Riera Enrique, Gallego-Juárez Juan A, Mason Timothy J
Instituto de Acústica, CSIC, Serrano, 144, 28006 Madrid, Spain.
Ultrason Sonochem. 2006 Feb;13(2):107-16. doi: 10.1016/j.ultsonch.2005.04.001. Epub 2005 Aug 19.
Sonochemistry is generally associated with the use of power ultrasound in liquid media. Under such circumstances acoustic cavitation can drive a range of reactions and processes. The use of airborne ultrasound in processing is less familiar because of the difficulties that relate to the use of ultrasound in gaseous systems. Firstly there is a greater attenuation (power loss) in the transmission of sound through air compared with that through liquid. Secondly the transfer of acoustic energy generated in air into a liquid or solid material is inefficient due to the mismatch between acoustic impedances of gases and solids or liquids. Despite this, applications do exist for airborne ultrasound but the source must be very powerful and efficient. In this way one can obtain levels of intensities at which it is possible to use ultrasound for specific applications such as to agglomerate fine dusts and to break down foams.
声化学通常与在液体介质中使用功率超声相关。在这种情况下，声空化可以驱动一系列反应和过程。由于在气体系统中使用超声存在困难，所以在加工过程中使用空气传播超声的情况不太常见。首先，与通过液体传播相比，声音在空气中传播时的衰减（功率损失）更大。其次，由于气体与固体或液体的声阻抗不匹配，空气中产生的声能向液体或固体材料的传递效率很低。尽管如此，空气传播超声仍有应用，但声源必须非常强大且高效。通过这种方式，可以获得能够将超声用于特定应用（如凝聚细粉尘和分解泡沫）的强度水平。
