Aerogels: A “Green” thermo-acoustic insulation material with nanoscale properties.

Abstract

Aerogels are a well-known class of thermal insulation derived from nanoscience that has “green” benefits including translucence, thinness, hydrophobicity, light weight, and flexibility. Recently, the acoustical properties of aerogels have been characterized. Aerogels are currently available in building materials like skylights and exterior glazing, fabrics-based roofing membranes, and flexible blankets for insulating underwater pipelines and building walls. In 2008–2009, laboratory testing and field research began on the acoustical properties of thin profile (2–8-mm) architectural “tensile membrane” fabrics incorporating silica aerogel granules. Data from a tension structure in Canada—where aerogel-enhanced fabric was used to block aircraft noise—exhibited excellent acoustic absorption and acoustic impedance matching properties compared to insulators of comparable thickness. The material increased transmission loss of exterior to interior noise and also reduced indoor reverberation. In the same period, US field tests demonstrated an aerogel blanket material as a surface treatment in open offices to reduce broadband reverberation, resulting in increased speech intelligibility and privacy and enhanced acoustical comfort. These acoustical attributes combined with aerogels’ thermal value, thin form factor, translucence, hydrophobicity, light weight, and absence of VOCs had led to growing interest in green building applications ranging from aircraft interiors to hospitals.