Tunable sound absorption of silicone rubber materials via mesoporous silica

In this contribution, a new pathway for the regulation of sound absorption properties of silicone rubber (SR) materials was presented using worm-like mesoporous silica (MS) with nanoscaled channels and pores. The MS enhanced the sound absorption coefficient of SR in a wide range of sound frequency from 1 to 5 kHz. By introducing the MS with an average pore diameter of 5.56 nm and a specific surface area of 1026 m² g^-1, the sound absorption coefficient of the MS/SR composite was as high as 0.83 at a sound frequency of 1.8 kHz, which is nearly triple that of the pure SR. Moreover, the mechanical and thermal properties of the SR were retained in the composite. The reflection and friction of sound waves between the pore walls and the depleted energy by viscous absorption were suggested as the main mechanism responsible for the enhanced sound absorption coefficient. It is helpful to design and fabricate rubber materials with tunable sound absorption properties.