ABSTRACT Electrostatic discharge (ESD) influences a lot in the industries of petrochemistry, semiconductor, and electronics. ESD is one of the reasons for the deterioration of the lubricant in the lubrication system. In this study, to understand the performance of the frictional electrification of the lubricant, the circumrotating frictional electrification tester with the measurement systems is employed to investigate the friction electrification under the dry and lubricated conditions. The materials of the specimens are made of Fe and PTFE, and the paraffin base oil is used as the lubricant. Furthermore, the effects of the load, the sliding speed, and the sliding distance on the friction electrification are investigated. Results show that the electrification voltage and the surface voltage in the lubricated condition is much lower than in the dry condition for the pair of Fe/PTFE. Because the capacitance effect is almost disappears in the lubricated condition for the pair of Fe/PTFE. When two conductors become a capacitor by inserting an insulator, such as Fe/PTFE in the dry condition, the surface voltage is about 3~4 times higher than in the lubricated condition, and the frictional voltage is about 10 times higher than in the lubricated condition because of the isolator capacitance. Moreover, the oil, the PTFE and the Fe have different polarities. The surface voltage of PTFE and output voltages of Fe are negative, and surface voltage of oil are positive. The normal load, the sliding speed, and the sliding distance also affect the surface voltage of PTFE and output voltage of Fe. Among them, the load is the most significant parameter for surface voltage of PTFE, the sliding speed is the most significant parameter for output voltage of Fe.

ABSTRACT Electrostatic discharge (ESD) influences a lot in the industries of petrochemistry, semiconductor, and electronics. ESD is one of the reasons for the deterioration of the lubricant in the lubrication system. In this study, to understand the performance of the frictional electrification of the lubricant, the reciprocating frictional electrification tester with the measurement systems is employed to investigate the friction electrification under the dry and lubricated conditions. The materials of the specimens are made of Fe and PTFE, and the paraffin base oil is used as the lubricant. Furthermore, the effects of the load, the sliding speed, and the duration of the friction on the friction electrification are investigated. Results show that the electrification voltage in the lubricated condition is much higher than that in the dry condition for the all-material pairs, but the surface voltage is reverse. The measured voltage is lower for the pair of Fe/PTFE and PTFE/Fe because the capacitance effect of the isolator disappears. When two conductors become a capacitor by inserting an insulator, such as Fe/PTFE-Fe, the frictional voltage is about 2~3 times higher than the other pairs because of the isolator capacitance. Moreover, the rotational speed, the normal load, and the duration also affect the output voltage. Among them, the rotational speed is the most significant parameter. At a certain normal load, the oil and the iron have different polarities, and their voltages increase with increasing rotational speed for Fe/Fe pair. In the polarity study; the tribo-electrification mechanism is proposed for Fe/PTFE, PTFE/Fe and Fe/PTFE-Fe pairs. The output voltages are negative at the lower and the upper specimens for Fe/PTFE and PTFE/Fe pairs, but negative and positive for Fe/PTFE-Fe pairs, respectively. After the surfaces of Fe and PTFE slide together, since the high residual negative voltage appears on PTFE, which causes the separation of induced charge on Fe, the surface residual voltage of PTFE dominates the polarity of output voltage. At Fe/PTFE-Fe pair, the polarity at the upper specimen of Fe is negative. However, the polarity at the lower specimen of Fe is positive, because the lower specimen is also influenced by the surface residual voltage of PTFE.

Thesis (Ph.D.)--University of Tulsa, 1976. / Bibliography: leaves 85-87.

Thesis (M.S.)--West Virginia University, 1998. / Title from document title page. "December 1998." Document formatted into pages; contains x, 78 p. : ill. Vita. Includes abstract. Includes bibliographical references (p. 57-58).

No description available.

ABSTRACT Because of a great variety of tribocomponents and lubricants, the phenomenon of frictional magnetization and electrification between tribocomponents becomes more obvious. In order to understand the effects of frictional magnetization and electrification on tribology characteristics and miniature electrical control component signal, the frictional magnetization and electrification test under dry friction condition is investigated by the reciprocating electrification tester. Three material-pair types will be investigated their frictional magnetization and electrification behavior under various operating parameters, e.g. driver speed, normal load, and sliding distance. Moreover, the worn surface will be observed by the optical microscopy and SEM. Results show that the magnetization and electrification on friction surfaces increases with increasing load, and decreases with the carbon content of a material, and depends on material-pair. It is found that wear particles have been magnetized on the friction surface, even that the wear particles has been adhered to the surface caused by electro static action. Moreover, in the microscopic view, the frictional magnetization and electrification are related to both friction and wear.

No description available.

Thesis (M.S.)--Virginia Polytechnic Institute and State University, 1992. / Vita. Abstract. Includes bibliographical references (leaf 113). Also available via the Internet.

No description available.

The molecular weight distributions of two high molecular weight (M[subscript w]>>1 million) polyethylene polymers, WSR-308 and WSR-301, were characterized with gel permeation chromatography (GPC) coupled with a multi-angle laser light scattering detector (MALLS). The M[subscript w] of the WSR-308 was found to be 5.10x10⁶ g/mol with a molecular weight range from about 1 million g/mol to as high as 10 million g/mol. The M[subscript w] of the WSR-301 was found to be 3.16x10⁶ g/mol with the lowest molecular weight about 400,000 g/mol while the highest molecular weight component may have been as high as 8 million g/mol. Attempts to measure the M[subscript w] of the two polymers using static light scattering (SLS) techniques proved to be difficult. In conjunction with these studies, drag reduction and shear degradation studies of the two polymers in water were also conducted. Solutions of the two polymers, ranging from 1 to 10 ppm including mixtures of the two, were tested in a pipe-flow apparatus to obtain friction factor and %DR data. In every case, the greater the concentration and/or the molecular weight of the polymer, the greater the drag reduction effects. Additionally, the higher molecular weight polymer and mixtures with a greater weight percentage of the higher molecular weight polymer were found to shear degrade less quickly than otherwise. A unique point along the maximum drag reduction asymptote (MDA) termed the "divergence point" was a focus of this study and an energy model based on frictional losses correlates well to the data. The correlation developed here relates the difference in frictional losses between the solvent by itself and the polymer solution directly to the mass concentration and molecular weight of the polymer. This frictional difference was proportional to the product of the mass concentration and molecular weight where both quantities were to approximately the first power. / Graduation date: 2002