JAKARTA – Tiny bits of plastic are everywhere, stretching from urban environments to pristine wilderness. Leaving it alone, it will take hundreds of years to completely degrade.
Sun-activated catalysts can speed up the process, but getting these compounds to interact with microplastics is difficult. In a proof-of-concept study, researchers at the American Chemical Society (ACS) Applied Materials & Interfaces developed a self-propelled microrobot that can swim, attach to plastic, and destroy it. 2021).
While plastic products are everywhere indoors, plastic waste and fragments are now also strewn outdoors. The smallest – microplastics measuring less than 5 mm – are difficult to pick up and remove. In addition, they can absorb heavy metals and pollutants, which can potentially harm humans or animals if consumed accidentally.
So, researchers previously proposed a low-energy way to remove plastic in the environment by using a catalyst that uses sunlight to produce highly reactive compounds that break down these types of polymers. However, connecting the catalyst and small pieces of plastic to each other is a challenge and usually requires pretreatment or a large mechanical stirrer, which is not easily scaled up. Martin Pumera and colleagues wanted to create a catalyst driven by sunlight that moves toward and sticks to microparticles and disassembles them.
To turn the catalytic material into a light-driven microrobot, the researchers fabricated star-shaped bismuth vanadate particles and then evenly coated the 4-8 micrometer-wide structure with magnetic iron oxide.
Microrobots can swim down a maze of channels and interact with pieces along the microplastic. The researchers found that under visible light, the microrobot firmly covered four common types of plastic.
The team then irradiated pieces of the four plastics covered with the microrobot catalyst for seven days in a dilute hydrogen peroxide solution. They observed that the plastic lost 3% of its weight and that the surface texture for all types changed from smooth to perforated, and small molecules and plastic components were found in the remaining solution.
The researchers say self-propelled microrobot catalysts pave the way to systems that can capture and degrade microplastics in hard-to-reach locations. (E-4)
News Source: RRI.co.id.
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