Microplastics, those microscopic plastic particles found in the air, water and soil, are a serious pollution problem and we have even found them in the bloodstream of animals and people around the world.
Most of these microplastics form as larger plastic products break down in the environment , but as if the problem wasn’t bad enough, we’ve been adding our own microplastic particles to other products for decades.
According to the European Chemicals Agency, some microplastics are deliberately introduced into agricultural chemicals, paints, cosmetics and detergents. To this end, the European Union (EU) has mandated that non-biodegradable microplastics be phased out by 2025.
Microplastics: a growing problem
It is an environmental problem that we must solve, but a new study could help eliminate a good part of them. The authors showed that silk could be a biodegradable replacement for microbeads and plastic particles that are often added to cosmetics, paints and other products.
After years of research, researchers at the Massachusetts Institute of Technology (MIT) and other scientists have come up with a silk-based device that could be cheap and easy to make.
“We cannot solve the entire microplastics problem with a one-size-fits-all solution,” explained Benedetto Marelli, lead author of the study. “Ten percent of a big number is still a big number… We will solve climate change and world pollution one percent at a time.”
Silk, it seems, can not only do the same thing by encapsulating substances until needed, but it will quickly and safely biodegrade when finished. Textile-grade silk requires silkworm cocoons to be meticulously unraveled, but to make these microspheres, the cocoons can be dissolved in water in a process that is simple, scalable, and can be done using existing infrastructure, the team says. . And it can be used with low-quality silk that is currently wasted in large quantities, which is even better.
According to experts, the silk protein used in the new alternative material is readily available and less expensive. The technique is so simple and customizable that the material produced can be adapted to current manufacturing equipment, offering a “direct” solution using existing factories.
The team tested the silk coating material in the lab using existing aerosol-based manufacturing equipment to make a herbicide contained in silk capsules that dissolve in water to release the product over time.
When tested on corn in a greenhouse, the silk-encapsulated herbicide worked as well as existing products , but significantly reduced crop damage. The team say this silk coating could replace primary microplastics in most applications, such as cosmetics or even medicines, as silk is also broken down in the body.
“There is a great need to achieve high-content asset encapsulation to open the door to commercial use,” said Marelli. “The only way to make an impact is where we can not only replace a synthetic polymer with a biodegradable counterpart, but also achieve equal, if not better, performance.”
Referencia: Microencapsulation of High-Content Actives Using Biodegradable Silk Materials
Muchun Liu, Pierre-Eric Millard, Henning Urch, Ophelie Zeyons, Douglas Findley, Rupert Konradi, Benedetto Marelli
First published: 08 July 2022
DOI: https://doi.org/10.1002/smll.202201487
