Technologies

CNR-ISTEC develops geopolymer composites for thermostructural applications, such as: self-supporting cavities; thermal and acoustic insulation; thermal and fire barriers; high temperature coatings and damping; molds and cores for foundry; foams and refractory linings. Geopolymers are chemically bonded materials at T <300 ° C. Being inorganic polymers without water in the structure, they tolerate high temperatures: they are incombustible, do not emit gas or fumes and do not explode.

Mirrors for space applications, besides featuring suitable optical properties, should be light, resistant to mechanical stresses, and unsensitive to light-shadow thermal cycling. The standard optical materials easily fulfill optical and thermal requirements, but are fragile, and the mirrors must be thick (typically 1/6 of the diameter). For this reason they are heavy, and the only available solution is to lighten them, by removing material from the back side, still preserving the necessary mechanical robustness and optical quality.

Geopolymers belong to the class of chemically bonded ceramics: they are synthesized at low temperatures and are eco-friendly, as besides the low consolidation temperature required by the process they can be produced from secondary raw materials and industrial waste of various kinds, thus reducing the energy demand and the environmental impact of the entire production cycle. Materials such as fly ash, steel mill slag, biomass ash, sludge and silt, extractive residues, mineral and ceramic powders, organic or inorganic waste fibers, plastics, etc.