Organic-inorganic hybrid material, optical thin layer of this material, optical material comprising same, and process for producing same

A process for preparing a solution containing an organic-inorganic composite material in an apolar, aprotic solvent, in which the following successive steps are carried out:

• preparing a first suspension of colloidal particles of at least one inorganic compound selected from metal oxides and oxyhydroxides or metalloid oxides and oxyhydroxides by a hydrolysis-condensation process, in a protic or polar solvent;
• mixing the first suspension with an organic compound capable of surface-functionalising the particles, so as to obtain a second suspension comprising the colloidal particles and the organic compound in the polar or protic solvent;
• grafting the organic compound onto the surface of the colloidal particles, whereby a third suspension of the particles surface-functionalised with the organic compound in the polar or protic solvent is obtained;
• exchanging the protic or polar solvent of the third suspensions with an apolar, aprotic organic solvent, so as to obtain a fourth suspension of the particles surface-functionalised with the organic compound in the apolar, aprotic organic solvent;
• preparing a polymer solution by dissolving an organic or inorganic polymer in the apolar, aprotic organic solvent;
• mixing the fourth suspension and the polymer solution, so as to obtain an organic-inorganic hybrid solution.