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Supplementary information
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Molecular composition distribution of polycarbonate/polystyrene
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blends in cylindrical nanopores
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Hui Wu1, Zhaohui Su2 and Atsushi Takahara1
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1
Institute for Materials Chemistry and Engineering, Kyushu University, 744 Motooka, Nishi-ku,
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Fukuoka 819-0395, Japan;
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2
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Chemistry, Chinese Academy of Sciences, Changchun, Jilin 130022, P. R. China
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*E-mail: takahara@cstf.kyushu-u.ac.jp
State Key Laboratory of Polymer Physics and Chemistry, Changchun Institute of Applied
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1.
Determination of PC content in PC/PS blends by FTIR.
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To get a calibration curve of PC content in PC/PS blends, various compositions of PC and PS
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powder blends with known PC content of 9.6%, 15.8%, 25.0%, 35.9%, 43.9%, 51.9%, 56.4%,
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59.9%, and 65.0%, respectively, were each mixed with potassium bromide (KBr) powder in an
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agate mortar and pressed into transparent disks for FTIR measurements.
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dispersed uniformly within KBr matrix.
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FTIR spectrometer equipped with a MCT detector operating in the transmission mode.
The PC and PS were
FTIR spectroscopy was performed on a PerkinElmer
Each
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spectrum was collected at 2 cm-1 resolution with 128 scans.
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of PC/PS blends with various PC content.
A
906 888
a
Figure S1 show the FTIR spectra
B
906
888
c
Absorbance
Absorbance
b
d
e
f
g
h
i
2000 1800 1600 1400 1200 1000
-1
800
Wavenumber (cm )
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Figure S1.
930 915 900 885 870
-1
Wavenumber (cm )
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a
b
c
d
e
f
g
h
i
Infrared spectra of PC/PS blends with different PC content: (a) 9.6%; (b) 15.8%;
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(c) 25.0%; (d) 35.9%; (e) 43.9%; (f) 51.9%; (g) 56.4%; (h) 59.9%; and (i) 65.0%.
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enlarged spectra in (A) ranging between 930 and 865 cm-1.
(B) is the
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In the range from 930 to 865 cm-1 in FTIR spectra of PC/PS film (Figure S2a), three peaks
which located at 888, 906, and 918 cm-1 appear.
The peak at 888 and 918 cm-1 is caused by the
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C–CH3 stretching of PC1 (Figure S2b) and the peak at 906 cm-1 is the characteristic of
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out-of-plane vibration of benzene ring of PS2 (Figure S2c).
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the Levenberg-Maquardt least-squares algorithm routine of the OPUS software package ranging
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from 930 to 865 cm-1 to obtain the individual peak intensities (peak area) of 888 and 906 cm-1.
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The bandwidth of 888, 906, and 918 cm-1 band is about 14.0, 12.5, and 8.0, respectively. And a
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Curve fitting was performed using
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mixture shape of Lorentz and Gauss was employed to best match the original spectrum as
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indicated in Figure S2.
888
906
918
Absorbance
a
b
c
930
920
910
900
890
880
870
-1
Wavenumber (cm )
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Figure S2.
FTIR spectra of: (a) PC/PS film; (b) PC film; and (c) PS film. The dashed lines
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represent the result of curve-fitting ranging between 930 and 865 cm-1.
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By measuring the intensity ratio between these two peaks at 888 and 906 cm-1 for the above
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blends of known compositions, a calibration curve was obtained (Figure S3).
According to
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Beer’s law, the intensities of absorption bands are linearly proportional to the concentration of
Thus, the intensity ratio of peak at 888 cm-1 (PC)
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each component in a homogeneous mixture.
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to peak at 906 cm-1 (PS) is related to the concentration (mass) ratio because of the identical path
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length of source beam in the same mixed disks. Therefore, the ratio of the intensity of 888 to
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906 cm-1 band and the PC content in PC/PS blend films can be written by
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APC aPCbPCcPC aPC mPC
m



 k PC
APS aPSbPScPS aPS mPS
mPS
1
CPC 
2
(1)
mPC
APC

mPC  mPS APC  kAPS
(2)
where APC and APS are the intensity of PC and PS, as obtained by the absorbance areas ranging
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from 930 to 865 cm-1; mPC and mPS are the mass of PC and PS in the blends, k is the ratio of
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absorptive coefficients of aPC/aPS of PC at 888 cm-1 and PS at 906 cm-1, CPC is the content of PC
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components in the PC/PS blends.
Absorbance Ratio (A888/A906)
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10
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k = 4.47 ± 0.10
2
0
0.0
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0.5
1.0
1.5
Mass Ratio (mPC/mPS)
2.0
Calibration curve of the ratio of the absorbances of peak at 888 cm-1 to peak at 906
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Figure S3.
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cm-1 in PC/PS blend films.
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The k value was determined from the absorption measurements of mixtures containing known
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amounts of compounds PC and PS at two specified frequencies, 888 and 906 cm-1.
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calibration curves of PC/PS blends in Figure S3 which was fitted using linear regression, yields
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The
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Therefore, using the absorbance measurements of 888 and 906 cm-1
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the k value of 4.47±0.10.
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in the FTIR spectra, the following relationship is obtained to calculate the absolute PC content in
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PC/PS blend nanorods/film
A888
A888  4.47 A906
(3)
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CPS  100%  CPC
(4)
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where CPC, CPS represent the content of PC and PS in the PC/PS blends, A888 and A906 are the
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respective band area for peaks at 888 and 906 cm-1, 4.47 is the ratio of absorptive coefficients of
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the peak at 888 cm-1 to the peak at 906 cm-1.
CPC 
4
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2.
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The original PC/PS blend films with a thickness of 200 µm for the preparation of polymer blend
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nanorods were obtained by compression molding the cast PC/PS film at 250 °C for 4 min and
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quickly quenching the film in liquid nitrogen.
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at 250 °C for 3 h and quenched into liquid nitrogen.
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film for microscope observation were prepared by cutting the film using a razor blade.
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Optical micrographs of PC/PS blend film before and after annealing.
For the annealed film, the blend film was heated
Thin slices of the cross section of PC/PS
From the optical micrograph of the PC/PS film before and after annealing (Figure S4), many
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dots and strips existed in the film.
This indicates phase segregation was pronounced and PC/PS
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blends were partially miscible system at 250 ºC.
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strips were the PC-rich region, while the darker area was PS-rich region.
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homogeneous blend because PC/PS was a partially miscible system.
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FTIR analysis showed that the white dots or
The film was not a
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A
B
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Figure S4.
Optical micrographs of a thin slice of a PC/PS film before (A) and after (B)
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annealed at 250 °C for 3 h.
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3.
X-ray photoelectron spectroscopy (XPS) analysis of PC/PS film before and after
annealing.
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The XPS measurements were carried out on a PHI5800 (Physical Electronics Co., Ltd.) with an
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Al Kα X-ray source.
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chamber pressure was 10-9 Pa.
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The X-ray gun was operated at 14 kV and 350 mW, and the analyzer
Takeoff angles were kept constant at 45°.
The PC content was quantified by XPS from the atomic ratio (rC/O) of C and O, based on the
exclusive presence of oxygen in the PC:
CPC 
254
46  39rC/O
(5)
Before annealing, the PC content on the surface of the original PC/PS film was about 75.3%,
showing the surface was enriched with PC component.
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After annealed the PC/PS blend films at
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250 °C for 3 h and quickly quenched in liquid nitrogen, the PC content on the surface of PC/PS
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film decreased to 7.5 %, showing the PS component enriched on the surface.
C
Intensity
O
a
b
600
500
400
300
200
Bidning Energe (eV)
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Figure S5.
XPS spectra of PC/PS film before (a) and after (b) annealed at 250 °C for 3 h.
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REFERENCES
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1
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Lee, S. N., Stolarski, V., Letton, A. & Laane, J. Studies of Bisphenol-A-Polycarbonate
Aging by Raman Difference Spectroscopy. J. Mol. Struct. 521, 19-23 (2000).
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Liang, C. Y. & Krimm, S. Infrared Spectra of High Polymers. VI. Polystyrene. J. Polym.
Sci. 27, 241-254 (1958).
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