New hope in the fight against microplastics! Revolutionary hydrogel can eliminate them – SMARTmania.cz

• Microplastics enter all ecosystems and can also carry toxic substances
• Hydrogels with a triple architecture could become an effective solution for removing microplastics from water
• The developed hydrogel achieves a high efficiency, up to 95% for PVC and 93% for PP microplastics

Microplastics are small pieces of plastic, often smaller than 5 mm, that seriously threaten our environment. Microplastics enter terrestrial, freshwater or marine ecosystems, which significantly pollute them. They are so tiny that they even get into the food chain and can carry a whole range of toxic substances. Many studies are looking at ways to deal with this problem. Today we will look at a special hydrogel that can effectively remove microplastics from water.

New hydrogel offers hope

Triple architecture hydrogels containing chitosan (CS), polyvinyl alcohol (PVA) and polyaniline (PANI) are an excellent solution for removing microplastics (MP) from water. This material takes advantage of its special structural and functional properties, such as the strength or flexibility of its structure. An important feature of these hydrogels is their ability to adapt, which means that they can have different pore sizes and be mechanically flexible. This improves their ability to trap microplastics in the water.

PVA gives the hydrogel its strength, flexibility and ability to retain water. In addition, it provides chemical functional groups that enable the formation of a hydrogel polymer network. Conversely, CS, which is derived from chitin, is an excellent hydrogel material due to its ability to degrade in nature and its antibacterial effects. It also has the ability to bind microplastics to each other through electrostatic interactions. The hydrogen-containing functional groups between PVA and CS form a strong polymer network, which increases the strength of the hydrogel and its ability to retain water. In addition, the addition of PANI to the hydrogel improves the polymer cross-linking and thus the ability to capture microplastics.

The last part of this structure are copper polyoxometalate nanoclusters known as Cu-POM. These nanoclusters are key to increasing the effectiveness of the hydrogel in removing microplastics from water. In addition, the nanoclusters help the photodegradation of microplastics using UV radiation, which contributes to the cleaning of water bodies.

POM nanoclusters have a negative charge, while microplastics usually carry a negative charge depending on their type and the surrounding pH. The electrostatic attraction between the oppositely charged particles facilitates the entrapment of microplastics on the hydrogel. Thanks to van der Waals forces, the microplastics attach to both the surface of the hydrogel and the surface of the POM nanoclusters.

The hydrogel demonstrates a high microplastic removal efficiency of approximately 95% for PVC and 93% for PP microplastics at pH 6.5. Even more interesting is its ability to be reusable for up to five cycles without losing its effectiveness.