RAINBOW SNOW

• Rainbow Snow Experiment
• Take it Further!
• Take it Even Further!
• Take it Further Further!
• Additional Information
• Science Fair Connection

NOTE 1: Yardsticks and/or meter sticks can be pricey or even off limits if you plan to glue plastic cups to them. Any narrow strip of wood that looks like a yardstick will work just fine. You just have to be able to handle it and roll it easily in your hands.

NOTE 2: Strong, double-faced tape or sticky pads can replace the hot glue gun.

By now you can easily explain the change in the polymer and why it expanded when water was added to the cup. However, maybe you noticed that there was a bit less of a reaction and the snow level in each cup was a little lower this time than with uncolored water. What ideas do you have about why this happened? What was added this time that you did not use in making plain snow? Your colorful personality will probably suggest an answer: the dyes in the Color Fizzer Tablets! There are other chemicals in the tablets that may be involved but it is pretty clear that the expansion of the polymer was effected by something. In fact, if you look closely, you might even be able to see some differences in levels of the snow in the various dye colors in each cup. The chemicals used to create the various colors are tied to water molecules and can slow down the movement of water molecules into the polymer so the snow does not expand as much.

It is fun to combine science and art! When it comes right down to it, the principles artists use to create their works are direct applications of the rules of science. Monet’s impressionist dabs of color and Da Vinci’s use of perspective and pigment mixing provide us with great masterpieces to enjoy. Glazes, glass work, sculptures, and bronze come to us from talented people who rely on science to express themselves. How will you use your colored snow to express yourself? What happens if you mix some together? What if you leave some unmixed but let it dry out? Here’s your chance to discover something new about yourself!

Rainbow Snow is an amazing superabsorbent polymer (sodium polyacrylate or Hydrogel) that turns ordinary water into a white fluffy substance that looks like real snow. This polymer is a long chain of repeating molecules that instantly grabs loose water molecules and holds onto them. Rainbow Snow is the latest technology of this polymer used by movie makers to create incredibly realistic snow scenes without the hassle of cold temperatures, melting ice, potato flakes, or soap powders. Just add water and watch the polymer expand 300 to 500 times its original weight as it takes up the water!

A polymer very similar to this one is what you will find in the baby diaper your little brother or sister is wearing (perhaps you did, too, even!). A small amount of the polymer can be shaken from the filler material in a diaper (an unused diaper, please) and tested in your lab. You will notice that when it is wet, it is a slightly different type of polymer in that it is more “clumpy” and solid and holds it shape. The molecules in the diaper polymer are designed to stay together like this instead of separating into fluff like the polymer does in Rainbow Snow. However, both polymers can absorb a lot of, well, “warm liquid.”

Speaking of temperature, you will notice that even though you used warm water, a handful of Rainbow Snow feels very cool to the touch. Since molecules of warm water move faster, they leave the surface of your skin faster. The slower, colder water molecules are left behind and you sense this as a lower temperature on your skin. That is why you shiver when you get out of a swimming pool on a breezy day or step out of a tub or shower with water on your skin.

An important feature of Rainbow Snow is that it can be reused. (The used diaper polymer? Not so much.) Reusing Rainbow Snow is one reason you want to keep it clean. When you are finished working with it, spread it out into a single layer on a large pan or cookie sheet. Leave it exposed to the air but keep it out of reach of small children and pets. Depending upon several things, e.g. the amount of water you used, the temperature, the humidity, the time of year, the alignment of the planets (OK, kidding about that one.), the polymer will be ready for use again in a matter of days or weeks. Store the completely dried polymer in a sealable plastic bag (moist, dirty polymer might get moldy). On the other hand, if you want to just get rid of it, seal it in a plastic bag and toss it into the trash. Don’t dump it down the drain unless you know a really cheap plumber.

A reaction like this is a physical reaction and not a chemical reaction. It is physical because when you let Rainbow Snow dry out, you get back the materials you started with, i.e. the water (as vapor) and the dry polymer. Also, there are no new products made. Freezing and melting water is a physical reaction as are breaking a glass and cutting an apple. A chemical reaction results in products different from what went into the reaction. Mixing baking soda and vinegar is definitely a chemical reaction and so is digesting that apple and burning wood.
You can squeeze Rainbow Snow into a small wad but it does not hold that shape. It is not compressible into anything but a smaller size; kind of like gases at room temperature. Take the pressure off and it springs back to its original size and shape. Also notice that when you let Rainbow Snow dry out completely, you have the original amount of dry polymer again. If you could have collected it, the amount of water you used would have been the same as what you started with, too. This is called conservation of matter which tells you that no matter the reaction (chemical or physical), you will end up with exactly the same amount of matter you started with even though the form of matter you started with (solid, liquid, or gas) may come out of the reaction in a different form.

Changing the shape of the container for this reaction can lead to a whole new experience! What you did using a narrow container was to confine and slow the reaction so you could watch it move down the water-soaked Rainbow Snow inside the container. Think about it for a minute though. The water you poured in quickly mixed with the dry polymer so you weren’t watching the water move down the container. It had already done that. What you were seeing move down the inside was the actual reaction of the polymer grabbing the free water molecules and literally exploding to a size that could no longer fit inside the container. That “layer” you saw moving downward could be called the “reaction layer” which was where the polymer was doing what it was designed to do which is grabbing unattached water molecules.

You can use this set up to see the reaction in greater detail. You might be able to video the reaction (use time lapse even?) and watch what happens frame by frame. The narrow-container rig might be the ideal way to observe the reaction while testing a variable like, say, the water temperature. Start with a question to test: “What happens to the speed of the reaction if you change the water temperature?” Now there’s a question that needs several tests to find the answer. Yep – it has science fair written all over it!

Like soap bubbles and water drops, the shape you pull out of the box is spherical. Physicists will tell you that bubbles and water drops (this snowball is mostly water) want to use a minimum amount of surface area to enclose the volume of material trapped inside. The most efficient shape for water drops, bubbles, and the water-saturated snow is spherical. You might think you can just add more water and make a bigger snowball. Try it and see what the limits might be. Keep in mind, however, that you will want to have your snowballs collapse into a second container. In other words, make them from one container with the drier snow and let them fall apart over a second container of water-saturated snow. Since you are adding a lot more water to make a snowball than is needed to make plain snow, the saturation level in the snow will rise tremendously each time a snowball collapses into it. This means you will have to make more plain snow to supply what you need to find the limits of the snowball size you can create. Oh darn, it is such a bother to make more snow. Poor you!

At some point along the way to making plain snow, you might wonder if you can get rid of the cup and just make it in your hands. Keep the “clean hands” reminder in your thinking and go for it! It is much easier if you just make a watertight cup with both hands and have someone else do the polymer and water shtick but you can do it yourself with one hand in a pinch. This is what is called “hands on” science and it really connects you to the experience.

There is another way to break up one of your snowballs and that is just by adding a little salt. Plain old table salt is the enemy of this polymer because it breaks the water-grabbing bonds inside it and pulls the water out of the polymer. You end up with a salty goo that does not do anything but look icky. And yes, this is definitely a chemical reaction. There is no reversing the destruction, either, so keep any form of salt a long way from your supply of Rainbow Snow Polymer or batches you may be using or drying. You should sacrifice a little snow so you can see the reaction for yourself. That way if your little brother sneaks some polymer down the drain, you can dump salt into it and be the hero.

Additional Information

Rainbow Snow is Insta-Snow®. There is only one Insta-Snow® as indicated by that “circle R” thing. We don’t use the ® everywhere because it becomes somewhat annoying, but the name Insta-Snow is a federally registered trademark of Steve Spangler Inc. (Federal Trademark Registration #2928946). But that hasn’t stopped the knock-off companies from branding their own versions of a snow polymer. Our favorite knock-offs are the companies who believe that Insta-Snow is the same superabsorbent polymer found in a baby’s diaper. If this were true, every time the baby went potty, the diaper would erupt to an enormous size and explode! Might be a great way to potty train the kid, but it’s not true. Insta-Snow® is the only polymer that instantly ERUPTS when it comes in contact with water. The knock-off “snow” companies tell their customers to “…add water and stir the mixture for 20-30 seconds to make snow.” All you have after 30 seconds is a tired hand and a cup of baby diaper goo.

Science Fair Connection

Observing and discovering Rainbow Snow is pretty cool, but the demonstration isn’t a science fair project, yet. You can make it one simply by identifying a variable (something that might change the outcome) in the experiment (like using more or less water in a snowball); then testing that variable (as you did); and correctly reporting the results. Think about some variables like these that you might test:

• How might different liquids change the outcome with the snow polymer? How about testing milk or diet soda? vinegar? distilled water?
• Test different temperatures of liquid. How does that affect the amount or speed of absorption? What’s the ideal temperature of the ideal liquid to make the largest amount of Rainbow Snow from a single scoop?

These are just a couple of ideas, but you aren’t limited to them! Come up with different ideas of variables to test and give them a try. Remember, you can only change one variable at a time for each test. For example, if you are testing different water temperatures, make sure that all other factors in the test remain the same!