Transparent, hydrophobic composite aerogels with high mechanical strength and low high-temperature thermal conductivities.

A facile one-step polymer-incorporation sol-gel process, together with a surface modification and an ambient pressure drying processes, was developed to prepare silica-poly(vinylpyrrolidone) composite aerogels. These composite aerogels are with high hydrophobicity (static contact angle >120 degrees), good mechanical strength (Young's modulus of bending >30 MPa), and low high-temperature thermal conductivity (0.063 W/m-K at 300 degrees C), which are critical characteristics for practical applications of aerogels, particularly in energy saving areas, for long-term usage and large scale production.