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
- Depressive Symptoms in First Episode Psychosis
There are only few studies examining the course and development of depressive symptoms in patients with a FEP. This is important as there is an increased risk of suicide during the early phases of ...
- Amphetamine-induced Psychosis
Jørgen G Bramness; Øystein H Gundersen; Joar Guterstam; Eline B Rognli; Maija Konstenius; Else-Marie Løberg; Sigrid Medhus; Lars Tanum; Johan Franck In this context, we hypothesize that the ...
- Method efficiently breaks down plastic bottles into component parts
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 ...
- Use of metal-organic frameworks to degrade plastics
The researchers chose a zirconium-based MOF 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 ...
- Method efficiently breaks down plastic bottles into component parts
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 ...
Go deeper with Google Headlines on:
UiO-66
Go deeper with Bing News on:
Degrading plastics
- Machine Learning Helped Scientists Create an Enzyme That Breaks Down Plastic at Warp Speed
plastics that would otherwise take centuries to fully degrade. Polyethylene terephthalate, which thankfully is more widely known as PET, is a clear, strong, lightweight plastic; it’s also the chemical ...
- This new enzyme could break down plastic in just hours
Most of the plastic we use doesn’t get recycled. Instead, it ends up in landfills, where it can take as long as 450 years for it to fully decompose. Engineers and scientists at the University of Texas ...
- U.S. plastics recycling rate slumps below 6 percent, analysis finds
Plastics, the vast majority of which are made from fossil fuels, can take hundreds of years to decompose. Rather than fully degrade, plastic breaks down into smaller pieces called “microplastics.” ...
- Man-Made Enzyme Variant Eats up Hard-To-Degrade Plastics in Hours, Not Decades
Plastic pollution is everywhere and the fact that plastic itself is simply not biodegradable and has a very long lifespan is a major threat for the planet. Veuer's Maria Mercedes Galuppo has the story ...
- Scientists create enzyme that breaks down plastic in hours instead of decades
Scientists have created a new enzyme which can break down plastics that typically take decades or centuries to degrade within a matter of days or even hours. The team of researchers, including those ...
