In Situ Low‐Temperature Pre‐Reaction Method for Preparing K 2 O· n SiO 2 Laminated Anti‐Fire and Thermal‐Insulation Glass

ABSTRACT The K 2 O· n SiO 2 laminated anti‐fire and thermal‐insulation glass was prepared by a new low‐temperature in situ pre‐reaction method using the high‐solid content (55 wt%) and low‐viscosity (16.5 ± 0.1 mPa s (500 1/s)) SiO 2 sol. This method favored the preservation of the K 2 O· n SiO 2 precursor for a long time at low‐temperature environment, which promoted industrialized production. In this article, dynamics of in situ reaction, subsidence kinetics, failure characteristics, and mechanism at low temperatures and anti‐fire and thermal‐insulation mechanism were analyzed in detail. The curing reaction of the K 2 O· n SiO 2 precursor was a first‐order reaction with a reaction rate constant k T = 8.38 × 10 7 exp(−75.1 × 10 3 /( RT )). The hardness, low‐temperature, ultraviolet‐resistance, and thermal‐insulation performances were systematically characterized. The steel ball method was used to study the hardness of materials. The differential scanning calorimeter revealed the relationship between the low‐temperature performance of materials at the microscopic level and their freezable water content. And combined with liquid nitrogen‐assisted cryogenic imaging technology (LNACIT) to observe ice‐crystal growth, it revealed the failure characteristics and mechanism at low temperatures. The microporous structure that enhanced thermal‐insulation performance by prolonging heat transfer was clearly revealed in SEM. This work provided new approaches to improve reliability and safety of K 2 O· n SiO 2 material in extreme environments.