Plasma polymerization of tetrafluoroethylene. IV. Comparison of ethylene and tetrafluoroethylene by measurement of electron temperature and density of positive ions

Abstract

The double probe method was applied to plasma of tetrafluoroethylene (TFE) and ethylene and the electron temperature (Te) and density of positive ions (np) were measured at various discharge wattages. The probe current‐probe voltage diagrams for TFE were different from those for ethylene. The shape of its diagram indicates that a considerable number of negative ions exist in TFE plasma. The levels of np for TFE were also nearly six times greater than those for ethylene at the same discharge current. The dependence of TFE polymer deposition and the chemical structure of the polymer, based on ESCA data on discharge current, was related to Te and np measured by the probe method. The values of Te and np may not be directly related to the polymer formation in a plasma; the method provides a direct measure of plasma energy density where plasma polymerization takes place, whereas it cannot be accurately estimated by the input energy of a discharge. It was found that plasma energy density based on (npTe) for TFE plasma and that for ethylene differ significantly at the same level of input parameter (W/FM), where W is the discharge wattage, F is the volume flow rate, and M is the molecular weight of the monomer.

Preparation of Thin Cation-Exchange Membranes Using Glow Discharge Plasma Polymerization and Its Reactions

“…The contribution of the parent ion to polymer formation gives a polymer with minimal decomposition of sulfonyl fluoride and an aromatic structure. Because both electron temperature and concentration in the glow discharge plasma increase with applied discharge power, 35,36 decomposition reactions proceed, and small species generated by further fragmentation of the parent ion or other secondary decomposition reactions increase as shown by in situ mass spectrometry. Therefore a polymer with significant decomposition of sul-fonyl fluoride and benzene rings is deposited at high applied discharge power (Fig.…”

Chemical‐surface modification of polymers using atmospheric pressure nonequilibrium plasmas and comparisons with vacuum plasmas

“…Surface modification of polymers by vacuum nonequilibrium plasmas is well documented in the scientific literature. Examples of vacuum‐plasma chemical‐surface modification8, 13, 14 and physical‐surface modification15–17 plasma‐assisted chemical‐vapor deposition18–21 and surface‐property enhancement (e.g., adhesion improvement22–25) are prevalent. However, examples of polymer‐surface modification at atmospheric pressure with nonequilibrium plasmas are much rarer.…”

On the Effect of Film Deposition on Probe Surface in Measurement by the Insulated Pulse Probe Method

“…In particular, when the deposited film consists of an insulating material, the currentvoltage (I-V) characteristic of the probe is seriously distorted and fatal errors occur in the measurement. [3][4][5] Many researchers have investigated ways to solve this problem, which include heating the probe [6][7][8][9][10][11][12] or applying a high voltage bias to the probe. [13][14][15][16] In some cases, it is possible to avoid the deposition of insulating films on the probe surface by means of heating the probe to high temperature.…”