What do scissors do on the molecular level?

In terms of paper,

Paper is made of cellulose, and in papers there are two real main kinds of bonds, there are the strong intermolecular forces, such as hydrogen bonding between the microfibrils of cellulose, and there are weak intermolecular forces such as Van Der Waal’s forces. When you cut with scissors on paper the bonds that are going to be broken are the weak intermolecular forces.

The pressure created by the scissors deforms the material by poisson expansion (which essentially is when you apply pressure to the middle of something, it will split in both perpendicular directions) and breaks the weaker intermolecular forces in the material because the molecules with those bonds begin to become very distorted and out of shape. The weaker  bonds will break and create two seperate parts of the material with the odd strong bond in the way being broken too.

The reason you’re not able to reattach the two seperated bits of paper is that the layer of atoms exposed will oxidise very rapidly and for a barrier that stops reintegration. (Fun fact, this is the reason cold welding exists as in space the oxide layer can’t form and you can just put two pieces of metal together)  – see this for more details  http://www.coolsciencefacts.com/2006/metal.html 



Leave a Reply

Fill in your details below or click an icon to log in:

WordPress.com Logo

You are commenting using your WordPress.com account. Log Out / Change )

Twitter picture

You are commenting using your Twitter account. Log Out / Change )

Facebook photo

You are commenting using your Facebook account. Log Out / Change )

Google+ photo

You are commenting using your Google+ account. Log Out / Change )

Connecting to %s