Thermally insulating materials including spherical, hollow inorganic particles
AssigneePylote
InventorsLoïc MARCHIN, Marie-Laure DESSE
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Abstract
The invention concerns thermally insulating materials comprising the aforementioned particles, a process for the preparation of these particles and materials obtained by incorporation of these particles into matrices. The present invention also concerns inorganic spherical and hollow inorganic particles with low apparent density imparting thermal properties to various types of matrices in which they are dispersed.
Claims21
1-13. (canceled)
A thermally insulating material comprising inorganic particles and a matrix, wherein the inorganic particles are spherical, micrometric with an average diameter of from 0.1 to 10 micrometers, hollow and have an apparent density of from 100 to 700 kg/m3.
Inorganic particles, comprising spherical particles which are micrometric having an average diameter of from 0.1 to 10 micrometers, hollow, and have an apparent density of from 100 to 700 kg/m3.
A process for preparing inorganic particles by aerosol pyrolysis, comprising the steps of:
- a) nebulizing a liquid solution containing a precursor of an inorganic material from which to form particles at a molar concentration greater than or equal to 0.5 mol/L in the liquid solution, thereby obtaining a fog of solution droplets;
- b) heating the fog obtained at a temperature sufficient to evaporate a solvent for the liquid solution in order to increase a precursor concentration of the inorganic material on a periphery of the droplets, thereby forming particles;
- c) heating the particles obtained in step b) at a temperature sufficient to decompose the precursor in order to form the inorganic material with simultaneous complete precipitation and extraction of the solvent in order to form a shell of hollow particles;
- d) densifying the shell of the obtained particles;
- e) optionally, quenching the particles obtained;
- and
- f) recovering the particles formed.
Dependencies are inferred from the claim text.