How Many Nanoparticles Can Dance on the Head of a Pin?

by Michael Mullaney on June 20, 2011

Here’s a question for the ages: just how small are nanoparticles?

Well, Rensselaer resident nanotech expert and professor Linda Schadler helps put this quandary in perspective. In her Academic Minute, which aired today on NPR affiliates all across the country, she tackles the topic of nanoparticles, why they’re strange, and why they’re very important.

You can listen to the stellar 90-second piece at this site. The local NPR affiliate, WAMC Northeast Public Radio, launched its Academic Minute segment last year to great success. What started as a regional endeavor is now making waves nationally.

The transcript of Schadler’s Academic Minute is below:

We see composites – a mixture of two materials – in our skis, tennis racquets, airplanes, and cars. New composites made from nanoparticles and plastics may soon be improving electricity transmission, increasing the efficiency of light-emitting diodes (LEDs), and helping make computers even tinier.

A billion nanoparticles can fit on the head of a pin. They are so small, that they don’t scatter much light. That’s what zinc oxide sunscreen is no longer white – it has nanoparticles in it now.

That means that if you add nanoparticles to a clear plastic, you can give it new properties, but maintain the transparency. Think scratch-resistant, transparent coatings on your cars and glasses.

If you think about the surface area of a pin, and then the surface area of a billion particles, you can start to understand why composites made from tiny particles are so different. They have a huge amount of surface area. The composite is essentially made completely out of surfaces.

By engineering those surfaces, we are making materials that can be stretched twice as far before they break, without decreasing their stiffness or strength.

We have also made nanocomposites that can handle 50 percent more electric field, or last 100 times longer under electric field before failing.

These projects are a perfect example of why funding for fundamental research is so important. It has taken eight years of fund research to make some of these materials.

But some of them are finally ready for industry to being using them. And their potential impact is enormous.

For more on Schadler’s research, check out this blog post on “hairy” nanoparticles, this news story about nanoparticles in space, and – of course – this story about Linda’s leadership on the Molecularium Project.