Floating Dry Erase Marker Experiment


Dry Erase Marker Experiment

The floating dry erase marker experiment is a simple and education science project that’s safe for young children. But, you don’t have to be a kid to enjoy it! Basically, it involves drawing a picture and floating it off the surface using water. The project demonstrates key science concepts, including adhesion, solubility, and density.

Materials

All you need are basic household materials:

  • Dry erase markers
  • Water
  • Flat-bottom plate or dish

Make sure the dish you use is very clean and dry. If it is at all greasy or damp, writing on it is difficult.

What You Do

It’s easy:

  1. Write words or draw simple pictures on the bottom of the dish. For example, write you name, draw hearts or stars, or create a scene.
  2. Make sure the lines are thick and connected. You don’t want any blank spots or else you might wind up with a torn image.
  3. Carefully pour water into the container. Pour it down the side of dish and not right on top of the picture. Using a measuring cup with a spout or else pour water over the back of a spoon helps in gently adding water.

Depending on the brand of marker, the images either detach and float when wet or they need a bit of help. If the ink does not float, gently rock the container side to side to give the water a bit of a current. Or, carefully slide the back of a spoon beneath the ink and release it so it floats. If you like, capture the images using a spoon and examine them or place them on a new surface.

How the Floating Dry Erase Marker Experiment Works

The floating dry erase marker experiment works because the ink in the marker easily lifts off of the surface in water, the pigment particles stick together so the image remains intact, and the pigment is less dense than water so that it floats.

The main chemicals in dry erase markers are pigments, solvent (usually SD-alcohol 40 or isopropyl alcohol), and a release agent (resin or a silicone polymer).

The alcohol is the solvent that holds the pigments suspended in the marker. It’s much less toxic than other solvents that also work, like xylene and methanol. But, like these other solvents, it readily evaporates. That’s why markers don’t last very long if you leave them uncapped and also why the ink dries so quickly when you draw. The special ingredient in dry erase markers is the release agent. It sticks or adheres to a flat surface. It’s soluble (dissolves) in both alcohol and water, but sticky enough when it’s dry that it holds the pigment molecules together and onto the writing surface. It holds the pigment molecules to each other and to the surface mainly using van der Waals forces, where the slight electrostatic charge between the ink and surface loosely binds them together.

Keep in mind, dry erase markers only float away in water if you apply them to flat surfaces, like metal, glass, or plastic. If you use a rough surface, like a paper plate, the ink flows into the pores in the surface and absorbs rather than adsorbs. Your image won’t detach.

Why Permanent Markers Don’t Work

Permanent markers are much like dry erase and wet erase markers, except that they use an acrylic polymer instead of a release agent. Basically, it’s a permanent resin that adheres to the surface and does not dissolve in water.

If you accidentally use a permanent marker instead of a dry erase marker for this project, it’s not forever. The acrylic layer is thin enough that it comes off pretty easily using rubbing alcohol, acetone, or products that contain these ingredients, like nail polish remover.

Make It an Experiment

Really, this is a science project. But, it easily turns into a science experiment if you ask “what if” questions, make a prediction, and then perform an experiment and assess the outcome. For example:

  • Does water temperature matter? Try the floating dry erase marker experiment using hot water, room temperature water, and cold water. (Hint: Increasing the temperature increases the rate of chemical reactions, including dissolving.)
  • Do the floating images stick onto surfaces? For example, if you slide a plate underneath the image and lift it off, will it stick to it once it dries? Can you transfer the image onto your skin?
  • Does floating off the image change the color of the ink? If so, why do you think this happens?
  • Do all colors of dry erase marker work equally well? Do all brands work equally well?
  • What do you think happens if you use wet-erase instead of dry-erase markers?

References