Plasma treatment is a surface modification technique that can significantly alter the surface energy of polymers. It involves exposing the polymer surface to a plasma, which is an ionized gas containing a mixture of ions, electrons, and neutral species. The plasma is generated by applying an electric field to a gas, typically at low pressure. The interaction between the plasma and the polymer surface leads to various physical and chemical changes, which in turn affect the surface energy of the polymer.There are several ways in which plasma treatment can affect the surface energy of polymers:1. Surface cleaning: Plasma treatment can effectively remove organic contaminants and other impurities from the polymer surface. This cleaning process can increase the surface energy by exposing the underlying polar functional groups, which can improve the wettability and adhesion properties of the polymer.2. Surface etching: Plasma treatment can cause surface etching or ablation, which involves the removal of a thin layer of the polymer surface. This process can create a rougher surface with increased surface area, leading to a higher surface energy.3. Surface activation: Plasma treatment can introduce new functional groups or modify existing ones on the polymer surface. This process, known as surface activation, can increase the surface energy by creating more polar or reactive sites on the surface. Examples of functional groups that can be introduced or modified during plasma treatment include hydroxyl -OH , carboxyl -COOH , and amine -NH2 groups.4. Crosslinking: Plasma treatment can induce crosslinking between polymer chains, which can lead to a more rigid and dense surface structure. This process can increase the surface energy by reducing the mobility of polymer chains and increasing the number of polar functional groups on the surface.5. Chain scission: Plasma treatment can also cause chain scission or the breaking of polymer chains. This process can create new reactive sites on the polymer surface, which can increase the surface energy.Overall, plasma treatment can significantly alter the surface energy of polymers by modifying their surface chemistry and topography. The resulting changes in surface energy can lead to improved wettability, adhesion, and other surface properties, making plasma treatment a valuable tool for various applications in materials science, biomedical engineering, and other fields.