Photocatalytic coating and method for cleaning spacecraft surfaces

A photocatalytic coating based on titanium dioxide, and certain titanates is applied to the critical external optical spacecraft surfaces to be protected from contamination with polymerized hydrocarbon films. The thickness of the coating is within the range of 5 Angstrom to 2x104 Angstrom and it can...

Ausführliche Beschreibung

Gespeichert in:

Bibliographische Detailangaben
Hauptverfasser:	WILLIAMSON WELDON S, VAJO JOHN J
Format:	Patent
Sprache:	eng
Schlagworte:	ADHESIVES AIRCRAFT AVIATION CHEMICAL OR PHYSICAL PROCESSES, e.g. CATALYSIS OR COLLOIDCHEMISTRY CHEMICAL PAINT OR INK REMOVERS CHEMICAL SURFACE TREATMENT CHEMISTRY COATING BY VACUUM EVAPORATION, BY SPUTTERING, BY ION IMPLANTATIONOR BY CHEMICAL VAPOUR DEPOSITION, IN GENERAL COATING BY VACUUM EVAPORATION, BY SPUTTERING, BY IONIMPLANTATION OR BY CHEMICAL VAPOUR DEPOSITION, IN GENERAL COATING COMPOSITIONS, e.g. PAINTS, VARNISHES ORLACQUERS COATING MATERIAL WITH METALLIC MATERIAL COATING METALLIC MATERIAL CORRECTING FLUIDS COSMONAUTICS DIFFUSION TREATMENT OF METALLIC MATERIAL DYES FILLING PASTES INHIBITING CORROSION OF METALLIC MATERIAL OR INCRUSTATION INGENERAL INKS MATERIALS FOR MISCELLANEOUS APPLICATIONS, NOT PROVIDED FORELSEWHERE METALLURGY MISCELLANEOUS APPLICATIONS OF MATERIALS MISCELLANEOUS COMPOSITIONS NATURAL RESINS PAINTS PASTES OR SOLIDS FOR COLOURING OR PRINTING PERFORMING OPERATIONS PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL POLISHES SURFACE TREATMENT OF METALLIC MATERIAL BY DIFFUSION INTO THESURFACE, BY CHEMICAL CONVERSION OR SUBSTITUTION THEIR RELEVANT APPARATUS TRANSPORTING USE OF MATERIALS THEREFOR VEHICLES OR EQUIPMENT THEREFOR WOODSTAINS
Online-Zugang:	Volltext bestellen
Tags:	Tag hinzufügen Keine Tags, Fügen Sie den ersten Tag hinzu!

Beschreibung
Zusammenfassung:	A photocatalytic coating based on titanium dioxide, and certain titanates is applied to the critical external optical spacecraft surfaces to be protected from contamination with polymerized hydrocarbon films. The thickness of the coating is within the range of 5 Angstrom to 2x104 Angstrom and it can be applied using a variety of methods, such as sputtering, electron beam evaporation, or sol-gel processing. A method for cleaning the spacecraft surfaces initiated by a reaction of the coating with a UV-photon, followed by oxidation of the hydrocarbons adsorbed on the protected surfaces thus preventing their polymerization on the surfaces and causing their safe evaporation and dissipation into the environment. At orbital altitudes a stream of H2O2 or oxygen is directed at the surface, possibly continuously, and preferably, periodically, regenerating the original form of titanium in the photocatalytic coating and re-starting the cleaning cycle. The surfaces at orbital altitudes are cleaned by a combined action of the coating and oxygen.