Radio-frequency glow discharge systems

A long tube with the coupling coil at the middle was used for the plasma polymerization of TFE in an inductively coupled radio-frequency glow discharge using a flow system. Deposition rates and the chemical nature of the polymer were detected as a function of location in the reactor tube relative to the coupling coil and of applied... 

Several types of continuous discharges are easily available in the laboratory. These are radio frequency, Townsend, coronas, glows (normal and abnormal), and arcs. Each system possesses special characteristics which in effect govern the motion of charged particles between the electrodes, and apart from a few special cases the systems are too complex to lend themselves to simple analytical description for studying ion-molecule reactions. Here, two of the latter systems—namely, coronas and glows—will be treated in detail in order to demonstrate their feasibility for studying both exothermic and endothermic reactions. 

The distribution of polymer deposition observed in the plasma polymerization of acetylene at different flow rates (and different system pressures under plasma conditions) is shown in Figure 20.2. It should be noted that acetylene is the fastest polymerizing hydrocarbon and the system pressure decreases on the inception of glow discharge. In this particular configuration of reactor, the monomer does not pass the radio frequency coil, and presents a typical case in which the creation of chemically reactive species occurs at the boundary where the monomer meets the luminous gas phase, i.e., activation by luminous gas, not by ionization. 

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