via Northwestern University
Researchers first to demonstrate use of metal-organic frameworks to degrade plastics
What if the life cycle of the plastic bottle was circular? Where a used plastic bottle was returned to its original components, ready to be made into a new plastic bottle instead of possibly ending up in a landfill.
A Northwestern University research team is the first to demonstrate that a material called a metal-organic framework (MOF) is a stable and selective catalyst for breaking down polyester-based plastic into its component parts.
Only three things are needed: plastic, hydrogen and the catalyst. An important bonus is that one of the component parts the plastic is broken down into is terephthalic acid, a chemical used to produce plastic. With the Northwestern method, it isn’t necessary to go all the way back to oil and the expensive and energy-intensive production and separation of xylenes.
“We can do a lot better than starting from scratch when making plastic bottles,” said Omar Farha, a professor of chemistry in the Weinberg College of Arts and Sciences. He is the corresponding author of the study. “Our process is much cleaner.”
The work was published recently in the journal Angewandte Chemie.
The researchers chose a zirconium-basedMOF called UiO-66 because it is easy to make, scalable and inexpensive. Yufang Wu, the study’s first author and a visiting graduate student in Farha’s group, used the plastic that was most handy: the plastic water bottles her colleagues in the lab had discarded. She chopped them up, heated the plastic and applied the catalyst.
“The MOF performed even better than we anticipated,” Farha said. “We found the catalyst to be very selective and robust. Neither the color of the plastic bottle or the different plastic the bottle caps were made from affected the efficiency of the catalyst. And the method doesn’t require organic solvents, which is a plus.”
What are MOFs?
A class of nano-sized materials, MOFs have been widely investigated because of their highly ordered structures. Farha has studied MOFs for more than a decade and previously showed they can be used to destroy toxic nerve agents. In the current study, Farha said, MOFs act in much the same way — breaking an ester bond to degrade polyethylene terephthalate (PET). This plastic is one of the most popular consumer plastics worldwide.
“We’ve been using zirconium MOFs to degrade nerve agents for years,” Farha said. “The team then wondered if these MOFs could also degrade plastic even though the reactions and mechanism are different. That curiosity led to our recent findings.”
“This research helps to address long-standing challenges associated with plastic waste and opens up new areas and applications for MOFs,” Farha said.
Envision Tinkertoys
MOFs are made of organic molecules and metal ions or clusters which self-assemble to form multidimensional, highly crystalline, porous frameworks. To picture the structure of a MOF, Farha said, envision a set of Tinkertoys in which the metal ions or clusters are the circular or square nodes and the organic molecules are the rods holding the nodes together.
In addition to being easy to make, scalable and inexpensive, another advantage of UiO-66 is that the MOF’s organic linker, terephthalic acid (TA), is what you get when breaking down plastic.
Structural characterization studies revealed that during the degradation process, UiO-66 undergoes an interesting transformation into another zirconium-based MOF called MIL-140A. This MOF also showed great catalytic activity toward PET degradation.
Original Article: Method efficiently breaks down plastic bottles into component parts
More from: Northwestern University
The Latest Updates from Bing News & Google News
Go deeper with Bing News on:
UiO-66
- Phillips 66's Refining Margins Sink, Dragging Down Profits
Callaghan O'Hare / Bloomberg via Getty Images Phillips 66 reported a drop in first-quarter profits as refining margins thinned. The energy company's realized refining margins were nearly half what ...
- Ph.D. Dissertation Proposal Defense in Plastics Engineering: Taiyo Yamaguchi 4/26
This research examines the capabilities of UiO-66-NH2 metal organic frameworks by mechanically encapsulating them within a non woven fiber mat through a process of co-electrospinning/spraying. MOF ...
- Metal-organic framework coatings enable simple, reusable water contaminant testing
They then tested their technique with three zirconium-based MOFs known as UiO-66, DUT-52 and UiO-66-abdc, chosen for their stability and tunable pore structures. Detailed imaging revealed dense, even ...
- DocuSign and The Case for 66% Upside
The fact that equities, in general, are sliding this week has only made that more attractive and could support an upside of some 66% from where shares closed on Monday. JMP Securities also got in ...
- 2024 Lotus Type 66 - Review
Lotus has taken the covers off a new track-only car called the Type 66, an extremely exclusive machine that will match modern GT3 race cars around some of the world's most famous circuits.
Go deeper with Google Headlines on:
UiO-66
[google_news title=”” keyword=”UiO-66″ num_posts=”5″ blurb_length=”0″ show_thumb=”left”]
Go deeper with Bing News on:
Degrading plastics
- JU no to single-use plastic on campus
Jadavpur University issues circular re-emphasizing ban on single-use plastic on campus in response to student demonstration. Students call for action against environmental degradation and urge ...
- Scientists explore nature’s promise in combating plastic waste
By Claire Asher Plastic is a remarkably versatile and durable material, which has made it indispensable in almost every area of modern life. But these same properties, amplified by our ...
- Bacteria-seeded plastic is tough and degradable
Most TPU plastics used today end up in landfills ... As long as enough moisture and nutrients are around, the bacteria should wake up and degrade the polymer, Pokorski says. Katrina Knauer, a polymer ...
- Researchers Develop a Plastic That Digests Itself
A team led by researchers at the University of California San Diego have developed a type of biodegradable plastic that can begin digesting itself when it ...
- This week in science: biodegradable plastic, crops on Mars and deer vs. caribou
NPR's Juana Summers talks with Regina Barber and Emily Kwong of Short Wave about biodegradable plastic, simulating growing crops on Mars, and how deer are disrupting caribou populations.
Go deeper with Google Headlines on:
Degrading plastics
[google_news title=”” keyword=”degrading plastics” num_posts=”5″ blurb_length=”0″ show_thumb=”left”]