Conducting Polymer (CP) infrared electrochromics in spacecraft thermal control and military applications

Chandrasekhar, Prasanna; Zay, Brian J.; McQueeney, T.; Scara, A.; Ross, David; Birur, Gajanana C.; Haapanen, Siina I.; Kauder, Lonny R.; Swanson, Theodore D.; Douglas, D.

doi:10.1016/s0379-6779(02)00682-3

Cited by 44 publications

(28 citation statements)

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“…Variable emissivity surfaces can be classified as either changing the optical properties of the surface material itself or modifying the surface structurally to alter its radiation heat transfer performance. Polymer-based materials 1 and inorganic thin films 2 are two examples of the surfaces with variable optical properties. Two structurally active surfaces under development are electrostatic devices 3,4 (also called Electrostatic Switched Radiator (ESR)) and MEMS louvers.…”

Section: Introductionmentioning

confidence: 99%

Novel Method for Measurement of Total Hemispherical Emissivity

Moghaddam

Lawler

Currano

et al. 2007

Journal of Thermophysics and Heat Transfer

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The public reporting burden for this collection of information is estimated to average 1 hour per response, including the time for reviewing instructions, searching existing data sources, searching existing data sources, gathering and maintaining the data needed, and completing and reviewing the collection of information. Send comments regarding this burden estimate or any other aspect of this collection of information, including suggestions for reducing this burden, to Department of Defense, Washington Headquarters Services, Directorate for Information SPONSORING/MONITORING AGENCY REPORT NUMBER(S) AFRL-ML-WP-TP-2006-456 DISTRIBUTION/AVAILABILITY STATEMENTApproved for public release; distribution is unlimited. SUPPLEMENTARY NOTESThis is a Small Business Innovation Research (SBIR) Phase II report. This paper contains color. PAO Case Number: AFRL/WS 06-1287, 15 May 2006. This work, resulting in whole or in part from Department of the Air Force contract FA8650-05-C-5045, has been submitted to the AIAA for publication in the AIAA Journal of Thermophysics and Heat Transfer Guidelines. If published, AIAA may assert copyright. The United States has for itself and others acting on its behalf an unlimited, paid-up, nonexclusive, irrevocable worldwide license to use, modify, reproduce, release, perform, display, or disclose the work by or on behalf of the Government. All other rights are reserved by the copyright owner. ABSTRACTThis report was developed under a SBIR contract. This paper describes a heat flux-based method for measuring emissivity of a surface. In this method the emissivity of a surface is calculated using direct measurement of the heat flux passing through the surface. Unlike storage-based calorimetric methods, this method does not require application of known amounts of heat to the surface or the temperature history of a known amount of thermal mass to calculate the surface emissivity. Application and operation of this method is much simpler than calorimetric methods as it does not require careful thermal insulation of the heat radiating body from the surroundings. This technique allows emissivity measurements of the newly developed variable emissivity surfaces with significantly lighter and energy efficient measurement equipment that can operate for long term space missions. In this study, a commercially available thermopile heat flux sensor was used to measure the emissivity of a black paint and a variable emissivity surface, Electrostatic Switched Radiator (ESR). This paper details the concept, experimental setup, and the experiment results. Maryland, College Park, MD, 20742 Abstract. This paper describes a heat flux-based method for measuring emissivity of a surface. In this method the emissivity of a surface is calculated using direct measurement of the heat flux passing through the surface. Unlike storage-based calorimetric methods, this method does not require application of known amounts of heat to the surface or the temperature history of a known amount of thermal mass to calculate the surf...

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Section: Introductionmentioning

confidence: 99%

Novel Method for Measurement of Total Hemispherical Emissivity

Moghaddam

Lawler

Currano

et al. 2007

Journal of Thermophysics and Heat Transfer

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“…They are also increasingly inadequate for the greater thermal control needs of modern, energy‐intensive, large spacecraft. These latter include future manned missions where multiple coolant loops interface to crew quarters on one end and external radiators (e.g., louvers) on the other …”

Section: Introductionmentioning

confidence: 99%

“…Another, important property of thermal control materials is their solar absorptance, α(s), which is an absorptance that is integrated specifically over the solar spectrum, with predominant contributions in the 0.3–1.5 µm spectral region. It again varies from 0 to 1, with low values indicating low absorption of solar radiation.…”

Section: Introductionmentioning

confidence: 99%

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Variable‐emittance infrared electrochromic skins combining unique conducting polymers, ionic liquid electrolytes, microporous polymer membranes, and semiconductor/polymer coatings, for spacecraft thermal control

Chandrasekhar

Zay

Lawrence

et al. 2014

J of Applied Polymer Sci

121

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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.

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“…Regardless, to the best of our knowledge, there are no reports of incorporating an Fc derivative into a poly(acetylene) in a manner that enables direct modulation of the conjugated polymer backbone. We envisioned such a material to display electrochromic properties, which are useful for switchable display devices and for controlling thermal emission signatures . Moreover, if the material exhibited absorption in the near‐IR, new approaches to switching optical telecommunications networks, which utilize optical fibers comprised of silica transparent in the 1300–1550 nm region, may be realized.…”

Section: Introductionmentioning

confidence: 99%

Electrochromic Poly(acetylene)s with Switchable Visible/Near‐IR Absorption Characteristics

Pauly

Varnado

Bielawski

et al. 2013

Macromol. Rapid Commun.

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Ferrocene is incorporated into a poly(acetylene) derivative via the postpolymerization amidation of a polymer precursor bearing pentafluorophenyl ester-leaving groups with aminoferrocene. While the neutral polymer exhibits a strong absorbance at 553 nm due to its conjugated backbone, oxidation of the ferrocene moieties with silver tetrafluoroborate causes the material to absorb in the near-IR (λ max ≈ 1215 nm). Subsequent reduction of the oxidized polymer with decamethylferrocene restores the initial absorbance profile, demonstrating that the material features switchable visible/near-IR absorption characteristics.

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Conducting Polymer (CP) infrared electrochromics in spacecraft thermal control and military applications

Cited by 44 publications

References 0 publications

Novel Method for Measurement of Total Hemispherical Emissivity

Novel Method for Measurement of Total Hemispherical Emissivity

Variable‐emittance infrared electrochromic skins combining unique conducting polymers, ionic liquid electrolytes, microporous polymer membranes, and semiconductor/polymer coatings, for spacecraft thermal control

Electrochromic Poly(acetylene)s with Switchable Visible/Near‐IR Absorption Characteristics

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