Disclosed herein is a method of preparing a silica aerogel. The silica aerogel is prepared by adding a first water glass solution and an acid catalyst to a reactor to form a first silica wet gel. The method further includes adding a second water glass solution and an acid catalyst to the first silica wet gel. The method further includes adding a surface modifier solution to the first silica wet gel to form a second silica wet gel. The method further includes drying a silica wet gel including the first silica wet gel and the second silica wet gel. The prepared silica aerogel has a tap density of 0.032 to 0.070 g/mL and a carbon content of 11.2 to 12.1 wt %.

A production method for an aerogel includes a sol generation step by adding a silicon compound to an aqueous solution containing an acid catalyst and performing hydrolysis, where the silicon compound contains at least a quadri-functional silane compound and a tri-functional silane compound among quadri-functional silane compounds, tri-functional silane compounds, and di-functional silane compounds, the density of the aerogel is 0.15 g/cm.sup.3 or less, for example the silicon compound is a mixture of a quadri-functional silane compound, a tri-functional silane compound, and a di-functional silane compound having portions satisfying 0<Qx<50, 50≤Tx<100, 0≤Dx<30, and Qx+Tx+Dx=100, where Qx, Tx, and Dx represent the mass percentages of the quadri-functional silane compound, the tri-functional silane compound, and the di-functional silane compound, respectively. This provides aerogel having excellent thermal insulating characteristics and a large area.

The invention relates to a method for producing an aerogel under increased pressure, to the aerogel obtained using said method and to their use.

The present invention relates to a method of preparing ultra-pure silicon carbide in which a super-porous spherical silica aerogel is used as a silica raw material. By preparing the silica aerogel particles using low-cost water glass, a reaction area with respect to a carbon raw material is increased to enable low-temperature synthesis of silicon carbide, the size and shape of silicon carbide powder may be uniformly controlled to prepare ultra-pure silicon carbide, and economic efficiency and productivity of the silicon carbide synthesis may be improved. Thus, it is expected that the silicon carbide powder prepared by the preparation method of the present invention may be provided as an optimized raw material for the preparation of silicon carbide sintered body and single crystal (ingot).

The invention provides silica wet gel, silica aerogel, and methods that can be used to form an enhanced silica aerogel sheet having fewer optical defects along with other desirable properties.

The invention provides silica wet gel, silica aerogel, and methods that can be used to form an enhanced silica aerogel sheet having fewer optical defects along with other desirable properties.

The invention provides silica wet gel, silica aerogel, and methods that can be used to form an enhanced silica aerogel sheet having fewer optical defects along with other desirable properties.

The present invention relates to an aerogel blanket having a moisture impregnation rate of 28 days (MIR-28D) of 100 wt % or less, which is calculated by Equation 1 below:

Moisture impregnation rate of 28 days (MIR-28D,wt %)={(Aerogel blanket weight after impregnation in distilled water of 21±2° C. for 28 days−Aerogel blanket weight before impregnation in distilled water)/Aerogel blanket weight before impregnation in distilled water}×100.  [Equation 1]

A method for producing a micron-size spherical silica aerogel having a selectable or controllable average particle size, the method includes producing a surface-modified silica sol by adding a first organosilane compound to a aqueous acid-silica sol, which comprises an inorganic acid and a water glass solution, with a pH less than 3, dispersive mixing a non-polar organic solvent, a second organosilane compound, and the surface-modified silica sol, at a selected stilling rate which is inversely related to an average particle size, without adding any surfactant or dispersant, a micron-size spherical silica hydrogel and further a hydrophobic micron-size spherical silica gel are then produced. Following by drying or stirring the hydrophobic micron-size spherical silica gel to obtain a controllable micron-size silica aerogel in a spherical and powder forms, respectively.

The invention relates to a method for producing aerogels, in particular silica aerogels, by way of a sol-gel process.