Variable Emissivity Electrochromics Using Ionic Electrolytes and Low Solar Absorptance Coatings, Phase I

In recent work, this firm developed a highly promising, patented variable emittance technology based on electrochromic Conducting Polymers, with: (1) Thin (< 0.2 mm), flexible, lightweight (0.176 kg/m2), variable area (0.5 cm2 - 0.5 m2. (2) Impervious to flexing, micrometeoroids.(3) High Delta Emittance (0.5, range 0.13 - 0.89).(4) > 105 cycles, < 5 s switching, indefinite optical memory. (5) Low power, 0.30 W/m2 (6) Space durability: (10-6 Torr) 100,000 electrochromic cycles, 90 thermal cycles;. no UV degradation > 500 h. Durability against atomic-O. (7) Operating temperature (-) 45 oC to (+) 100 oC, durability (-) 196 oC to (+) 100 oC. (8) Easily applicable with space-qualified adhesive to any surface. (9) Cost ca. < $5K/m2. A key technical barrier of the earlier generation of this technology was the need for a hermetic seal for space durability. This was resolved through use of unique ionic electrolytes. An additional drawback remained: High solar absorptance of the dark-state. In very recent, unrelated work, this firm has developed coatings that are IR transparent from 2 to 25 microns while having very low solar absorptance (data herein). In the proposed work, these will be used to arrive at unique, variable emissivity materials with very low solar absorptance. Proposed work includes extensive space durability testing. More »