Amphiphilic Silica/Fluoropolymer Nanoparticles: Synthesis, Tem-responsive and Surface
Properties as Protein-resistance Coatings
Hongpu Huang, Jia Qu and Ling He*
Xi’an Jiaotong University, School of Science, Department of Chemistry, Xi’an, 710049, China
Supporting Information
SI-1. Synthesis of silica surface-initiator (SiO2-Br)
The first step was the synthesis of undec-10-enyl, 2-bromo-2-methyl propionate.10.0 ml
10-Undecen-1-ol (49.33 mmol), 20.0 ml dry methylene chloride and 8.0 ml triethylamine (57.39
mmol) were added to a 100 ml Schlenk flask. Then, 7.0 ml BMPB (56.63 mmol) was added
dropwisely at 0°C. The reaction was proceeded under nitrogen at 0°C for 2 h and then at room
temperature for 24 h. The crude product was isolated by filtration and extraction using an
aqueous-saturated ammonium chloride solution. The obtained undec-10-enyl, 2-bromo-2-methyl
propionate was then distilled at 55 °C under reduced pressure (6-7 mm Hg) (yield: 75%).
The second step was the hydrosilylation of undec-10-enyl, 2-bromo-2-methyl propionate. 2.0 ml
undec-10-enyl, 2-bromo-2-methyl propionate (10.45 mmol), 90µl Karstedt’s catalyst and 5.0 ml
triethoxysilane (27.09 mmol) were added to a 100 ml dried Schlenk flask, and allow the mixture
react in the dark for 24 h at 75 °C under nitrogen protection. The catalyst was removed by quickly
filtering the product through a short plug of dry silica. The excess triethoxysilane was removed under
reduced pressure, and then the product was used directly for the next step to obtain silica initiator.
(purity: 90%).
The last step was the synthesis of silica surface-initiator (SiO2-Br). Silica particles were prepared
by sel-gel method and were dispersed in dry THF by ultrasonication. A solution of freshly
synthesized hydrosilylated undec-10-enyl, 2-bromo-2-methyl propionate-silane in dry THF was
injected via a syringe to the flask containing THF-dispersed nanoparticles. Then, 0.1mol-l NH3.H2O
was introduced through a cannula. The reaction was carried out under N2 atmosphere at 45 °C for 40
h. The particles were isolated by centrifugation and were redispersed in dry THF. This washing
process was repeated four times, followed by drying in a vacuum. The purified particles were
redispersed in 10 ml of DMF and the solution was used as silica initiator for ATRP. The scheme of
synthesis initiator SiO2-initiator was given in Scheme SI-1.
Scheme SI-1 Synthesis of SiO2-Br initiator
It was confirmed of UBMP in Fig.SI-1(I) as δ 1.29 (d, 12H, CH2), 1.67 (e, 2H, CH2), 1.93 [g, 6H,
(CH3)2], 2.04 (c, 2H, CH2), 4.16 (f, 2H, CH2), 4.91–5.01 (a, 2H, CH2), 5.80 (b,1H, CH) and in Fig.
SI-1(II) for hydrosilylated UBMP: δ 0.58 [f, 2H, -CH2-Si], 0.86 (e, 2H, CH2), 1.21–1.31 [d, K, 23H,
(CH2)7,CH3], 1.62 (c, 2H, -CH2-), 2.02 (a, 6H, -CH3), 3.83 [g, 6H, -CH2-], 4.17 (b, 2H, CH2).
g
(I)
d
f
b
7
6
e
c
a
5
4
3
2
1
0
ppm
a
(II)
dk
g
b
c
7
6
5
4
3
2
e f
1
0
ppm
Fig.SI-1 1H NMR spectra of undec-10-enyl, 2-bromo-2-methyl propionate (I) and the hydrosilylated
undec-10-enyl, 2-bromo-2-methyl propionate (II)
The end groups of -Si(OCH2CH3)3 in hydrosilylated undec-10-enyl, 2-bromo-2-methyl
propionate were served as the chemical bond with -OH groups in the surface of silica particles to
obtain ATRP-initiator (SiO2-initiator). The FTIR spectrum (Fig.SI-2) for SiO2-initiator showed the
absorption at 2983 and 2899 cm-1 due to the alkyl C-H stretching vibration and at 1735 cm-1 due to
the C=O but it was absent in SiO2 particles, which indicated that the initiator has been polymerized
onto the SiO2 particle’s surface for SiO2-initiator. If the mass percent of the residue at 800 °C was
used as the reference, the weight increase of SiO2-initiator particles relative to that of SiO2 would be
7.8%. Calculations show that the density of SiO2-initiator was 0.244 mmol per gram SiO2-initiator.
(a)
(b)
C-H
4000
3500
3000
C=O
2500
2000
1500
1000
-1
500
Wavenumbers(cm )
Fig.SI-2 FIIR spectra of SiO2 (a), SiO2-Br (b)
SI-2. The synthesis of SiO2-g-PPEGMA
0.40
0.35
ln(M0/M)
0.30
0.25
0.20
0.15
0.10
0.05
0.00
0
60
120
180
240
300
360
Time(min)
Fig.SI-3 First-order kinetic plots of P(PEGMA)
4
-1
Mn 1.54*e g.mol ,Mw/Mn 1.23
S1(1/28.28)
S2(1/42.46)
S3(1/56.37)
4
-1
Mn 1.13*e g.mol ,Mw/Mn 1.33
4
-1
Mn 2.12*e g.mol ,Mw/Mn 1.26
20
22
24
26
28
30
Time(minute)
Fig.SI-4 GPC curves for SiO2-g-P(PEGMA) (S1, S2 and S3)
Table SI-1 The molecular weight of SiO2-g-P(PEGMA) and SiO2-g-P(PEGMA)-b-P(12FMA)
Samples
Mn(×104)(GPC)
g·mol-1
Mn(×104)(NMR)
g·mol-1
Mn(×104)(theo)
g·mol-1
S1
1.13
-
1.37
S2
1.54
-
2.05
S3
2.12
-
2.72
S4
-
1.51
1.85
S5
-
1.89
2.53
S6
-
2.46
3.20