How does hair absorb oil? do we need a lot of hairs then how to join the hair to make it work?

Question

How does hair absorb oil? do we need a lot of hairs then how to join the hair to make it work?

Answer 1

To make what work?  I'll assume that you're referring to the use of hair to clean up oil spills.

Hair does not "absorb" oil.  Instead, it "adsorbs" oil, meaing that the oil clings to the outside of the hair and doesn't get absorbed into the hair.  This is one of the reasons that it makes sense to use hair to clean up oil spills because you can simply wring the oil out of the hair and it can then be used instead of being discarded.

A lot of hair is needed to adsorb a large oil spill, but then again, a lot of hair ends up in landfills anyway.

There is no need to join it together.  Hair can be stuffed into porous sacks or made into mats that are then used to clean up oil spills.