Synthesis of macroporous ceramic with enhanced sound absorption capability in low and medium frequency.

We propose a novel hybrid method to produce macroporous ceramic with excellent sound absorption coefficient at medium and low frequency noise and multimodal pore size distribution. Macroporous ceramics with pore sizes from 100 nm to 2000 μm and apparent porosity in the range 85%–90% were fabricated by twice-foaming method and two pore-forming agents. These ceramics display a sound absorption coefficients from 0.11 to 0.99 in the sound-wave frequency range of 200–2000 Hz with sufficient connectivity rate above 99%. This ceramic represents a highly expected industrialization of properties for noise control and reduction at corrosive environments and high temperatures. [ABSTRACT FROM AUTHOR]