Nanotech - Staying Small: The Pulse of the Planet daily radio program offers free legal online mp3 downloads, exploring the world of sound in nature, culture and science, with audio adventures, world music, extraordinary sound portraits, science diaries, and nature ring-tones; an amazing sonic experience.

Airdate: Jun 07, 2016
Scientist: Deborah Berhanu

Nanotech - Staying Small

Nanotech - Staying Small
If they're going to retain their special properties, nanoparticles have to stay small!

Nanotech Staying Small

Ambience: Bunsen Burner
When an element like gold is broken down into tiny nanoparticles, they have different properties than bulk gold, properties that scientists use to create things like smaller and faster electronic components. The problem is making sure the nanoparticles stay small. I'm Jim Metzner and this is the Pulse of the Planet

Berhanu: The stability of nanoparticles is a challenging area.

Deborah Berhanu is an assistant professor at the City University of NY at Kingsborough Community College. She says that nanoparticles which are stable at room temperature may not be so stable if they're heated up.

Berhanu: So our laptops heat, and if the nanoparticles are not stable, the laptop will not be working anymore. Nanoparticles have this tendency to come together, just like soap bubbles. And they coalesce and they form a larger grain.

I have a glass slide on which I have put gold nanoparticles. The surface is red. When I put this glass slide on top of the Bunsen Burner and I'm now heating it, suddenly the color changes and I can now see the yellow that is characteristic of gold. This is telling me that my nanoparticles have come together and they have grown into normal gold.
By changing the size of nanoparticles we are changing the way they behave.

Professor Berhanu is trying design ways of coating the nanoparticles to prevent them from merging together without changing their other special properties. Pulse of the Planet is made possible in part by the Center for Earth and Environmental Nanotechnology and the National Science Foundation.