There is provided a method for preparing a surface-modified
aerogel with hydrophobicity and a surface-modified
aerogel prepared therefrom. The method includes: A) adding a water glass (
sodium silicate) to 0.5-2N HCl at a
room temperature until the pH of solution is adjusted to 3 to 4; B) forming a
silica gel by adding 1.5-10 % (percent) by weight of a non-ionic surfactant to the resulting solution, based on the total weight of the finally prepared silica
powder particles, and by adding water glass so that the solution is under an acidic condition of pH 4-6; C) washing the formed
silica gel with
distilled water and filtering the washed
silica gel; D) adding a mixture
solvent of 1-40 % (percent) by weight of n-pentanol and 99-60 % (percent) by weight of n-
butanol to the silica gel and further adding a silylizing agent; E) putting the mixture solution of the silica gel, the mixture
solvent and the silylizing agent into a reactor, separating the
solvent and
moisture while maintaining a
pressure level of 200 to 30 mmHg (
millimeter Hg) at a temperature of 45 to 6O DEG C (centigrade) in a reactor, and then removing the
moisture and refluxing the solvent again, followed by repeating this process until the
moisture is completely removed from the silica gel; and F) closing a
reflux line when the moisture is removed from the silica gel, and
drying the solvent from the silica gel until thesilica gel is prepared in the
powder form. The method may be useful to prepare a silica
aerogel in the form of permanently hydrophobic
powder in a short time, wherein the a silica aerogel has a highspecific surface area and high functionality, and is prepared by subjecting a wet gel to a solvent exchange process and a silylizing process in a mixture solvent including a silylizing agent at the same time, the wet gel being prepared using a water glass as a
raw material and adding a surfactant at a
room temperature.