Thermal Conductivity of Monolithic Organic Aerogels

• Published in: Science (American Association for the Advancement of Science) Vol. 255; no. 5047; pp. 971 - 972
• Main Authors: Lu, X., Arduini-Schuster, M. C., Kuhn, J., Nilsson, O., Fricke, J., Pekala, R. W.
• Format: Journal Article
• Language: English
• Published: Washington, DC American Society for the Advancement of Science 21-02-1992; American Association for the Advancement of Science; The American Association for the Advancement of Science
• Subjects: 540120 - Environment, Atmospheric- Chemicals Monitoring & Transport- (1990-); Aerogels; AIR POLLUTION ABATEMENT; Astronomy; Chemistry; CHLOROFLUOROCARBONS; Colloidal gels. Colloidal sols; Colloidal state and disperse state; Conduction; Conductivity; Density; ENVIRONMENTAL SCIENCES; Exact sciences and technology; Gas density; Gas pressure; Gels; General and physical chemistry; Heat; Heat conduction; Infrared radiation; INFRARED SPECTRA; Infrared spectrum; ORGANIC CHLORINE COMPOUNDS; ORGANIC COMPOUNDS; ORGANIC FLUORINE COMPOUNDS; ORGANIC HALOGEN COMPOUNDS; PHYSICAL PROPERTIES; Physics; POLLUTION ABATEMENT; Solids; SPECTRA; THERMAL CONDUCTIVITY; THERMAL INSULATION; THERMODYNAMIC PROPERTIES; Topography; Colloidal gel; Thermal properties; Infrared spectrometry; Aerogel; Thermal conductivity; Formaldehyde; Resorcinol
• ISSN: 0036-8075; 1095-9203
• DOI: 10.1126/science.255.5047.971

The total thermal conductivity λ of resorcinol-formaldehyde aerogel monoliths has been measured as a function of density ρ in the range from ρ = 80 to 300 kilograms per cubic meter. A record-low conductivity value in air at 300 K of λ ≈ 0.012 watt per meter per kelvin was found for ρ ≈ 157 kilograms per cubic meter. Caloric measurements under variation of gas pressure as well as spectral infrared transmission measurements allowed the determination of solid conductivity, gaseous conductivity, and radiative conductivity as a function of density. The development of such low conductivity materials is of great interest with respect to the substitution of environmentally harmful insulating foams made from chlorofluorocarbons.