A heat-insulation sheet includes a first silica xerogel layer, a second silica xerogel layer, and a composite layer. The first silica xerogel layer includes a first silica xerogel, and the second silica xerogel layer includes a second silica xerogel. The composite layer is located between the first silica xerogel layer and the second silica xerogel layer, and includes at least one type of unwoven fabric fibers, and a third silica xerogel. The third silica xerogel is located in a spatial volume of the unwoven fabric fibers.

A heat-insulation sheet includes a first silica xerogel layer, a second silica xerogel layer, and a composite layer. The first silica xerogel layer includes a first silica xerogel, and the second silica xerogel layer includes a second silica xerogel. The composite layer is located between the first silica xerogel layer and the second silica xerogel layer, and includes at least one type of unwoven fabric fibers, and a third silica xerogel. The third silica xerogel is located in a spatial volume of the unwoven fabric fibers.

A process for separations and recovery from mixtures via specific adsorption using high-surface area, flexible silica-based nanostructured gel adsorbents and articles of manufacture relating to same.

Provided is a silica aerogel with enhanced physical properties. The silica aerogel can have a tap density of 0.030 to 0.070 g/mL, and a carbon content of 11.2 to 12.1 wt %.

Provided is a silica aerogel with enhanced physical properties. The silica aerogel can have a tap density of 0.030 to 0.070 g/mL, and a carbon content of 11.2 to 12.1 wt %.

A heat-insulation sheet includes a first silica xerogel layer, a second silica xerogel layer, and a composite layer. The first silica xerogel layer includes a first silica xerogel, and the second silica xerogel layer includes a second silica xerogel. The composite layer is located between the first silica xerogel layer and the second silica xerogel layer, and includes at least one type of unwoven fabric fibers, and a third silica xerogel. The third silica xerogel is located in a spatial volume of the unwoven fabric fibers.

A heat-insulation sheet includes a first silica xerogel layer, a second silica xerogel layer, and a composite layer. The first silica xerogel layer includes a first silica xerogel, and the second silica xerogel layer includes a second silica xerogel. The composite layer is located between the first silica xerogel layer and the second silica xerogel layer, and includes at least one type of unwoven fabric fibers, and a third silica xerogel. The third silica xerogel is located in a spatial volume of the unwoven fabric fibers.

A heat insulating material includes an aerogel that has macro-pores and meso-pores. A method for manufacturing a heat insulating material, including: a sol preparation step of adding a gelling agent into sodium silicate such that a molar ratio of the gelling agent relative to NaO.sub.2 is 0.1 to 0.75, and adjusting a sol into which macro-pores are introduced by leaving unreacted Na and non-cross-linked oxygen in a siloxane skeleton; an impregnating and gelling step of impregnating a nonwoven fabric fiber structure with the sol to form a composite of hydrogel-nonwoven fabric fiber; a hydrophobizating step of mixing the formed composite of hydrogel-nonwoven fabric fiber with a silylating agent to modify a surface thereof; and a drying step of removing a liquid contained in the surface modified composite of hydrogel-nonwoven fabric fiber by drying under a temperature and pressure lower than respective critical values.

A heat insulating material includes an aerogel that has macro-pores and meso-pores. A method for manufacturing a heat insulating material, including: a sol preparation step of adding a gelling agent into sodium silicate such that a molar ratio of the gelling agent relative to NaO.sub.2 is 0.1 to 0.75, and adjusting a sol into which macro-pores are introduced by leaving unreacted Na and non-cross-linked oxygen in a siloxane skeleton; an impregnating and gelling step of impregnating a nonwoven fabric fiber structure with the sol to form a composite of hydrogel-nonwoven fabric fiber; a hydrophobizating step of mixing the formed composite of hydrogel-nonwoven fabric fiber with a silylating agent to modify a surface thereof; and a drying step of removing a liquid contained in the surface modified composite of hydrogel-nonwoven fabric fiber by drying under a temperature and pressure lower than respective critical values.

The present invention relates to a method for producing a silica aerogel and a silica aerogel produced thereby. More specifically, a first water glass solution is used to form a first silica wet gel, and then a second water glass solution is additionally added to form a second silica wet gel organically bonded to the first silica wet gel which serves as a basic skeleton, so that a silica aerogel with enhanced physical properties is formed to increase the resistance to shrinkage in ambient drying. Thus, a low-density silica aerogel may be formed, and the concentrations of the first and second water glass solutions may be adjusted to control the physical properties of the silica aerogel.