Lightweight and high-strength glass foams prepared by a novel green spheres hollowing technique

Lightweight and high-strength glass foams were fabricated from recycled glass powder by a novel green spheres hollowing technique. Utilizing green spheres could tailor the microstructure features and properties of the foams and reduce the sintering temperatures to 680–800 °C. The foaming process of the sample consists of six consecutive stages. The obtained glass foams show uniform structure and small cell size, with apparent density, porosity, thermal conductivity and compressive strength values of 0.129–0.229 g/cm3, 91–95%, 0.055–0.077 W/m K and 0.85–5.92 MPa, respectively. In comparison to glass foams prepared via traditional methods, the obtained glass foams have exceptionally high mechanical strengths. The green spheres hollowing technique is a general, energy-saving and easy scale-up approach for the fabrication of inorganic foams.