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Disappearing Water
Recommended Grade Level(s):
Appropriate for: All Grade Levels
Time Requirements:
Activity Time: 30 minutes
Teaching Topics & Concepts:
• To illustrate the absorbing power of the polymer found in diapers
and other disposable hygiene products.
• Polymers, osmosis, diffusion, absorption, and atoms.
• Measurements, calculations, and observations.
• Structure and properties of matter; gels, solids, and liquids.
Background:
From cloth and pins to game-changing superabsorbent-polymers, disposable hygiene products have come a long way, baby!
The advanced materials used in disposable absorbent hygiene products such as diapers and feminine pads have made life a lot
easier for all of humanity. Feminine pads and baby/adult diapers share similar functions and materials. The absorption capacity
of disposable absorbent products had significantly improved when manufacturers began using superabsorbent polymers (SAPs).
Students can discover the science behind SAPs' ability to absorb up to 1,000 times their own weight in water in this activity.
Materials:
• Acrylic sodium salt polymer (A.S.A.P.), diaper powder, or potassium polyacrylate
• Styrofoam cup
• Bottle of water
• Piece of cardboard
Procedure:
1. Cover the bottom of a white Styrofoam cup with a thin layer of ASAP powder before class.
2. Show the class that the cup is empty by tilting it towards them. (The diaper powder is white and, as a result, cannot be seen.)
3. Pour a small amount of the bottled water (~10 mL) into the cup.
4. Glance in the cup to check if all the powder was wetted by water. If not, add some more water.
5. Place a piece of cardboard over the top of the cup and then invert the cup.
6. Place the cup over a student's head and then remove the cardboard.
7. Allow the student to look up and then reveal the empty cup to the class.
+
ward
'
s
science
Safety
• Read the S.D.S. sheets for acrylic sodium salt polymer.
• Adult supervision required when handling chemicals.
• Wear safety glasses and gloves.
• Water/powder may fall out of the cup.
• Do not ingest any of the materials used in the activity.
• Minimize inhalation of chemicals used. This activity should be done in a well-ventilated area.
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