Colorless Transparent Melamine–Formaldehyde Aerogels for Thermal Insulation

Aerogels have many unique properties such as low density and low thermal conductivity, and, in particular, transparent silica aerogels are attractive for thermal insulating windows. Practical applications of silica aerogels, however, have been limited because of their low mechanical strength, and it is still challenging to synthesize transparent and mechanically strong aerogels. Here, we report colorless transparent melamine–formaldehyde (MF) aerogels prepared via a nonaqueous synthetic strategy. The obtained transparent MF aerogel with a density of 0.18 g cm^–3 shows significantly higher mechanical strength and a lower thermal conductivity of ca. 13 mW m^–1 K^–1 compared to conventional silica aerogels with similar density.