1. Electrostatic Charge:
- When we peel Sellotape or cling film from its roll, friction between the tape and the surface creates an electrostatic charge. This charge can make the tape or film negatively charged.
- Our hands, through contact with various materials, can also acquire a static charge. When the charged tape or film is brought near our hand, the opposite charges attract each other, causing the tape or film to "stick" to our hand.
2. Van der Waals Forces:
- In addition to electrostatic charge, van der Waals forces also play a role in the attraction between Sellotape or cling film and our hands. Van der Waals forces are weak intermolecular forces that arise due to the fluctuations in the electron clouds of atoms and molecules.
- These forces are always present but become significant when two surfaces come very close to each other, as in the case of Sellotape or cling film touching our skin.
- The van der Waals forces contribute to the adhesion between the tape or film and our hand.
The strength of the attraction between Sellotape or cling film and our hand depends on several factors, including the amount of static charge accumulated, the surface roughness of the tape or film, humidity, and other environmental conditions.
In summary, the attraction between Sellotape or cling film and our hand is a result of a combination of electrostatic charge and van der Waals forces.