The alarmism and hysteria about so called forever plastics (PFAS) is highly irrational! And how harmful are these very useful chemicals really!
I recently blogged here, here about other, newly discovered ways to break down PFAS chemicals. As so often, human ingenuity won!
So in the year 2024 alone, about four papers have been published on how to deal with PFAS!
Alert: Plastophobia is a serious disorder. Please seek immediate medical help! (Caution: satire)
"Per- and polyfluoroalkyl substances, or PFAS, are an incredibly useful group of chemicals found in products such as non-stick cookware, firefighting foams, water-repellent clothing, and food packaging. Unfortunately, they are also linked to a variety of health problems and, because they are difficult to break down, tend to accumulate in the environment.
Thankfully, scientists are developing solutions. Two groups of chemists, one in Fort Collins, Colorado and one in Hefei, China, have discovered methods that break down PFAS compounds at realistic temperatures (as low as 40 °C, or 104 °F). These processes could potentially be used to treat wastewater and soil, preventing the build-up of the toxic compounds."
From the abstract (1):
"... Here, we report an organic photoredox catalyst system that can efficiently reduce C–F bonds to generate carbon-centered radicals, which can then be intercepted for hydrodefluorination (swapping F for H) and cross-coupling reactions. This system enables the general use of organofluorines as synthons under mild reaction conditions. We extend this method to the defluorination of polyfluoroalkyl substances (PFAS) and fluorinated polymers, a critical challenge in the breakdown of persistent and environmentally damaging forever chemicals."
From the abstract (2):
"... Despite recent advances in non-incineration approaches for the destruction of functionalized PFASs, processes for the recycling of perfluorocarbons (PFCs) as well as polymeric PFASs such as polytetrafluoroethylene (PTFE) are limited to methods that use either elevated temperatures or strong reducing reagents.
Here we report the defluorination of PFASs with a highly twisted carbazole-cored super-photoreductant KQGZ. A series of PFASs could be defluorinated photocatalytically at 40–60 °C. PTFE gave amorphous carbon and fluoride salts as the major products. Oligomeric PFASs such as PFCs, perfluorooctane sulfonic acid (PFOS), polyfluorooctanoic acid (PFOA) and derivatives give carbonate, formate, oxalate and trifluoroacetate as the defluorinated products. This allows for the recycling of fluorine in PFASs as inorganic fluoride salt. The mechanistic investigation reveals the difference in reaction behaviour and product components for PTFE and oligomeric PFASs. This work opens a window for the low-temperature photoreductive defluorination of the ‘forever chemicals’ PFASs, especially for PTFE, as well as the discovery of new super-photoreductants."
‘Forever’ chemicals can be destroyed with clever chemistry — now test these techniques outside the lab "Chemistry that can break carbon–fluorine bonds in persistent molecules called PFAS could help to clean up the environment. Testing in real-world settings must come next."
Photocatalytic C–F bond activation in small molecules and polyfluoroalkyl substances (1, no public access)
Photocatalytic low-temperature defluorination of PFASs (2, no public access)
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