兔子是毛茸茸的, 烂泥是黏糊糊的, 气球是有弹性的. 那么什么物质即毛茸茸又黏糊糊又有弹性，而且还很好玩呢? 这就是弹性橡皮泥（Silly Putty）, 加克（Gak）和粘液!
另外这些物质还让我们困惑。因为大部分这些物质在低温时会变硬，而随着自身温度的升高变得更易流动。我们可以回忆一下，天冷的时候，蜂蜜是从瓶口缓慢地流出来的，而天气炎热的时候，它就会快速地从瓶子里冒出来。弹性橡皮泥（Silly Putty）, 加克（Gak）和粘液是不一样的。当你把它们紧握在拳头里时你会感觉到它们像固体一样坚硬，但是一旦你松开拳头，它们就会像浓稠的液体一样从你的手指间滑下。为什么粘液会不一样？在这个实验活动中，你将会制作你自己的粘液，还可以玩一玩，从中还能发现是什么让粘液流动了！
- 已做过防护处理的工作空间(和工作服) ，这样粘液粘在上面时不会被损坏
- Pour one half cup of glue and one quarter cup of warm water in a container. Note that this solution has 2/3 (or 67 percent) glue.
- Optional: If you like colored slime, you can mix in a few drops of food coloring. Another option is to put the tip of a marker into the water for a short time so the ink dissolves in the water.
- Stir the glue/water mixture with the stirring rod.
- Add five tablespoons of the borax solution to your glue/water mix.
- Stir with the stirring rod. After some stirring, you should see a substance sticking to your stirrer. Does the sticky substance look like a solid or like a liquid—or can you not tell yet?
- If your substance is still watery, add more borax solution ¼ tablespoon at a time until there is very little watery solution left.
- Collect the sticky substance in your hands and work it with your hands for about one minute. How does the slime feel? How does the stickiness and stretchiness change when you work it for a while?
- Would you say the slime is a liquid, or is it more like a solid?
- Squeeze your slime into an oval and use both hands to pull it apart quickly. Does it tear or elongate?
- Squeeze your slime into an oval again and use both hands to pull it apart slowly. Does it tear or elongate? How thin can you get it?
- Work your slime with your hands to form a ball. Try to stick your finger into it forcefully. How deep does your finger go?Does it feel like you poked your finger into something solid, or something liquid?
- Now try to stick your finger into it gently. How deep does your finger go?Does it feel like you poked your finger into something solid, or something liquid?
- Squeeze your slime into a ball again and put it in a container. What do you think will happen if you leave it there for a while? Will it stay in an oval, like a solid would do, or will it relax into a puddle and take the form of the container, like a liquid would do?
- Optional: To keep your slime nice and soft, store it in an airtight container or ziplock bag.
- Extra: Add other substances, such as shaving cream or liquid soap, to your glue/water solution. Will you still obtain slime? How will this slime feel and look different?
- Extra: Leave your slime uncovered for a day. What do you think will happen? Will it become more like a solid, or start to flow easier? Why do you think this will happen?
Observations and results
Did the slime sometimes feel like a solid and sometimes like a fluid? This is expected.
This type of slime thickens or becomes harder or more viscous when you squeeze or stir it. This happens because it is made up of very long particles that are cross-linked. When you leave the particles alone they will coil up, and the coils can slide over each other. When you apply pressure by squeezing or stirring, some coils unwind and become entangled, making it harder for the slime to flow.
When you stirred your slime, tried to rip it apart or poked your finger into it with force, the polymers were entangled and it looked like a solid. As a result, it was hard to stir, it ripped apart, and your finger bounced back.
When you left your slime alone to rest, gently pulled it apart or gently poked your finger in it, the polymers were curled up. They could slide over one another, and it felt more like a liquid. As a result, the slime took the form of the container, it could be stretched thin, and your finger could move through it. It did not flow as easily as water because it consists of long cross-linked particles, whereas water consists of small particles. When a substance keeps its volume but loses its form when left alone, scientists call it a liquid.
Do not pour glue solutions or slime down a drain because they can form clogs. Instead, throw them away in the garbage. Wash all equipment with soapy water.