Boehmite Nanofiber–Melamine–Formaldehyde Composite Aerogels and Derivatives for Thermal Insulation and Optical Applications

Machinable composite aerogels combining melamine resin and boehmite nanofibers were successfully prepared by using a sol–gel reaction in a mixed solvent of aqueous acetic acid and N,N-dimethyl­formamide. The composite aerogel exhibits low thermal conductivity and surface processability, making it a potential thermal insulating material for electronic substrates. Transparent γ-alumina aerogels and black alumina–graphite aerogels with a designed surface topography were also prepared through computer numerical control (CNC) machining and calcination. These aerogels with precise surface structures are expected to have applications in fields such as optical materials.