Supporting Information
Synthesis of Snowman-like Polymer-Silica
Asymmetric Particles by Combination of Hydrolytic
Condensation Process with γ-Ray Radiation Initiated
Seeded Emulsion Polymerization
Feng-Wei Wang, Hua-Rong Liu*, Yang zhang, He-Wen Liu, Xue-Wu Ge, Xing-Yuan Zhang
CAS Key Laboratory of Soft Matter Chemistry, Department of Polymer Science and Engineering, University
of Science and Technology of China, Hefei, Anhui 230026, China
Corresponding author: hrliu@ustc.edu.cn
*
To whom all the correspondence should be addressed. E-mail: hrliu@ustc.edu.cn
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Figure S1. FT-IR spectrum of P(St-DVB-AA) microspheres
Figure S1 presents the FT-IR spectrum of P(St-DVB-AA) microspheres. The peak at 1706 cm-1
corresponds to the stretching vibration of C=O groups (υC=O) of PAA, which indicates that the
acrylic acid has been successfully introduced into the polymer microspheres.
Figure S2. TEM and SEM images of the calcinated P(St-DVB-AA)@SiO2 particles formed in
the presence of second monomer.
Figure S2 shows the TEM and SEM images of the calcinated P(St-DVB-AA)@SiO2 particles
formed in the presence of second monomer. After calcinations, only silica shells were left,
indicating the formation of core-shell structures.
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Figure S3. TEM images of snowman-like asymmetric particles after adding (a)Fe2+, (b)Ni2+ after
the hydrolytic condensation process of TOES.
Figure S3 shows that after the addition of metal ions (such as Fe2+ and Ni2+) right after the
hydrolytic condensation process of TEOS. The formed inorganic nanoparticles were found to be
only adsorbed on the silica shell of the snowman-like asymmetric particles after γ-ray radiation.
Figure S4. TGA curve of sample 7 listed in Table 1. The silica content is about 81.442 w%.
Figure S4 shows the thermogravimetric analysis of sample 7 listed in Table 1. The initial
weight loss of 5.774% can be ascribed to the evaporation of physically absorbed water. And the
silica content is about 24.52 wt%, which is higher than that of sample 2 listed in Table 1 (14.84
wt% according to Figure 2b).
Table S1. Recipes of asymmetric particles fabricated by different second monomers and
precursors
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Sample
P(St-DVB-AA)
H2O
NH4OH
/g
/g
/g
Second
Monomer
Precursor
/g
/g
1
0.1
10
0.25
MMA/0.2
TEOS/0.2
2
0.1
10
0.25
tBA/0.2
TEOS/0.2
3
0.1
10
0.25
St/0.2
TBT/0.2
4
0.1
10
0.25
St/0.2
MPS/0.2
5
0.1
10
0.25
St/0.2
APTMS/0.2
6
0.1
10
0.25
St/0.2
OTS/0.2
Figure S5. Composite particles fabricated by using different second monomers: (a) MMA, (b)
tBA.
Figure S5 shows that when MMA was used as the second monomer, network-like PMMA
surrounded particles were formed (Fig. S5a), that may be caused by the relative hydrophilicity of
MMA compared with St. While in the tBA case, uneven golf-ball like particles were obtained
(Fig. S5b), that may be ascribed to easy hydrolyzation of tBA in alkaline conditions leading to the
penetration of water into the seeds during the swelling process.
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Figure S6. TEM images of composite particles fabricated by using different precursors: (a)
APTMS, (b) MPS, (c) OTS, (d) TBT.
From Figure S6, it was found that except for core-shell structured composite particles formed
by using APTMS (Figure S6a), dumbbell- (for MPS, Figure S6b) or snowman-like particles (for
OTS or TBT, Figure S6c and d) were obtained.
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Figure S7. Photographs of snowman-like particles covered P(NIPAM-MBA) (a) died state, (b)
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wet state; SEM image of (c) snowman-like particles covered P(NIPAM-MBA), (d) boundary of
the snowman-like particles covered surface and the uncovered corrugated surface, (e)
morphology of the uncovered P(NIPAM-MBA) surface, (f) a magnified plicated layer with seed
parts of asymmetric particles stick on the surface and head parts face toward outside. Inserted is
a schematic illustration of the plicated layer.
Figure S7a and b show the dried state and wet state of the obtained particles. After absorbing
the water, the particles turn transparent and the sizes are about three times larger than the original
ones. The morphology of these particles was further characterized by SEM (Figure S7c). The
polymerized P(NIPAM-NBA) show a corrugated surface with snowman-like asymmetric
particles covered outside (Figure S7d). It seems that some of the asymmetric particles are likely
to be stripped after the polymerization (Figure S7e) which may be caused by the contraction
during the drying process. Figure S7f shows a magnified image of the snowman-like particles
covered plicated layer. The seed parts are more like to stick on the surface, while the heads are
likely to face towards outside.
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