Abstract: The present invention relates to a process for producing aerogels, comprising the following successive steps: a) formation or casting of a sol in a reactor, optionally in the presence of a reinforcing material and/or an additive, b) complete gelling of the sol into a lyogel; c) optionally hydrophobization of the lyogel resulting in a hydrophobized lyogel; d) drying of the optionally hydrophobized lyogel so as to obtain an aerogel; said process being characterized in that the complete gelling step b) comprises dielectric heating by microwave or high-frequency electromagnetic irradiation, inducing an increase in temperature so as to reach a set temperature for complete gelling Tb in a range of from 100° C. to 200° C., preferably from 100° C. to 150° C., the temperature Tb being maintained in this range for a period of time U sufficient to attain complete gelling of the lyogel, and more particularly the end of syneresis of the lyogel.

Abstract: The present invention is related to a process for manufacturing xerogels optionally containing a fibrous reinforcement material, to an insulating, self-supporting single-layer composite panel of thickness between 30 mm and 70 mm of xerogel comprising a fibrous reinforcement material comprising a nonwoven fibrous batting obtainable by this process and to the use thereof for the manufacture of building materials and thermal insulations.

Abstract: The present invention relates to a process for producing aerogels, comprising the following successive steps: a) formation or casting of a sol in a reactor, optionally in the presence of a reinforcing material and/or an additive, b) complete gelling of the sol into a lyogel; c) optionally hydrophobization of the lyogel resulting in a hydrophobized lyogel; d) drying of the optionally hydrophobized lyogel so as to obtain an aerogel; said process being characterized in that the complete gelling step b) comprises dielectric heating by microwave or high-frequency electromagnetic irradiation, inducing an increase in temperature so as to reach a set temperature for complete gelling Tb in a range of from 100° C. to 200° C., preferably from 100° C. to 150° C., the temperature Tb being maintained in this range for a period of time U sufficient to attain complete gelling of the lyogel, and more particularly the end of syneresis of the lyogel.