2 September 2008 Photochemical processes in a two-component molecular contaminant film
Author Affiliations +
Abstract
Previously, significant laboratory work has been performed on the photochemical deposition and darkening of molecular contaminant films. Much of this work addresses single, purified molecular species to understand fundamental photochemical processes. However, some of this work disagrees with other studies involving mixed, real spacecraft materials. There are also points of disagreement with contaminated returned optics from the Hubble Space Telescope where mixed contaminants were found. In this paper, we describe a method for vacuum depositing a controlled, reproducible contaminant film containing two molecular species: tetramethyl-tetraphenyl trisiloxane (DC 704) and dioctyl phthalate (DOP). We use this film to show differences in photochemical processes compared to a pure film of DC 704. We show that some photopolymerization processes occur more slowly in a two-component, mixed film during accelerated exposure to vacuum ultraviolet (VUV) radiation.
© (2008) COPYRIGHT Society of Photo-Optical Instrumentation Engineers (SPIE). Downloading of the abstract is permitted for personal use only.
Kenneth T. Luey, Dianne J. Coleman, "Photochemical processes in a two-component molecular contaminant film", Proc. SPIE 7069, Optical System Contamination: Effects, Measurements, and Control 2008, 706903 (2 September 2008); doi: 10.1117/12.793502; https://doi.org/10.1117/12.793502
PROCEEDINGS
12 PAGES


SHARE
Back to Top