Low temperature plasma treatment can effectively purify, activate, coarsene, etch and deposit the surface of materials.
1. The surface cleaning effect of plasma treatment: it can effectively remove organic pollutants and oxides on the surface of objects.
Main Features: Any wet cleaning method, the surface will have residue, only low temperature plasma surface treatment can achieve thorough purification, get ultra-clean surface, and low temperature plasma only on the surface of the material nano level, will not change the original characteristics of the material, in the process of high requirements for surface cleanliness, is replacing wet treatment process and is widely used.
Treatment mechanism: It mainly relies on the "activation" of active particles in plasma to achieve the purpose of removing stains on the surface of objects. The gas is excited into a plasma state; Heavy particles strike solid surfaces; Electrons and active groups react with the solid surface to resolve into a new gas phase substance and leave the surface.
The biggest feature of plasma cleaning technology is that it can be treated regardless of the substrate type of the treatment object. It can handle metals, semiconductors, oxides and most polymer materials, such as polypropylene, polyester, polyimide, polychloroethane, epoxy, and even polytetrafluoroethylene well, and can realize the overall and local cleaning as well as complex structures.
2. Activation of plasma treatment:
Hydroxyl groups C=O Carbonyl, -COOH Carboxyl and ?OH hydroxyl can be formed on the surface of an object treated by low temperature plasma. These groups have stable hydrophilic functions and have positive effects on bonding and coating.
Main Features: Can make the polymer surface appear part of the active atoms, free radicals and unsaturated bonds, these active groups and plasma in the active particles react to generate new active groups, so as to increase the surface energy, change the chemical characteristics of the surface, enhance the surface adhesion, bonding force, tension, including rubber, composite materials, glass, cloth, metal and other processing, involving all walks of life.
3. Surface coarsening and etching effect of plasma treatment:
Corresponding to different materials, the corresponding gas combination is used to form a strong etching gas-equivalent ionization body and the body of the material surface chemical reaction and physical impact, so that the solid substance on the surface of the material is vaporized, such as CO, CO2, H2O and other gases, so as to achieve the purpose of micro-etching.
Main features: uniform etching, does not change the characteristics of the material matrix; It can coarsene the surface of the material effectively and control the amount of micro-erosion accurately.
4, plasma treatment of coating (deposition, grafting) effect:
The plasma treatment process can also be applied to the micro coating of materials. Two corresponding different gases are selected to enter the plasma reaction chamber at the same time. When the two gases are excited and repolymerized in the plasma environment, new compounds will be deposited on the surface of the material to form a new coating. By using this special effect of plasma treatment, the material that is not easy to be coated can be coated on the surface of the object. For example, heart stents, artificial blood vessels of anti-coagulation coating, materials of anti-scratch surface and hydrophobic coating.
Main features: Can make the material surface molecular chain fracture to produce new free radicals, double bonds and other active groups, followed by cross-linking, grafting and other reactions, the active gas will be polymerized on the surface of the material to produce a layer of sedimentary layer, to achieve the purpose of material surface modification.
In fact, in the process of low-temperature plasma processing of objects, various positive and negative ions, high-energy and high-speed moving electrons, heavy particles and so on in the plasma gas will have physical and chemical reactions on the surface of the material being treated, so the above mentioned four (or five) effects of low-temperature plasma surface treatment are usually produced simultaneously.
