Magnetic Nanoparticles Lead to a New Class of Composites

Greater control over material orientation leads to a new class of composites

2 min read

Magnetic Nanoparticles Lead to a New Class of Composites

How can you make a material that is simultaneously strong, flexible and light? The answer has long been advanced composites that combine plastics, metals and ceramics to get the best characteristics out of each of them.

But achieving a balance between these materials' qualities of strength, flexibility and lightness is difficult to come by and often comes down to being able to manipulate the various materials into the perfect orientation to each other.

Researchers at ETH-Zürich have developed a process that gives them a far greater control over that orientation than ever before. The result is an entirely new class of composite that mimics the precise layering seen in nature's abalone seashell.

The idea was simple. Why not get the materials to move to where you wanted them to go by the use of magnetic force, not unlike a bar magnet orienting iron fillings? However, the obvious problem is that not all materials used in composites are magnetic.

The researchers, who published their work in the January 13th issue of the journal Science in an article entitled "Composites Reinforced in Three Dimensions by Using Low Magnetic Fields," overcame this obstacle by adding a small amount of magnetic nanoparticles to the nonmagnetic materials.

The researchers discovered that this process of adding magnetic nanoparticles only works with stiff elements in the micrometer size range, which just so happens to overlap with the sizes the composite industry uses.

One would have to believe that this research will quickly find itself in commercial use as the ETH-Zürich researchers are continuing this work in collaboration with composite companies to get this straight into industrial processes.

The material will certainly get early adopters in any industry in which strong, light and flexible are sought after characteristics. While aerospace immediately comes to mind, the growing market of wind turbines should likely be another.

The addition of nanomaterials into advanced composites no longer seems like a mere marketing ploy,  but is increasingly becoming a way of actually making composites stronger or imbuing them with greater functionality. Perhaps nanocomposites are finally coming into their own.

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