To combat the menace of plastic pollution, scientists at the Indian Institute of Science (IISc) have designed a sustainable hydrogel to remove microplastics from water. In a press release, Bengaluru-based IISc explained that the hydrogel has a unique intertwined polymer network that can bind the contaminants and degrade them using UV light irradiation.
All Images Courtesy: IISc
Microplastics have been discovered practically everywhere on the Earth, from mountains to oceans. The United Nations Development Programme (UNDP) claims these microscopic plastic particles, which are less than five millimetres, have found their way into our land, oceans, and even the air we breathe. These microscopic particles are extremely dangerous to our health since they can get into our systems through the water we drink.
Prior attempts by scientists to eliminate microplastics have involved the use of filtering membranes. However, these membranes can become clogged with these tiny particles, making them unsustainable. Next, in search of a solution, the IISc team under the direction of Professor Suryasarathi Bose of the Department of Materials Engineering looked to 3D hydrogels.
The team’s innovative hydrogel is made up of three distinct polymer layers that are entwined to form an Interpenetrating Polymer Network (IPN) architecture: Chitosan, polyvinyl alcohol, and polyaniline. The researchers added copper replacement polyoxometalate (Cu-POM) nanoclusters to this matrix. These nanoclusters function as catalysts, breaking down the microplastics with the help of UV light. According to the press release, “The polymers and nanoclusters combined to create a robust hydrogel that can both adsorb and degrade significant amounts of microplastics.”
The majority of microplastics result from the partial decomposition of common household fibres and plastics. In order to replicate this in the laboratory, the group crushed food container lids and other everyday plastic items to produce polyvinyl chloride and polypropylene, two of the most prevalent microplastics found in nature.
“Along with treatment or removal of microplastics, another major problem is detection. Because these are very small particles, you cannot see them with the naked eye,” noted Soumi Dutta, SERB National post-doctoral scholar in the Department of Materials Engineering and the study’s first author.
To be able to track how much of the hydrogel was being adsorbed and broken down under various circumstances, the researchers included a fluorescent dye into the microplastics as a solution to this issue. According to Dutta, “We examined the removal of microplastics at various water pH levels, temperatures, and microplastic concentrations.”
The group crushed food container lids and other everyday plastic items to produce polyvinyl chloride and polypropylene, two of the most prevalent microplastics found in nature. To monitor the amount of microplastics that the hydrogel was absorbing and breaking down under various circumstances, they additionally added a fluorescent dye to the particles.
“It was discovered that the hydrogel was extremely effective; at approximately pH 6.5, it was able to eliminate roughly 95% and 93% of the two distinct kinds of microplastics from water,” Bose stated. After the hydrogel’s useful life is over, it can be recycled to create carbon nanoparticles that can be used to remove heavy metals from contaminated water. The next step for the researchers is to create a large-scale tool that will assist in eliminating microplastics from different water sources.
