<
https://scitechdaily.com/goodbye-microplastics-new-recyclable-plastic-breaks-down-safely-in-seawater/>
"Researchers led by Takuzo Aida at the RIKEN Center for Emergent Matter Science
(CEMS) have created a groundbreaking plastic that combines durability with
eco-friendliness. This innovative material is not only as strong as
conventional plastics but is also biodegradable, with a unique ability to break
down in seawater. By addressing a critical environmental issue, this plastic
holds the potential to significantly reduce microplastic pollution, which
accumulates in oceans, soils, and eventually enters the food chain. The team’s
findings were published today (November 22) in the journal
Science.
Efforts to develop sustainable alternatives to traditional plastics, which are
non-biodegradable and environmentally harmful, have been ongoing for years.
While some biodegradable and recyclable options already exist, a major
challenge persists: many of these materials, such as PLA, fail to degrade in
ocean environments because they are water-insoluble. This limitation allows
microplastics—tiny fragments smaller than 5 mm—to persist in marine ecosystems,
harming aquatic life and making their way into the food chain, including into
humans.
In their new study, Aida and his team focused on solving this problem with
supramolecular plastics—polymers with structures held together by reversible
interactions. The new plastics were made by combining two ionic monomers that
form cross-linked salt bridges, which provide strength and flexibility. In the
initial tests, one of the monomers was a common food additive called sodium
hexametaphosphate and the other was any of several guanidinium ion-based
monomers. Both monomers can be metabolized by bacteria, ensuring
biodegradability once the plastic is dissolved into its components.
“While the reversible nature of the bonds in supramolecular plastics has been
thought to make them weak and unstable,” says Aida, “our new materials are just
the opposite.” In the new material, the salt bridge structure is irreversible
unless exposed to electrolytes like those found in seawater. The key discovery
was how to create these selectively irreversible cross-links."
Via Aladár Mézga and Susan ****
Cheers,
*** Xanni ***
--
mailto:xanni@xanadu.net Andrew Pam
http://xanadu.com.au/ Chief Scientist, Xanadu
https://glasswings.com.au/ Partner, Glass Wings
https://sericyb.com.au/ Manager, Serious Cybernetics
