Method of preparing metal oxide-silica composite aerogel and metal oxide-silica composite aerogel prepared by the same
Provided are a method of preparing a metal oxide-silica composite aerogel, and a metal oxide-silica composite aerogel having an excellent weight reduction property prepared by the method. The method includes a step of adding an acid catalyst to a first water glass solution to prepare an acidic water glass solution (step 1); a step of adding a metal ion solution to the acidic water glass solution to prepare a precursor solution (step 2); and a step of adding a second water glass solution to the precursor solution and performing a gelation reaction (step 3) to yield a metal oxide-silica composite wet gel, wherein, in steps 2 and 3, bubbling of an inert gas is performed during the adding of the metal ion solution or the second water glass solution, respectively.
1. A metal oxide-silica composite aerogel having:
a full width at half maximum (FWHM) value of 7 nm or less in a pore diameter-dependent distribution;
an effective pore volume of 1 to 3 cm 3 /g; and
a particle diameter change rate of 10% or less as measured by Equation 1:
Particle
diameter
change
rate
(
%
)
=
[
1
-
D
50
(
1
bar
)
D
50
(
0
bar
)
]
×
100
(
%
)
[
Equation
1
]
wherein:
D 50 (1 bar) denotes an average particle diameter under a compression shear pressure of 1 bar, and
D 50 (0 bar) denotes an average particle diameter under a compression shear pressure of 0 bar.
2. The metal oxide-silica composite aerogel according to claim 1 , wherein the metal oxide comprises one or more metals selected from the group consisting of alkali metals, alkaline earth metals, lanthanides, actinides, transition metals, and metals in Group 13 (IIIA).
3. The metal oxide-silica composite aerogel according to claim 1 , wherein the metal oxide comprises one or more metal elements selected from the group consisting of calcium (Ca), magnesium (Mg), copper (Cu), zinc (Zn), manganese (Mn), cadmium (Cd), lead (Pb), nickel (Ni), chromium (Cr), silver (Ag), titanium (Ti), vanadium (V), cobalt (Co), molybdenum (Mo), tin (Sn), antimony (Sb), strontium (Sr), barium (Ba), and tungsten (W).
4. The metal oxide-silica composite aerogel according to claim 1 , wherein the metal oxide-silica composite aerogel has the full width at half maximum (FWHM) value of 0.05 to 2 nm in a pore diameter-dependent distribution.
5. The metal oxide-silica composite aerogel according to claim 1 , wherein the metal oxide-silica composite aerogel has the effective pore volume of 1.3 to 2.5 cm 3 /g.
6. The metal oxide-silica composite aerogel according to claim 1 , wherein the metal oxide-silica composite aerogel has a single particle effective density of 0.7 g/ml or less.
7. The metal oxide-silica composite aerogel according to claim 1 , wherein the metal oxide-silica composite aerogel has a single particle effective density of 0.01 to 0.6 g/ml.
8. The metal oxide-silica composite aerogel according to claim 1 , wherein the metal oxide-silica composite aerogel has a density reduction rate of 3% or more.
9. The metal oxide-silica composite aerogel according to claim 1 , wherein the metal oxide-silica composite aerogel has a density reduction rate of 5 to 20%.
10. The metal oxide-silica composite aerogel according to claim 1 , wherein the metal oxide-silica composite aerogel has a pore diameter of 50 nm or less.
11. The metal oxide-silica composite aerogel according to claim 1 , wherein the metal oxide-silica composite aerogel has a specific surface area of 500 m 2 /g or more.
12. The metal oxide-silica composite aerogel according to claim 1 , wherein the metal oxide-silica composite aerogel has a specific surface area of 800 m 2 /g to 1500 m 2 /g.
13. The metal oxide-silica composite aerogel according to claim 1 , wherein the metal oxide-silica composite aerogel has the particle diameter change rate of 5.5% or less.