Kids, let’s pop colored bubbles onto a piece of paper to make bubble prints. Bubble prints are like fingerprints except made with bubbles. You can make bubble prints and learn about how bubbles are shaped and how pigments combine to make different colors.
Please note: All chemicals and experiments can entail an element of risk, and no experiments should be performed without proper adult supervision.
Bubble prints are made by adding color to a bubble solution, blowing bubbles, and pressing paper onto the bubbles. You need brightly-colored bubbles in order to get a good picture. Tempera paint powder works really well, but you can substitute other water-soluble paints if you like. Here’s everything you need: bubble solution (buy it or make your own), tempera paint powder, white paper, straws, and some small plates.
First make your colored bubble solution. Pour a little bubble solution into a plate. Stir in paint powder until you have a thick paint. You want the thickest paint you can get, yet still able to make bubbles from it. If you get the three primary colors of tempera paint then you can mix them in order to make other colors. You can add black or white paint, too.
Make Bubble Prints
- Put the straw into the colored bubble solution and blow bubbles. It may help to tilt the dish slightly. You can experiment with a few large bubbles versus many small bubbles.
- Touch the bubbles with a sheet of paper. Don't press the paper down into the paint - just catch the impressions of the bubbles.
- You can switch between colors. For multicolored bubbles, add two colors together but don't mix them. Blow bubbles into the un-mixed solutions.
Learn About Bubbles
Bubbles consist of a thin film of soapy water filled with air. When you blow a bubble, the film expands outward. The forces acting cause it to form the shape that encloses the most volume with the least surface area -- a sphere. Look at the bubble prints that you have made. When bubbles stack, do they remain spheres? Probably not, because when two bubbles meet they will merge their walls to minimize their surface area. If bubbles that are the same size meet, then the wall that separates them will be flat. If bubbles that are different sizes meet, then the smaller bubble will bulge into the large bubble. Bubbles meet to form walls at an angle of 120°. If enough bubbles meet, the cells will form hexagons. Can you can see this structure in the images you’ve made?
--------------
Kathleen Carrado Gregar, PhD, Argonne National Labs
[email protected]
March 2009
----------------
References: Dr. Anne Marie Helmenstine at http://chemistry.about.com/od/bubbles/a/bubbleprints.htm
