Interesting Science Experiments

Interesting Links to Science and Experiments:

Experiment #1: Baby Diaper Magic

Super absorbent baby diapers have a chemical called Sodium Polyacrylate embedded in the padding. If removed it can make an interesting experiment.

Note: Use of bag is to prevent fibers and chemical from drifting into the air. Though non-toxic it can be an irritant to eyes and nose if breathed.

Pull apart the inner lining and you will feel a "sand" like substance.
Rub the liner and pull apart the pads to remove as much of this as possible within the bag.
When the pad is in small pieces seal the bag and shake it to get most of the rest out.
Shake the bag to get the "sand" to one corner, snip off the corner and pour the contents into a glass.
Remove any remaining "fluff" from the sand like substance.
Slowly add distilled water (or tap water) to the glass, the substance will expand to 400 times its original size. (Salts or minerals in tap water will cause it to absorb less liquid)
You will find that it will absorb many ounces and still remain a solid gel.
Once you have a cup of gel, pour it onto a plate as a mound.
If you shake salt on this, the chemical will release its water (very quickly).
Do not pour the residue down the drain unless you have salted it first (it can plug pipes).
Another similar substance is: Polyacrylamide marketed as "Soil Moist". This will form large water crystals. In this case they are not subject to the "salt" effect and will remain crystals until the water evaporates.
Sodium Polyacrylate:
[CH2 - CH]n
|
C=O
|
O-Na
(Water bonds here)
Polyacrylamide:
[CH2 - CH]n
|
C=O
|
N
/ \
H H
| |
| | (Water Bonds Here)
O O
/ \ / \
H H H H

Experiment #2: Slimy Stuff - White

Caution: Borax can irritate the skin or eyes if left in contact (just as any other detergent) it is recommended that children under 12 should be supervised.

The glue is mostly Polyvinyl Acetate.
The molecule is long and thin.
Borax is used as a cross-linking agent to make the long thin molecules stick to each other.
In the end you have made long , thin, tangled molecules that are stuck to each other, therefore no longer are stickey or glue like.

Experiment #3: Slimy Stuff - Gel

Elmer's School Glue (The white stuff)
Borax Powder (Degergent section of store)
Caution: Borax can irritate the skin or eyes if left in contact (just as any other detergent) it is recommended that children under 12 should be supervised.
Food coloring if you want the slimy stuff to be colored

Disolve the borax in water until no more will disolve (Saturated 40g/l)
Add food coloring if desired.
Dilute the Elmer's Gel Glue by adding two parts water to one part glue. Stir and let sit over night to get the lumps out.
Mix about 4 parts of the diluted Elmers Gel Glue with one part borax solution.
Knead well for several minutes.
At first it will be very sticky but will become less so as you knead it.
Note that it will streach if pulled slowley or break if pulled fast.
How does this differ from the "white stuff"

The Elmers Gel Glue is mostly Polyvinyl Alcohol, a water soluble plastic.
The molecule is long and thin with many -OH groups
Borax hooks onto these OH groups and is used as a cross-linking agent to make the long thin molecules stick to each other.
In the end you have made long , thin, tangled molecules that are stuck to each other, therefore no longer are stickey or glue like.