Abstract: A method for producing silica aerogel according to the present invention includes: a solation step of generating a sol by adding monoalkyltrialkoxysilane to an acidic aqueous solution containing silicic acid; and a gelation step of generating a wet gel by gelating the sol. Moreover, the production method includes a drying step of removing a solvent, which is contained in the wet gel, from the wet gel by drying the wet gel at less than a critical temperature of the solvent and at less than a critical pressure of the solvent. Then, the monoalkyltrialkoxysilane is added to the acidic aqueous solution so that an amount of silicon in the monoalkyltrialkoxysilane becomes 1 mol part or more with respect to 1 mol part of an amount of silicon in the acidic aqueous solution containing the silicic acid.

Abstract: A method for producing a silica aerogel includes a gelation step of adding a monoalkyltrialkoxysilane to an acidic aqueous solution containing a surfactant to prepare a sol, and then gelating the sol to prepare a wet gel. The method further includes a separation step of immersing the wet gel in a solvent mixture of a first solvent and a second solvent immiscible with the first solvent. The first solvent has an ETN value of 0.5 or less, and the second solvent has an ETN value between those of the first solvent and water. The method further includes a drying step of drying the wet gel at a temperature lower than a critical temperature of the first solvent under a pressure lower than a critical pressure of the first solvent to remove the first solvent from the wet gel.

Abstract: A method for producing silica aerogel according to the present invention includes: a solation step of generating a sol by adding monoalkyltrialkoxysilane to an acidic aqueous solution containing silicic acid; and a gelation step of generating a wet gel by gelating the sol. Moreover, the production method includes a drying step of removing a solvent, which is contained in the wet gel, from the wet gel by drying the wet gel at less than a critical temperature of the solvent and at less than a critical pressure of the solvent. Then, the monoalkyltrialkoxysilane is added to the acidic aqueous solution so that an amount of silicon in the monoalkyltrialkoxysilane becomes 1 mol part or more with respect to 1 mol part of an amount of silicon in the acidic aqueous solution containing the silicic acid.

Abstract: A method for producing a silica aerogel includes a gelation step of adding a monoalkyltrialkoxysilane to an acidic aqueous solution containing a surfactant to prepare a sol, and then gelating the sol to prepare a wet gel. The method further includes a separation step of immersing the wet gel in a solvent mixture of a first solvent and a second solvent immiscible with the first solvent. The first solvent has an ETN value of 0.5 or less, and the second solvent has an ETN value between those of the first solvent and water. The method further includes a drying step of drying the wet gel at a temperature lower than a critical temperature of the first solvent under a pressure lower than a critical pressure of the first solvent to remove the first solvent from the wet gel.