Anyone know of a product that expands on contact with water/liquid?

Question

Hi All,

Im trying to find a product that expands on contact with water/liquid....must be a non food item. Something like expanding foam that comes as a small pellet but when it comes into contact with water, it expands to a much bigger solid size....any ideas anyone?
Kind Regards

Answer 1

go to the toy dept of any dept store and get those little capsules that you put in water and they turn into dinosaur (or other shapes) shaped sponges! my kids love them!

Answer 2

I know you want a non-food item, but....here is something very interesting. It explains how tree roots are able to bust through concrete.

I has to do with the swelling of starches. Here is a really amazing experiment to show the incredible amount of force generated....

Get a heavy steel pipe with two end caps that screw on. Fill the pipe completely with dried lentils. After the pipe is filled with lentils, add water to the pipe to fill up the air spaces between the lentils. This might be tricky because the lentils will try to float out, a screen holding them down might help. Now put the other cap on the pipe. Here is the amazing part.....In about 2 to 3 hours the pipe with burst!

Somebody calculated that the pressure generated by the expanding starch in the lentils is on the order of 15 tons/ in2.

In Japan a daikon radish poked its way up through a paved road.

Here is a great link that shows the amazing power of plants bursting things.

http://waynesword.palomar.edu/pljuly96.htm

Aside from this, I know of various dehydrated plastics that expand greatly on contact with water.