Monday, August 11, 2014

Gizmos, Gadgets, and Goo – Wacky Fun with Science Week 5 : Squish! Polymers, Diapers, and Goo…Oh My!

Be prepared to get messy as we explore the powers of polymers  by dissecting diapers and mixing up  a batch of Oobleck  -- the original Non-Newtonian solid (it behaves as both a solid and a liquid at the same time!) 
For grades 1-5.

As kids arrive, played video on polymers: 
image (this and all other videos used today can be found on my playlist

Opened with: “I Tried to Do My Homework” from What a Day It Was at School! poems by Jack Prelutsky (had shared on some school visits)

Read:  The Secret Science Project that Almost Ate the School – Judy Sierra

Booktalked: Bartholomew & the Oobleck – Dr. Seuss  (too long to read in this program…)

Discussion: Whatever we call it “Slime, goo…Oobleck”…soft material called “polymer” …some polymers in nature: rubber, wool, silk, proteins in our hair & nails, cellulose in trees…some polymrs synthetic “man made” e.g. nylon (“on” indicates a polymer) or polyester or polystyrene “poly” is a clue that it is a polymer too.
The word polymer means “many parts.” The individual parts that actually combine to form a polymer chain are called monomers.  Sometimes a substance can actually help polymer chains link together and form a more solid substance. The youtube video we saw as you were coming in showed the basic formation of polymers and linked polymer chains.  Polymers can be found just about everywhere – Even the double-helix strand of DNA is a form of a polymer known as a “biopolymer.”

DEMO: Oobleck, this version is a natural polymer made only from cornstarch & water.  In the 18th c. Sir Isaac Newton discovered that most liquids flow quickly when heated and resist movement when cooled…but this slimy polymer acts “weird” it is called a non-Newtonian fluid – it looks and feels like both a solid and a liquid, depending on how you handle it.

Mix together 2 parts cornstarch, 1 part water …let kids feel it…see how it flows but then acts solid.

Showed videos:

Pool of Oobleck:

Creeping Oobleck:
image – tennis racket with goo – cool!

Three experiment tables today:
Experiment #1:  Diaper Magic
Tiny polymers no larger than a grain of sand are mixed into the cotton lining the inside of a diaper. Modern diapers actually contain a super absorbent polymers no larger than grains of sand – they are called polyacrylic acid and are designed to attract water molecules.
§ Diapers (we used Luvs size 2) – 1 per child
§ Scissors
§ Gallon-sized zip-top plastic bags
§ Clear plastic cups (1 for each child)
§ Popsicle sticks for stirring
§ Cut into the lining, pull apart the cotton, put the diaper in a zip-top bag and shake the bags.
§ Pour the polymers into a clear plastic cup, then add water..a little at a time, stirring if necessary – have kids guess how much water they can pour in and still be able to turn the cup upside down without spilling!
Result: The polymers absorb the water and congeal to form a squishy, gel-like substance. If the gel-like substance is powdery and loose, it can still absorb water; if the substance is moist, it has reached the capacity of the polymers. Each polymer can absorb about 30 times its weight in water!  If you leave the cup full of squishy polymers on a counter top for a few days (or longer) and allow the water to evaporate, the polymers should return to their original state…what do you think?

Experiment #2:  Goo! formula provided by Science Bob
(I found using 1T. of each ingredient and 1 drop of food coloring was sufficient. We mixed the goo in 5 oz. plastic cups using popsicle sticks.  The resulting goo is lots of fun to handle -- solid enough to pick up in your hands, stretch, pull apart and squeeze back together.)
Another version: silly putty:

Experiment #3: Changing properties – 4 types of Oobleck using different amounts of water --from: Oobleck, Slime, & Dancing Spaghetti by Jennifer Williams -- each has different characteristics.  Data sheet on pg. 52 (didn’t have time to use).

Beforehand: Mix the Sodium Borate solution -- 1 cup 20 Mule Team Borax with 1 quart/liter of hot water in a bottle or pitcher.  Shake or stir well.  If possible, let it set overnight.  Shake well before using.
All of these mix  the same amount of glue (which contains hundreds of polymers) & sodium borate solution (which is a binding agent) to lock the polymer molecules together…adding different amounts of water will affect how tightly the chains of polymers can link together…the more water, the more the polymer can “stretch,” and the less it can bounce and hold its shape.

Red Oobleck:1 T. white glue
1  drop food coloring
2 t. sodium borate

Green Oobleck:1 T. white glue
1  drop food coloring
1 t. water
2 t. sodium borate

Yellow Oobleck:1 T. white glue
1  drop food coloring
1T.  water
2 t. sodium borate

Green Oobleck:1 T. white glue
1  drop food coloring
2T.  water
2 t. sodium borate

For each color of ooblick:
§ Mix glue and food coloring in a plastic cup.
§ Add  water (if applicable) and stir till well-blended
§ Slowly pour the sodium borate solution and stir for about a minute
§ Lift the spoon slowly out of the cup and observe the Oobleck. What does each look like?
§ Feel or knead the oobleck …how do they differ?  Can you roll it into a ball?
§ If you put it on the table, does it hold its shape or start to flatten out after a while?
§ If you can make it into a ball, how well does it bounce?

Have zip-top sandwich bags for them to use to take home their creations.
Another version of slime:

Much of this program was inspired by:

BWL 11/14

1 comment:

  1. Also check out this great program plan:


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