BENGALURU: Plastic is harmful for the environment and humans microplastics pose a greater risk. This is because tiny pieces of plastic debris enter human bodies through water and other liquids consumed, thus increasing risks of illnesses.
They are also an environmental hazard as they are found in polar ice caps and deep inside the ocean. Multiple studies revealed the increasing quantities of plastic and microplastics in water bodies. Researches have also been undertaken to study the quantity of blue plastic and remove it from water.
But thanks to researchers at IISc who designed a hydrogel that removes microplastics from water. The material has intertwined polymer network that binds contaminants and degrades them using UV light irradiation.
Earlier, scientists tried using filtering membranes to remove microplastics but found that it was getting clogged. The team lead by Suryasarathi Bose, professor at the Department of Materials Engineering, then decided to use 3D hydrogels.
This unique hydrogel comprises of three different polymer layers – chitosan, polyvinyl alcohol and polyaniline – intertwined together, making an Interpenetrating Polymer Network architecture. These nanoclusters acted as catalysts that use UV light to degrade microplastic. The combination of the polymers and nanoclusters resulted in a strong hydrogel which could adsorb and degrade large amounts of microplastics.
Researchers noted that most microplastics are a product of incomplete breakdown of household plastics and fibres. To mimic this in the lab, the team crushed food container lids and other daily-use plastic products to create the most common microplastic existing in nature- polyvinyl chloride and polypropylene.
“Besides, another major problem with the removal of microplastics, is detection. These tiny particles cannot be seen with the naked eye,” said Soumi Dutta, first author of the study published in Nanoscale and SERB National Post-doctoral fellow at Department of Materials Engineering.
To address this, researchers added fluorescent dye to the microplastics. They found hydrogel could remove about 95% and 93% of the two different types of microplastics in water. “We wanted a material that is more sustainable and can be used repetitively. Hydrogel can be used for up to five cycles and after it has outlived its use,” Bose said.