How To Make Expo Marker Float On Water

Brand Your Drawings Bladder!

An animative science project from Science Buddies

Make Your Drawings Float! — Describe away! Employ a little chemistry to make your own moving sketches. Credit: George Retseck

Key concepts
Chemical science
Polymer
Solvents
Material science

Introduction
Have you ever wished your drawings would come up alive and the stick figures or objects on your paper could move around? It'due south not as incommunicable as information technology sounds! In this action you volition make your cartoon movement effectually by letting it float on h2o. What makes this possible is the interesting chemistry of dry-erase markers. These markers are normally used to write on whiteboards or glass surfaces and can easily be erased. It turns out they are also perfect for doing science!

Background
You might have a whiteboard in your school classroom. To draw on this surface, your teacher probably uses a whiteboard pen or dry-erase marking. The writing from these markers can easily be erased from the whiteboard without leaving whatever marks.

This is possible because dry-erase markers contain special ingredients. They include a solvent, which is usually some kind of alcohol. This is used to dissolve the color pigments that decide the marker's color. In addition, a resin or polymer is added, which is the primal to making the ink erasable. In a dry out-erase marker the resin is an oily silicone polymer, which acts every bit a "release agent." This makes the ink of the mark very slippery and prevents information technology from sticking to the whiteboard'south surface. This is why the ink can easily be wiped off from a very shine nonporous surface such as a whiteboard or glass.

You might know dry out-erase markers can stain other surfaces such as clothes permanently. This is because textile doesn't have a smoothen surface, so the ink can soak into its pores—staining them forever! In existent permanent markers the resin used is an acrylic polymer that functions as a "binding agent" and makes the ink stick to the surface. Only the blazon of polymer differentiates a permanent marker from an erasable marking. Find out how this departure affects how your drawings float in in this activity!

Materials

Two shallow trays or plates with smooth surfaces that you have permission to draw on with markers
Dry out-erase markers (different colors)
Permanent marker
Cup
H2o
Rubbing booze
Paper towels

Preparation

Discover a work area that can tolerate water spills.
Make full your cup with room-temperature h2o and set it next to your trays or plates.

Procedure

Choose one colour of your dry-erase markers and make a drawing on your first plate such every bit a stick figure, a eye or discussion. Does information technology look like the ink is sticking to the surface of your plate?
Let it dry for a couple of seconds and and so use a dry finger to wipe across your drawing. Does your finger wipe off the drawing, or can you still see it after?
If the drawing came off, make a new drawing. Otherwise, keep the sometime i. And so pour only plenty h2o onto your plate to cover the drawing. Wait and discover. If cypher happens, shake the plate a little fleck. What happens to the ink after a while? Does your cartoon begin to float and come up to life?
Next use a permanent mark to make a drawing on the second plate. Do you see a departure from how the dry-erase mark looked on the surface?
Let it dry out for a couple of seconds and utilize a dry finger to wipe across your drawing. Does your drawing disappear once you lot wipe it with your finger? Can you explain why or why not?
If the drawing came off, make a new drawing. Otherwise keep the onetime ane. Then pour some water on your plate to cover the drawing. Wait and notice. What happens to the cartoon this time? Does information technology float? How are your results different from the previous ones?
Extra: Brand drawings with different colors of dry-erase marking. Do all of them acquit the aforementioned way or are they different? Which color floats all-time?
Extra: What happens if you pour rubbing alcohol on acme of your cartoon instead of h2o? Does your drawing nevertheless float? Do dry-erase and permanent markers give you lot the aforementioned result? Why or why not?
Extra: Can you erase your floating drawing? Try to pick up your cartoon from the h2o's surface with your fingers. What happens to information technology when you pull information technology out of the water? What exercise you call up the material y'all at present have in your hand is made of?

Observations and results
Did you go your drawings to bladder? Y'all should have—but merely when using the dry out-erase marker. When y'all make your drawing on the surface of a smooth plate or tray the solvent, or alcohol, that dissolves the ink ingredients volition evaporate. This leaves the colour pigment and polymer behind on the surface. With the permanent and dry out-erase markers, information technology actually looks like the colour is sticking. When you wipe across your drawing with your finger, however, only the cartoon that yous made with the dry-erase mark will disappear. This is because the oily silicone polymer in the dry-erase marker prevents information technology from sticking whereas the acrylic polymer resin in the permanent marker makes information technology stick to the surface.

The fun starts when you pour water on your drawing. You lot should take observed your dry-erase marker cartoon magically detached from the plate and rose to the water's surface. There, it could float and move equally if it were alive! The permanent marker drawing should have remained stuck to the plate. This difference is due to the special polymer in the dry-erase marker ink—because this ingredient prevents the ink from attaching to the plate, and the h2o can slip underneath. And because the ink is lighter than h2o information technology can float. When yous poured rubbing booze on your drawings, however, you should have seen them both slowly dissolve. This is because alcohol is used as the solvent in both markers.

Cleanup
Remove all remaining drawings from your plates by rubbing them with a paper towel soaked in rubbing alcohol. And so rinse them with warm water and lather before reusing them.

More than to explore
Make Your Ain Markers, from Science Buddies
Chromatography: Be a Colour Detective, from Scientific American
Soluble Scientific discipline: Making Tie-Dye T-Shirts with Permanent Markers, from Scientific American
Science Activity for All Ages!, from Science Buddies

This activity brought to you in partnership with Science Buddies

Science Buddies