Supporting Information Synthesis and Characterization of Solvent ...
Supporting Information
Synthesis and Characterization of Solvent-Invertible Amphiphilic Hollow Particles Cheng Hao Lee,1 Chun Him Wong,1 Djamila Ouhab,2 Redouane Borsali,2 Pei Li1* 1
Department of Applied Biology and Chemical Technology, The Hong Kong Polytechnic
University, Hung Hom, Kowloon, Hong Kong SAR, P. R. China; 2
Centre de Recherches sur les Macromolécules Végétales (CERMAV-CNRS), and
Joseph Fourier University, BP 53, F-38041 Grenoble Cedex 9, France * Author to whom correspondence should be addressed. E-mail: [email protected]
Figure S1. TEM micrograph of the PMMA/PEI core-shell particles which displays three observable regions: the white center part is the PMMA homopolymer; the middle grey area contains mixed PEI and PMMA segments; and the darker outer region is PEI-rich segment.
1
H-NMR characterization 1
H-Nuclear
magnetic
resonance
(1H-NMR)
spectroscopy
and
relaxation
measurements were carried out on a Bruker UltrashieldTM Plus 400 FT-NMR spectrometer (400 MHz) using CDCl3, D2O or a mixture of CDCl3 and CD3OD as solvents. The dried samples were dissolved in a 600 µL deuterium solvent. a)
H N N
D2O y
x NH2
b)
a
a
CH3
mm mr rr
b
CH2
c
CDCl3
C
b
C
n O
O
CH3
c
c) PEI-g-PMMA hollow particle obtained from water a
b
c
mm mr rr
CD3OD
d) PEI-g-PMMA hollow particle treated with DCM
a mm mr rr
b
c
7.0
6.0
5.0
4.0
3.0
2.0
1.0
ppm (t1)
Figure S2. 1H-NMR spectra of a) native PEI in D2O; b) PMMA homopolymer isolated from the core-shell particles in CDCl3; c) PEI-g-PMMA hollow particles obtained from water in D2O; d) PEI-g-PMMA hollow particles treated with DCM in a mixture of CD3OD and CDCl3 (equal volume).
In Figure S3a, peak-fitting and deconvolution of the high resolution C1s peak consist of C-C and C-H components at 285.0 eV and C-N component at 286.0 eV. Peak-fitting and deconvolution of the N1s peak in Figure S3b reveal two binding energy peaks at 399.1 and 401.23 eV, which are typical values for neutral and cationic amines. These results indicate that the PEI chains are localized on the outer shell. Besides the C1s and N1s peaks, an O1s peak at a binding energy of 530.9 eV was also detected (Figure S3c). To verify the molecular structure of the O1s peak, the sample was treated with either argon ion sputtering or thermal desorption process. It was found that the O1s peak intensity was reduced approx. 51% atomic concentration after 30 min argon ion sputtering. However, reduction of O1s peak intensity did not change the envelope profile of the high resolution C1s and N1s peaks. Moreover, changing in O1s peak profile at 530.9 eV by ion sputtering had no correlation with the C1s deconvolution profiles, indicating that there was no C-O bonding. These results suggest that the O1s peak in Figure S3c is attributed to the presence of physisorbed oxygen molecules on the particle surface, not the PMMA polymer.
10000
C 1s
C-C/C-H 6000 4000
C-N
2000
N 1s
6000
N
4000
N+
2000 0
0 300
(b)
8000
Counts/s
Counts/s
8000
10000
(a)
296
292
288
284
280
408
404
400
396
Binding Energy (eV)
Binding Energy (eV)
5000
(c)
Counts/s
4000
O 1s
3000 2000 1000 0 544
540
536
532
528
Binding Energy (eV)
Figure S3. XPS spectra of PEI-g-PMMA hollow particles treated with water. (a) Deconvolution profile of C1s core spectrum, (b) Deconvolution profile of N1s core spectrum, (c) O1s core spectrum.
7000 6000
(a)
C 1s
Counts/s
5000
C-H
4000 3000 C-C
2000 C=O
O-CH3
1000 0 300
295
290
285
280
Binding Energy (eV)
7000
Counts/s
6000
(b)
O 1s
5000 4000 3000
O=C
O-CH3
2000 1000 0 538
536
534
532
530
528
Binding Energy (eV)
Figure S4. XPS spectra of PEI-g-PMMA hollow particles treated with DCM. (a) Deconvolution profile of C1s core spectrum, (b) Deconvolution profile of O1s core spectrum.
Figure S4 shows C1s and O1s peaks as major elemental peaks. Peak-fitting and deconvolution of the high resolution C1s peak reveal that there are four binding energy
peaks at 285.0, 285.6, 286.7 and 289 eV, which are characteristic binding energies of aliphatic carbon atoms (C–H and C–C), carbon atom in ester group (C–O), and carbonyl carbon atom (O–C=O). The peak-fitting and deconvolution of the O1s peak reveal two peaks at binding energies of 532 eV and 533.8 eV, which are attributed to oxygen in carbonyl and ester groups, respectively. The atomic ratio of carbon to oxygen atoms is 2.58, which is very close to the calculated ratio of carbon to oxygen atom in the PMMA molecule (C : O ratio = 2.5). These results indicate that the surface layer of the dispersed hollow particle in DCM is PMMA grafts.
Table 1. Comparison of XPS peak area ratios of methyl carbon to ester carbon of PMMA Sample
C 1s
Binding
Deconvoluted
Ratio of
Energy (eV)
Peak area
methyl carbon to ester carbon of PMMA4
Pure PMMA film1
C-C/C-H C-O O-C=O
283.8 284.9 288.0
40.83 19.59 19.38
1.04
DCM-treated hollow
C-C/C-H
285.0
57.70
1.37
C-O O-C=O
286.6 288.9
25.30 16.99
C-C/C-H C-O O-C=O
285.0 286.0 288.9
55.49 27.70 16.79
particle film
2
Thermally annealed DCM-treated hollow particle film3 1 2
1.25
See Figure S5(a) for C1s core XPS spectra
See Figure S5(b) for C1s core XPS spectra The DCM-treated hollow particle film was thermally annealed at 110 0C for 60 min. See Figure S5(c) for C1s core XPS spectra 4 Ratio = (C-C/C-H) peak area over (C-O + O-C=O) peak area 3
7000
(a) Pure flat PMMA sheet
Counts/s
6000
C-C/C-H
5000 4000
O-CH3
3000 2000 1000
C=O
0 292
290
288
286
284
282
280
Binding Energy (eV)
7000 (b) DCM-treated hollow particle 6000
Counts/s
5000
C-C/C-H
4000 3000
O-CH3 C=O
2000 1000 0 292
290
288
286
284
282
280
Binding Energy (eV)
7000 (c) Thermally annealed DCM-treated
Counts/s
6000
hollow particles C-C/C-H
5000 4000
O-CH3
3000 2000
C=O
1000 0 292
290
288
286
284
282
280
Binding Energy (eV)
Figure S5. C1s core XPS spectra of (a) Pure PMMA sheet; (b) DCM-treated hollow particle film; (c) DCM-treated hollow particle film thermally annealed at 110oC for 1 hr.
Synthesis and Characterization of Solvent-Invertible Amphiphilic Hollow Particles Cheng Hao Lee,1 Chun Him Wong,1 Djamila Ouhab,2 Redouane Borsali,2 Pei Li1* 1
Department of Applied Biology and Chemical Technology, The Hong Kong Polytechnic
University, Hung Hom, Kowloon, Hong Kong SAR, P. R. China; 2
Centre de Recherches sur les Macromolécules Végétales (CERMAV-CNRS), and
Joseph Fourier University, BP 53, F-38041 Grenoble Cedex 9, France * Author to whom correspondence should be addressed. E-mail: [email protected]
Figure S1. TEM micrograph of the PMMA/PEI core-shell particles which displays three observable regions: the white center part is the PMMA homopolymer; the middle grey area contains mixed PEI and PMMA segments; and the darker outer region is PEI-rich segment.
1
H-NMR characterization 1
H-Nuclear
magnetic
resonance
(1H-NMR)
spectroscopy
and
relaxation
measurements were carried out on a Bruker UltrashieldTM Plus 400 FT-NMR spectrometer (400 MHz) using CDCl3, D2O or a mixture of CDCl3 and CD3OD as solvents. The dried samples were dissolved in a 600 µL deuterium solvent. a)
H N N
D2O y
x NH2
b)
a
a
CH3
mm mr rr
b
CH2
c
CDCl3
C
b
C
n O
O
CH3
c
c) PEI-g-PMMA hollow particle obtained from water a
b
c
mm mr rr
CD3OD
d) PEI-g-PMMA hollow particle treated with DCM
a mm mr rr
b
c
7.0
6.0
5.0
4.0
3.0
2.0
1.0
ppm (t1)
Figure S2. 1H-NMR spectra of a) native PEI in D2O; b) PMMA homopolymer isolated from the core-shell particles in CDCl3; c) PEI-g-PMMA hollow particles obtained from water in D2O; d) PEI-g-PMMA hollow particles treated with DCM in a mixture of CD3OD and CDCl3 (equal volume).
In Figure S3a, peak-fitting and deconvolution of the high resolution C1s peak consist of C-C and C-H components at 285.0 eV and C-N component at 286.0 eV. Peak-fitting and deconvolution of the N1s peak in Figure S3b reveal two binding energy peaks at 399.1 and 401.23 eV, which are typical values for neutral and cationic amines. These results indicate that the PEI chains are localized on the outer shell. Besides the C1s and N1s peaks, an O1s peak at a binding energy of 530.9 eV was also detected (Figure S3c). To verify the molecular structure of the O1s peak, the sample was treated with either argon ion sputtering or thermal desorption process. It was found that the O1s peak intensity was reduced approx. 51% atomic concentration after 30 min argon ion sputtering. However, reduction of O1s peak intensity did not change the envelope profile of the high resolution C1s and N1s peaks. Moreover, changing in O1s peak profile at 530.9 eV by ion sputtering had no correlation with the C1s deconvolution profiles, indicating that there was no C-O bonding. These results suggest that the O1s peak in Figure S3c is attributed to the presence of physisorbed oxygen molecules on the particle surface, not the PMMA polymer.
10000
C 1s
C-C/C-H 6000 4000
C-N
2000
N 1s
6000
N
4000
N+
2000 0
0 300
(b)
8000
Counts/s
Counts/s
8000
10000
(a)
296
292
288
284
280
408
404
400
396
Binding Energy (eV)
Binding Energy (eV)
5000
(c)
Counts/s
4000
O 1s
3000 2000 1000 0 544
540
536
532
528
Binding Energy (eV)
Figure S3. XPS spectra of PEI-g-PMMA hollow particles treated with water. (a) Deconvolution profile of C1s core spectrum, (b) Deconvolution profile of N1s core spectrum, (c) O1s core spectrum.
7000 6000
(a)
C 1s
Counts/s
5000
C-H
4000 3000 C-C
2000 C=O
O-CH3
1000 0 300
295
290
285
280
Binding Energy (eV)
7000
Counts/s
6000
(b)
O 1s
5000 4000 3000
O=C
O-CH3
2000 1000 0 538
536
534
532
530
528
Binding Energy (eV)
Figure S4. XPS spectra of PEI-g-PMMA hollow particles treated with DCM. (a) Deconvolution profile of C1s core spectrum, (b) Deconvolution profile of O1s core spectrum.
Figure S4 shows C1s and O1s peaks as major elemental peaks. Peak-fitting and deconvolution of the high resolution C1s peak reveal that there are four binding energy
peaks at 285.0, 285.6, 286.7 and 289 eV, which are characteristic binding energies of aliphatic carbon atoms (C–H and C–C), carbon atom in ester group (C–O), and carbonyl carbon atom (O–C=O). The peak-fitting and deconvolution of the O1s peak reveal two peaks at binding energies of 532 eV and 533.8 eV, which are attributed to oxygen in carbonyl and ester groups, respectively. The atomic ratio of carbon to oxygen atoms is 2.58, which is very close to the calculated ratio of carbon to oxygen atom in the PMMA molecule (C : O ratio = 2.5). These results indicate that the surface layer of the dispersed hollow particle in DCM is PMMA grafts.
Table 1. Comparison of XPS peak area ratios of methyl carbon to ester carbon of PMMA Sample
C 1s
Binding
Deconvoluted
Ratio of
Energy (eV)
Peak area
methyl carbon to ester carbon of PMMA4
Pure PMMA film1
C-C/C-H C-O O-C=O
283.8 284.9 288.0
40.83 19.59 19.38
1.04
DCM-treated hollow
C-C/C-H
285.0
57.70
1.37
C-O O-C=O
286.6 288.9
25.30 16.99
C-C/C-H C-O O-C=O
285.0 286.0 288.9
55.49 27.70 16.79
particle film
2
Thermally annealed DCM-treated hollow particle film3 1 2
1.25
See Figure S5(a) for C1s core XPS spectra
See Figure S5(b) for C1s core XPS spectra The DCM-treated hollow particle film was thermally annealed at 110 0C for 60 min. See Figure S5(c) for C1s core XPS spectra 4 Ratio = (C-C/C-H) peak area over (C-O + O-C=O) peak area 3
7000
(a) Pure flat PMMA sheet
Counts/s
6000
C-C/C-H
5000 4000
O-CH3
3000 2000 1000
C=O
0 292
290
288
286
284
282
280
Binding Energy (eV)
7000 (b) DCM-treated hollow particle 6000
Counts/s
5000
C-C/C-H
4000 3000
O-CH3 C=O
2000 1000 0 292
290
288
286
284
282
280
Binding Energy (eV)
7000 (c) Thermally annealed DCM-treated
Counts/s
6000
hollow particles C-C/C-H
5000 4000
O-CH3
3000 2000
C=O
1000 0 292
290
288
286
284
282
280
Binding Energy (eV)
Figure S5. C1s core XPS spectra of (a) Pure PMMA sheet; (b) DCM-treated hollow particle film; (c) DCM-treated hollow particle film thermally annealed at 110oC for 1 hr.
