‘Wood you believe it?’ Engineers fortify wood with eco-friendly nano-iron

Florida Atlantic University researchers find nanocrystalline iron oxyhydroxide strengthens wood cell walls with minimum extra weight.

From Florida Atlantic University 02/05/25 (first released 28/04/25)

Scientists and engineers are developing high-performance materials from eco-friendly sources like plant waste.

A key component, lignocellulose – found in wood and many plants – can be easily collected and chemically modified to improve its properties.

By using these kinds of chemical changes, researchers are creating advanced materials and new ways to design and build sustainably.

With about 181.5 billion tons of wood produced globally each year, it’s one of the largest renewable material sources.

Researchers from the College of Engineering and Computer Science at Florida Atlantic University, and collaborators from the University of Miami and Oak Ridge National Laboratory, wanted to find out if adding extremely hard minerals at the nanoscale could make the walls of wood cells stronger – without making the wood heavy, expensive or bad for the environment.

Few studies have investigated how treated wood performs at different scales, and none have successfully strengthened entire pieces of wood by incorporating inorganic minerals directly into the cell walls.

The research team focused on a special type of hardwood known as ring-porous wood, which comes from broad-leaf trees like oak, maple, cherry and walnut.

These trees feature large, ring-shaped vessels in the wood that transport water from the roots to the leaves.

For the study, researchers used red oak, a common hardwood in North America, and introduced an iron compound into the wood through a simple chemical reaction.

By mixing ferric nitrate with potassium hydroxide, they created ferrihydrite, an iron oxide mineral commonly found in soil and water.

Results of the study, published in the journal ACS Applied Materials and Interfaces, revealed that a simple, cost-effective chemical method using a safe mineral called nanocrystalline iron oxyhydroxide can strengthen the tiny cell walls within wood while adding only a small amount of extra weight.

Although the internal structure became more durable, the wood’s overall behavior – such as how it bends or breaks – remained largely unchanged.

This is likely because the treatment weakened the connections between individual wood cells, affecting how the material holds together on a larger scale.

The findings suggest that, with the right chemical treatment, it’s possible to enhance the strength of wood and other plant-based materials without increasing their weight or harming the environment.

These bio-based materials could one day replace traditional construction materials like steel and concrete in applications such as tall buildings, bridges, furniture and flooring.

“Wood, like many natural materials, has a complex structure with different layers and features at varying scales.

To truly understand how wood bears loads and eventually fails, it’s essential to examine it across these different levels,” said Vivian Merk, Ph.D., senior author and an assistant professor in the