Tangled seaweed inspires one-size-fits-all cleaners for ocean microplastics
Inspired by naturally occurring mats and balls of seaweed, researchers have created highly porous, superadhesive meshes capable of capturing both large and small microplastic particles—a longstanding challenge in the field. The mesh can clean microplastics from both saltwater and freshwater and is made from sustainable, widely available biopolymers.
Microplastics—a catch-all term that refers to plastic particles less than 5 millimeters in size—represent a major pollution problem that poses risks to both human health and the environment. One area of particular concern is the impact of microplastics on aquatic ecosystems, leading to a wide range of efforts aimed at removing these pollutants from water.
Efforts to capture plastic microparticles in water have faced a significant challenge. Some methods can capture larger microparticles—around a millimeter in size. Others can capture smaller microparticles—those measured in micrometers or nanometers. But efficiently capturing both in a single process has been a challenge.
"Our goal here was to develop a multiscale structure that allows us to capture the full range of plastic microparticles," says Orlin Velev, S. Frank and Doris Culberson Distinguished Professor of Chemical and Biomolecular Engineering at North Carolina State University and corresponding author of an article on the new work published in Science Advances.
Velev and his collaborators drew inspiration from floating mats of seaweed and so-called "Neptune balls"—spherical balls of tangled seaweed—which have been shown to collect microplastics. "We wanted to create structures that mimicked what the tangled seaweed is already doing," Velev says.
The researchers created "cleaners" consisting of a mesh of porous fibers made from the biopolymers alginate and chitosan, which are derived from seaweed and crustacean shells. The surface of the mesh is covered in a layer of very fine chitosan fibers. This surface layer consists of soft dendritic colloids—structures that branch repeatedly into finer and finer filaments, ending in a tuft-like crown of nanofibers. This structure allows the soft dendritic colloids to stick to almost any surface and directly capture polymer microparticles and nanoparticles from water.
"What you end up with looks like a fluffy net," Velev says. "The 'net' part of the structure is a mesh capable of capturing the larger plastic microparticles—a millimeter or larger in size. Further, the individual strands of the net are 'fluffy' because they are coated with soft dendritic colloids, which are able to capture even very small plastic microparticles by adhesion—down to tens of nanometers in size."
In proof-of-concept testing, the researchers found that their superadhesive meshes were effective at capturing lab-produced model nanoparticles and real-world microplastics across a wide range of sizes in both freshwater and saltwater.
So, what happens once the fluffy mesh has captured its harvest of microplastics?
The researchers say the loaded mesh could be swept up and reprocessed. One possibility would be to use microbial digestion to break down the microplastics and mesh and biosynthesize more of the biopolymer material—for making more fluffy nets.
"We've demonstrated that this design works," Velev says. "And the materials we used are of natural origin and relatively inexpensive. So, it may present a viable path forward. Can it be used on a large scale? That depends on the extent to which we want to invest in scaling up such cleanup approaches."
Publication details
Haeleen Hong et al, Artificial Neptune balls: Superadhesive biomimetic networks for broad size microplastics capture and removal, Science Advances (2026). DOI: 10.1126/sciadv.aeg0819. www.science.org/doi/10.1126/sciadv.aeg0819
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Citation: Tangled seaweed inspires one-size-fits-all cleaners for ocean microplastics (2026, August 5) retrieved 5 August 2026 from https://phys.org/news/2026-08-tangled-seaweed-size-cleaners-ocean.html
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