A new polymer with low dielectric constant based on trifluoromethyl-substituted arene: Preparation and properties

Article abstract of DOI:10.1039/c4ra07201d

A new polymer with low dielectric constant is reported here. This polymer contains a trifluoromethyl-substituted phenyl unit and a binaphthyl unit, and shows high thermostability with a glass transition temperature of 244 °C and a 5 wt% loss at temperature 518 °C under nitrogen. The polymer also exhibits good film-forming ability, and the formed films exhibit high hydrophobicity with a contact angle of 103.6° with water. In a range of frequencies from 1 to 25 MHz, the polymer reveals an average dielectric constants of about 2.56. In regard to the mechanical properties, the polymer film shows an average hardness of 0.37 GPa and a Young's modulus of 15.07 GPa. These results indicate that the polymer could be used as a varnish for enameled wire, sizing agents for high-performance carbon fiber, and the matrix resin for the production of laminated composites utilized in the printed-circuit-board (PCB) industry. This journal is

Full text of DOI:10.1039/c4ra07201d

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PAPER
A new polymer with low dielectric constant based
on trifluoromethyl-substituted arene: preparation
and properties
Cite this: RSC Adv., 2014, 4, 40782
Jiajia Wang, Kaikai Jin, Fengkai He, Jing Sun and Qiang Fang*
A new polymer with low dielectric constant is reported here. This polymer contains a trifluoromethyl-
substituted phenyl unit and a binaphthyl unit, and shows high thermostability with a glass transition
ꢀ
ꢀ
temperature of 244 C and a 5 wt% loss at temperature 518 C under nitrogen. The polymer also exhibits
good film-forming ability, and the formed films exhibit high hydrophobicity with a contact angle of
ꢀ
1
03.6 with water. In a range of frequencies from 1 to 25 MHz, the polymer reveals an average dielectric
Received 16th July 2014
Accepted 13th August 2014
constants of about 2.56. In regard to the mechanical properties, the polymer film shows an average
hardness of 0.37 GPa and a Young's modulus of 15.07 GPa. These results indicate that the polymer could
be used as a varnish for enameled wire, sizing agents for high-performance carbon fiber, and the matrix
resin for the production of laminated composites utilized in the printed-circuit-board (PCB) industry.
DOI: 10.1039/c4ra07201d
www.rsc.org/advances
containing the least polarizable bonds, such as C–F bond in
1
. Introduction
29–37
molecular backbone and/or side chains;
the other is to
However, favorable size
signicant attention for many years because they are a kind of and distribution of the pores should be carefully controlled.
necessary materials for fabrication of insulating the varnish of
Because polymeric materials have the advantage of easy
38–46
Polymers with low dielectric constants (low k) have attracted generate pores in polymer networks.
enameled wire in the electrical industry, as well as for the structure design, as a result, their k values and other properties
production of printed circuit boards (PCB) in the electronics such as thermostability and mechanical could be tunable via
1–4
industry.
In recent years, the development of multilevel well-dened molecular structures. It is noted that poly(aryl
interconnection technology in the production of ultra-large- ether)s show high bonding strength to metals and low thermal
scale integration (ULSI) circuits has raised (up) an urgent expansion coefficients (CTE) and that uoro-containing poly-
47,48
requirement of the low k materials because of the fact that they mers exhibit lower k values.
Thus, the studies on the
play a very important role in decreasing cross-talk noise, power synthesis and properties of the new poly(aryl ether)s with uoro
dissipation and interconnecting signal delay (RC delay) gener- groups are signicant.
3
ated with a minimization of electronic devices in the micro-
Previously, we have reported a thermally cross-linkable
5
–10
electronics industry.
Accordingly, various polymers have molecule composed of bis(triuoromethyl)benzene and ben-
been well investigated, and low k materials have been devel- zocyclobutene units, which shows both low dielectric constants
11–28
oped.
Nevertheless, commercially available low k polymers at high frequencies and high thermostability. In order to further
utilized at high frequencies (>10 MHz) are rare. It is known that investigate the properties of the organic materials containing
the materials having a k value below 3.0 at high frequencies can bis(triuoromethyl)benzene units, we design and synthesize a
meet the requirement of a 90 nm procedure in ultra-large-scale new polymer composed of a binaphthyl unit and a bis(tri-
6
–8
integration (ULSI) circuits. Moreover, such low k materials are uoromethyl)benzene unit, whose chemical structure is shown
also desirable for the production of high-frequency printed in Scheme 1. The polymer exhibits good lm-forming ability,
circuit boards. Therefore, the exploration and development of and the formed lms possess high hydrophobicity with a
the polymers with a low k values at high frequencies is still
necessary.
To date, there are two methods for scaling down the dielec-
tric constants of polymers. One is to use the polymers
Laboratory of Synthetic and Self-Assembly Chemistry for Organic Functional
Molecules, Shanghai Institute of Organic Chemistry, Chinese Academy of Sciences,
3
45 Lingling Road, Shanghai 200032, PR China. E-mail: qiangfang@mail.sioc.ac.cn;
Fax: +86-21-54925337; Tel: +86-21-54925337
Scheme 1 Chemical structure of the new polymer in this work.
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ꢀ
contact angle of 103.6 with water. In a frequencies range of 1 to was further puried by recrystallization from n-hexane. Pure
5 MHz, the polymer reveals an average dielectric constants of monomer 2 was obtained as a white solid with a yield of 67%
2
1
about 2.56. Moreover, the polymer shows high thermostability with a purity of 99.6% (HPLC). H NMR (400 MHz, CDCl ) d
3
and good mechanical properties. These data suggest that the (TMS, ppm): 7.02–7.03 (dd, 2H), 7.25 (s, 2H), 7.45–7.49 (t, 2H),
polymer could be used as the insulating varnish for enameled 7.54–7.57 (td, 4H), 7.73–7.75 (d, 2H), 7.92–7.94 (m, 2H), 8.15–
1
9
wire, sizing agents for high-performance carbon ber, and the 8.17 (dd, 2H). F NMR (376 MHz, CDCl
3
) d (TMS, ppm): À62.57
) d (TMS, ppm): 113.98,
117.94, 121.64, 122.36, 125.01, 125.48, 125.81, 126.65, 127.79,
27.19, 128.11, 135.23, 150.62, 151.86.
1
3
matrix resin for the production of laminated composites (s, 6F). C NMR (100 MHz, CDCl
utilized in the printed-circuit-board (PCB) industry.
3
1
2
. Experimental
Synthesis of the polymer
Materials
Monomer 2 (0.498 g, 1 mmol) was dissolved in 1,1,2,2-tetra-
All starting materials were purchased from Aldrich and Acros
companies and used without further purication unless other-
wise stated. 1,4-Bis(triuoromethyl)-3,5-dibromobenzene (1)
chloroethane (3.5 mL) at room temperature under argon. The
ꢀ
obtained solution was cooled to À5 C and then added to a
mixture of anhydrous iron(III) chloride (0.406 g, 2.5 mmol) in
3,49,50
was prepared according to the method previously reported.
1
,1,2,2-tetrachloroethane (1.5 mL) under argon atmosphere.
1
Characterization: H NMR (400 MHz, CDCl ) d (TMS, ppm): 8.02
3
ꢀ
Aer being stirred at À5 C for 24 h, the reaction mixture was
poured into methanol (200 mL) containing a small amount of
concentrated HCl. The obtained precipitate was puried by
1
9
(
s, 2H); F NMR (376 MHz, CDCl ) d (TMS, ppm): 63.94 (s, 6F).
3
All the solvents were dehydrated and distilled under an inert
atmosphere before use.
2 3 3
column chromatography on neutral Al O with CHCl as the
eluent. Aer the solvents were evaporated, the polymer was re-
Measurement
dissolved in chloroform and reprecipitated with methanol. A
1
13
19
ꢀ
H NMR, C NMR and F NMR spectra were obtained on a yellowish powder was thus obtained, which was dried at 80 C
Bruker AV400 instrument. Elemental analysis was carried out for 12 h under vacuum to get the polymer sample. Yield: 80%.
1
on an Elementar vario EL III system. Molecular weights were Characterization: H NMR (400 MHz, acetone-d
measured at room temperature by gel-permeation chromatog- 7.37–7.39 (d, 2H), 7.46–7.54 (m, 4H), 7.59–7.61 (d, 2H), 7.64–
) d (TMS, ppm):
6
1
9
raphy (GPC) with a Waters Breeze2a 200 GPC system, equipped 7.70 (m, 2H), 7.78 (s, 2H), 8.37–8.39 (d, 2H). F NMR (376 MHz,
1
3
with a UV detector using tetrahydrofuran (THF) as the eluent. acetone-d ) d (TMS, ppm): À62.87 (s, 6F). C NMR (100 MHz,
All the data are relative to polystyrene standards. Differential CDCl ) d (TMS, ppm): 113.01, 118.56, 121.11, 121.91, 123.83,
scanning calorimetric (DSC) analysis was determined with a TA 126.04, 126.59, 126.86, 127.52, 128.01, 134.60, 134.79, 150.61,
6
3
ꢀ
À1
Instrument DSC Q200 at a heating rate of 10 C min under 152.05. Elemental analysis, calcd. for C28
16 2 6
H O F : C, 67.47; H,
nitrogen. Thermogravimetric analysis (TGA) was measured on a 3.24; F, 22.87. Found: C, 67.65; H, 3.45; F, 22.86.
ꢀ
À1
Netzsch TG 209F1 apparatus with a heating rate of 10 C min
under nitrogen and air atmosphere, respectively. The surface Preparation of the lm for the measurement of k value,
toughness of the polymer lm was measured by atomic force surface toughness and contact angle
microscopy (AFM) on a Shimadzu SPM-9500J3 instrument. The
A polymer solution in toluene (30 wt%) was spin-coated on an
ꢀ
contact angle of water on the lm was characterized at 20 Æ 1 C
aluminum-backed silicon wafer (heavily doped single-crystal
using a sessile-drop method on a dynamic contact angle
measurement instrument (JC2000C). Deionized water was
selected as the testing liquid. The dielectric constants of the
polymer lms were investigated at room temperature on a
À3
silicon with a resistivity of 3.5 Â 10 U cm) to form a lm. The
wafer was placed into a quartz-tube furnace and maintained at
ꢀ
1
80 C for 3 h to completely remove the solvent. Thus, the lms
for the measurement of the surface toughness and contact
angles were obtained.
4294A Precision Impedance Analyzer (Agilent).
To prepare the lm used for the measurement of the k value,
an additional procedure was used and described in the
following manner: a top electrode (aluminium with the diam-
Synthesis of the monomer 1,4-bis(1-naphthalenyloxy)-2,5-
bis(triuoromethyl)-benzene (2)
A mixture of 1-naphthol (8.65 g, 60 mmol), 1,4-bis(tri- eter of 3 mm) was deposited on the lm surface via vacuum
uoromethyl)-2,5-dibromobenzene (1, 7.438 g, 20 mmol), NaOH evaporation; the thickness of the lm was measured by eld

(
2.8 g, 70 mmol), DMSO (60 mL), and toluene (100 mL) was emission-scanning electron microscopy (FE-SEM).
ꢀ
heated to reux (near 150 C), and the water formed during the
reaction was removed by a Dean–Stark trap. Aer being main-
tained at a temperature of about 150–160 C for 8 h, the reaction
3
. Results and discussion
ꢀ
Synthesis and characterization
mixture was cooled to room temperature, poured into 200 mL of
water and extracted with ethyl acetate. The organic layer was As shown in Scheme 2, monomer 2 was prepared by the ether-
washed with saturated brine and dried over anhydrous Na SO . ization reaction between 1,4-bis(triuoromethyl)-2,5-dibromo-
2
4
The crude product was puried by column chromatography benzene (1) and 1-naphthol in the presence of a strong base.
using n-hexane as an eluent on silica gel. The obtained product Because compound 1 contained –CF groups with strong
3
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the molar ratio of FeCl
3
and monomer 2 from 2 : 1 to 2.5 : 1, the
reaction resulted in a polymer with higher M . The best result
n
was obtained when the molar ratio of FeCl /monomer 2 was
3
ꢀ
2
.5 : 1 and the polymerization was carried out at À5 C. The
obtained polymer with a M
n
of 62 000 was used to perform the
following performance tests.
The obtained polymer was soluble in common organic
solvents such as THF, toluene and chloroform, and had good

lm-forming ability when cast from either chloroform or
toluene solutions. The polymer lm was transparent, exible
and pale-yellow in color.
Scheme 2 The procedure for the synthesis of the monomer and
polymer.
The chemical structure of the polymer was conrmed by
1
13
19
H NMR, C NMR, F NMR, and elemental analysis (EA).
The results are listed in the experimental section. For
electron-withdrawing ability, the aromatic ring was highly
activated. Therefore, monomer 2 was easily prepared in a
moderated yield. In contrast, in many cases, the etherization
reaction between aryl halides and phenols was not easy and
13
example, C NMR of the polymer is shown in Fig. 1. All of the
13
data of NMR for the polymer are consistent with the
proposed.
51,52
required transition metal complexes as the catalysts.
The
Thermostability of the polymer
1
chemical structure of monomer 2 was characterized by H NMR,
1
9
13
Fig. 2 shows the DSC trace of the polymer, which indicates that
F NMR, C NMR and elemental analysis, as shown in the
ꢀ
the polymer has a glass transition temperature (T
This high T
g
) of 244 C.
experimental section.
is attributed to the existence of rigid, rod-like
The target polymer was synthesized by employing an
oxidative homopolymerization route (Scholl reaction). In most
cases, the Scholl polycondensation was carried out in the
g
binaphthyl units in the polymer backbone. TGA analysis (Fig. 3)
shows that the polymer exhibits a 5 wt% loss temperature at
ꢀ
ꢀ
2
1,53
518 C and shows a residual of 53.22% at 1000 C under
nitrogen. Even in air, the polymer also possesses high heat
presence of Fe(III) in nitrobenzene as solvent.
To avoid
using highly toxic nitrobenzene, we chose 1,1,2,2-tetrachloro-
ꢀ
5
4
resistance with a 5 wt% loss temperature at 474 C. From the
ethylene as the solvent to study the polymerization. Initially,
when the reaction was carried out at room temperature, gela-
tion occurred and an insoluble deep-yellow solid was
obtained, suggesting that monomer 2 possessed very high
view of application, the heat resistance of the polymer could
meet the requirements of insulating enameled wire and printed
8,10,55
circuit boards (PCB).
ꢀ
reactivity. When the temperature was lowered to 0 C, the
reaction resulted in the polymer with two fractions. One was Dielectric and mechanical properties of the polymer
insoluble gel, and the other was soluble in common organic
The dielectric constant of the polymer lm was measured by the
capacitance method. Fig. 4 reveals the relationship of dielec-
solvents. The soluble part showed a M
n
ꢀ
of 11 800. Further
54
examination of the polymerization at À5 C exhibited that the
tric constants (k) and dielectric loss (tan d) with the frequency
ranging from 1 to 25 MHz at room temperature. As depicted in
Fig. 4, the polymer lm shows an average k value of about 2.56.
This dielectric constant is comparable to the values of the
commercially organic low-k materials such as polyimides (3.1–
M
n
increased to 17 000. However, when the polymerization
ꢀ
was carried out at a temperature below À10 C, the polymer
n
was obtained with lower M (see Table 1). These results indi-
cate that the reactivity of the monomer 2 increased with the
rising temperature.
It was noted that the amount of oxidant (FeCl ) also had an
3
21,53
inuence on the Scholl reaction.
Subsequently, we changed
Table 1 Preparation of the polymer
a
ꢀ
b
c
d
w
e
Entry
T ( C)
FeCl
3
(equiv.)
M
n
M
PDI
1
2
0
À5
2.0
2.0
11 800
17 000
62 000
11 700
25 800
9700
22 300
33 500
190 000
23 200
55 800
17 000
52 500
1.89
1.97
3.00
1.99
2.16
1.77
2.25
2
.5
2.0
.5
2.0
.5
3
4
À10
À15
2
2
23 300
a
b
Temperature of the polymerizations. Equivalents comparing to
c
d
13
3
monomer 2. The number average molecular weight. The weight Fig. 1 Expanded C NMR spectrum of the polymer (100 MHz, CDCl ,
average molecular weight. Distribution of molecular weight.
e
ꢀ
25 C).
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À1
Fig. 5 XRD patterns of the polymer in two forms (powder and casting
film).
2
Fig. 2 DSC trace of the polymer at a heating rate of 10 C min in N .
The mechanical properties of the polymer lm were
measured on a nanoindenter system. The polymer lm showed
an average hardness of 0.37 GPa and a Young's modulus of
15.07 GPa, respectively. It is noted that the low k materials
utilized in the microelectronics industry must possess high
hardness and Young's modulus to meet the requirement of a
6,8
back-end-of-the-line (BEOL) production procedure. Based on
its mechanical properties, the polymer satises the BEOL
procedure.
Morphology, lm uniformity and hydrophobicity of the
polymer
ꢀ
À1
Fig. 3 TGA curves of the polymer at a heating rate of 10 C min in N
red line) and air (blue line).
2
(
Fig. 5 shows X-ray diffraction (XRD) patterns of the polymer
in two forms (powder and casting lm). As shown in Fig. 5,
the polymer is essentially amorphous, suggesting that
there is no closed aggregation between the polymer chains.
Thus, the polymer exhibits low density, which is favorable
for decreasing the dielectric constant of the polymer.
Fig. 6 illustrates the contact angle of water on the polymer

lm, which indicates the high hydrophobicity of the polymer.
Such high hydrophobicity is highly efficient for keeping
constant insulating properties when the materials are used
under moisture conditions.
An AFM image of the polymer lm is shown in Fig. 7. As
illustrated in Fig. 7, the polymer shows good lm uniformity
with surface roughness of less than 5 nm over a 4 mm square
area.
Fig. 4 Dielectric constants (k) and dissipation factors (tan d) of the
polymer film depending on the frequencies.
6
,8
56
3
.4) and polycyanate esters (2.61–3.12). Such good dielectric
properties that the polymer exhibits are probably caused by
CF groups with large free volume.
The dissipation factors of the polymer were also measured,
–
3
which was below 0.05, with frequencies ranging from 1 MHz
to 25 MHz (see Fig. 4). Such data were also comparable to
these of the aforementioned commercially organic low-k
8
materials.
Fig. 6 Contact angle of water on the polymer film.
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7
R. Farrell, T. Goshal, U. Cvelbar, N. Petkov and M. A. Morris,
Electrochem. Soc. Interface, 2011, 20, 39–46.
8
9
G. Maier, Prog. Polym. Sci., 2001, 26, 3–64.
S. J. Martin, J. P. Godschalx, M. E. Mills, E. O. Shaffer II and
P. H. Townsend, Adv. Mater., 2000, 12, 1769–1778.
1
1
1
1
1
1
0 H. Treichel, G. Ruhl, P. Ansmann, R. Wurl, C. Muller and
M. Dietlmeier, Microelectron. Eng., 1998, 40, 1–19.
1 K. Zhang, Q. Zhuang, X. Liu, R. Cai, G. Yang and Z. Han, RSC
Adv., 2013, 3, 5261–5270.
2 Z. Geng, S. Zhang, J. Mu, X. Jiang, P. Huo, Y. Lu, J. Luan and
G. Wang, J. Appl. Polym. Sci., 2013, 129, 3219–3225.
3 Z. Geng, J. Ba, S. Zhang, J. Luan, X. Jiang, P. Huo and
G. Wang, J. Mater. Chem., 2012, 22, 23534–23540.
4 J. Y. Wang, S. Y. Yang, Y. L. Huang, H. W. Tien, W. K. Chin
and C. C. M. Ma, J. Mater. Chem., 2011, 21, 13569–13575.
5 P. Huang, A. Gu, G. Liang and L. Yuan, J. Appl. Polym. Sci.,
2
011, 120, 451–457.
16 Y. T. Chern and J. Y. Tsai, Macromolecules, 2008, 41, 9556–
564.
Fig. 7 An AFM image of the polymer film on a silicon wafer.
9
17 J. Liu, Y. Min, J. Chen, H. Zhou and C. Wang, Macromol.
Rapid Commun., 2007, 28, 215–219.
4
. Conclusions
18 B. Chen, Y. Fang and J. Cheng, Macromol. Symp., 2006, 242,
34–39.
A new polymer with a triuoromethyl-substituted arene was
synthesized via oxidative coupling polymerization. The polymer 19 X. Z. Jin and H. Ishii, J. Appl. Polym. Sci., 2006, 100, 4240–
ꢀ
has a glass transition temperature of 244 C and shows a 5 wt%
4246.
ꢀ
loss temperature at 518 C in nitrogen. The polymer lms 20 K. Fukukawa, Y. Shibasaki and M. Ueda, Macromolecules,
exhibit high hydrophobicity with a contact angle to water of
1
2004, 37, 8256–8261.
ꢀ
03.6 . Moreover, the polymer reveals an average of dielectric 21 K. Tsuchiya, H. Ishii, Y. Shibasaki, S. Ando and M. Ueda,
constants of about 2.56 in a range of frequencies from 1 to 25
Macromolecules, 2004, 37, 4794–4797.
MHz. In regard to the mechanical properties, the polymer lm 22 A. Mitra, T. Cao, H. Wang, Z. Wang, L. Huang, S. Li, Z. Li and
shows an average hardness of 0.37 GPa and a Young's modulus
Y. Yan, Ind. Eng. Chem. Res., 2004, 43, 2946–2949.
of 15.07 GPa. Those data suggest that the polymer could be used 23 K. Goto, T. Akiike, Y. Inoue and M. Matsubara, Macromol.
as the varnish for enameled wire, sizing agents for high-
Symp., 2003, 199, 321–332.
performance carbon ber, and the matrix resin for the 24 D. J. Liaw and W. T. Tseng, Macromol. Symp., 2003, 199, 351–
production of laminated composites utilized in the printed-
circuit-board (PCB) industry.
362.
25 A. Heise, C. Nguyen, R. Malek, J. L. Hedrick, C. W. Frank and
R. D. Miller, Macromolecules, 2000, 33, 2346–2354.
2
6 S. Mikoshiba and S. Hayase, J. Mater. Chem., 1999, 9, 591–
98.
7 A. L. Rusanov, T. A. Stadnik and K. Myullen, Russ. Chem.
Rev., 1999, 68, 685–698.
Acknowledgements
5
2
Financial support from the Ministry of Science and Technology
of China (2011ZX02703) and the Natural Science Foundation of
China (NSFC, no. 21374131) are gratefully acknowledged.
2
2
8 Y. T. Chern, Macromolecules, 1998, 31, 5837–5844.
9 R. Purushothaman, M. Palanichamy and I. M. Bilal, J. Appl.
Polym. Sci., 2014, DOI: 10.1002/app.40508.
3
0 S. Sheng, D. Li, T. Lai, X. Liu and C. Song, Polym. Int., 2011,
Notes and references
60, 1185–1193.
1
2
3
4
Y. Jung, T. H. Yeo, W. Yang, Y. Kim, K. Woo and J. Moon, J. 31 L. Tao, H. Yang, J. Liu, L. Fan and S. Yang, J. Polym. Sci., Part
Phys. Chem. C, 2011, 115, 25056–25062. A: Polym. Chem., 2010, 48, 4668–4680.
X. Chen, K. Li, S. Zheng and Q. Fang, RSC Adv., 2012, 2, 6504– 32 C. Ma, S. Sheng, M. Wei, W. He and C. Song, J. Appl. Polym.
508.
Sci., 2010, 118, 2959–2968.
F. He, C. Yuan, K. Li, S. Diao, K. Jin, J. Wang, J. Tong, J. Ma 33 C. M. Lew, Z. Li, S. Li, S. J. Hwang, Y. Liu, D. I. Medina,
6
and Q. Fang, RSC Adv., 2013, 3, 23128–23132.
Y. Huang and J. Economy, Macromolecules, 2006, 39, 1850–
M. Sun, J. Wang, M. E. Davis and Y. Yan, Adv. Funct.
Mater., 2008, 18, 3454–3460.
1
853.
34 C.-P. Yang, S.-H. Hsiao and C.-L. Chung, Polym. Int., 2005,
54, 716–724.
5
6
X. Zhao and H. Liu, Polym. Int., 2010, 59, 597–606.
W. Vloksen, R. D. Miller and G. Dubois, Chem. Rev., 2010, 35 G.-D. Fu, Z. Yuan, E.-T. Kang, K.-G. Neoh, D. M. Lai and
110, 56–110.
A. C. H. Huan, Adv. Funct. Mater., 2005, 15, 315–322.
40786 | RSC Adv., 2014, 4, 40782–40787
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3
3
3
6 T. Miyagawa, T. Fukushima, T. Oyama, T. Iijima and 46 S. Baskaran, J. Liu, K. Domansky, N. Kohler, X. Li, C. Coyle,
M. Tomoi, J. Polym. Sci., Part A: Polym. Chem., 2003, 41,
61–871.
G. E. Fryxell, S. Thevuthasan and R. E. Williford, Adv. Mater.,
2000, 12, 291–294.
8
7 T. Dang, P. T. Mather, M. D. Alexander Jr, C. J. Grayson, 47 E. Murotani, J. K. Lee, M. Chatzichristidi, A. A. Zakhidov,
M. D. Houtz, R. J. Spry and F. E. Arnold, J. Polym. Sci., Part
A: Polym. Chem., 2000, 38, 1991–2003.
P. G. Taylor, E. L. Schwartz, G. G. Malliaras and C. K. Ober,
ACS Appl. Mater. Interfaces, 2009, 1, 2363–2370.
8 Z. Geng, M. Huo, J. Mu, S. Zhang, Y. Lu, J. Luan, P. Huo, 48 T. M. Long and T. M. Swager, J. Am. Chem. Soc., 2003, 125,
Y. Du and G. Wang, J. Mater. Chem. C, 2014, 2, 1094–
103.
9 Y. L. Liu and M. H. Fangchiang, J. Mater. Chem., 2009, 19,
643–3647.
0 F. Liu, C. Li, L. Ren, X. Meng, H. Zhang and F. Xiao, J. Mater.
Chem., 2009, 19, 7921–7928.
14113–14119.
1
49 P. Horcajada, F. Salles, S. Wuttke, T. Devic, D. Heurtaux,
G. Maurin, A. Vimont, M. Daturi, O. David, E. Magnier,
N. Stock, Y. Filinchuk, D. Popov, C. Riekel, G. Ferey and
C. Serre, J. Am. Chem. Soc., 2011, 133, 17839–17847.
50 D. Izuhara and T. M. Swager, J. Am. Chem. Soc., 2009, 131,
17724–17725.
3
4
4
4
3
1 B. Yang, H. Xu, Z. Yang and X. Liu, J. Mater. Chem., 2009, 19,
9038–9044.
51 S. A. R. Mulla, S. M. Inamdar, M. Y. Pathan and S. S. Chavan,
Tetrahedron Lett., 2012, 53, 1826–1829.
2 H. W. Ro, H. Peng, K. Niihara, H. J. Lee, E. K. Lin, A. Karim,
D. W. Gidley, H. Jinnai, D. Y. Yoon and C. L. Soles, Adv. 52 L. W. Xu, C. G. Xia, J. W. Li and X. X. Hu, Synlett, 2003, 13,
Mater., 2008, 20, 1934–1939. 2071.
3 K. Heo, S. G. Park, J. Yoon, K. S. Jin, S. Jin, S. W. Rhee and 53 K. Tsuchiya, Y. Shibasaki, M. Aoyagi and M. Ueda,
M. Ree, J. Phys. Chem. C, 2007, 111, 10848–10854. Macromolecules, 2006, 39, 3964–3966.
4 G. Fu, B. Zong, E. Kang, K. G. Neoh, C. C. Lin and D. J. Liaw, 54 C. Yuan, K. Jin, K. Li, S. Diao, J. Tong and Q. Fang, Adv.
Ind. Eng. Chem. Res., 2004, 43, 6723–6730. Mater., 2013, 25, 4875–4878.
5 J. H. Yim, Y. Y. Lyu, H. D. Jeong, S. K. Mah, J. H. Lee, 55 P. Ihalainen, A. Maattanen, J. Jarnstrom, D. Tobjork,
4
4
4
J. H. Hahn, G. S. Kim, S. Chang and J. G. Park, J. Appl.
Polym. Sci., 2003, 90, 626–634.
R. Osterbacka and J. Peltonen, Ind. Eng. Chem. Res., 2012,
51, 6025–6036.
56 T. Fang and D. A. Shimp, Prog. Polym. Sci., 1995, 20, 61–118.
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