Airdate: Jan 22, 2019
Scientist: Paul Westerhoff
The Ubiquitous White Powder
What do toothpaste, powdered donuts and sunscreen all have in common?
The Ubiquitous White PowderWhat do toothpaste, powdered donuts and sunscreen all have in common? Here's a clue it's small, really small. I'm Jim Metzner and this is the Pulse of the Planet.Westerhoff: A nano material is about 1000 times smaller than the diameter of a hair. Of all the nano materials produced in the globe, titanium dioxide is about the third most abundant materials produced and engineered every year. Paul Westerhoff is Regents Professor in the School of Sustainable Engineering in the Built Environment at Arizona State University.Westerhoff: So it's in lots of products that we see and use every day. They put it in toothpaste, partially to make it white, partially to make it an abrasive on your teeth. We put it in food, it's in chocolates, and if you ever put some titanium dioxide powder between your fingers, it's almost oily. It's really smooth and it adds a really unique texture without adding any sugar or fat to a food.It's in sunscreen so it protects us against skin cancer. Nano particles of titanium dioxide are also used in purifying air and water. And it's used in automobile coatings. One of the things as nano particles get really small, especially with titanium dioxide, you can actually see through them. So they become transparent, but they still have unique functions. When you shine sunlight on it, it can actually become self cleaning. It forms small amounts of oxidants that can break down dust and dirt on window shields for example. So if you drive a Mercedes, some of the window coatings will have nano titanium dioxide on them.We'll hear more about Titanium Dioxide in future programs. Pulse of the Planet is made possible in part by the Center for Earth and Environmental Nanotechnology and the National Science Foundation. I'm Jim Metzner.