The present invention relates to a method of preparing a high hydrophobic silica aerogel having a high specific surface area and a low tap density, and a hydrophobic silica aerogel prepared thereby. The method of preparing a hydrophobic silica aerogel according to the present invention may have good productivity and economic efficiency, because preparation time is reduced by simultaneously performing surface modification, gelation, and solvent substitution in a single step, and may control a degree of hydrophobicity of the prepared silica aerogel by controlling a surface modification reaction by including a step of adding ammonium hydroxide. Thus, the preparation method according to the present invention and the hydrophobic silica aerogel are suitable for industries that need the method and the hydrophobic silica aerogel, particularly, industries that need a silica aerogel having high hydrophobicity or industries that need a silica aerogel having various degrees of hydrophobicity.

The present invention relates to a method for producing a silica aerogel and a silica aerogel produced thereby. The present invention provides a two-step process of a nucleation step of forming silica colloid particles by using a low-concentration silica precursor and a growth step of further adding a relatively high-concentration silica precursor to form a silica wet gel by using the silica colloid particles as a seed. Thus, the present invention provides a method for producing a silica aerogel of which mechanical stability is improved to enhance pore characteristics, and physical properties are readily controllable, and also provides a silica aerogel produced thereby.

The present invention relates to a method for producing a silica aerogel and a silica aerogel produced thereby. The present invention provides a two-step process of a nucleation step of forming silica colloid particles by using a low-concentration silica precursor and a growth step of further adding a relatively high-concentration silica precursor to form a silica wet gel by using the silica colloid particles as a seed. Thus, the present invention provides a method for producing a silica aerogel of which mechanical stability is improved to enhance pore characteristics, and physical properties are readily controllable, and also provides a silica aerogel produced thereby.

The present invention relates to a method of preparing a high hydrophobic silica aerogel having a low tap density and a hydrophobic silica aerogel prepared thereby. The method of preparing a hydrophobic silica aerogel according to the present invention may have good productivity and economic efficiency, because preparation time is reduced by simultaneously performing surface modification and solvent substitution in a single step, and may control a degree of hydrophobicity of the prepared silica aerogel by controlling a surface modification reaction by including a step of adding ammonium hydroxide. Thus, a hydrophobic silica aerogel having excellent physical properties, such as tap density and specific surface area, as well as high hydrophobicity obtained by controlling the degree of hydrophobicity may be prepared.

The present invention relates to a method of preparing a high hydrophobic silica aerogel having a low tap density and a hydrophobic silica aerogel prepared thereby. The method of preparing a hydrophobic silica aerogel according to the present invention may have good productivity and economic efficiency, because preparation time is reduced by simultaneously performing surface modification and solvent substitution in a single step, and may control a degree of hydrophobicity of the prepared silica aerogel by controlling a surface modification reaction by including a step of adding ammonium hydroxide. Thus, a hydrophobic silica aerogel having excellent physical properties, such as tap density and specific surface area, as well as high hydrophobicity obtained by controlling the degree of hydrophobicity may be prepared.

An abrasive type silica with low refractive index and high transparency, a preparation method and an application thereof are disclosed. The preparation method of the present invention includes the following steps: S1, a sodium sulfate solution is added into a reaction tank, the solution is heated to 80-95 C., a sodium silicate solution and a sulfuric acid solution are added at the same time while stirring, the dropping rate of the sodium silicate solution is controlled at 13-15 m.sup.3/h, the dropping rate of the sulfuric acid solution is controlled to ensure that the pH value of the reaction process is 3.0-4.5, and stirring is continued for 10-15 min after the adding is finished; and S2, the formed silica is filter pressed, washed, spray-dried and airflow crushed to prepare the abrasive type silica with low refractive index and high transparency.

An abrasive type silica with low refractive index and high transparency, a preparation method and an application thereof are disclosed. The preparation method of the present invention includes the following steps: S1, a sodium sulfate solution is added into a reaction tank, the solution is heated to 80-95 C., a sodium silicate solution and a sulfuric acid solution are added at the same time while stirring, the dropping rate of the sodium silicate solution is controlled at 13-15 m.sup.3/h, the dropping rate of the sulfuric acid solution is controlled to ensure that the pH value of the reaction process is 3.0-4.5, and stirring is continued for 10-15 min after the adding is finished; and S2, the formed silica is filter pressed, washed, spray-dried and airflow crushed to prepare the abrasive type silica with low refractive index and high transparency.

A composition and method for prod Icing the ultra-tough nanocomposite aerogel are disclosed. The ultra-tough nanocomposite aerogel may include a dispersion of at least one filler in an aerogel. This method is used to improve the mechanical properties of aerogel by preserving the microstructural and thermal properties of the aerogel, as the addition of the filler leads to an increase in the mechanical properties without any significant increase in the density.

A composition and method for prod Icing the ultra-tough nanocomposite aerogel are disclosed. The ultra-tough nanocomposite aerogel may include a dispersion of at least one filler in an aerogel. This method is used to improve the mechanical properties of aerogel by preserving the microstructural and thermal properties of the aerogel, as the addition of the filler leads to an increase in the mechanical properties without any significant increase in the density.

The present invention relates to a hydrophilic silica aerogel blanket for ultra-high temperature insulation, a production method thereof, and a construction method thereof. More specifically, the present invention provides a production method a hydrophilic silica aerogel blanket, the method capable of strengthening the structure of a silica gel by adding a basic catalyst in an aging step, reducing processing time and cost by omitting a surface modification step, thereby reducing manufacturing cost, and suppressing the generation of a bad odor during construction by fundamentally blocking a volatile organic compound (VOC), a hydrophilic silica aerogel blanket produced thereby, and a construction method of a hydrophilic silica aerogel blanket, the method capable of suppressing the generation of a bad odor when constructing the hydrophilic aerogel blanket on an ultra-high temperature piping equipment, and at the same time, preventing the loss of heat insulation performance due to moisture in the air.