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Polyaniline microtubes synthesized via supercritical CO2 and aqueous interfacial polymerization
Synthetic Metals 155 (2005) 523–526
Polyaniline microtubes synthesized via supercritical CO2 and aqueous interfacial polymerization Jimin Du, Jianling Zhang, Buxing Han ∗ , Zhimin Liu, Meixiang Wan ∗ Center for Molecular Sciences, Institute of Chemistry, Chinese Academy of Sciences, Beijing 100080, China Received 27 June 2005; received in revised form 8 July 2005; accepted 25 July 2005 Available online 2 November 2005
Abstract We report a new route to prepare polyaniline (PANI) microtubes via supercritical (SC) CO2 /aqueous interfacial polymerization. The synthesis is based on the well-known chemical oxidative polymerization of aniline in an acidic environment, with ammonium peroxydisufate (APS) as the oxidant, and sodium dodecyl sulfate (SDS) surfactant was used as the template. The main feature of this route is that the monomer (aniline) which is dissolved in SC CO2 phase, slowly polymerized at the interface of SC CO2 and aqueous solution to form the PANI microtubes. The morphologies, phase structure, composition and some properties of PANI microtubes were characterized by TEM, SEM, XRD, IR, XPS UV–vis and SYSTEM DM digital multimeter, respectively. © 2005 Elsevier B.V. All rights reserved. Keywords: Polyaniline; Interfacial polymerization; SC CO2 ; XRD
1. Introduction In the past 15 years, conducting polymer PANI has been extensively studied due to its unique electrical, electrochemical, and optical properties, which enable its wide use in diverse areas such as energy storage [1], electronics [2], sensors [3], and separation science [4]. Recently, much attention has been paid to low-dimensional PANI nanostructres, including nanofibers and nanotubes [5]. The PANI nanofibers and nanotubes are usually prepared by polymerization of monomers in the presence of soft [6] and hard [7] templates. Recently, Huang et al. [8,3] have reported interfacial polymerization method to synthesize sub-50 nm diameters fibers of PANI at the interface of organic/aqueous solution, respectively. Wang’s group successfully prepared the chiral PANI nanofibers by oligomer-assisted synthesis [9]. Also, Zhang et al. have applied nanofiber seeding to synthesize PANI nanofibers [10]. Despite all of these synthetic efforts, there is a need for a benign and practical synthetic route capable of making pure, uniform motif in bulk quantities. SC CO2 has been extensively studied for chemical reactions, material synthesis and separations because it is environmen∗
Corresponding authors. Tel.: +86 10 62562821; fax: +86 10 62559373. E-mail address: [email protected] (B. Han).
0379-6779/$ – see front matter © 2005 Elsevier B.V. All rights reserved. doi:10.1016/j.synthmet.2005.07.336
tal benign and minimizes the liquid waste problem [11]. SC CO2 can dissolve solutes and yet possesses low viscosity, high diffusivity and zero surface tension. Moreover, SC CO2 solvation power can be tuned by changing temperature and pressure. Meanwhile, unreacted materials and byproducts can be easily removed from the system; thus high purity is possible. In the present paper, we report a new route to prepare PANI microtubes via polymerization at the interface of SC CO2 /aqueous solution. The synthesis is based on the well-known chemical oxidative polymerization of aniline in an acidic environment with APS as the oxidant [12], and surfactant SDS was used as the template. The main characteristic of this route is that the monomer aniline which is dissolved in SC CO2 phase, slowly polymerized at the interface of SC CO2 /aqueous solution to form the PANI microtubes. 2. Experimental section 2.1. Materials Aniline, sodium dodecyl sulfate (SDS), ammonium peroxydisulfate ((NH4 )2 S2 O8 ) (ASP) provided by Beijing Chemical Reagent Company were all analytical grade. Carbon dioxide (99.95%) was supplied by Beijing Analytical Factory.
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J. Du et al. / Synthetic Metals 155 (2005) 523–526
ples was carried out using an X-ray diffractometer (XRD, Model ˚ D/MAX2500, Rigaka) with Cu K␣ radiation (λ = 1.5406 A). The IR spectrum was recorded using an IR spectrometer (TENSOR 27). X-ray photoelectron spectra (XPS) was performed on ES-300 (Kratos). The conductivity at room temperature was measured by a Keithley 196 SYSTEM DM digital multimeter and an ADVANTEST R6142 programmable dc voltage/current source through a standard four-probe method. 3. Results and discussion Fig. 1. Schematic diagrams of the apparatus: (1) aniline, (2) aqueous solution, (3) beaker, (4) view autoclave, (5, 6) valve, (7) water bath.
2.2. Synthesis of PANI microtubes In a typical experiment, 0.9 ml aniline was injected into the view autoclave with an internal volume of 58 ml. The solution with 8 ml deionized water, 10.0 mmol APS, 5.0 mmol SDS and 10 l hydrochloric acid (1 M) was prepared in a 20 ml beaker. The beaker was placed into the view autoclave. The aniline did not contact with the aqueous solution, as shown in Fig. 1. The view autoclave was then placed in the constant temperature water bath of 323.2 K, and CO2 was compressed into the view autoclave up to the 8.5 MPa using a high-pressure syringe pump (Model DB-80). Aniline was dissolved in SC CO2 and slowly polymerized at the SC CO2 /aqueous solution interface. After 12 h, the entire aqueous phase is filled with dark-green PANI. After releasing CO2 , the aqueous was centrifuged. The obtained product was washed several times with deionized water and ethanol. Finally the product was dried in a vacuum oven at 323 K for 12 h. 2.3. Characterization The morphology of the PANI structures was characterized by scanning electron microscopy (SEM, Hitachi-530) and transmission electron microscopy (TEM, Hitachi, H-9000). A TU-1201 spectrophotometer was used to determine the UV–vis spectra of PANI in deionized water. X-ray diffraction analysis of the sam-
The SEM and TEM micrographs of the PANI samples synthesized at 323.2 K and 8.5 MPa are shown in Figs. 2a and 2b. It is demonstrated that the PANI products obtained have diameters with about 120 nm and lengths of around several micrometers (Fig. 2a). Interestingly, it is clearly seen from the TEM image (Fig. 2b) that PANI products display hollow core due to the distinct color difference between the shell and inner region. In order to make sure the PANI degree of the crystllinity, Fig. 3 shows that two broad peaks centered at 2θ = 20◦ and 24.8◦ appear in the XRD pattern of the composite, which shows the resulting PANI microtubes are amorphous [13]. The peak at 2θ = 20◦ may be ascribed to periodicity parallel to the polymer chain, while the peak at 2θ = 24.8◦ may be caused by the periodicity perpendicular to the polymer chain [14]. It is well known that PANI has a simple and reversible acid/base (doping/dedoping) chemistry enabling control of its properties, such as electrical conductivity [3] and optical activity [15]. By observation, the doped and dedoped PANI complexes form green and blue suspensions in aqueous solution, respectively. The UV–vis spectra of the doped and dedoped PANI microtubes are shown in Fig. 4. The characteristic bands of doped PANI appear at 326, 418, and 850 nm with a free carrier tail extending into the near-infrared region, which were attributed to -* , polaron-* , and -polaron transitions, respectively [16]. For the dedoped form, there exist two peaks at around 320 and 674 nm in the UV–vis spectra. However, the band of the dedoped PANI microtubes of this work at 674 nm is wider than those reported by other authors [3,17], which may result from the difference in morphology and size.
Fig. 2. SEM (a) and TEM (b) images of synthesized PANI microtubes.
J. Du et al. / Synthetic Metals 155 (2005) 523–526
Fig. 3. X-ray diffraction patterns of PANI microtubes.
Hitherto, the conductivity of PANI reported in the literature covers a wide range5 , which depends on many factors, such as doping level and the properties of dopants used. The room temperature conductivity of the PANI/SDS microtubes pellets of this work was 0.36 S/cm, as was determined by the standard Van Der Pauwe DC four-probe method [18]. To verify the composition of the PANI microtubes, we also measured the infrared (IR Fig. 5) spectra of the products. The peaks at 1577 and 1503 cm−1 can be assigned to the stretching vibration of quinoid ring and benzenoid ring of PANI, respectively [19]. The band at 1295 cm−1 corresponds to C H stretching of the aromatic amine [20]. The absorption band at 3437 cm−1 may be attributed to N H stretching vibration [21] as suggested by other authors. The bands at 2931, 2860 and 1446 cm−1 associate with methyl hydrogen stretching vibration and methylene bending vibration, respectively, which are all typical bands of SDS. The 1303 and 1161 cm−1 bands, cor-
Fig. 4. UV–vis spectra of PANI microtubes.
525
Fig. 5. IR spectra of PANI microtubes.
responding to the stretching mode of S O in the SO3 group, can be observed, indicating that SO3 groups exist in the products [20]. The above results indicate that the microtubes are composed of PANI and SDS. In addition, XPS were also used to characterize the surface composition of the PANI microtubes. It shows that the ratio of sulfur atom to nitrogen atom is 0.276. Three bands (at about 398.2, 399.2, and >400 eV) in the N1S core level spectra (Fig. 6) can be attributed to ( N ), ( NH ) and ( N+ ), respectively [22], which agrees well with the IR results. In our comparative experiments, PANI microtubes cannot be obtained in the absence of the surfactant SDS, and the other reaction conditions are the same. It shows that surfactant SDS plays an important role in synthesizing the PANI microtubes. Therefore, we propose the following surfactant-induced formation mechanism. In our experimental conditions, SC CO2 is a nonpolar solvent, and water is a polar solvent. If SDS is used
Fig. 6. XPS spectra of N1S core level.
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J. Du et al. / Synthetic Metals 155 (2005) 523–526
as the surfactant, it orderly arrays between the interface of SC CO2 and aqueous solution because of the amphiphilic properties of the SDS [23]. The monomer aniline may mainly assembly around the hydrophobic tail (CH3 –CH2 . . .) of the surfactant in SC CO2 phase; but the hydrophilic head ( SO3 − ) of the surfactant is immerged into the aqueous phase. The monomer aniline was oxidatively polymerized by APS between the interface of SC CO2 and aqueous solution. With the polymerization proceeding, the PANI microtubes can be formed and prolonged on the local conditions of the linear arrangement of the surfactant [24]. 4. Conclusion In summary, we have demonstrated a new method for the synthesis of PANI microtubes. This route has the following advantages: (i) well-dispersed PANI microtubes can be easily obtained; (ii) the diameter of PANI microtubes is relatively uniform, which possibly dictates their superior performance as chemical sensors; (iii) SC CO2 is a kind of benign solvent and minimizes the environmental pollution; (iv) unreacted materials and byproducts are easily removed from the system by flushing the system with SC CO2 . Acknowledgement The authors are grateful to the National Natural Science Foundation of China (20133030). References [1] F. Fusalba, P. Gouerec, D. Villers, D. Belanger, J. Electrochem. Soc. 148 (2001) A1. [2] G. Gustafsson, Y. Cao, G.M. Treacy, F. Klavetter, N. Colaneri, A.J. Heeger, Nature 357 (1992) 477.
[3] J.X. Huang, S. Virji, B.H. Weiller, R.B. Kaner, J. Am. Chem. Soc. 125 (2003) 314. [4] S. Tan, V. Viau, D. Cugnod, D. Beleanger, Electrochem. Solid. State. Lett. 5 (2002) E55. [5] G.C. Li, Z.K. Zhang, Macromolecules 37 (2004) 2683; Z.X. Wei, M.X. Wan, L. Tong, L.M. Dai, Adv. Mater. 15 (2003) 136. [6] J.C. Michaelson, A.J. McEvoy, Chem. Commun. 79 (1994); H.J. Qiu, M.X. Wan, Macromolecules 34 (2001) 675; S.J. Choi, S.M. Park, Adv. Mater. 12 (2000) 1547. [7] C.G. Wu, T. Bein, Science 264 (1994) 1757; C.R. Martin, Chem. Mater. 8 (1996) 1739; C.W. Wang, Z. Wang, H.L. Li, Chem. Phys. Lett. 341 (2001) 431. [8] J.X. Huang, R.B. Kaner, J. Am. Chem. Soc. 126 (2004) 851. [9] W.G. Li, H.L. Wang, J. Am. Chem. Soc. 126 (2004) 2278. [10] X.Y. Zhang, W.J. Goux, S.K. Manohar, J. Am. Chem. Soc. 126 (2004) 4502. [11] W.X. Wang, A. Naylor, S.M. Howdle, Macromolecule 36 (2003) 5424; Y.N. Chang, Q. Xu, M.Y. Liu, Y.D. Wang, Q.X. Zhao, J. Appl. Poly. Sci. 90 (2003) 2040. [12] W.S. Huang, B.D. Humphrey, A.G. Macdiarmid, J. Chem. Soc. Faraday Trans. 82 (1986) 2385. [13] Z.X. Wei, Z.M. Zhang, M.X. Wan, Langmuir 18 (2002) 917. [14] J.C. Chiang, A.G. MacDiarmid, Synth. Met. 13 (1986) 193. [15] Y.N. Xia, J.M. Wiesinger, A.G. MacDiarmid, A.J. Epstein, Chem. Mater. 7 (1995) 443. [16] F.L. Lu, F. Wudl, M. Nowak, A.J. Heeger, J. Am. Chem. Soc. 108 (1986) 8311; S. Stafstrom, J.L. Breadas, A.J. Epstein, H.S. Woo, D.B. Tenner, W.S. Huang, A.G. Macdiarmid, Phys. Rev. Lett. 59 (1987) 1464. [17] M.A. Habib, S.P. Maheswari, J. Electrochem. Soc. 135 (1989) 1050. [18] L.T. Van der Pauwe, Philips Res. Rep. 13 (1958) 1. [19] Z.M. Zhang, Z.X. Wei, M.X. Wan, Macromolecules 35 (2002) 5937. [20] H. Liu, X. Hu, J.Y. Wang, R.I. Boughton, Macromolecules 35 (2002) 9414. [21] S.A. Chen, H.T. Lee, Macromolecules 28 (1995) 2858; L. Dai, J.W. White, Polymer 32 (1991) 2120. [22] J.C. Chiang, A.G. Mac Diarmid, Synth. Met. 13 (1986) 193. [23] J. Penfold, E. Staples, I. Tucker, R.K. Thomas, Langmuir 20 (2004) 1269. [24] J. Jung, H. Kobayashi, K.J.C. van Bommel, S. Shinkai, T. Shimizu, Chem. Mater. 14 (2002) 1445.
Polyaniline microtubes synthesized via supercritical CO2 and aqueous interfacial polymerization Jimin Du, Jianling Zhang, Buxing Han ∗ , Zhimin Liu, Meixiang Wan ∗ Center for Molecular Sciences, Institute of Chemistry, Chinese Academy of Sciences, Beijing 100080, China Received 27 June 2005; received in revised form 8 July 2005; accepted 25 July 2005 Available online 2 November 2005
Abstract We report a new route to prepare polyaniline (PANI) microtubes via supercritical (SC) CO2 /aqueous interfacial polymerization. The synthesis is based on the well-known chemical oxidative polymerization of aniline in an acidic environment, with ammonium peroxydisufate (APS) as the oxidant, and sodium dodecyl sulfate (SDS) surfactant was used as the template. The main feature of this route is that the monomer (aniline) which is dissolved in SC CO2 phase, slowly polymerized at the interface of SC CO2 and aqueous solution to form the PANI microtubes. The morphologies, phase structure, composition and some properties of PANI microtubes were characterized by TEM, SEM, XRD, IR, XPS UV–vis and SYSTEM DM digital multimeter, respectively. © 2005 Elsevier B.V. All rights reserved. Keywords: Polyaniline; Interfacial polymerization; SC CO2 ; XRD
1. Introduction In the past 15 years, conducting polymer PANI has been extensively studied due to its unique electrical, electrochemical, and optical properties, which enable its wide use in diverse areas such as energy storage [1], electronics [2], sensors [3], and separation science [4]. Recently, much attention has been paid to low-dimensional PANI nanostructres, including nanofibers and nanotubes [5]. The PANI nanofibers and nanotubes are usually prepared by polymerization of monomers in the presence of soft [6] and hard [7] templates. Recently, Huang et al. [8,3] have reported interfacial polymerization method to synthesize sub-50 nm diameters fibers of PANI at the interface of organic/aqueous solution, respectively. Wang’s group successfully prepared the chiral PANI nanofibers by oligomer-assisted synthesis [9]. Also, Zhang et al. have applied nanofiber seeding to synthesize PANI nanofibers [10]. Despite all of these synthetic efforts, there is a need for a benign and practical synthetic route capable of making pure, uniform motif in bulk quantities. SC CO2 has been extensively studied for chemical reactions, material synthesis and separations because it is environmen∗
Corresponding authors. Tel.: +86 10 62562821; fax: +86 10 62559373. E-mail address: [email protected] (B. Han).
0379-6779/$ – see front matter © 2005 Elsevier B.V. All rights reserved. doi:10.1016/j.synthmet.2005.07.336
tal benign and minimizes the liquid waste problem [11]. SC CO2 can dissolve solutes and yet possesses low viscosity, high diffusivity and zero surface tension. Moreover, SC CO2 solvation power can be tuned by changing temperature and pressure. Meanwhile, unreacted materials and byproducts can be easily removed from the system; thus high purity is possible. In the present paper, we report a new route to prepare PANI microtubes via polymerization at the interface of SC CO2 /aqueous solution. The synthesis is based on the well-known chemical oxidative polymerization of aniline in an acidic environment with APS as the oxidant [12], and surfactant SDS was used as the template. The main characteristic of this route is that the monomer aniline which is dissolved in SC CO2 phase, slowly polymerized at the interface of SC CO2 /aqueous solution to form the PANI microtubes. 2. Experimental section 2.1. Materials Aniline, sodium dodecyl sulfate (SDS), ammonium peroxydisulfate ((NH4 )2 S2 O8 ) (ASP) provided by Beijing Chemical Reagent Company were all analytical grade. Carbon dioxide (99.95%) was supplied by Beijing Analytical Factory.
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J. Du et al. / Synthetic Metals 155 (2005) 523–526
ples was carried out using an X-ray diffractometer (XRD, Model ˚ D/MAX2500, Rigaka) with Cu K␣ radiation (λ = 1.5406 A). The IR spectrum was recorded using an IR spectrometer (TENSOR 27). X-ray photoelectron spectra (XPS) was performed on ES-300 (Kratos). The conductivity at room temperature was measured by a Keithley 196 SYSTEM DM digital multimeter and an ADVANTEST R6142 programmable dc voltage/current source through a standard four-probe method. 3. Results and discussion Fig. 1. Schematic diagrams of the apparatus: (1) aniline, (2) aqueous solution, (3) beaker, (4) view autoclave, (5, 6) valve, (7) water bath.
2.2. Synthesis of PANI microtubes In a typical experiment, 0.9 ml aniline was injected into the view autoclave with an internal volume of 58 ml. The solution with 8 ml deionized water, 10.0 mmol APS, 5.0 mmol SDS and 10 l hydrochloric acid (1 M) was prepared in a 20 ml beaker. The beaker was placed into the view autoclave. The aniline did not contact with the aqueous solution, as shown in Fig. 1. The view autoclave was then placed in the constant temperature water bath of 323.2 K, and CO2 was compressed into the view autoclave up to the 8.5 MPa using a high-pressure syringe pump (Model DB-80). Aniline was dissolved in SC CO2 and slowly polymerized at the SC CO2 /aqueous solution interface. After 12 h, the entire aqueous phase is filled with dark-green PANI. After releasing CO2 , the aqueous was centrifuged. The obtained product was washed several times with deionized water and ethanol. Finally the product was dried in a vacuum oven at 323 K for 12 h. 2.3. Characterization The morphology of the PANI structures was characterized by scanning electron microscopy (SEM, Hitachi-530) and transmission electron microscopy (TEM, Hitachi, H-9000). A TU-1201 spectrophotometer was used to determine the UV–vis spectra of PANI in deionized water. X-ray diffraction analysis of the sam-
The SEM and TEM micrographs of the PANI samples synthesized at 323.2 K and 8.5 MPa are shown in Figs. 2a and 2b. It is demonstrated that the PANI products obtained have diameters with about 120 nm and lengths of around several micrometers (Fig. 2a). Interestingly, it is clearly seen from the TEM image (Fig. 2b) that PANI products display hollow core due to the distinct color difference between the shell and inner region. In order to make sure the PANI degree of the crystllinity, Fig. 3 shows that two broad peaks centered at 2θ = 20◦ and 24.8◦ appear in the XRD pattern of the composite, which shows the resulting PANI microtubes are amorphous [13]. The peak at 2θ = 20◦ may be ascribed to periodicity parallel to the polymer chain, while the peak at 2θ = 24.8◦ may be caused by the periodicity perpendicular to the polymer chain [14]. It is well known that PANI has a simple and reversible acid/base (doping/dedoping) chemistry enabling control of its properties, such as electrical conductivity [3] and optical activity [15]. By observation, the doped and dedoped PANI complexes form green and blue suspensions in aqueous solution, respectively. The UV–vis spectra of the doped and dedoped PANI microtubes are shown in Fig. 4. The characteristic bands of doped PANI appear at 326, 418, and 850 nm with a free carrier tail extending into the near-infrared region, which were attributed to -* , polaron-* , and -polaron transitions, respectively [16]. For the dedoped form, there exist two peaks at around 320 and 674 nm in the UV–vis spectra. However, the band of the dedoped PANI microtubes of this work at 674 nm is wider than those reported by other authors [3,17], which may result from the difference in morphology and size.
Fig. 2. SEM (a) and TEM (b) images of synthesized PANI microtubes.
J. Du et al. / Synthetic Metals 155 (2005) 523–526
Fig. 3. X-ray diffraction patterns of PANI microtubes.
Hitherto, the conductivity of PANI reported in the literature covers a wide range5 , which depends on many factors, such as doping level and the properties of dopants used. The room temperature conductivity of the PANI/SDS microtubes pellets of this work was 0.36 S/cm, as was determined by the standard Van Der Pauwe DC four-probe method [18]. To verify the composition of the PANI microtubes, we also measured the infrared (IR Fig. 5) spectra of the products. The peaks at 1577 and 1503 cm−1 can be assigned to the stretching vibration of quinoid ring and benzenoid ring of PANI, respectively [19]. The band at 1295 cm−1 corresponds to C H stretching of the aromatic amine [20]. The absorption band at 3437 cm−1 may be attributed to N H stretching vibration [21] as suggested by other authors. The bands at 2931, 2860 and 1446 cm−1 associate with methyl hydrogen stretching vibration and methylene bending vibration, respectively, which are all typical bands of SDS. The 1303 and 1161 cm−1 bands, cor-
Fig. 4. UV–vis spectra of PANI microtubes.
525
Fig. 5. IR spectra of PANI microtubes.
responding to the stretching mode of S O in the SO3 group, can be observed, indicating that SO3 groups exist in the products [20]. The above results indicate that the microtubes are composed of PANI and SDS. In addition, XPS were also used to characterize the surface composition of the PANI microtubes. It shows that the ratio of sulfur atom to nitrogen atom is 0.276. Three bands (at about 398.2, 399.2, and >400 eV) in the N1S core level spectra (Fig. 6) can be attributed to ( N ), ( NH ) and ( N+ ), respectively [22], which agrees well with the IR results. In our comparative experiments, PANI microtubes cannot be obtained in the absence of the surfactant SDS, and the other reaction conditions are the same. It shows that surfactant SDS plays an important role in synthesizing the PANI microtubes. Therefore, we propose the following surfactant-induced formation mechanism. In our experimental conditions, SC CO2 is a nonpolar solvent, and water is a polar solvent. If SDS is used
Fig. 6. XPS spectra of N1S core level.
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J. Du et al. / Synthetic Metals 155 (2005) 523–526
as the surfactant, it orderly arrays between the interface of SC CO2 and aqueous solution because of the amphiphilic properties of the SDS [23]. The monomer aniline may mainly assembly around the hydrophobic tail (CH3 –CH2 . . .) of the surfactant in SC CO2 phase; but the hydrophilic head ( SO3 − ) of the surfactant is immerged into the aqueous phase. The monomer aniline was oxidatively polymerized by APS between the interface of SC CO2 and aqueous solution. With the polymerization proceeding, the PANI microtubes can be formed and prolonged on the local conditions of the linear arrangement of the surfactant [24]. 4. Conclusion In summary, we have demonstrated a new method for the synthesis of PANI microtubes. This route has the following advantages: (i) well-dispersed PANI microtubes can be easily obtained; (ii) the diameter of PANI microtubes is relatively uniform, which possibly dictates their superior performance as chemical sensors; (iii) SC CO2 is a kind of benign solvent and minimizes the environmental pollution; (iv) unreacted materials and byproducts are easily removed from the system by flushing the system with SC CO2 . Acknowledgement The authors are grateful to the National Natural Science Foundation of China (20133030). References [1] F. Fusalba, P. Gouerec, D. Villers, D. Belanger, J. Electrochem. Soc. 148 (2001) A1. [2] G. Gustafsson, Y. Cao, G.M. Treacy, F. Klavetter, N. Colaneri, A.J. Heeger, Nature 357 (1992) 477.
[3] J.X. Huang, S. Virji, B.H. Weiller, R.B. Kaner, J. Am. Chem. Soc. 125 (2003) 314. [4] S. Tan, V. Viau, D. Cugnod, D. Beleanger, Electrochem. Solid. State. Lett. 5 (2002) E55. [5] G.C. Li, Z.K. Zhang, Macromolecules 37 (2004) 2683; Z.X. Wei, M.X. Wan, L. Tong, L.M. Dai, Adv. Mater. 15 (2003) 136. [6] J.C. Michaelson, A.J. McEvoy, Chem. Commun. 79 (1994); H.J. Qiu, M.X. Wan, Macromolecules 34 (2001) 675; S.J. Choi, S.M. Park, Adv. Mater. 12 (2000) 1547. [7] C.G. Wu, T. Bein, Science 264 (1994) 1757; C.R. Martin, Chem. Mater. 8 (1996) 1739; C.W. Wang, Z. Wang, H.L. Li, Chem. Phys. Lett. 341 (2001) 431. [8] J.X. Huang, R.B. Kaner, J. Am. Chem. Soc. 126 (2004) 851. [9] W.G. Li, H.L. Wang, J. Am. Chem. Soc. 126 (2004) 2278. [10] X.Y. Zhang, W.J. Goux, S.K. Manohar, J. Am. Chem. Soc. 126 (2004) 4502. [11] W.X. Wang, A. Naylor, S.M. Howdle, Macromolecule 36 (2003) 5424; Y.N. Chang, Q. Xu, M.Y. Liu, Y.D. Wang, Q.X. Zhao, J. Appl. Poly. Sci. 90 (2003) 2040. [12] W.S. Huang, B.D. Humphrey, A.G. Macdiarmid, J. Chem. Soc. Faraday Trans. 82 (1986) 2385. [13] Z.X. Wei, Z.M. Zhang, M.X. Wan, Langmuir 18 (2002) 917. [14] J.C. Chiang, A.G. MacDiarmid, Synth. Met. 13 (1986) 193. [15] Y.N. Xia, J.M. Wiesinger, A.G. MacDiarmid, A.J. Epstein, Chem. Mater. 7 (1995) 443. [16] F.L. Lu, F. Wudl, M. Nowak, A.J. Heeger, J. Am. Chem. Soc. 108 (1986) 8311; S. Stafstrom, J.L. Breadas, A.J. Epstein, H.S. Woo, D.B. Tenner, W.S. Huang, A.G. Macdiarmid, Phys. Rev. Lett. 59 (1987) 1464. [17] M.A. Habib, S.P. Maheswari, J. Electrochem. Soc. 135 (1989) 1050. [18] L.T. Van der Pauwe, Philips Res. Rep. 13 (1958) 1. [19] Z.M. Zhang, Z.X. Wei, M.X. Wan, Macromolecules 35 (2002) 5937. [20] H. Liu, X. Hu, J.Y. Wang, R.I. Boughton, Macromolecules 35 (2002) 9414. [21] S.A. Chen, H.T. Lee, Macromolecules 28 (1995) 2858; L. Dai, J.W. White, Polymer 32 (1991) 2120. [22] J.C. Chiang, A.G. Mac Diarmid, Synth. Met. 13 (1986) 193. [23] J. Penfold, E. Staples, I. Tucker, R.K. Thomas, Langmuir 20 (2004) 1269. [24] J. Jung, H. Kobayashi, K.J.C. van Bommel, S. Shinkai, T. Shimizu, Chem. Mater. 14 (2002) 1445.