- Email: [email protected]
The coordination and phase separation in nylon–copper chloride system
Journal of Molecular Structure 613 (2002) 67–71 www.elsevier.com/locate/molstruc
The coordination and phase separation in nylon –copper chloride system A.F. Xiea,b, D.L. Taoa, Z.B. Zhangb, Y.Z. Xua,c, Y.J. Wuc, T.D. Hud, B.Y. Gub, J.G. Wua,*, G.Z. Yangb, D.F. Xuc a
State Key Laboratory of Rare Earth Material Chemistry and Application, Department of Chemistry, Peking University, 100871 Beijing, People’s Republic of China b Laboratory of Optical Physics, Institute of Physics, Chinese Academy of Sciences, P.O. Box 603, 100080 Beijing, People’s Republic of China c State Key Laboratory of Polymer Physics and Chemistry, Institute of Chemistry, Chinese Academy of Sciences, 100080 Beijing, People’s Republic of China d Synchrotron Radiation Laboratory, Institute of High Energy Physics, Chinese Academy of Sciences, 100039 Beijing, People’s Republic of China Received 10 December 2001; revised 5 March 2002; accepted 5 March 2002
Abstract In this paper, the spectroscopic and morphological behaviors of nylon 6 – copper chloride systems have been investigated. The temperature-variable Fourier transform infrared (FT-IR) spectra of nylon – copper chloride systems shows that a new band of 1600 cm21 appeared between the amide I band at about 1639 cm21 and the amide II band around 1552 cm21 compared with the FT-IR spectra of pure nylon, which indicates that there was the coordination between copper ions and the amide groups of nylon. The processed spectra of extended X-ray absorption fine-structure of copper ions at K edge showed that one copper ion can coordinate two oxygen atoms and two chloride ions in nylon 6 – copper chloride systems. Phase separation in nylon – copper chloride systems was observed by using near-field scanning optical microscopy. q 2002 Published by Elsevier Science B.V. Keywords: Nylon; Near-field scanning optical microscopy; Fourier transform infrared spectroscopy; Coordination; Phase separation
1. Introduction Extensive investigation has revealed that amide groups of the polymer possess considerable ability to coordinate to the metal ions in the polymer – metal ion system [1 – 4]. Vibrational spectroscopic studies have shown that such coordination can invoke significant * Corresponding author. Tel.: þ86-10-6275-7951; fax: þ 86-106275-1708. E-mail address: [email protected] (J.G. Wu).
variation of amide I band and the extent of variation depends on the charge and ionic radius of the metal ions [5,6]. This coordination effect provides a potential way to modify the processing and performance of polymers. As far as nylon, a polymer with broad application in plastics and fiber, is concerned, large amount of work has revealed that interactions between metal ions and the amide groups of nylon occur in nylon – metal ion blend systems. For instance, the hydrogen bond network of nylon break in nylon – GaCl3 system and therefore Ga3þ may open a new
0022-2860/02/$ - see front matter q 2002 Published by Elsevier Science B.V. PII: S 0 0 2 2 - 2 8 6 0 ( 0 2 ) 0 0 1 0 7 - 2
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A.F. Xie et al. / Journal of Molecular Structure 613 (2002) 67–71
approach to process nylon [7,8]. In nylon –LiCl and LiBr blend systems, lithium ions could drastically reduce the crystallization rate of nylon and increase the viscosity of molten nylon greatly. In addition, introducing lithium halide into nylon can successfully produce high-modulus nylon fiber [9 – 13]. In our previous work, thermal and spectroscopic behaviors of nylon – lithium salt and nylon – lanthanide salt systems have been investigated [14,15]. The significant decreasing of melting point seems to stem from the formation of stronger hydrogen bonds. Copper ions are often added into nylon system as an ingredient to stabilize nylon. In this paper, we choose this system to further investigate the coordination and phase separation behavior in polymer – metal ion system. Temperature-variable Fourier transform infrared (FT-IR) spectra and extended X-ray absorption fine-structure (EXAFS) spectra of copper at K edge indicate there is the coordination of the copper ions to amide groups of nylon. It is known that in ultraviolet – visible region, nylon – copper chloride blend system has a few absorption bands, but the pure nylon has no absorption in this region, so it is possible to use near-field scanning optical microscopy (NSOM) with Ar ion laser as light source to directly observe the phase separation existing in the thin film of nylon –copper chloride blend system.
2. Experimental Nylon –copper ion blend systems were prepared by dissolving nylon 6 and CuCl2 into formic acid with different weight ratios. The thin films for the temperature-variable FT-IR spectra and NSOM image were acquired by spin coating method. The sample of nylon –copper ion system for EXAFS experiment was made of nylon film soaked in the concentrated aqueous solution of CuCl2 so that copper ions could diffuse into nylon matrix as much as possible. The temperature-variable FT-IR spectra of the sample were recorded on a Nicolet Magna 750 FT-IR spectrometer with Perkin – Elmer’s p/n 21.000 temperature-variable cell and a Mercury –Cadmium – Telluride detector. In order to remove the adsorbed water and prevent the oxidation of the sample during the heating process, all the measurement was
performed in vacuum. Moreover, 256 scans were co-added with a resolution of 0.5 cm21 to improve the S/N ratio. The interference of vapor water bands is eliminated from the amide I and II bands of nylon and its copper complex with a spectral program made in our laboratory. EXAFS spectra of copper ion at K edge were recorded at room temperature in transmission mode of the beam line 4WIB in Beijing synchrotron radiation facility. This apparatus used in this experiment has been described in detail elsewhere [16,17] and here is only a brief description. The spot line of X-ray photons was defined by a slit of size 0.5(H) £ 12(V) mm2 and monochromatized by a Si(111) double-crystal monochromator. Higher harmonics were rejected by detuning the Bragg angle of the second crystal of the monochromator. The electron energy and current of the storage ring were 2.2 GeV and 40 –70 mA, respectively, during the experiment. The energy resolution is better than 3 eV. Data analysis was carried out using the program of EXCURV92 of the Daresbury Laboratory, UK. All plots and evaluations were done with k3 weighted spectrum. The evaluated k-range is 3 – 15 A21 in all cases. Background subtraction was performed by cubic spine. The transmission NSOM used in this experiment is from RHK Technology in USA and its detailed description can be found in other places [18,19]. The brief description of the NSOM used in our experiment is as below. The tapered aluminum-coated cantilevered optical fiber probe is 50 nm in diameter and maintained in the near-field (no more than 20 nm) of the sample surface using optical tapping mode feedback with the possibility to obtain optical superresolution [20,21]. The feedback signal provides a topography image of the sample generated with the optical image simultaneously. The 514.5 nm light from argon ion laser is coupled into the fiber probe and then illuminated the sample by the evanescent light from the tip end to acquire maximum optical contrast. Because Cu2þ has a wide adsorption banded around 514 nm, and nylon has negligible absorption at this wavelength, therefore the light transmitted the sample can be used to investigate the dispersion of Cu2þ in polymer matrix. The transmitted light was collected by an objective (32 £ 0.4 Zeiss), filtered with bandpass 514 nm and detected with an avalanche
A.F. Xie et al. / Journal of Molecular Structure 613 (2002) 67–71
Fig. 1. FT-IR spectra of nylon film and the film of nylon 6 –CuCl2 blend complex with the weight ratio 5:1.
photodiode detector (SPCM AQR-15) from EG&G. The optical images were obtained by mapping the intensity of the transmitted light as a function of the lateral scanning positions. During this experiment, the NSOM was performed under ambient conditions and the film could be directly used by using spinning coating method and was not damaged when the experiment was over.
3. Results and discussion The temperature-variable FT-IR spectra of nylon – copper chloride blend system in weight ratio 5:1 are shown in Fig. 1. Significant variations occur on the spectra. The most remarkable variation is found between the amide I and II bands. Besides the amide I and II bands for pure nylon at about 1639 and 1552 cm21, a new band appears around 1600 cm21. According to our previous work, this band is attributed to the amide groups of nylon that coordinate with copper ions. As the content of Cu2þ ions increases, the 1600 cm21 band is stronger and become the dominant band in the amide I and II regions. In comparison with our previous work on nylon – lithium system and nylon – lanthanide system, the spectral behavior of nylon – CuCl2 system is similar to that of nylon – lanthanide system as far as the amide I and II bands are concerned. However, the 1639 and 1552 cm21 bands still remain even if the molar ratio between the Cu2þ and amide group amounts to 1:1. This is assigned to the fact that not
69
every copper ion takes part in the coordination with the amide group of nylon and the coordination is not simply determined by the molar ratio of nylon and CuCl2, therefore the phase separation and the formation of ionic cluster may exist in this system as shown in the following images from NSOM. The coordination number can be deduced from the EXAFS spectra of copper ion at K edge. The result of EXAFS data analysis indicates that two oxygen atoms and two chloride ions coordinate to one copper ion, therefore the coordinate number of copper ion is 4 and this number does not change with the difference of the ratios of nylon – copper chloride system. Fig. 2(a) and (b) shows the NSOM topographic and optical images for the film of the nylon þ 20 wt% CuCl2 system. The scan area is 10 mm £ 10 mm. With the spinning speed of 2100 rounds per minute, the thickness of the film is nearly 100 nm. From the NSOM topography image of Fig. 2(a), there are some different shape bright domains (the thicker part of the surface) and dark domains (the thinner part of the surface), which shows that the surface of the film is not flat and the roughness is about 50 nm according to the recording mechanism of the topography image. From the NSOM absorption image of Fig. 2(b), there also are some bright domains (the less absorption part) and dark domains (the more absorption part). The cross-sections of line B and line C in Fig. 2(a) and (b) shown in Fig. 2(aB) and (bB), and Fig. 2(aC) and (bC), respectively, indicate that the brighter domains in topographic image is also brighter in absorption image, and the darker domains in topographic image is also darker in the absorption image. That is to say, the different intensity distribution in the NSOM transmission image does not result from the roughness of the film surface. Thus, we can say that there are the phase separation in the nylon –CuCl2 blend system, and the dark domains are the phase of the nylon coordinating with the rich Cu2þ ions and the bright domains the phase of the nylon with little Cu2þ ions.
4. Conclusion The results in this paper show that the copper ions can coordinate with the amide groups of nylon in the nylon –CuCl2 blend system and there are two phases consisting of the phase of the nylon coordinating with
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Fig. 2. Topography (a) and transmission (b) NSOM images of the film of nylon 6–CuCl2 complex with the weight ratio 5:1 obtained simultaneously. The scan area is 10 mm £ 10 mm, the cross-plot of line B for topography NSOM image (aB) and for transmission NSOM image (bB) and the cross-plot of line C for topography NSOM image (aC) and transmission NSOM image (bC).
the rich Cu2þ ions and the phase of the nylon with poor Cu2þ ions or no Cu2þ ions. Therefore, the structure of nylon changed after being added to metal ions. At the same time, this paper provides the experimental ways to analyze the polymer – metal ion system from both spectroscopic and morphological points of view.
Acknowledgements This project is supported by State Key Project of Basic Research MOST G1998061307, Natural Science Foundation of China (NSFC, grant No. 59733060, 59873030, 59953001, 59903008), and Major Project of Knowledge Renovation of Chinese Academy of Sciences (grant No. KJCX1-Y-03), National Scientific Foundation (29671002), Key project (39730160, 20023005), Doctoral Project, and
Foundation of High Institute of High Education of National.
References [1] A. Eisenberg, M. King, in: R.S. Stein (Ed.), Polymer Physics, vol. 2, Academic Press, New York, 1977. [2] NATO ASI SERIES, in: M. Pineri, A. Eisenberg (Eds.), Series C: Mathematical and Physical Sciences, vol. 198, Reidel, Dordrecht, 1987. [3] A. Eisenberg, F.E. Bailey (Eds.), Coulombic Interactions in Macromolecular Systems, American Chemical Society, Washington, DC, 1986. [4] C.W. Lantman, W.J. Macknight, Annual Review of Material Science 19 (1989) 296. [5] W.-X. Sun, Y.-Z. Xu, W. Tian, Z.-H. Xu, S.-F. Weng, J.-G. Wu, D.-F. Xu, G.-X. Xu, Chinese Journal of Rare Earth 17 (1999) 7. [6] Y.-Z. Xu, Z.-H. Xu, W. Tian, J. Bian, S.-F. Weng, L.-M. Li, D.-F. Xu, J.-G. Wu, G.-X. Xu, SPIE 2089 (1993) 198 –199.
A.F. Xie et al. / Journal of Molecular Structure 613 (2002) 67–71 [7] M.F. Roberts, S.A. Jenekhe, Chemistry of Materials 2 (1990) 224. [8] M.F. Roberts, S.A. Jenekhe, Macromolecules 24 (1991) 3142. [9] D. Acierno, F.P. La Mantia, G. Polizzotti, G.C. Alfonso, A. Ciferri, Polymer Letters Edition 15 (1977) 323. [10] B. Valenti, E. Bianchi, G. Greppi, A. Tealdi, A. Ciferri, Journal of Physical Chemistry 77 (1973) 389. [11] E. Bianchi, A. Ciferri, A. Tealdi, R. Torre, B. Valenti, Macromolecules 7 (1973) 495. [12] A. Richardson, I.M. Ward, Journal Polymer Science, Polymer Physics Edition 19 (1981) 1549. [13] T. Kunugi, K. Chida, A. Suzuki, Journal of Applied Polymer Science 67 (1998) 1993. [14] Y.Z. Xu, W.X. Sun, W.H. Li, X.B. Hu, H.B. Zhou, S.F. Weng, F. Zhang, X.X. Zhang, J.G. Wu, D.F. Xu, G.X. Xu, Journal Applied Polymer Science 77 (2000) 2685.
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[15] W.X. Sun, X.B. Hu, Y.Z. Xu, L.W. Qu, Z.L. Yang, D.J. Wang, X.X. Liu, F.X. Guo, S.F. Weng, J.G. Wu, D.F. Xu, Chimica Acta 58 (2000) 1602. [16] T.D. Hu, Y.N. Xie, S. Qiao, Y.L. Jin, D.C. Xian, Physical Review B 50 (1994) 2216. [17] T.D. Hu, Y.N. Xie, Y.L. Jin, T. Liu, Journal of Physics: Condensed Materials 9 (1997) 5507. [18] M.A. Paesler, P.J. Moyer, Near-field Optics Theory: Instrumentation and Applications, 1996. [19] E. Betizig, J.K. Trautman, Science 257 (1992) 190. [20] E. Betizig, J.K. Trautman, T.D. Harris, J.S. Weiner, R.L. Kostelak, Science 251 (1991) 1468. [21] H. Murama, N. Chiba, K. Homma, K. Nakajima, T. Ataka, S. Ohta, A. Kusumi, M. Fujira, Applied Physics Letter 66 (1995) 3245.
The coordination and phase separation in nylon –copper chloride system A.F. Xiea,b, D.L. Taoa, Z.B. Zhangb, Y.Z. Xua,c, Y.J. Wuc, T.D. Hud, B.Y. Gub, J.G. Wua,*, G.Z. Yangb, D.F. Xuc a
State Key Laboratory of Rare Earth Material Chemistry and Application, Department of Chemistry, Peking University, 100871 Beijing, People’s Republic of China b Laboratory of Optical Physics, Institute of Physics, Chinese Academy of Sciences, P.O. Box 603, 100080 Beijing, People’s Republic of China c State Key Laboratory of Polymer Physics and Chemistry, Institute of Chemistry, Chinese Academy of Sciences, 100080 Beijing, People’s Republic of China d Synchrotron Radiation Laboratory, Institute of High Energy Physics, Chinese Academy of Sciences, 100039 Beijing, People’s Republic of China Received 10 December 2001; revised 5 March 2002; accepted 5 March 2002
Abstract In this paper, the spectroscopic and morphological behaviors of nylon 6 – copper chloride systems have been investigated. The temperature-variable Fourier transform infrared (FT-IR) spectra of nylon – copper chloride systems shows that a new band of 1600 cm21 appeared between the amide I band at about 1639 cm21 and the amide II band around 1552 cm21 compared with the FT-IR spectra of pure nylon, which indicates that there was the coordination between copper ions and the amide groups of nylon. The processed spectra of extended X-ray absorption fine-structure of copper ions at K edge showed that one copper ion can coordinate two oxygen atoms and two chloride ions in nylon 6 – copper chloride systems. Phase separation in nylon – copper chloride systems was observed by using near-field scanning optical microscopy. q 2002 Published by Elsevier Science B.V. Keywords: Nylon; Near-field scanning optical microscopy; Fourier transform infrared spectroscopy; Coordination; Phase separation
1. Introduction Extensive investigation has revealed that amide groups of the polymer possess considerable ability to coordinate to the metal ions in the polymer – metal ion system [1 – 4]. Vibrational spectroscopic studies have shown that such coordination can invoke significant * Corresponding author. Tel.: þ86-10-6275-7951; fax: þ 86-106275-1708. E-mail address: [email protected] (J.G. Wu).
variation of amide I band and the extent of variation depends on the charge and ionic radius of the metal ions [5,6]. This coordination effect provides a potential way to modify the processing and performance of polymers. As far as nylon, a polymer with broad application in plastics and fiber, is concerned, large amount of work has revealed that interactions between metal ions and the amide groups of nylon occur in nylon – metal ion blend systems. For instance, the hydrogen bond network of nylon break in nylon – GaCl3 system and therefore Ga3þ may open a new
0022-2860/02/$ - see front matter q 2002 Published by Elsevier Science B.V. PII: S 0 0 2 2 - 2 8 6 0 ( 0 2 ) 0 0 1 0 7 - 2
68
A.F. Xie et al. / Journal of Molecular Structure 613 (2002) 67–71
approach to process nylon [7,8]. In nylon –LiCl and LiBr blend systems, lithium ions could drastically reduce the crystallization rate of nylon and increase the viscosity of molten nylon greatly. In addition, introducing lithium halide into nylon can successfully produce high-modulus nylon fiber [9 – 13]. In our previous work, thermal and spectroscopic behaviors of nylon – lithium salt and nylon – lanthanide salt systems have been investigated [14,15]. The significant decreasing of melting point seems to stem from the formation of stronger hydrogen bonds. Copper ions are often added into nylon system as an ingredient to stabilize nylon. In this paper, we choose this system to further investigate the coordination and phase separation behavior in polymer – metal ion system. Temperature-variable Fourier transform infrared (FT-IR) spectra and extended X-ray absorption fine-structure (EXAFS) spectra of copper at K edge indicate there is the coordination of the copper ions to amide groups of nylon. It is known that in ultraviolet – visible region, nylon – copper chloride blend system has a few absorption bands, but the pure nylon has no absorption in this region, so it is possible to use near-field scanning optical microscopy (NSOM) with Ar ion laser as light source to directly observe the phase separation existing in the thin film of nylon –copper chloride blend system.
2. Experimental Nylon –copper ion blend systems were prepared by dissolving nylon 6 and CuCl2 into formic acid with different weight ratios. The thin films for the temperature-variable FT-IR spectra and NSOM image were acquired by spin coating method. The sample of nylon –copper ion system for EXAFS experiment was made of nylon film soaked in the concentrated aqueous solution of CuCl2 so that copper ions could diffuse into nylon matrix as much as possible. The temperature-variable FT-IR spectra of the sample were recorded on a Nicolet Magna 750 FT-IR spectrometer with Perkin – Elmer’s p/n 21.000 temperature-variable cell and a Mercury –Cadmium – Telluride detector. In order to remove the adsorbed water and prevent the oxidation of the sample during the heating process, all the measurement was
performed in vacuum. Moreover, 256 scans were co-added with a resolution of 0.5 cm21 to improve the S/N ratio. The interference of vapor water bands is eliminated from the amide I and II bands of nylon and its copper complex with a spectral program made in our laboratory. EXAFS spectra of copper ion at K edge were recorded at room temperature in transmission mode of the beam line 4WIB in Beijing synchrotron radiation facility. This apparatus used in this experiment has been described in detail elsewhere [16,17] and here is only a brief description. The spot line of X-ray photons was defined by a slit of size 0.5(H) £ 12(V) mm2 and monochromatized by a Si(111) double-crystal monochromator. Higher harmonics were rejected by detuning the Bragg angle of the second crystal of the monochromator. The electron energy and current of the storage ring were 2.2 GeV and 40 –70 mA, respectively, during the experiment. The energy resolution is better than 3 eV. Data analysis was carried out using the program of EXCURV92 of the Daresbury Laboratory, UK. All plots and evaluations were done with k3 weighted spectrum. The evaluated k-range is 3 – 15 A21 in all cases. Background subtraction was performed by cubic spine. The transmission NSOM used in this experiment is from RHK Technology in USA and its detailed description can be found in other places [18,19]. The brief description of the NSOM used in our experiment is as below. The tapered aluminum-coated cantilevered optical fiber probe is 50 nm in diameter and maintained in the near-field (no more than 20 nm) of the sample surface using optical tapping mode feedback with the possibility to obtain optical superresolution [20,21]. The feedback signal provides a topography image of the sample generated with the optical image simultaneously. The 514.5 nm light from argon ion laser is coupled into the fiber probe and then illuminated the sample by the evanescent light from the tip end to acquire maximum optical contrast. Because Cu2þ has a wide adsorption banded around 514 nm, and nylon has negligible absorption at this wavelength, therefore the light transmitted the sample can be used to investigate the dispersion of Cu2þ in polymer matrix. The transmitted light was collected by an objective (32 £ 0.4 Zeiss), filtered with bandpass 514 nm and detected with an avalanche
A.F. Xie et al. / Journal of Molecular Structure 613 (2002) 67–71
Fig. 1. FT-IR spectra of nylon film and the film of nylon 6 –CuCl2 blend complex with the weight ratio 5:1.
photodiode detector (SPCM AQR-15) from EG&G. The optical images were obtained by mapping the intensity of the transmitted light as a function of the lateral scanning positions. During this experiment, the NSOM was performed under ambient conditions and the film could be directly used by using spinning coating method and was not damaged when the experiment was over.
3. Results and discussion The temperature-variable FT-IR spectra of nylon – copper chloride blend system in weight ratio 5:1 are shown in Fig. 1. Significant variations occur on the spectra. The most remarkable variation is found between the amide I and II bands. Besides the amide I and II bands for pure nylon at about 1639 and 1552 cm21, a new band appears around 1600 cm21. According to our previous work, this band is attributed to the amide groups of nylon that coordinate with copper ions. As the content of Cu2þ ions increases, the 1600 cm21 band is stronger and become the dominant band in the amide I and II regions. In comparison with our previous work on nylon – lithium system and nylon – lanthanide system, the spectral behavior of nylon – CuCl2 system is similar to that of nylon – lanthanide system as far as the amide I and II bands are concerned. However, the 1639 and 1552 cm21 bands still remain even if the molar ratio between the Cu2þ and amide group amounts to 1:1. This is assigned to the fact that not
69
every copper ion takes part in the coordination with the amide group of nylon and the coordination is not simply determined by the molar ratio of nylon and CuCl2, therefore the phase separation and the formation of ionic cluster may exist in this system as shown in the following images from NSOM. The coordination number can be deduced from the EXAFS spectra of copper ion at K edge. The result of EXAFS data analysis indicates that two oxygen atoms and two chloride ions coordinate to one copper ion, therefore the coordinate number of copper ion is 4 and this number does not change with the difference of the ratios of nylon – copper chloride system. Fig. 2(a) and (b) shows the NSOM topographic and optical images for the film of the nylon þ 20 wt% CuCl2 system. The scan area is 10 mm £ 10 mm. With the spinning speed of 2100 rounds per minute, the thickness of the film is nearly 100 nm. From the NSOM topography image of Fig. 2(a), there are some different shape bright domains (the thicker part of the surface) and dark domains (the thinner part of the surface), which shows that the surface of the film is not flat and the roughness is about 50 nm according to the recording mechanism of the topography image. From the NSOM absorption image of Fig. 2(b), there also are some bright domains (the less absorption part) and dark domains (the more absorption part). The cross-sections of line B and line C in Fig. 2(a) and (b) shown in Fig. 2(aB) and (bB), and Fig. 2(aC) and (bC), respectively, indicate that the brighter domains in topographic image is also brighter in absorption image, and the darker domains in topographic image is also darker in the absorption image. That is to say, the different intensity distribution in the NSOM transmission image does not result from the roughness of the film surface. Thus, we can say that there are the phase separation in the nylon –CuCl2 blend system, and the dark domains are the phase of the nylon coordinating with the rich Cu2þ ions and the bright domains the phase of the nylon with little Cu2þ ions.
4. Conclusion The results in this paper show that the copper ions can coordinate with the amide groups of nylon in the nylon –CuCl2 blend system and there are two phases consisting of the phase of the nylon coordinating with
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A.F. Xie et al. / Journal of Molecular Structure 613 (2002) 67–71
Fig. 2. Topography (a) and transmission (b) NSOM images of the film of nylon 6–CuCl2 complex with the weight ratio 5:1 obtained simultaneously. The scan area is 10 mm £ 10 mm, the cross-plot of line B for topography NSOM image (aB) and for transmission NSOM image (bB) and the cross-plot of line C for topography NSOM image (aC) and transmission NSOM image (bC).
the rich Cu2þ ions and the phase of the nylon with poor Cu2þ ions or no Cu2þ ions. Therefore, the structure of nylon changed after being added to metal ions. At the same time, this paper provides the experimental ways to analyze the polymer – metal ion system from both spectroscopic and morphological points of view.
Acknowledgements This project is supported by State Key Project of Basic Research MOST G1998061307, Natural Science Foundation of China (NSFC, grant No. 59733060, 59873030, 59953001, 59903008), and Major Project of Knowledge Renovation of Chinese Academy of Sciences (grant No. KJCX1-Y-03), National Scientific Foundation (29671002), Key project (39730160, 20023005), Doctoral Project, and
Foundation of High Institute of High Education of National.
References [1] A. Eisenberg, M. King, in: R.S. Stein (Ed.), Polymer Physics, vol. 2, Academic Press, New York, 1977. [2] NATO ASI SERIES, in: M. Pineri, A. Eisenberg (Eds.), Series C: Mathematical and Physical Sciences, vol. 198, Reidel, Dordrecht, 1987. [3] A. Eisenberg, F.E. Bailey (Eds.), Coulombic Interactions in Macromolecular Systems, American Chemical Society, Washington, DC, 1986. [4] C.W. Lantman, W.J. Macknight, Annual Review of Material Science 19 (1989) 296. [5] W.-X. Sun, Y.-Z. Xu, W. Tian, Z.-H. Xu, S.-F. Weng, J.-G. Wu, D.-F. Xu, G.-X. Xu, Chinese Journal of Rare Earth 17 (1999) 7. [6] Y.-Z. Xu, Z.-H. Xu, W. Tian, J. Bian, S.-F. Weng, L.-M. Li, D.-F. Xu, J.-G. Wu, G.-X. Xu, SPIE 2089 (1993) 198 –199.
A.F. Xie et al. / Journal of Molecular Structure 613 (2002) 67–71 [7] M.F. Roberts, S.A. Jenekhe, Chemistry of Materials 2 (1990) 224. [8] M.F. Roberts, S.A. Jenekhe, Macromolecules 24 (1991) 3142. [9] D. Acierno, F.P. La Mantia, G. Polizzotti, G.C. Alfonso, A. Ciferri, Polymer Letters Edition 15 (1977) 323. [10] B. Valenti, E. Bianchi, G. Greppi, A. Tealdi, A. Ciferri, Journal of Physical Chemistry 77 (1973) 389. [11] E. Bianchi, A. Ciferri, A. Tealdi, R. Torre, B. Valenti, Macromolecules 7 (1973) 495. [12] A. Richardson, I.M. Ward, Journal Polymer Science, Polymer Physics Edition 19 (1981) 1549. [13] T. Kunugi, K. Chida, A. Suzuki, Journal of Applied Polymer Science 67 (1998) 1993. [14] Y.Z. Xu, W.X. Sun, W.H. Li, X.B. Hu, H.B. Zhou, S.F. Weng, F. Zhang, X.X. Zhang, J.G. Wu, D.F. Xu, G.X. Xu, Journal Applied Polymer Science 77 (2000) 2685.
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[15] W.X. Sun, X.B. Hu, Y.Z. Xu, L.W. Qu, Z.L. Yang, D.J. Wang, X.X. Liu, F.X. Guo, S.F. Weng, J.G. Wu, D.F. Xu, Chimica Acta 58 (2000) 1602. [16] T.D. Hu, Y.N. Xie, S. Qiao, Y.L. Jin, D.C. Xian, Physical Review B 50 (1994) 2216. [17] T.D. Hu, Y.N. Xie, Y.L. Jin, T. Liu, Journal of Physics: Condensed Materials 9 (1997) 5507. [18] M.A. Paesler, P.J. Moyer, Near-field Optics Theory: Instrumentation and Applications, 1996. [19] E. Betizig, J.K. Trautman, Science 257 (1992) 190. [20] E. Betizig, J.K. Trautman, T.D. Harris, J.S. Weiner, R.L. Kostelak, Science 251 (1991) 1468. [21] H. Murama, N. Chiba, K. Homma, K. Nakajima, T. Ataka, S. Ohta, A. Kusumi, M. Fujira, Applied Physics Letter 66 (1995) 3245.