Fake Frost and Window Crystals

Saw this fake frost on the store windows at a Bass Pro Shop today.  I do not know how it was made, but it shows pretty crystal patterns.  For comparison, the van windows have real frost.  One can saturate water with Epsom salt (magnesium sulfate) and paint the solution on dark-colored paper.  When the water on the paper dries, the white salt crystals look like frost. When I was a graduate student some twenty years ago, I would occasionally work with organic compounds that melted at temperatures not far above room temperature.  Sometimes a flask with a film of this melted liquid would cool in my hands.  As the film solidified, pretty crystal stars would form along the walls of the flask.  This was always fun to see.  Update on 6-4-13:  today one of my kids got some Crayola Crystal Effects Window Markers.  When the marker ink dries it makes pretty crystal stars.

National Chemistry Week 2012

The theme for this year's 25th Annual National Chemistry Week (October 21-27, 2012) is nanotechnology.  In the spirit of that I set up a display at Bradley University about nanotechnology and a ruler next to a sign saying "How tall are you in nanometers?"  The idea is adapted from a display that I saw at the University of Texas-Austin last year.

Analogy for Brownian motion

I was feeding a potato chip to a pool full of small fish and I noticed that as the little fish surrounded the chip and nibbled at it, the chip moved around randomly.  I thought this was sort of an analogy for Brownian motion, where collisions between solvent molecules and small suspended particles causes the particles to move around in a random fashion.

Cover picture

The October, 2012, issue of the Journal of Chemical Eduation came out recently. I have two papers in it: one from work done at Bradley University "Take-Home Nanochemistry: Fabrication of a Gold- or Silver-Containing Window Cling", and the other from work at the University of Texas "New Nanotech from an Ancient Material: Chemistry Demonstrations involving Carbon-based Soot". A picture from the soot research was used for the cover.

Thermal Conductivity Demo

Saw this thermal conductivity demo at the old Lakeview Museum in Peoria yesterday.

Neil Armstrong's Passing

Just heard that Neil Armstrong passed away this past weekend. I was born about a month after his trip to the moon. Anybody who rides a rocket the size of the Saturn V has my respect - demos with small rockets are crazy enough. The picture was taken late last year at the Houston Space Center - very cool.

Beer Fluorescence

 

Many carbon-containing materials fluoresce.  Green laser pointers (e.g., 532 nm) can produce yellow or orange fluorescence and violet laser pointers (e.g., 405 nm) can produce whitish fluorescence. Here lasers cause beer to fluoresce in a colorless glass bottle.