Traditional methods for imparting hydrophobic properties are
carried with wet chemistry. The disadvantage of this method is that
it produces large amounts of toxic effluents. Liquid processes have
many disadvantages when compared to gas phase processes. These
disadvantages include the disposal of the used solvents, diffusion
limited transport and poor control of reactants among others [6]. It
is desirable to graft the monomer without producing toxic effluents
in a dry process. Plasma technology presents a solution to this problem,
since it is a dry and clean technology and it has matured enough
to be used on industrial scale. Plasma is defined as a medium
composed of radicals, metastable molecules, photons and charged
particles such as ions and electrons. In general plasmas are generated
by exposing a gas to radiofrequency or microwave electrical
discharges. Microwave creates a plasma with higher density than
radiofrequency. Plasma technology is becoming more attractive for
surface modification of substrates. The advantage of using plasma
is that there is no need to use toxic radicals as initiators or crosslinkers
and the amount of toxic effluents is minimized. Furthermore,
plasma is a cold process, thus, there is no thermal degradation of
the substrate.