Vibration and structure-borne sound isolation properties of silica aerogels

Vibration reduction and structure-borne sound insulation create a healthy environment in housing by reducing the exposure of the habitants from sources outside or inside the building (railway and road traffic, neighbors). Current solutions include textiles, polymer foams, rubber mats and metal springs, but for many applications, highly sought after. Although thermal insulation drives the silica aerogel market, acoustic applications are increasingly gaining attention. Most acoustic studies focus on airborne sound absorption, but structure-borne sound and vibration isolation remain unexplored. In this paper, we compare the vibroacoustic properties of silica aerogel granules to those of recycled rubber and expanded cork to assess the suitability for vibration damping or vibration isolation. With a remarkably low resonance frequency (<12 Hz) and dynamic stiffness (<0.1 N/mm3), silica aerogels provide superior vibration isolation performance compared to recycled rubber (by 8 dB) over a wide range of static loads (0.02–0.12 MPa), and silica aerogel may become a viable solution for vibration isolation in construction.