3. How to modify the surface of plastic materials?

The surface of plastic materials can be modified:

• or by physical treatment (plasma techniques, accelerated electron beams, etc.);

• or by chemical treatments such as adsorption (deposition) or radiografting of a molecule carrying a bioactive functionality onto the receptor support (here, a plastic material).

The lifetime of the functionality imparted to a surface is a key parameter in the application of modified materials. It is short-lived following physical treatment, due to the recombination of radical species generated by the treatment. On the other hand, after adsorption or grafting of bioactive molecules, it depends on the nature of the bonds established at the support/modified layer interface, i.e. hydrogen bonds (reversible) or covalent bonds (permanent).