Wednesday, January 22, 2014

Spontaneous Assembly (or "Self Assembly") of Hot Dog Slices and Meatballs


Originally posted May 22, 2012:
Cut hot dogs into ~1 cm thick slices and place them in a pan of water. They will float at the water's surface and attractive capillary interactions will draw them together into an organized close-packed array.
References:
Dungey, K. E. J. Chem. Educ. 2000, 77, 618.
Campbell, D. J.; Freidinger, E. R.; Hastings, J. M.; Querns, M. K. "Spontaneous Assembly of Soda Straws." J. Chem. Educ., 2002, 79, 201.
Campbell, D. J.; Freidinger, E. R.; Querns, M. K. "Spontaneous Assembly of Magnetic LEGO® Bricks." The Chemical Educator, 2001, 6, 321.
Campbell, D. J.; Freidinger, E. R.; Hastings, J. M.; Querns, M. K. "Spontaneous Assembly of LEGO®s." Chem13 News, Sept., 2001, 8.
ABOVE LEFT: Cutting hot dogs into slices. ABOVE RIGHT: Floating them in a pan of water. Note: sometimes tapping the pan will help shake out some of the defects in the assembled pattern.
Updated January 22, 2014:
BELOW: Assembly of meatballs after being churned about in boiling water.

Saturday, January 18, 2014

A Redneck "Bleeper"?

It seems that when I fire a piezoelectric grill lighter near my TV tuner, it interferes with the picture a little and cuts out the sound for a about one syllable's length of time.  Another lighter on another tuner seems to just make a brief horizontal line on the screen but not so effective with cutting the sound.  Must be some radio-frequency emission in that electrical pulse? The effect happened on the 3 channels I tried. I do not really have a picture for that experiment, so I will use this pic of a fiery demo. The Bradley University Chemistry Club Demo Crew had their 120th show on Wednesday.  Thank God, we finally reached the 10,000 customer mark.  I was acting as the spotter as a student squirted water into burning liquid wax. If overdone, the flames could probably hit the lecture hall ceiling.  

Sunday, January 12, 2014

"Yogurt Lab" (not a demo)

My family and I were in Minneapolis, MN, this past Friday, and while we were exploring the skyway we found a frozen yogurt place called "Yogurt Lab."  It's part of a chain in Minnesota, see: http://www.yogurtlabs.com/. We enjoyed the snack and I loved the decor, especially the lamps that looked (but happily did not smell) like triethylamine molecules.



Monday, January 6, 2014

Very hot water in very cold air

During the present cold snap that is gripping much of the nation (-8 F for a high here in Peoria today), the Internet and other media outlets have been describing what happens when you toss near-boiling water into the very cold air.  Basically, the hot water breaks into fine droplets which instantly freeze to make an ice cloud, see: http://www.huffingtonpost.com/2014/01/04/boiling-water-extreme-cold-water-gun-ice-crystals_n_4538522.html?utm_hp_ref=mostpopular for more explanation.  I tried it, too, with cold water as a control experiment (no "cloud" was produced).  CAUTION: I have heard that people are burning themselves with hot water!  The air is not cold enough to freeze all of the water.  Throw the water away from you and downwind!