WATERBORNE AEROGEL AND METHOD FOR PRODUCING SAME
CROSS REFERENCE TO RELATED APPLICATION
[0001] This application claims the benefit of Korean Patent Application No. KR 10-
2014-0186685, filed December 23, 2014, which is hereby incorporated by reference in
its entirety into this application.
BACKGROUND OF THE INVENTION
1. Technical Field
[0002] The present invention relates to a water-dispersed aerogel and a method of
manufacturing the same and, more particularly, to a water-dispersed aerogel, which has
an eco-friendly composition that contains an organic solvent in a decreased amount
while increasing ease of use of aerogel microparticles in a liquid phase, and to a method
of manufacturing the same.
2. Description of the Related Art
[0003] Silica aerogel in an ultrafine powder phase has a very low bulk density (about
0.04 ~ 0.1 g/cm3), and the volume thereof is very large relative to the weight, thus
increasing the transport cost and requiring a large space upon storage. Hence,
workability may become poor and storage costs may increase. In particular, the case
where silica aerogel in an ultrafine powder phase is used may undesirably generate dust,
and thus the available applications of such an aerogel are limited. To solve these
problems, research is ongoing into dispersion of silica aerogel in a liquid phase using an
organic solvent. Although the silica aerogel dispersion solution in a liquid phase
manufactured using an organic solvent is easily handled and the workability thereof may
be improved, it may become gel due to dispersion instability upon long-term storage.
Hence, a silica aerogel dispersion solution using an organic solvent has to be directly
produced on-site. Further, when the silica aerogel dispersion solution using an organic
solvent, as supplied from manufacturers, becomes a gel, the gelled silica aerogel has to
be re-dispersed through treatment before use, which is regarded as disadvantageous in
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terms of process efficiency and profitability. To overcome the gelation of the silica
aerogel dispersion solution using the organic solvent, an auxiliary agent such as an
additive, a pH modifier, a surfactant, or a stabilizer may be used. In this case, however,
inherent superhydrophobic and porous properties of the silica aerogel in an ultrafine
powder phase may drastically change upon drying. Furthermore, the auxiliary agent is
unlikely to be removed through treatment before the manufacturing process. If such
removal is possible, economic benefits may be negated due to the additional process.
Accordingly, there is required to develop a water-dispersed aerogel having an ecofriendly
composition, which is in a liquid phase and is thus easily handled, and may be
directly applied to the manufacturing process without the addition of an auxiliary agent
to thereby improve profitability and workability.
SUMMARY OF THE INVENTION
[0004] Accordingly, the present invention has been made keeping in mind the problems
encountered in the related art, and an object of the present invention is to provide a
water-dispersed aerogel, which is in a liquid phase and may thus be easily handled and
may possess high profitability and workability. The water-dispersed aerogel according
to the present invention does not contain an auxiliary agent such as an additive, a pH
modifier, a surfactant or a stabilizer, thus maintaining inherent superhydrophobic and
porous properties of the aerogel microparticles upon drying. Also, this aerogel may be
easily used because there is no gelation due to dispersion instability upon long-term
storage, and may be directly applied to the manufacturing process without the need to
remove the auxiliary agent through treatment before the manufacturing process.
Furthermore, since the aerogel, which is in a conventional powder phase that is easily
scattered due to low bulk density, is used in a liquid phase, it may be relatively easily
added in a predetermined amount in the manufacturing process, and no dust is generated,
thus protecting a work environment and the health of workers.
[0005] Another object of the present invention is to provide new applications of the
water-dispersed aerogel having an eco-friendly composition in which the use of an
organic solvent is decreased.
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[0006] In order to accomplish the above objects, the present invention provides a waterdispersed
aerogel, comprising: a mixture of water (A) and an organic solvent (B), and
particles (C) having i) a BET specific surface area of 300 ~ 1500 m2/g and ii) a porosity
of 50% or more, wherein the mixture of water (A) and organic solvent (B) includes the
water (A) and the organic solvent (B) at a weight ratio of 4:1 ~ 1:1, and the particles (C)
are contained in an amount of 1 ~ 25 parts by weight based on 100 parts by weight of the
mixture of water (A) and organic solvent (B).
[0007] In addition, the present invention provides a method of manufacturing a waterdispersed
aerogel comprising a mixture of water (A) and an organic solvent (B), and
particles (C) having i) a BET specific surface area of 300 ~ 1500 m2/g and ii) a porosity
of 50% or more, comprising: mixing the mixture of water (A) and organic solvent (B)
with the particles (C) so that the particles (C) are dispersed in the mixture of water (A)
and organic solvent (B), wherein the mixture of water (A) and organic solvent (B)
includes the water (A) and the organic solvent (B) at a weight ratio of 4:1 ~ 1:1, and the
particles (C) are contained in an amount of 1 ~ 25 parts by weight based on 100 parts by
weight of the mixture of water (A) and organic solvent (B).
[0008] According to the present invention, a water-dispersed aerogel is in a liquid phase
and can thus be easily handled and can exhibit high profitability and workability. Since
the water-dispersed aerogel obviates the need for an auxiliary agent such as an additive,
a pH modifier, a surfactant or a stabilizer, inherent superhydrophobic and porous
properties of the aerogel microparticles upon drying can be maintained. Further, the
aerogel can be easily used because there is no gelation due to dispersion instability upon
long-term storage, and can be directly applied to the manufacturing process without the
need to remove the auxiliary agent through treatment before the manufacturing process.
Furthermore, since the aerogel, which is in a conventional powder phase that is easily
scattered due to low bulk density, is used in a liquid phase, it can be relatively easily
added in a predetermined amount in the manufacturing process, and no dust is generated,
thus protecting a work environment and the health of workers. Moreover, new
applications of the water-dispersed aerogel having an eco-friendly composition with an
organic solvent in a decreased amount can be provided.
BRIEF DESCRIPTION OF THE DRAWINGS
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[0009] FIG. 1 illustrates (I) microparticles (C) according to the present invention, (II) a
mixture of water (A) and isopropyl alcohol (IPA) (B) at a weight ratio of 1:1 as a
dispersion solvent, and (III) the results (10 wt% concentration) of dispersion of the
microparticles of (I) in the dispersion solvent of (II); and
[0010] FIG. 2 illustrates phase separation and gelation, 24 hr after dispersion of
microparticles using only an organic solvent.
DESCRIPTION OF THE SPECIFIC EMBODIMENTS
[0011] Hereinafter, a detailed description will be given of the present invention.
[0012] According to the present invention, a water-dispersed aerogel comprises a
mixture of water (A) and an organic solvent (B), and particles (C) having i) a BET
specific surface area of 300 ~ 1500 m2/g and ii) a porosity of 50% or more, wherein the
mixture of water (A) and organic solvent (B) includes the water (A) and the organic
solvent (B) at a weight ratio of 4:1 ~ 1:1, and the particles (C) are contained in an
amount of 1 ~ 25 parts by weight based on 100 parts by weight of the mixture of water
(A) and organic solvent (B).
[0013] In the water-dispersed aerogel of the present invention, the mixture of water (A)
and organic solvent (B) includes the water (A) and the organic solvent (B) at a weight
ratio of 4:1 ~ 1:1. Although the aerogel is not physically mixed with water because of
superhydrophobic and porous properties thereof, it may be easily dispersed in a solution
even at weak stirring strength via gentle swirling by using a minimum amount of the
organic solvent, especially isopropyl alcohol (IPA) in an embodiment of the invention.
If the mixture includes the organic solvent in an amount greater than the above upper
limit, dispersibility may increase for a short period of time, but stability may deteriorate,
making it difficult to store due to gelation. In contrast, if the mixture includes the
organic solvent in an amount less than the above lower limit, dispersion of the
superhydrophobic aerogel becomes difficult. Given the above amount range of the
organic solvent, the water-dispersed aerogel having an eco-friendly composition
including the organic solvent in a lower amount may be variously applied.
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[0014] The organic solvent (B) may include at least one selected from the group
consisting of methanol, ethanol, acetone, isopropyl alcohol (IPA), propanol, butanol,
pentanol, octanol, and isomers thereof. Particularly useful is isopropyl alcohol (IPA).
Also, the mixture of water (A) and organic solvent (B) preferably includes the water (A)
and the organic solvent (B) at a weight ratio of 2:1 ~ 1:1.
[0015] In an embodiment of the present invention, when using isopropyl alcohol (IPA),
dispersion is efficiently performed even in the presence of high silica content, compared
to when using the other organic solvents. Specifically, the dispersion solution
comprising water and IPA at a weight ratio of 1:1 is stably maintained even after several
weeks. Although phase separation occurs after a long period of time, re-dispersion
becomes possible via gentle swirling. When 10 wt% of silica microparticles is dispersed
in the dispersion solution comprising IPA and deionized (DI) water at 1:1, there is no
color change in the dispersion solution.
[0016] The particles (C) are contained in an amount of 1 ~ 25 parts by weight based on
100 parts by weight of the mixture of water (A) and organic solvent (B). Given the
above amount range of the particles (C), dispersion is efficiently carried out, and there is
no gelation due to dispersion instability upon long-term storage. Hence, an auxiliary
agent, such as an additive, a pH modifier, a surfactant, or a stabilizer is obviated to
prevent the gelation, and thus inherent superhydrophobic and porous properties of the
aerogel microparticles may be maintained upon drying. Accordingly, there is no need to
remove the auxiliary agent through treatment before the manufacturing process, and the
aerogel may be directly applied to the manufacturing process.
[0017] More specifically, the particles (C), which are contained in the water-dispersed
aerogel according to the present invention, may include any component without
limitation so long as it has the properties of i) and ii) as above. Specific examples
thereof may include, but are not limited to, inorganic oxides, such as silica (SiO2),
alumina, titania (TiO2), carbon, inorganic compounds, organic polymers, ion exchange
resins, metals, metal salts, etc. Particularly useful is silica (SiO2). The particles (C) may
have a particle size ranging from 2 nm to 50 mm, and the particles have a BET specific
surface area of 300 ~ 1500 m2/g, preferably 500 ~ 1500 m2/g, and more preferably 600 ~
1500 m2/g. Also, the particles may possess superhydrophobicity with a water contact
angle of 125° or more, preferably 135° or more, and more preferably 140° or more.
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Also, the particles (C) may have a particle size ranging from 2 nm to 50 mm and
superhydrophobicity with a water contact angle of 125° or more.
[0018] The particles have a porosity of 50% or more, and preferably 90% or more.
Since the water-dispersed aerogel according to the present invention includes the
particles having the properties as above, for example, when water is added to a
superabsorbent polymer, agglomeration of the superabsorbent polymer may be
remarkably decreased despite the use of the aerogel dispersion solution. Furthermore,
even when the dispersion solution including a relatively small amount of particles
compared to conventional silica is used, permeability of the superabsorbent polymer is
improved. Also, a reduction in absorption under pressure (AUP) is curbed, anti-caking
efficiency is increased, and high moisture content may be easily maintained.
[0019] In the present invention, a reduction in the contact angle of the water-dispersed
aerogel is preferably 50% or less, and more preferably 10% or less, compared to the
particles (C).
[0020] In addition, the present invention addresses a method of manufacturing the waterdispersed
aerogel comprising a mixture of water (A) and an organic solvent (B) and
particles (C) having i) a BET specific surface area of 300 ~ 1500 m2/g and ii) a porosity
of 50% or more, comprising: mixing the mixture of water (A) and organic solvent (B)
with the particles (C) so that the particles (C) are dispersed in the mixture of water (A)
and organic solvent (B), wherein the mixture of water (A) and organic solvent (B)
includes the water (A) and the organic solvent (B) at a weight ratio of 4:1 ~ 1:1, and the
particles (C) are contained in an amount of 1 ~ 25 parts by weight based on 100 parts by
weight of the mixture of water (A) and organic solvent (B).
[0021] In the method of manufacturing the water-dispersed aerogel according to the
present invention, the mixture of water (A) and organic solvent (B) includes the water
(A) and the organic solvent (B) at a weight ratio of 4:1 ~ 1:1. Although the aerogel is
not physically mixed with water due to superhydrophobic and porous properties thereof,
it may be easily dispersed in a solution even at weak stirring strength via gentle swirling
by using a minimum amount of an organic solvent, especially IPA in an embodiment of
the invention. If the mixture includes the organic solvent in an amount greater than the
above upper limit, dispersibility may increase for a short period of time, but stability
may deteriorate, making it difficult to store due to gelation. In contrast, if the mixture
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includes the organic solvent in an amount less than the above lower limit, dispersion of
the superhydrophobic aerogel becomes difficult. Given the above amount range of the
organic solvent, the water-dispersed aerogel having an eco-friendly composition
including the organic solvent in a lower amount may be variously applied.
[0022] The organic solvent (B) may include at least one selected from the group
consisting of methanol, ethanol, acetone, IPA, propanol, butanol, pentanol, octanol, and
isomers thereof. Particularly useful is IPA. Also, the mixture of water (A) and organic
solvent (B) preferably includes the water (A) and the organic solvent (B) at a weight
ratio of 2:1 ~ 1:1.
[0023] In an embodiment of the present invention, the use of IPA enables the dispersion
process to be efficiently carried out even in the presence of high silica content, compared
to when using the other organic solvents. Specifically, the dispersion solution
comprising water and IPA at a weight ratio of 1:1 is stably maintained even after several
weeks. Although phase separation occurs after a long period of time, re-dispersion
becomes possible via gentle swirling. Further, when 10 wt% of silica microparticles is
dispersed in the dispersion solution comprising IPA and DI water at 1:1, no color change
of the dispersion solution may result.
[0024] The particles (C) are contained in an amount of 1 ~ 25 parts by weight based on
100 parts by weight of the mixture of water (A) and organic solvent (B). Given the
above amount range of the particles (C), dispersion efficiently progresses, and there is
no gelation due to dispersion instability upon long-term storage. Hence, an auxiliary
agent, such as an additive, a pH modifier, a surfactant or a stabilizer, need not be added
to prevent the gelation, thus making it possible to maintain inherent superhydrophobic
and porous properties of the aerogel microparticles upon drying. Accordingly, the
resulting aerogel may be directly applied to the manufacturing process without the need
to remove the auxiliary agent through treatment before the manufacturing process.
[0025] More specifically, the particles (C), which are used in the method of
manufacturing the water-dispersed aerogel according to the present invention, may
include any component without limitation so long as it has the properties of i) and ii) as
above. Specific examples thereof may include, but are not limited to, inorganic oxides,
such as silica (SiO2), alumina, titania (TiO2), carbon, inorganic compounds, organic
polymers, ion exchange resins, metals, metal salts, etc. Particularly useful is silica
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(SiO2). The particles (C) may have a particle size ranging from 2 nm to 50 mm, and may
also possess a BET specific surface area of 300 ~ 1500 m2/g, preferably 500 ~ 1500
m2/g, and more preferably 600 ~ 1500 m2/g. Also, the particles have
superhydrophobicity with a water contact angle of 125° or more, preferably 135° or
more, and more preferably 140° or more. Also, the particles (C) may have a particle size
ranging from 2 nm to 50 mm and superhydrophobicity with a water contact angle of 125°
or more.
[0026] The particles have a porosity of 50% or more, and preferably 90% or more.
Since the method of manufacturing the water-dispersed aerogel according to the present
invention includes the particles having the properties as above, for example, when water
is added to a superabsorbent polymer, agglomeration of the superabsorbent polymer may
be remarkably decreased despite the use of the aerogel dispersion solution. Also, even
when the dispersion solution including a relatively small amount of particles compared
to conventional silica is used, permeability of the superabsorbent polymer is improved.
Also, AUP reduction is curbed, anti-caking efficiency is increased, and high moisture
content may be easily maintained.
[0027] In the method of manufacturing the water-dispersed aerogel according to the
present invention, a reduction in the contact angle of the water-dispersed aerogel is
preferably 50% or less, and more preferably 10% or less, compared to the particles (C).
[0028] A better understanding of the present invention may be obtained via the
following examples that are set forth to illustrate, but are not to be construed as limiting
the scope of the present invention. The scope of the present invention is shown in the
claims, and also contains all modifications within the meaning and range equivalent to
the claims. Unless otherwise mentioned, “%” and “part” showing the amount in the
following examples and comparative examples refers to a mass basis.
[0029] Examples
[0030] As porous superhydrophobic microparticles, an Aerogel (available from JIOS)
was dispersed in an aqueous solution using a dispersion aid, that is, an organic solvent.
The porous superhydrophobic aerogel microparticles had an average particle size of 5
mm, a BET specific surface area of 720 m2/g, a water contact angle of 144°, and a
porosity of 95%. The particle size of the Aerogel was measured through Laser
Diffraction using HELOS (Helium-Neon Laser Optical System) based on ISO 13320.
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The specific surface area thereof was measured using a BET meter (Micromeritics
3Flex). The porosity thereof was determined from the tap density (rt) and the true
density (rs) of Equation 1 below.
[Equation 1]
Porosity (%) = (1 - rt/rs)*100
[0031] In order to measure the true density, a pycnometer (Accupyc II 1340) was used,
and the tap density was measured using a volumeter (Engelsmann Model STAV II).
[0032] The water contact angle was measured using a contact angle analyzer (KRUSS
DSA100), and was specifically determined in a manner in which double-sided tape was
attached to a flat glass plate, microparticles were applied in a monolayer thereon, and
then 5 mL of ultrapure water was placed in the form of drop on the monolayer, and the
angle between the water drop and the glass plate was measured four times and averaged.
[0033] In dispersion solutions comprising water and methanol, ethanol, IPA and acetone
in various amounts, the porous superhydrophobic aerogel microparticles were dispersed,
after which the extent of dispersion thereof was checked. When the organic solvent was
used alone to disperse the porous superhydrophobic aerogel microparticles, without the
use of water, efficient dispersion was initially observed in all of organic solvents. After
24 hr, however, phase separation and gelation occurred, as illustrated in Table 1 and
FIG. 2. Upon dispersion using IPA among the organic solvents, when silica content was
increased to 20 wt% from 10 wt%, stickiness was increased but dispersion was
efficiently carried out compared to when using the other organic solvents, as is apparent
from the results of Table 1 below.
[Table 1]
Dispersion of 10 wt% and 20 wt% of hydrophobic porous silica in organic solvent
Organic solvent
Dispersion at 10 wt% Dispersion at 20 wt%
0 hr After 24 hr 0 hr After 24 hr
MeOH O Phase separation C C
EtOH O Phase separation & Gelation C C
IPA O Phase separation & Gelation D D
Acetone O Phase separation & Gelation C C
O: good dispersion D: fair (hydrophobic porous silica powder is not present) C: no
dispersion
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[0034] When the porous superhydrophobic aerogel microparticles were dispersed with
the mixture of water and organic solvent having the composition as shown in Table 2
below, the dispersion solution using the mixture of water and IPA at a weight ratio of
1:1 was stable even after several weeks. Although phase separation took place after a
long period of time, re-dispersion efficiently occurred via gentle swirling.
[0035] The dispersion was efficiently performed under conditions of IPA and DI water
at a weight ratio of 1:2, but ease of use of the resulting solution was decreased due to
high stickiness. Hence, the ratio of 1:1 was determined to be the most appropriate.
Specifically, FIG. 1 illustrates (I) porous superhydrophobic microparticles (C) according
to the present invention, (II) a mixture of water (A) and IPA (B) at a weight ratio of 1:1
as a dispersion solvent, and (III) illustrates the results (10 wt% concentration) of
dispersing the porous superhydrophobic microparticles of (I) in the dispersion solvent of
(II). Based on the results of observation of the dispersion stability for one month or
more, the color of the dispersion solution turned to yellow when using acetone.
However, when 10 wt% of the porous superhydrophobic aerogel microparticles was
dispersed in the dispersion solution of IPA and DI water at a weight ratio of 1:1, the
color of the dispersion solution was not changed.
[Table 2]
Dispersion of hydrophobic porous silica in (water + organic solvent)
Organic solvent Water:Organic solvent (mass ratio)
Dispersion at 10 wt% Dispersion at 5 wt%
0 hr After 24 hr 0 hr After 24 hr
MeOH 1:1 D D O Phase separation
EtOH
2:1 O D D Phase separation
1:1 O D O Phase separation
IPA
4:1 D D O Phase separation
3:1 D D O Phase separation
2:1 O O O Phase separation
1:1 O O O Phase separation
Acetone
2:1 D D O Phase separation
1:1 O D O Phase separation
O: good dispersion D: fair (hydrophobic porous silica powder is not present) C: no
dispersion
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[0036] As is apparent from the results of Tables 1 and 2, the dispersion stability over
time was increased when using both the water and the organic solvent to disperse the
porous superhydrophobic aerogel microparticles, compared to when using the organic
solvent alone.
[0037] Comparative Examples
[0038] Comparative Example 1
[0039] When a fluid that is pressurized to ultrahigh pressure is passed through a fine
orifice module, an ultrasonic flow rate is generated depending on a drastic reduction in
pressure. Using a high pressure homogenizer for subjecting the particles to impact,
cavitation, turbulence and shear so as to be dispersed at the ultrasonic flow rate, the
same porous superhydrophobic aerogel microparticles as in the above example were
dispersed in water at a maximum pressure of 22,000 psi. As such, such particles
appeared to be temporarily dispersed, but phase separation between the water and the
superhydrophobic microparticles was immediately caused.
[0040] Comparative Example 2
[0041] Porous superhydrophobic aerogel microparticles were dispersed in an aqueous
solution using a surfactant as a dispersion aid. The same porous superhydrophobic
aerogel microparticles as in the above example were used, and the surfactant was sodium
dodecylsulfate (SDS) and TritonTM X-100. For dispersion, stirring was performed at a
rate of 2,000 rpm for 1 hr using a magnetic bar. As for SDS, a 1 M aqueous solution
was prepared, and the porous superhydrophobic aerogel microparticles were dispersed at
a concentration of 5 wt% therein. In a 0.1 M SDS solution, the porous
superhydrophobic aerogel microparticles were not dispersed, but floated on the solution.
As for TritonTM X-100, a 0.25 M aqueous solution was prepared, and the porous
superhydrophobic aerogel microparticles were dispersed at a concentration of 5 wt%
therein.
[0042] Test Example
[0043] Using a contact angle meter, inherent contact angle of silica as porous
superhydrophobic microparticles was measured. The water contact angle was measured
using a contact angle analyzer (KRUSS DSA100), and was specifically determined in a
manner in which double-sided tape was attached to a flat glass plate, microparticles were
applied in a monolayer thereon, and then 5 mL of ultrapure water was placed in the form
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of drop on the monolayer, and the angle between the water drop and the glass plate was
measured four times and averaged.
[0044] The porous superhydrophobic silica microparticles were dispersed as in the
above example, and dried, after which the contact angle thereof was measured. To dry
samples, each sample was placed in an oven at 50°C and allowed to stand for one day.
By measuring the contact angle, changes in hydrophobic properties of the porous
superhydrophobic aerogel microparticles before and after dispersion were checked. The
results are shown in Table 3 below.
[0045] Consequently, there was little change in hydrophobic properties of the porous
superhydrophobic aerogel microparticles dispersed in the mixture of water and IPA. On
the other hand, upon dispersion using the surfactant and then drying, the contact angle
was drastically decreased. Based on the above results, inherent hydrophobic properties
of the porous superhydrophobic aerogel microparticles were not maintained upon
dispersion using the surfactant. Also, when the aerogel was dispersed using water and
IPA, it was scattered again in a powder phase after drying, from which the original
powder phase thereof can be confirmed to be maintained. In two cases using the
surfactant as in Comparative Example 2, the powder was agglomerated in a solid phase,
and thus porous properties disappeared.
[Table 3]
Measurement of contact angle
Sample Contact angle (degree)
Hydrophobic porous silica 144°
(Hydrophobic porous silica / water + IPA)
dispersion and then drying
143°
(Hydrophobic porous silica / water + Triton X-100) dispersion and then
drying
60°
(Hydrophobic porous silica / water + SDS)
dispersion and then drying
29°
Measurement of contact angle using 5 mL of DI water
DM-30S contact angle: 133°
[0046] Based on the above results, the water-dispersed aerogel according to the present
invention is easy to handle as a liquid, and has high profitability and workability. Also,
there is no gelation due to dispersion instability upon long-term storage, and thus the
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aerogel is easily stored and used. As porous superhydrophobic microparticles that are
easily scattered in a conventional powder phase are used in a liquid phase, they may be
relatively easily added in a predetermined amount in the manufacturing process and no
dust is generated, thereby protecting a working environment and the health of workers.
Moreover, the water-dispersed aerogel according to the present invention is
manufactured without the use of an auxiliary agent such as an additive, a pH modifier, a
surfactant or a stabilizer, thus maintaining inherent superhydrophobic and porous
properties of the porous superhydrophobic microparticles upon drying. Since an
auxiliary agent is not added upon manufacturing the water-dispersed aerogel of the
present invention, removal of the auxiliary agent through pre-treatment is obviated, and
the aerogel may be directly applied to the manufacturing process, effectively exhibiting
work efficiency and shortening the process time. Therefore, the water-dispersed aerogel
according to the present invention is applicable to superabsorbent polymers.

WHAT IS CLAIMED IS:
1. A water-dispersed aerogel, comprising:
a mixture of water (A) and an organic solvent (B), and particles (C) having i) a
BET specific surface area of 300 ~ 1500 m2/g and ii) a porosity of 50% or more,
wherein the mixture of water (A) and organic solvent (B) comprises the water
(A) and the organic solvent (B) at a weight ratio of 4:1 ~ 1:1, and the particles (C) are
contained in an amount of 1 ~ 25 parts by weight based on 100 parts by weight of the
mixture of water (A) and organic solvent (B).
2. The water-dispersed aerogel of claim 1, wherein the particles (C) have a
particle size ranging from 2 nm to 50 mm.
3. The water-dispersed aerogel of claim 1, wherein the particles (C) have
superhydrophobicity with a water contact angle of 125° or more.
4. The water-dispersed aerogel of claim 1, wherein the particles (C) have a
particle size ranging from 2 nm to 50 mm and superhydrophobicity with a water contact
angle of 125° or more.
5. The water-dispersed aerogel of claim 1, wherein the particles (C) have a BET
specific surface area of 500 ~ 1500 m2/g.
6. The water-dispersed aerogel of claim 1, wherein the particles (C) have a BET
specific surface area of 600 ~ 1500 m2/g.
7. The water-dispersed aerogel of claim 3, wherein the particles (C) have
superhydrophobicity with a water contact angle of 135° or more.
8. The water-dispersed aerogel of claim 3, wherein the particles (C) have
superhydrophobicity with a water contact angle of 140° or more.
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9. The water-dispersed aerogel of claim 1, wherein the particles (C) have a
porosity of 90% or more.
10. The water-dispersed aerogel of claim 1, wherein the particles (C) are at least
one selected from the group consisting of silica (SiO2), alumina, carbon, and titania
(TiO2).
11. The water-dispersed aerogel of claim 1, wherein the particles (C) are silica
(SiO2).
12. The water-dispersed aerogel of claim 1, wherein the organic solvent (B) is at
least one selected from the group consisting of methanol, ethanol, acetone, isopropyl
alcohol (IPA), propanol, butanol, pentanol, octanol, and isomers thereof.
13. The water-dispersed aerogel of claim 1, wherein the organic solvent (B) is
isopropyl alcohol (IPA).
14. The water-dispersed aerogel of claim 1, wherein the mixture of water (A) and
organic solvent (B) comprises the water (A) and the organic solvent (B) at a weight ratio
of 2:1 ~ 1:1.
15. The water-dispersed aerogel of claim 1, wherein a reduction in contact angle
of the water-dispersed aerogel is 50% or less compared to the particles (C).
16. The water-dispersed aerogel of claim 1, wherein a reduction in contact angle
of the water-dispersed aerogel is 10% or less compared to the particles (C).
17. A method of manufacturing a water-dispersed aerogel comprising a mixture
of water (A) and an organic solvent (B), and particles (C) having i) a BET specific
surface area of 300 ~ 1500 m2/g and ii) a porosity of 50% or more, comprising:
mixing the mixture of water (A) and organic solvent (B) with the particles (C) so
that the particles (C) are dispersed in the mixture of water (A) and organic solvent (B),
16
wherein the mixture of water (A) and organic solvent (B) comprises the water
(A) and the organic solvent (B) at a weight ratio of 4:1 ~ 1:1, and the particles (C) are
contained in an amount of 1 ~ 25 parts by weight based on 100 parts by weight of the
mixture of water (A) and organic solvent (B).
18. The method of claim 17, wherein the particles (C) have a particle size
ranging from 2 nm to 50 mm.
19. The method of claim 17, wherein the particles (C) have superhydrophobicity
with a water contact angle of 125° or more.
20. The method of claim 17, wherein the particles (C) have a particle size
ranging from 2 nm to 50 mm and superhydrophobicity with a water contact angle of 125°
or more.
21. The method of claim 17, wherein the particles (C) have a BET specific
surface area of 500 ~ 1500 m2/g.
22. The method of claim 17, wherein the particles (C) have a BET specific
surface area of 600 ~ 1500 m2/g.
23. The method of claim 19, wherein the particles (C) have superhydrophobicity
with a water contact angle of 135° or more.
24. The method of claim 19, wherein the particles (C) have superhydrophobicity
with a water contact angle of 140° or more.
25. The method of claim 17, wherein the particles (C) have a porosity of 90% or
more.
26. The method of claim 17, wherein the particles (C) are at least one selected
from the group consisting of silica (SiO2), alumina, carbon, and titania (TiO2).
17
27. The method of claim 17, wherein the particles (C) are silica (SiO2).
28. The method of claim 17, wherein the organic solvent (B) is at least one
selected from the group consisting of methanol, ethanol, acetone, isopropyl alcohol
(IPA), propanol, butanol, pentanol, octanol, and isomers thereof.
29. The method of claim 17, wherein the organic solvent (B) is isopropyl alcohol
(IPA).
30. The method of claim 17, wherein the mixture of water (A) and organic
solvent (B) comprises the water (A) and the organic solvent (B) at a weight ratio of 2:1 ~
1:1.
31. The method of claim 17, wherein a reduction in contact angle of the waterdispersed
aerogel is 50% or less compared to the particles (C).
32. The method of claim 17, wherein a reduction in contact angle of the waterdispersed
aerogel is 10% or less compared to the particles (C).