Surface characterization of LDEF materials

dc.contributor.authorGrammer, Holly L.en
dc.contributor.departmentChemistryen
dc.date.accessioned2023-01-27T04:47:49Zen
dc.date.available2023-01-27T04:47:49Zen
dc.date.issued1993en
dc.description.abstractThe NASA Long Duration Exposure Facility (LDEF), a passive experimental satellite, was placed into low-Earth orbit by the Shuttle Challenger in April 1984. The LDEF spent an unprecedented 69 months in space. The flight and recovery of the LDEF has provided a wealth of information on the long-term space environmental effects of a variety of materials exposed to the low-Earth orbit environment. Surface characterization of LDEF materials included polymers, composites, thermal control paints, and aluminum. X-ray photoelectron spectroscopy (XPS}, Auger electron spectroscopy (AES), scanning electron microscopy (SEM), and contact angle analysis were used to document changes in both the surface composition and surface chemistry of these materials. Detailed XPS analysis of the polymer systems, such as KaptonĀ®, polyimide polysiloxane copolymers, and fluorinated ethylene propylene thermal blankets on the backside of the LDEF revealed significant changes in both the surface composition and surface chemistry as a result of exposure to the low-Earth orbit environment. Polymer systems such as KaptonĀ®, polyimide polysiloxane copolymers, and polysulfone showed a common trend of decreasing carbon content and increasing oxygen content with respect to the control sample. Carbon ls curve fit XPS analysis of the composite samples, in conjunction with SEM photomicrographs, revealed significant ablation of the polymer matrix resin to expose the carbon fibers of the composite during exposure to the space environment. Surface characterization of anodized aluminum tray clamps, which were located at regular intervals over the entire LDEF frame, has provided the first results to evaluate the extent of contamination with respect to position on the LDEF. The XPS results clearly showed that the amount and state of both silicon and fluorine contamination were directly dependent upon the position of the tray clamp on the LDEF.en
dc.description.degreeM.S.en
dc.format.extentxvi, 236 leavesen
dc.format.mimetypeapplication/pdfen
dc.identifier.urihttp://hdl.handle.net/10919/113502en
dc.language.isoenen
dc.publisherVirginia Polytechnic Institute and State Universityen
dc.relation.isformatofOCLC# 29687339en
dc.rightsIn Copyrighten
dc.rights.urihttp://rightsstatements.org/vocab/InC/1.0/en
dc.subject.lccLD5655.V855 1993.G735en
dc.subject.lcshMaterials -- Effect of space environment onen
dc.subject.lcshSpace environmenten
dc.titleSurface characterization of LDEF materialsen
dc.typeThesisen
dc.type.dcmitypeTexten
thesis.degree.disciplineChemistryen
thesis.degree.grantorVirginia Polytechnic Institute and State Universityen
thesis.degree.levelmastersen
thesis.degree.nameM.S.en

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