Technology

Today Plasma technology offers a valid alternative to conventional chemistry in the process of surface finishing of materials, with many benefits due to its high eco-sustainability.Plasma chemistry is a “dry and green” chemistry working without solvents and with minimal use of reagents. 

Plasma technology is based on the physical principle that by supplying energy to matter, changes in its state happen so that solids becomes liquid, and liquids becomes gaseous. If energy is supplied to a gas, it is ionized and generates the PLASMA , called the fourth state of matter. This is an ionized gas rich of reactive species such as radicals, ions and electrons able to modify the surface properties of the materials exposed to it. It becomes possible to finely tune the surface properties of the materials through the fine adjustment of the experimental parameters, resulting in a customized “surface tailoring “ of materials, without affecting their bulk properties.

Materials exposed to a glow discharge are modified through the interaction of the species generated in the gas plasma phase (atoms, radicals, ions) with the surface of the material. Plasma processes modify the surface of materials through the synthesis of stable interfaces. Covalent bonds are formed between the active species in the plasma phase and the substrate material. It becomes possible to finely tune the surface properties of the materials through the fine adjustment of the experimental parameters, resulting in a customized “surface tailoring “ of materials, without affecting their bulk properties.

Three main classes of plasma processes can be defined, namely:

Plasma Etching, Plasma Enhanced Chemical VapourDeposition (PE-CVD) and Plasma Treatment 

The ablation of materials through the formation of volatile products after interaction of the material with the active species produced in the plasma.This class of processes is most commonly used in microelectronics, for designing integrated circuits with high spatial resolution, by means of the anisotropic chemical attack on silicon. Furthermore these processes underlie the technologies of cleaning or sterilization.

Grafting of functional groups on materials. Grafted functional groups may be partially associated with a certain degree of cross-linking of the treated surface. Plasma treatments are generally used to impart new surface properties on polymers, paper, textiles and other materials with negligible addition or subtraction of mass. Stable changes from hydrophobic to hydrophilic surfaces (and viceversa) are possible, and many others for uses like enhanced printing capability, dyeing, metallization, enhanced/ reduced wettability, and many others.

Plasma Enhanced Chemical Vapour Deposition (PE-CVD) deposition of thin (5-1000nm) organic or inorganic coatings, this is probably the widest class of plasma processes.PE-CVD processes can apply many different classes of coatings to tailor the surface of materials,with composition and properties that span from teflon-like to silica-like to nano-composite, from superhydrophobic to hydrophilicto hydrogel-like.It is possible to adjust at the best of the customer needs or applications the stability of the coating-material interface, a property that is crucial for uses like corrosion protection and functionalization of biomedical polymers.