Vietnamese, Singaporean scientists turn aircraft scrap into oil-absorbing aerogel

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Published in the scientific journal waste management, the study brings together researchers from the National University of Singapore (NUS), the University of Science under the Vietnam National University Ho Chi Minh City, and the Institute of Tropical Technology.

Their work tackled a persistent challenge in materials science.

Carbon fiber reinforced epoxy is exceptionally durable during its working life, but notoriously difficult to recycle once discarded.

Valued for being lightweight, durable, and corrosion-resistant, carbon fiber and epoxy composites are staple materials across aviation, wind turbines, automobiles, and maritime vessels.

But epoxy is a thermoset polymer whose tightly cross-linked network cannot simply be melted down and reshaped like ordinary plastics.

Most conventional recycling techniques focus on salvaging the valuable carbon fibers while destroying, discarding, or downgrading the resin—often relying on extreme heat, caustic chemicals, or heavy energy consumption.

Rather than separating the components, the team led by Assoc. Prof. Duong Minh Hai of NUS found a way to repurpose the entire composite.

They mechanically milled the scrap into a mixture of fine powder and short fiber strands before combining it with carboxymethyl cellulose, a natural binder derived from plant cell walls. The mixture was then freeze-dried into an aerogel—a porous, featherlight solid composed almost entirely of trapped air.

Duong Minh Hai (right), who led the study, with the aerogel material developed by his team. Photo courtesy of NUS

According to the study published on June 29 in Waste Management, the resulting aerogel is exceptionally light, with hollow pores accounting for 91% to 94% of its total volume. This pocketed air significantly impedes thermal transfer, while the sponge-like matrix helps deaden sound waves. In laboratory tests, the aerogel demonstrated very low thermal conductivity alongside reliable acoustic absorption, highlighting its promise for thermal insulation and noise reduction in buildings and industrial equipment.

The researchers also treated the surface of several samples to repel water while aggressively drawing in oil. As a result, a single gram of the aerogel can absorb some 14.4 grams of oil, opening up practical applications in cleaning up oil spills and separating oil from water.

When living cells were exposed to various concentrations of the material, more than 88% survived and grew normally.

This high viability rate demonstrated that, despite originating from industrial scrap, the aerogel is safe for applications involving direct human or environmental contact.

"Through a green, solvent-free, and energy-efficient process, composite waste is transformed into a multifunctional aerogel capable of thermal insulation, oil absorption, noise reduction, and many other industrial uses," Hai wrote on LinkedIn.

In their paper, the authors emphasized the approach as "upcycling"—elevating discarded composite into a higher-value, multifunctional product rather than merely recovering raw materials.

"I believe the future of the circular economy will not only be about managing waste better, but designing technologies so that waste is no longer waste," Hai said.

The team is now seeking partnerships across aerospace, advanced materials, manufacturing, and waste management to scale up the process, while assessing its economic viability and environmental impact.