Saturday, October 27, 2007


I know I never posted anything work-related on this blog before - well, I guess this will be the first post. In fact, I did something really enjoyable today at work. No worries, I usually don't go to work on Saturdays, but this was a special occasion. We had 300 kids coming from middle and high school here at UC Berkeley with the objective of spending a day learning something about 'Nanoscience and nanotechology'. Nicola and I volunteered to present a one-hour activity, which we showed three times during the day to about 20 kids at a time. Actually I really enjoyed it. The kids were quite excited when they got to play with solutions of gold nanoparticles of cool colors, and we showed them cool machines moving at the microscale.. so for your own enjoyment, here is a picture of solutions of gold nanoparticles of different sizes (most likely from 10 to 200 nanometers - a nanometer is a billionth of a meter). Would you have ever guessed that gold is pink or purple when it's tiny???
I think I'm going to take a picture of my own solutions, they were much nicer.
In my next 'outreach' talk I want to talk about food and nanoscience.. I'm sure it would have some success. :)


bee said...

presume it is a colloidal suspension. does the color depend on the medium of suspension or dispersion (particle size dependent)? or some other reason. curious! --jai

chemcookit said...

Jai - very good, yeah, it is a colloidal suspension, and the color does depend on particle size. In fact, we had the kids play a trick on them: if you add salt (just whatever salt, such as the one we add on food), it neutralizes their surface charges, and they stick together, thus making bigger particles and changing color. Kind of cool!