In-situ preparation and performance of cold resistant K2O·5SiO2 based anti-fire glass

We describe a method for the synthesis of cold resistant K2O·5SiO2 based anti-fire material using a new high content and low viscosity SiO2 core–shell emulsion (HSLVCS SiO2 emulsion). The anti-fire glass which wasn't frozen at −71 ± 1 °C was prepared by the in-situ reaction. The onion-shaped core–shell structure was clearly shown in scanning electron microscopy (SEM) micrographs, the viscosity of HSLVCS SiO2 emulsion (50 wt%) was 431.4 ± 12.1 mPa·s(48 rpm). Its in-situ reaction process for preparation of the K2O·5SiO2 followed a first-order reaction, the reaction rate constant kn = 1.774 × 108 exp (−Ea/RT) with the apparent activation energy Ea = 79.80 kJ/mol. The low-temperature-withstanding capability was tested at extreme-cold environment (−71 ± 1 °C), and the reasons for this were found by the thermogravimetric analysis (TG). The weather resistance capacity was more than 1000 h through ultraviolet (UV) test and the sponge-like microporous insulation layer can increase the fire insulation time by the fire-resistant test. This work provided a new routine toward the synthesis of the high quality anti-fire glass with various shapes, including curved surface structures.