Dilatant materials

On January 2, 2007, in Did you know?, by Tom

A dilatant material is one in which viscosity increases with the rate of shear.” (wikipedia)

In other words, a dilatant material will become “thicker” or “harder” when it is hit. This is counter-intuitive… imagine a liquid that becomes solid when it is hit, then quickly returns to a liquid.

A simple example of a dilatant material is called “oobleck“. Oobleck is a mixture of cornstarch and water. Click here to learn how to make oobleck at home.

There is currently research going on that uses dilatant materials for flexible body armor. When a bullet strikes the fluid, it immediately becomes hard, protecting the person wearing it. The armor is full of polyethylene glycol with nano-particles of silica suspended in it. For you super-nerds: polyethylene glycol is a relative if ethylene glycol (anit-freeze), and is used to thicken shampoo and cosmetics.

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1 Response » to “Dilatant materials”

  1. Teck Lau says:

    You are right about the dilatant. But, do you know how to produce it?

    Reply

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