The present invention relates to aerogels, and more particularly to ambient pressure methods for the synthesis of silica aerogels. In embodiments, the invention relates to methods for preparing controlled-shape fibre reinforced silica aerogel composites.

The present invention provides an aerogel blanket including a blanket base, aerogel coupled on the surface of the blanket base, and aerogel located at a space between the blanket bases, the aerogel coupled on the surface of the blanket base is 50 wt % based on the total weight of aerogel, wherein the aerogel blanket has the number of aerogel particles separated from the aerogel blanket ranging from 13,600 to 90,000 per ft.sup.3, when vibrating the aerogel blanket at a frequency of 1 Hz to 30 Hz for 2 hours to 10 hours.

The invention provides hydrophobic silica wet gel, hydrophobic silica aerogel, and methods that can be used to form an enhanced hydrophobic silica aerogel sheet having an advantageous combination of properties. Some embodiments of the invention provide a hydrophobic silica aerogel having advantageous properties, such as desirable performance on visible transmission, haze, or both.

The invention provides hydrophobic silica wet gel, hydrophobic silica aerogel, and methods that can be used to form an enhanced hydrophobic silica aerogel sheet having an advantageous combination of properties. Some embodiments of the invention provide a hydrophobic silica aerogel having advantageous properties, such as desirable performance on visible transmission, haze, or both.

An aerogel particle is produced by following processes. A mixing process: an alkoxysilane compound is mixed with an organic solvent to form a first mixed solution. A hydrolysis process: an acid catalyst is added into the first mixed solution to perform a hydrolysis reaction, thereby obtaining a sol. A condensation process: an alkali catalyst is added into the sol to perform a condensation reaction, and a hydrophobic dispersion solvent is added and stirred during the condensation process, thereby subjecting sol to be gelled when it is stirred, further producing the aerogel particle with a uniform structure.

The invention relates to a method for producing organically modified aerogels. The problem addressed by the invention is that of providing an economical method for producing hydrophobic aerogels which can be implemented cost-effectively, simply, and safely, and which operates to save on resources. This problem is solved by the provision of a method for producing organically modified aerogels, wherein a sol containing [SiO.sub.4,2] units is produced, and the sol obtained is dispersed in a continuous phase. The sol forms a separate phase and the continuous phase contains at least 20 wt % organosiloxane, a gel is formed from the sol in the continuous phase, and the gel obtained is surface-modified in the presence of a phase mediator in the continuous phase, wherein acids or chlorosilanes or mixtures thereof are added as initiator and the gels obtained are dried. The aerogels provided can be used as insulating materials, in particular in thermal insulation.

The invention relates to a method for producing organically modified aerogels. The problem addressed by the invention is that of providing an economical method for producing hydrophobic aerogels which can be implemented cost-effectively, simply, and safely, and which operates to save on resources. This problem is solved by the provision of a method for producing organically modified aerogels, wherein a sol containing [SiO.sub.4,2] units is produced, and the sol obtained is dispersed in a continuous phase. The sol forms a separate phase and the continuous phase contains at least 20 wt % organosiloxane, a gel is formed from the sol in the continuous phase, and the gel obtained is surface-modified in the presence of a phase mediator in the continuous phase, wherein acids or chlorosilanes or mixtures thereof are added as initiator and the gels obtained are dried. The aerogels provided can be used as insulating materials, in particular in thermal insulation.

Provided is a method for recycling supercritical waste liquid and a method for producing a silica aerogel blanket capable of reducing the production costs and preventing the deterioration in thermal insulation performance of a silica aerogel blanket, the method including adding sulfuric acid to supercritical waste liquid to remove ammonium ions in the form of ammonium sulfate salt, the ammonium ions which are present in the supercritical waste liquid, and reusing supercritical waste liquid from which the ammonium ions are removed.

Provided is a method for recycling supercritical waste liquid and a method for producing a silica aerogel blanket capable of reducing the production costs and preventing the deterioration in thermal insulation performance of a silica aerogel blanket, the method including adding sulfuric acid to supercritical waste liquid to remove ammonium ions in the form of ammonium sulfate salt, the ammonium ions which are present in the supercritical waste liquid, and reusing supercritical waste liquid from which the ammonium ions are removed.

The present invention relates to a method for aerogel production and to a composite material produced by said method and comprising an aerogel and mineral fibers. An aerogel material produced on the basis of silicate with a coefficient of thermal conductivity of <18 mW/mK is obtainable by rendering it hydrophobic with HMDSO in the presence of nitric acid.