Given space and weight limitations, what would you take with you to Mars? The ideal option might be a single material that can transform into any object you imagine.
In the morning, you can mold the material to make utensils for eating. After breakfast, you can also swap your forks and knives for spades and tend to your Martian garden. And when it comes to happy hour on the Red Planet, that spade might just turn into a cup of Mars beer.
What sounds like science fiction is probably one step closer to reality. Researchers at the University of Chicago's Pritzker School of Molecular Engineering have developed a new type of plastic with properties that can be cured with heat and then set by rapid cooling, known as tempering. Unlike traditional plastics, this material maintains this stiffness even when returned to room temperature.
The findings, published Thursday in the journal Science, could one day change the way astronauts pack for space.
“Instead of carrying around all these different plastics, you just take this one plastic and give it the properties you need based on your needs,” said Stuart Rowan, a chemist at the University of Chicago and author of the new study. states. .
But this material isn't just useful in space. Dr. Rowan's team also sees potential in other environments where resources are scarce, such as at sea or on the battlefield. It could also be used to make soft robots and improve plastic recycling.
“We all depend on plastics in our daily lives,” said Shreish Patel, a chemical engineer at the University of Chicago and author of the new study. But foam cups, garbage bags and eyeglass lenses, for example, all require plastics with different properties.
Meanwhile, the ability to create a single material for different needs “simplifies how plastics are manufactured,” Dr. Patel said. It also makes plastic more sustainable as all items can be processed together when recycled. He explained that plastics need to be separated when only a small portion is reused through recycling.
Modern plastics are made of permanently bonded chains of molecules that are difficult to break down. But the Chicago researchers say their new material is “pluripotent” (a term typically used to describe a general property of stem cells), meaning it can be cut and reformed using heat. It states that it is made up of possible combinations.
These were inspired by the way blacksmiths temper steel in their furnaces, that is, gradually heat it up and then rapidly cool it. However, unlike metal, plastic is lightweight and can be molded at temperatures achievable in an oven or stovetop.
The researchers heated the reddish, translucent plastic to temperatures between 140 degrees Fahrenheit and 230 degrees Fahrenheit, then placed it in a freezer to rapidly cool it down. Tempering at lower temperatures forms more molecular bonds, making the plastic harder. However, as the temperature increases, the material becomes softer and more sticky.
The researchers molded plastic into a spoon hard enough to scoop peanut butter out of a jar and a fork that could hold cheese. I also made some glue strong enough to stick two pieces of glass together, and some little claws like the ones on toy machines.
Julia Callow, a chemist at Northwestern University who was not involved in the study but wrote an opinion piece on the results in Science, says a variety of properties can be achieved with a single material. I felt the idea was unique and exciting. “Now that we know that we have the potential to help achieve this property, it will inspire many other researchers to find new ways to achieve that goal,” she said. .
First generation multifunctional plastics have limitations. The researchers have shown that the material can be reprocessed at least seven times and maintains its shape for at least a month, but there is uncertainty about its shelf life.
“They are not yet drop-in replacements for commodity plastics,” says Nicholas Boynton, a graduate student at the University of Chicago who led the study's experiments. This material is not yet as strong as, say, a plastic bag or as resilient as a rubber band.
“We're not there yet, but we're pretty close,” Boynton said. “I think it's really exciting at the moment that he has one material that he can access this huge range of.”
