Why Is Sponge Absorbent?

Sponge is a porous material with good water absorption and can be used to clean things.

Commonly used sponges are made of wood cellulose fibers or foamed plastic polymers. In addition, there are also natural sponges made of sponge animals. Most natural sponges are used for body cleaning or painting. In addition, there are three types of synthetic sponges made of other materials, namely low-density polyether (non-absorbent sponge), polyvinyl alcohol (high-absorbent material without obvious pores) and polyester.

The sponge material itself has many small voids, which are filled with air. When the sponge is pressed to absorb water, the sponge is pressurized to discharge its own air, and when released, it will restore its original shape and at the same time inhale the original air. In the case of water, it is subject to atmospheric pressure on the one hand, and on the other hand, it has the characteristics that both high pressure and high pressure will balance to low pressure. , The pressure of the sponge on the surroundings is relatively small, so water will enter the sponge. After the sponge absorbs water, the water will sink when it is left standing, because it is affected by atmospheric pressure and gravity.