With space and weight limitations, what would you bring if you went to Mars? An ideal choice might be a single material that can shift shapes to any object you can imagine.
In the morning, you could mold this stuff into dinnerware. When you finish breakfast, you can transform your fork and knife into a shovel to tend your garden on Mars. And then, when it’s happy hour on the red planet, that shovel could become a cup for your Martian beer.
What sounds like science fiction is, perhaps, one step closer to reality. Researchers at the University of Chicago Pritzker School of Molecular Engineering have created a new type of plastic with properties that can be set with heat and then locked in place by rapid cooling, a process known as curing. Unlike classic plastics, the material retains this rigidity when it returns to room temperature.
The findings, published in the journal Science on Thursday, could one day change the way astronauts prepare for space.
“Instead of taking all the different plastics with you, you take this one plastic with you and then give it the properties you need as you want,” said Stuart Rowan, a chemist at the University of Chicago and author of the new study. .
But space isn’t the only place the hardware could be useful. The team of Dr. Rowan also sees its 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 Shrayesh 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.
A single material that can be made for different needs, on the other hand, “simplifies the way plastics are made,” said Dr. It would also make plastic more sustainable because items could be processed all together in recycling. This plastic should be sorted when recycling contributes to the reuse of only a small fraction, he explained.
Modern plastics are made of chains of molecules that are permanently linked, which makes them difficult to break down. But the Chicago researchers say their new material is “multipotent” — a term commonly used to describe the general property of stem cells — or made up of bonds that can be broken and re-formed using heat.
They were inspired by the way blacksmiths temper, or gradually heat and then rapidly cool, steel in a furnace. But unlike metal, plastics are lightweight and can be molded at temperatures achieved by an oven or stovetop.
The researchers heated the reddish, translucent plastic to temperatures between 140 and 230 degrees Fahrenheit, then placed it in a freezer to cool quickly. When cured at lower temperatures, more molecular bonds were formed, making the plastic stiffer. But at higher temperatures, the material became softer and stickier.
The team made the plastic into a spoon stiff enough to scoop peanut butter out of a jar and a fork that could pick up cheese. They also made glue strong enough to stick two pieces of glass together and a small claw similar to what you might find on a toy machine.
Julia Kalow, a chemist at Northwestern University who was not involved in the study but wrote an outlook on the results for Science, found the idea of ​​a single material that could achieve a variety of properties unique and exciting. “Now that we know it can be useful to achieve this property, many other researchers will be inspired to find new ways to achieve this goal,” he said.
There are limitations to the first generation of multipurpose plastic. Although the team has shown that the material can be reprocessed at least seven times and retain its shape for at least a month, there is uncertainty about its lifespan.
“They’re not going to replace commodity plastics yet,” said Nicholas Boynton, a graduate student at the University of Chicago who led the experiments for the study. The material cannot yet reach the hardness of a plastic bag, for example, nor the elasticity of a rubber band.
“We’re not quite there yet, but we’re very close,” Mr. Boynton said. “I think having a hardware that can access that huge range is what’s really exciting at this point.”
