Bivalve mollusc shells are made mainly of CaCO3 (ca 95%), with a small fraction of organic material. If from these shells this mineral is retrieved, they could become a renewable and sustainable “mine” of a “blue” CaCO3. Bivalve mollusc shells, also after the removal of the animal flesh, maintain a certain quantity of organic substances, part in the muscle and part in the shell.
Technologies
In this section it is possible to view, also through targeted research, the technologies inserted in the PROMO-TT Database. For further information on the technologies and to contact the CNR Research Teams who developed them, it is necessary to contact the Project Manager (see the references at the bottom of each record card).
Displaying results 1 - 6 of 6
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.
Geopolymers are synthetic inorganic polymers obtained from an aluminosilicate powder and an aqueous solution of alkaline hydroxides or silicates. The material is mesoporous and a multidimensional and functional porosity can be generated through the addition of fillers or the use of specific techniques.
The mix-design of the mixture, pure or composite, allows to change the chemical-physical properties of the final material, also thanks to the nucleation of zeolitic phases. Geopolymers also possess ion exchange and electrostatic interaction capabilities.
Chemical solution deposition of metal-organic precursors have favoured the research and development of thin films of simple and complex oxides such as Pb(Zr,Ti)O3, and Al2O3, up to their industrial application in pyroelectric and capacitor devices. Deposition methods used are spin-on and dip-coating. The advantages of the techniques are:
(i) low cost of equipment and chemicals
(ii) large area deposition
(iii) low crystallisation temperatures
The proposing team that works at CNR ISTEC has recently patented a technology for the production of the Smart Polycrystals (SP), i.e. transparent YAG-based ceramic polycrystals (Y3Al5O12) variably doped with rare earths ions and transition metals ions. The SPs solve the problem of the reduction of the efficiency in the solid state laser systems caused by the inhomogeneous heating of the single crystals during the emission process.
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.