Acoustic Properties of Aerogels: Current Status and Prospects |
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Authors: | Tatiana Budtova Tapio Lokki Sadeq Malakooti Ameya Rege Hongbing Lu Barbara Milow Jaana Vapaavuori Stephanie L. Vivod |
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Affiliation: | 1. MINES Paris, PSL University, Center for Materials Forming (CEMEF), UMR CNRS 7635, CS 10207, 06904 Sophia Antipolis, France;2. Department of Signal Processing and Acoustics, Aalto University, 02150 Espoo, Finland;3. NASA Glenn Research Center, Materials and Structures Division, 21000 Brookpark Rd, Cleveland, OH, 44135 USA;4. Department of Aerogels and Aerogel Composites, Institute of Materials Research, German Aerospace Center (DLR), Linder Höhe, 51147 Cologne, Germany;5. Department of Mechanical Engineering, The University of Texas at Dallas, Richardson, TX, 75080 USA;6. Department of Chemistry and Material Science, Aalto University, 02150 Espoo, Finland |
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Abstract: | Noise reduction remains an important priority in the modern society, in particular, for urban areas and highly populated cities. Insulation of buildings and transport systems such as cars, trains, and airplanes has accelerated the need to develop advanced materials. Various porous materials, such as commercially available foams and granular and fibrous materials, are commonly used for sound mitigating applications. In this review, a special class of advanced porous materials, aerogels, is examined, and an overview of the current experimental and theoretical status of their acoustic properties is provided. Aerogels can be composed of inorganic matter, synthetic or natural polymers, as well as organic/inorganic composites and hybrids. Aerogels are highly porous nanostructured materials with a large number of meso- and small macropores; the mechanisms of sound absorption partly differ from those of traditional porous absorbers possessing large macropores. The understanding of the acoustic properties of aerogels is far from being complete, and experimental results remain scattered. It is demonstrated that the structure of the aerogel provides a complex three-dimensional architecture ideally suited for promising high-performance materials for acoustic mitigation systems. This is in addition to the numerous other desirable properties that include low density, low thermal conductivity, and low refractive index. |
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Keywords: | silica aerogels acoustic properties bio-aerogels composite aerogels polymer aerogels |
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