Polymer glazing for silver mirrors
This paper reports on an evaluation and modification of polymeric glazings to protect silver mirrors. The mirrors were made using Corning 7809 glass as a substrate onto which a thin silver film is deposited. The modified polymeric films are then cast from solution onto the silver. The mirrors were characterized by measuring the hemispherical reflectance and the specular reflectance at 660 nm and selected acceptance angles (7.5 mrad or 3.5 mrad). The mirrors were exposed to environmental degradation using accelerated weathering devices and outdoor exposure. Empirical evidence has demonstrated that polymethylmethacrylate is a stable polymer in a terrestrial environment, but the polymer does not provide adequate protection for the silver reflector. The crucial role in degradation played by ultraviolet (uv) light is shown by several experimental results. It has been demonstrated that uv stabilizers added to the polymer improve the weatherability of mirrors. The relative effectiveness of different stabilizers will be discussed in terms of the weathering modes, retention of optical properties, and effectiveness of the additives. The process for silver deposition influences the reflectance of silver mirrors, and the optical properties depend on subtle relationships between the metallization and the dielectric (polymeric) films that are in contact with the silver.
- Research Organization:
- Solar Energy Research Inst., Golden, CO (USA)
- DOE Contract Number:
- AC02-83CH10093
- OSTI ID:
- 5573649
- Report Number(s):
- SERI/TP-255-2724; CONF-850887-3; ON: DE85012140
- Country of Publication:
- United States
- Language:
- English
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Related Subjects
141000* -- Solar Collectors & Concentrators
DATA
DEPOSITION
ELECTROMAGNETIC RADIATION
ELEMENTS
EQUIPMENT
ESTERS
EXPERIMENTAL DATA
GLAZING MATERIALS
INFORMATION
MATERIALS
METALS
MIRRORS
NUMERICAL DATA
OPTICAL PROPERTIES
ORGANIC COMPOUNDS
ORGANIC POLYMERS
PHYSICAL PROPERTIES
PMMA
POLYACRYLATES
POLYMER GLAZING
POLYMERS
POLYVINYLS
RADIATIONS
REFLECTANCE
SILVER
SILVER DEPOSITION
SILVER MIRRORS
SOLAR CONCENTRATORS
SOLAR EQUIPMENT
SOLAR REFLECTORS
SPECTRAL REFLECTANCE
STABILITY
SURFACE COATING
THERMAL DEGRADATION
TRANSITION ELEMENTS
ULTRAVIOLET RADIATION
UV STABILIZERS
WEATHERING