Aerogel precursor and aerogel produced using same
Provided is a hydrophobic silica aerogel precursor, and a hydrophobic silica aerogel produced using the same. In the methods, a linear silane crosslinking agent containing a PEG-derived unit is introduced when preparing a hydrophobic aerogel precursor, resulting in the production of a hydrophobic silica aerogel having improved high-temperature thermal stability and improved physical properties.
1. A method for preparing a hydrophobic aerogel precursor, the method comprising:
preparing an alkoxysilane compound or pre-hydrolyzed alkoxysilane compound; and
adding a linear silane crosslinking agent to polymerize the alkoxysilane compound or pre-hydrolyzed alkoxysilane compound, wherein
the linear silane crosslinking agent comprises a polyethylene glycol (PEG)-derived unit,
wherein a weight average molecular weight (MW) of the hydrophobic aerogel precursor is 500-6,500 g/mol.
2. The method of claim 1 , wherein the linear silane crosslinking agent is a compound of Formula 1:
wherein n is 3 to 24.
3. The method of claim 1 , wherein the linear silane crosslinking agent is added in an amount of 0.5-20 mol % based on the total number of moles of the alkoxysilane compound or the pre-hydrolyzed alkoxysilane compound.
4. The method of claim 1 , wherein the hydrophobic aerogel precursor comprises 0.2-10 wt % of a PEG-derived unit.
5. The method of claim 1 , wherein the hydrophobic aerogel precursor has a carbon content of 20 wt % or greater.
6. A method for producing hydrophobic silica aerogel, comprising:
performing a gelation reaction by adding a base and/or an acid catalyst to the hydrophobic aerogel precursor prepared according to the method of claim 1 to yield a silica wet gel; and
drying the silica wet gel to yield a hydrophobic silica aerogel.
7. The method of claim 6 , wherein no surface modification is performed.
8. A method for preparing a hydrophobic aerogel precursor, the method comprising:
preparing an alkoxysilane compound or pre-hydrolyzed alkoxysilane compound; and
adding a linear silane crosslinking agent to polymerize the alkoxysilane compound or pre-hydrolyzed alkoxysilane compound,
wherein the linear silane crosslinking agent comprises a polyethylene glycol (PEG)-derived unit, and
wherein a degree of hydration of the pre-hydrolyzed alkoxysilane compound is 50-80%.
9. The method of claim 8 , wherein the linear silane crosslinking agent is a compound of Formula 1:
wherein n is 3 to 24.
10. The method of claim 8 , wherein the linear silane crosslinking agent is added in an amount of 0.5-20 mol % based on the total number of moles of the alkoxysilane compound or the pre-hydrolyzed alkoxysilane compound.
11. The method of claim 8 , wherein a weight average molecular weight (MW) of the hydrophobic aerogel precursor is 500-6,500 g/mol.
12. The method of claim 8 , wherein the hydrophobic aerogel precursor comprises 0.2-10 wt % of a PEG-derived unit.
13. The method of claim 8 , wherein the hydrophobic aerogel precursor has a carbon content of 20 wt % or greater.
14. A method for producing hydrophobic silica aerogel, comprising:
performing a gelation reaction by adding a base and/or an acid catalyst to the hydrophobic aerogel precursor prepared according to the method of claim 8 to yield a silica wet gel; and
drying the silica wet gel to yield a hydrophobic silica aerogel.
15. Hydrophobic silica aerogel comprising a unit derived from the hydrophobic aerogel precursor of claim 14 .
16. A hydrophobic aerogel precursor, comprising:
an alkoxysilane compound-derived unit; and
a PEG-derived unit,
wherein a weight average molecular weight (MW) of the hydrophobic aerogel precursor is 500-6,500 g/mol.
17. The hydrophobic aerogel precursor of claim 16 , wherein the PEG-derived unit is present in an amount of 0.2-10 wt %.
18. The hydrophobic aerogel precursor of claim 16 , wherein the hydrophobic aerogel precursor has a carbon content of 20 wt % or greater.
19. Hydrophobic silica aerogel comprising a unit derived from the hydrophobic aerogel precursor of claim 16 .