Preparation of ultralight glass foams via vacuum-assisted foaming

•Ultralight glass foams were fabricated using vacuum-assisted foaming approach.•Green spheres play an important role during the foaming process.•Both closed-cell and open-celled glass foams are successfully fabricated.•The compressive strength is higher than that reported in pertinent literatures.

We report a novel vacuum-assisted foaming technique for preparing ultralight glass foams using green spheres as raw material. The green spheres were sintered to form ultralight glass foams under vacuum pressure. The effect of sintering temperature and vacuum pressure on the preparation and properties of glass foams was investigated. The porosity and cell size increased with the decrease of vacuum pressure. Glass foams were fabricated at vacuum pressure of 30–70 kPa, with bulk density, porosity and compressive strength values of 0.081–0.122 g/cm3, 95.2–96.8% and 0.29–1.18 MPa, respectively. The ultralight glass foams have potential applications as thermal and acoustic insulation materials.

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