When you scrub or rub a material, electron transfer can occur due to a phenomenon called triboelectric effect. The triboelectric effect involves the transfer of electrons between two materials that are in contact and then separated.
At the quantum level, electron transfer during the triboelectric effect can be explained by differences in the electron affinity and ionization energy of the materials involved. Electron affinity refers to the tendency of a material to attract and hold electrons, while ionization energy is the energy required to remove an electron from an atom or molecule.
When two materials come into contact and are rubbed together, their surface atoms interact, and electron transfer can take place. The atoms in the material with a higher electron affinity tend to attract electrons from the material with a lower electron affinity. This leads to an accumulation of negative charge on one material and a corresponding positive charge on the other.
The triboelectric effect is not universally applicable to all materials. The ability of a material to release electrons through friction depends on its electron affinity, ionization energy, and surface properties. Some materials have a strong tendency to release electrons and become positively charged, while others tend to gain electrons and become negatively charged. The specific behavior depends on the combination of materials involved in the rubbing process.
Furthermore, factors such as humidity, temperature, and surface conditions can influence the triboelectric charging process. For example, dry environments tend to promote more significant electron transfer than humid environments.
It's important to note that the triboelectric effect and electron transfer during rubbing are not the only mechanisms through which electrons can be emitted from a material. Other processes such as thermionic emission and field emission can also contribute to electron release under different circumstances.
In summary, the triboelectric effect allows for the transfer of electrons between materials during rubbing, resulting in the accumulation of charges on the surfaces. However, not all matter releases electrons through friction, as the behavior depends on the electron affinity, ionization energy, and surface properties of the materials involved.