who led the research. “Now that we have established this foundation and have shown that it can be done, we can really move forward in using this framework to design polymers with specific properties.”

The results were published Oct. 21 in Science Advances.

Designing polymers difficult due to long strings of atoms

Polymers exhibit amorphous, disordered structures that cannot easily be defined using the techniques that scientists have developed to study metals or other crystalline materials.

Polymer molecules consist of large arrays of atoms arranged in a very long string, sometimes comprising millions of “monomers.” Every polymer molecule is different. Not only is the length different, but the sequence in which the atoms are arranged can vary considerably.

Length and sequence have a great influence on the properties of a polymeric molecule, and the extraordinarily large number of possible length and sequence combinations is a central challenge in designing molecules with specific properties. Trial-and-error approaches are of limited use and generating the necessary experimental data to inform a rational design strategy would be very demanding.

That is where machine-learning comes in. The researchers set out to answer the question: “Can machine learning algorithms ‘learn’ how to predict the properties of polymers according to their sequence, and, if so, how large of a dataset would be needed to train the underlying algorithms?”

Creating a database to learn polymer sequences

To create the database, the researchers used nearly 2,000 computationally constructed polymers, all having different sequences, and ran molecular simulations to predict their properties and behavior. When they first used a neural network to figure out which properties were based on which molecular sequences, they were unsure if they would find a reasonable answer.

“We didn’t know how many different polymer sequences were necessary to learn the behavior of materials,” de Pablo said. “The answer could have been millions.”

Luckily, the network only needed less than a few hundred different sequences to learn the properties and predict the behavior of completely new molecular sequences. That meant that experimentalists could now follow a similar strategy

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New novel follows the journey of two men as they devise a practical system designed to bring socioeconomic justice and save the planet

Manuel Januário announces the release of ‘Our Land’

ARLINGTON, Mass., Oct. 15, 2020 (GLOBE NEWSWIRE) — Two unlikely friends — a wealthy landowner and an immigrant college student — explore ways to bring economic equity and social justice while saving the planet in this engaging story of Manuel Januário’s “Our Land” (published by Archway Publishing).

 

Written as a historical fiction, the book features André Castro, a very rich Latin American landowner, and his close friend Mário Garcia, an optimistic visionary immigrant, who share deep conversations about a better world for the disenfranchised member of the society. Although from different backgrounds, they both come to the USA to learn how to overcome economic underdevelopment in their own countries. Unfortunately, they discover that the American economic system perpetuates conditions of poverty for many while others become unreasonably rich, leaving behind a trail of environmental degradation. They both endure many challenges and seriously risk their lives as together they explore practical ways to address economic justice problems.

 

“My book is an honest reflection of many years of direct experience with social programs designed to eradicate socioeconomic inequalities and to promote social change,” the author describes. “This book highlights current and urgent societal issues of economic injustice even more apparent today during the 2020 pandemic. It also brings forth positive examples of how we can change and replace some of our environmentally unsustainable practices with innovative ways of addressing these issues.”

 

“Our Land” is a work of fiction touching upon pertinent issues in a creative and dynamic way. With it, Januário hopes to inspire readers to dream better world and feel that together people can each build a piece of it. To purchase a copy, visit https://www.archwaypublishing.com/en/bookstore/bookdetails/803214-our-land.

 

“Our Land”

By Manuel Januário

Hardcover | 6 x 9in | 326 pages | ISBN 781480891258

Softcover | 6 x 9in | 326 pages | ISBN 9781480891241

E-Book | 326 pages | ISBN 9781480891265

Available at Amazon and Barnes & Noble

 

About the Author

Manuel Januário is an American born in the Azores who earned his master’s degree in adult and continuing education from Washington State University, USA. His vast and rich experience includes being the executive director of the Community Action Council of Spokane County, Washington State, as well as the director of the Employment Development Consortium of five Native American tribal governments. He is a lifelong long advocate for social justice and equity and currently lives in a rural community with his wife. “Our Land” is his first publication.

Simon & Schuster, a company with nearly ninety years of publishing experience, has teamed up with Author Solutions, LLC, the worldwide leader in self-publishing, to create Archway Publishing. With unique resources to support books of all kind, Archway Publishing offers a specialized approach to help every author reach his or her desired audience. For more information, visit www.archwaypublishing.com or call 844-669-3957.

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CONTACT: Marketing Services Archway Publishing 844-669-3957 [email protected]

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