Preparation of Silica Capsules via an Acid-Catalyzed Sol–Gel Process in Inverse
Miniemulsions
Zhijie Chen1, Liu Yang2, Yingjie Yan2, Dongming, Qi1, *, Zhihai Cao1, *,
1
Key Laboratory of Advanced Textile Materials and Manufacturing Technology and
Engineering Research Center for Eco-Dyeing & Finishing of Textiles, Ministry of Education,
Zhejiang Sci-Tech University, Hangzhou, 310018, China
2
College of Materials, Chemistry and Chemical Engineering, Hangzhou Normal University,
Xuelin Street 16, Hangzhou 310036, China
Corresponding author: caozhihai@gmail.com; dongmingqi@zstu.edu.cn
Fig. S1. SEM image of the calcined silica capsules. (The TEOS and CTAB amounts were 0.75
g and 0.1 g, respectively; the concentration of HClaq was 1 mol·L−1; see Table 1, run1).
Table S1. Formulations of S1 Experiment
run
CTAB
HClaq amount (g)
(wt%)
HClaq
NaCl
TEOS
particle
concentration
(g)
(g)
morphology
0.05g
0.75
Capsule/solid
(mol·L–1)
S1
8.0
1.25
1.00
particles
800
0.05 g of NaCl
size (nm)
600
400
200
0
0
400
800
1200
1600
Time (min)
Figure S2. Particle size evolution over time in the system with 0.05 g NaCl (Table 1, run S1).
Table S2. Recipes for the viscosity measurement of the aqueous silica solutions.
run
S2
S3
S4
HClaq (1mol·L-1)
amount (g)
100
100
100
TEOS amount (g)
40
80
160
mass ratio of TEOS to
HClaq
0.5:1.25
1.0:1.25
2.0:1.25
Dparticles-Ddroplets (nm)
1000
800
600
400
200
0
0
1
2
3
4
5
6
HCl concentration (mol/L)
Fig. S3. Influence of the HCl concentration on the size difference between particles and
droplets (see Table 1, runs 13–19).
Table S3. Formulations for the experiments using HClaq with different concentrations and with
1.5 g of TEOS.
run
CTAB
HClaq amount (g)
(wt%)a
HClaq
TEOS
particle
concentration
(g)
morphology
(mol·L–1)
a
S5
8.0
1.25
1.0
1.5
solid
S6
8.0
1.25
2.0
1.5
solid
S7
8.0
1.25
4.0
1.5
solid
S8
8.0
1.25
6.0
1.5
solid
Relative to aqueous HCl.
a
b
c
d
Fig. S4. Silica particles synthesized via sol–gel process in inverse miniemulsion under
acidic conditions with different HClaq concentrations. (a, 1 mol·L–1; b, 2 mol·L–1; c, 4
mol·L–1; d, 6 mol·L–1; The TEOS and CTAB amounts are 1.5 g and 0.1 g, respectively;
see Table S3, runs S5–S8).