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Advanced materials with large and dynamic variation in thermal properties, sought for urgent defense and space applications, have heretofore been elusive. Conducting polymers (CPs) have shown some intrinsic variation of mid‐ to far‐infrared (IR) signature in this respect, but the practical utilization of this has remained elusive. We report herein the first significant IR electrochromism in any material, to our knowledge, in the 0.4 through 45 μm region. This is seen in practical CP devices in the form of thin (<0.5 mm), flexible, entirely solid‐state, variable area (1 cm2 to 1 m2) flat panels. Typical properties include: very high reflectance variation; switching times <2 s; cyclabilities of 105 cycles; emittance variation from 0.32 to 0.79; solar absorptance variation from 0.39 to 0.79; operating temperatures of –35 to +85 °C; durability against γ‐radiation to 7.6 Mrad, vacuum to 10–6 torr, and simulated solar wind (e.g., 6.5 × 1016 e/cm2 @ 10 keV).

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Direct electropolymerization of a family of aromatic amines yields novel, stable conducting polymers with good conductivity and ca. 8 weight/weight percent (0.3M) or higher solubility in doped and undoped states in organic media. The polymers are electroactive in solution and recastable as films with spectroelectrochemical and electrochemical activity identical to virgin films. Detailed properties are reported in the present communication for two of the polymers, poly(N,N′‐diphenyl benzidine) and poly(benzidine), including solution electrochemistry, film properties of virgin vs. recast films, spectroelectrochemical properties which show broad‐band absorption across the visible spectral region and clear development of bipolaron bands, and charging capacities. Chronocoulometry, chronoamperometry, and chronovoltabsorptometry (optical transmission at specific wavelength as function of time and applied potential) show reversible behavior for films of poly(N,N′‐diphenyl benzidine) over several thousand cycles for pulses as short as 0.1 s, but polymer degradation on extended cycling for poly(benzidine). Polymer structural elucidation indicates a combination of N‐ andpara‐linkages for poly(N,N′‐diphenyl benzidine).

Variable emittance (e) is a property vital for the increasing needs in thermal control of future microspacecraft. This article describes fabrication, function, and performance of thin-film, flexible, variable-emittance (V-E) electrochromic skins that use a conducting polymer/-Au/-microporous membrane (CP/Au/mP) base, and a new, unique ionic liquid electrolyte (IonEl). Poly(aniline-codiphenyl amine) with a long-chain polymeric dopant is used as the CP. A unique, patented device design yields no barrier between the active, electrochromic CP surface and the external environment, except for a thin, infrared-transparent semiconductor/polymer film that lowers solar absorptance [a(s)] and protects from atomic-O/far-UV. Use of the IonEl requires special activation methods. Data presented show tailorable e variations from 0.19 to 0.90, De values of >0.50 (which is the highest reported thus far for any functional V-E material, to our knowledge), a(s) < 0.35, and nearly indefinite cyclability. Extended space durability testing, including calorimetric thermal vacuum and continuous light/dark cycling over >7 months under space conditions (<10 25 Pa vacuum, far-UV), show excellent durability. Other data show resistance to solar wind, atomic-O, electrostatic discharge, and micrometeoroids. These lightweight, inexpensive, advanced polymeric materials represent the only technology that can work with micro-(<20 kg) and nano-(<2 kg) spacecraft, thus eventually allowing for much greater flexibility in their design and potentially "democratizing" the entire space industry, for example, allowing small firms to launch their own, dedicated satellites. V C 2014 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2014, 131, 40850.