Spatial Inhomogeneity of Plasma Polymer Properties for Deposition Inside Small Diameter Tubing at Low Pressures: its (A) Use for Process Diagnosis and (B) Elimination by `residence Time Synchronized Pulsing'

Abstract

Deposition rate profiles within a tubular reactor (length = 51 cm, diameter = 1.1 cm) were found to be sensitive indicators of Yasuda's (W/FM)c for plasma polymers of tetramethyldisiloxane (TMDSO) at 40 W radio frequency (RF) power (13.56 MHz). (W/FM)c has been obtained for n-hexane, cyclohexane, cyclohexene, and benzene plasmas. Plasma polymer films of TMDSO deposited, as above, for long residence times (1.6 s) were chemically nonuniform along the length of the reactor, and had good physical properties. Those deposited at short residence times (0.2 s) were chemically uniform; however, yield was low, and physical properties were poor. The combination of good yield (>50%), desirable physical properties (<5% soluble in toluene, withstood Scotch tape test for adhesion to glass), and spatial uniformity of chemical properties was obtained for TMDSO using a water-jacketed reactor and Residence Time Synchronized Pulsing (ReTSyP). The low power portion of the pulse period was set≥the residence time. The effects of residence time and deposition site on chemical and physical properties were studied with FTIR spectroscopy and measurements of deposition rates and solubilities. This method can be used in other, less extreme, cases to achieve deposition of a chemically uniform product.

Department(s)

Chemical and Biochemical Engineering

International Standard Serial Number (ISSN)

0570-4898

Document Type

Article - Conference proceedings

Document Version

Citation

File Type

text

Language(s)

English

Rights

© 2024 The Authors, All rights reserved.

Publication Date

01 Dec 1994

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