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Composite Structure of Liquid Crystal/Polymer Nanotubes Revealed by High-Angle Annular Dark-Field Scanning Transmission Electron Microscopy

Published online by Cambridge University Press:  28 September 2007

Andreas K. Schaper
Affiliation:
Material Sciences Center, Philipps University, Hans-Meerwein-Str., 35032 Marburg, Germany
Hiroki Kurata
Affiliation:
Institute for Chemical Research, Kyoto University, Uji, Kyoto-fu 611-0011, Japan
Taiyo Yoshioka
Affiliation:
Institute for Chemical Research, Kyoto University, Uji, Kyoto-fu 611-0011, Japan
Masaki Tsuji
Affiliation:
Institute for Chemical Research, Kyoto University, Uji, Kyoto-fu 611-0011, Japan
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Abstract

We have applied high-angle annular dark-field microscopy to the characterization of the structure of template-grown nanotubes composed of a polymer and a discotic liquid crystalline material. Selective staining of the liquid crystal phase with ruthenium tetroxide was used to develop adequate Z-contrast that allows us to distinguish between the two phases. At appropriate staining conditions, we could clearly visualize, in the annular dark-field mode, a 5–15-nm thin liquid crystalline layer precipitated on the inner surface of the polymer tubes. Cryo-electron diffraction has shown high alignment of the discotic columns within the layer parallel to the tube axis. However, although the polymer/liquid crystal phase separation is almost complete, the wetting behavior of the polymer in relation to the template appears to be sensitively influenced by kinetic factors.

Type
MATERIALS APPLICATIONS
Copyright
© 2007 Microscopy Society of America

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References

REFERENCES

Adam, D., Schuhmacher, P., Simmerer, J., Häussling, L., Siemensmeyer, K., Etzbach, K.-H., Ringsdorf, H. & Haarer, D. (1994). Fast photoconduction in the highly ordered columnar phase of a discotic liquid crystal. Nature 371, 141143.Google Scholar
Bals, S., Kilaas, R. & Kisielowski, C. (2005). Nonlinear imaging using annular dark field TEM. Ultramicroscopy 104, 281289.Google Scholar
Bals, S., Van Tendeloo, G. & Kisielowski, C. (2006). A new approach for electron tomography: Annular dark-field transmission electron microscopy. Adv Mater 18, 892895.Google Scholar
Bushby, R.J. & Lozman, O.R. (2002). Discotic liquid crystals 25 years on. Curr Opin Colloid Interface Sci 7, 343354.Google Scholar
Carlsson, A., Brorson, M. & Topsøe, H. (2006). Supported metal sulphide nanoclusters studied by HAADF-STEM. J Microsc 223, 179181.Google Scholar
Chung, T.M., Ho, R.M., Kuo, J.C., Tsai, J.C., Hsiao, B.S. & Sics, I. (2006). Trilayer crystalline lamellar morphology under confinement. Macromolecules 39, 27392742.Google Scholar
Egerton, R.F. (1996). Electron Energy-Loss Spectroscopy in the Electron Microscope. 2nd ed. New York: Plenum Press.
Figueiredo, P., Geppert, S., Brandsch, R., Bar, G., Thomann, R., Spontak, R.J., Gronski, W., Samlenski, R. & Müller-Buschbaum, P. (2001). Ordering in cylindrical microdomains in thin films of hybrid isotropic/liquid crystalline triblock copolymers. Macromolecules 34, 171180.Google Scholar
Glüsen, B., Kettner, A. & Wendorff, J.H. (1997). A plastic columnar discotic phase. Mol Cryst Liq Cryst 303, 115120.Google Scholar
Heckmann, W. (1993). Staining techniques. In Procedures in Electron Microscopy, Robards, A.W. & Wilson, A.J. (Eds.), pp. 7.113. New York: Wiley.
Heckmann, W. & Frechen, T. (2006). Characterization of water born polymers by transmission electron microscopy. In 16th International Microscopy Congress, Ichinose, H. & Sasaki, T. (Eds.), Vol. 3, p. 1813. Sapporo, Japan: Publication Committee of IMC16.
Howie, A. (1979). Image contrast and localized signal selection techniques. J Microsc 117, 1123.Google Scholar
Hurata, M., Kurata, H. & Isoda, S. (2006a). High resolution ADF-STEM analysis of organic molecular crystals. In 16th International Microscopy Congress, Ichinose, H. & Sasaki, T. (Eds.), Vol. 3, p. 1791. Sapporo, Japan: Publication Committee of IMC16.
Hurata, M., Masuno, A., Kan, D., Azuma, M., Isojima, S., Kurata, H., Takano, M., Shimakawa, Y. & Isoda, S. (2006b). Atomic resolution HAADF-STEM analysis of layered double perovskites La2CuSnO6. In 16th International Microscopy Congress, Ichinose, H. & Sasaki, T. (Eds.), Vol. 3, p. 1767. Sapporo, Japan: Publication Committee of IMC16.
Kirkmeyer, B.P., Taubert, A., Kim, J.S. & Winey, K.I. (2002). Vesicular ionic aggregates in poly(styrene-ran-methacrylic acid) ionomers neutralized with Cs. Macromolecules 35, 26482653.Google Scholar
Lakner, H., Bollig, B., Ungerechts, S. & Kubalek, E. (1996). Characterization of III–V semiconductor interfaces by Z-contrast imaging, EELS and CBED. J Phys D Appl Phys 29, 17671778.Google Scholar
Lauerer, J.H. & Winey, K.I. (1998). Direct imaging of ionic aggregates in Zn-neutralized poly(ethylene-co-methacrylic acid) copolymers. Macromolecules 31, 91069108.Google Scholar
Liu, C.P., Preston, A.R., Boothroyd, C.B. & Humphreys, C.J. (1999). Quantitative analysis of ultrathin doping layers in semiconductors using high-angle annular dark field images. J Microsc 194, 171182.Google Scholar
Martin, C.R. (1994). Nanomaterials: A membrane-based synthetic approach. Science 266, 19611966.Google Scholar
Michler, G. (1980). Electron microscope investigation of the morphology of bulk polymers. Plaste & Kautschuk 27, 301306 (in German).Google Scholar
Midgley, P.A. & Weyland, M. (2003). 3D electron microscopy in the physical sciences: The development of Z-contrast and EFTEM tomography. Ultramicroscopy 96, 413431.Google Scholar
Midgley, P.A., Weyland, M., Thomas, J.M. & Johnson, B.F.G. (2001). Z-contrast tomography: A technique in three-dimensional nanostructural analysis based on Rutherford scattering. Chem Commun 18, 907908.Google Scholar
Midgley, P.A., Weyland, M., Yates, T.J.V., Arslan, I., Dunin-Borkowski, R.E. & Thomas, J.M. (2006). Nanoscale scanning transmission electron tomography. J Microsc 223, 185190.Google Scholar
Montezinos, D., Wells, B.G. & Burns, J.L. (1985). The use of ruthenium in hypochlorite as a stain for polymeric materials. J Polym Sci Polym Lett Ed 23, 421425.Google Scholar
Morel, D.E. & Grubb, D.T. (1984). Staining of melt crystallized isotactic polystyrene by RuO4. Polym Commun 25, 6871.Google Scholar
Nellist, P.D., Chisholm, M.F., Dellby, N., Krivanek, O.L., Murfitt, M.F., Szilagyi, Z.S., Lupini, A.R., Borisevich, A., Sides, W.H. & Pennycook, S.J. (2004). Direct sub-ångström imaging of a crystal lattice. Science 305, 1741.Google Scholar
Nishikawa, Y., Kawada, H., Hasegawa, H. & Hashimoto, T. (1993). Grain boundary morphology of lamellar microdomains. Acta Polym 44, 247255.Google Scholar
Ozkaya, D., Zhou, W., Thomas, J.M., Midgley, P., Keast, V.J. & Hermans, S. (1999). High-resolution imaging of nanoparticle bimetallic catalysts supported on mesoporous silica. Catalysis Lett 60, 113120.Google Scholar
Pennycook, S.J., Berger, S.D. & Culbertson, R.J. (1986). Elemental mapping with elastically scattered electrons. J Microsc 144, 229249.Google Scholar
Pennycook, S.J. & Nellist, P.D. (1999). Z-contrast scanning transmission electron microscopy. In Impact of Electron and Scanning Probe Microscopy on Materials Research, Rickerby, D.G., Valdrè, G. & Valdrè, U. (Eds.), NATO Science Series E, Vol. 364, pp. 161207. New York: Kluwer.
Pennycook, S.J., Rafferty, B. & Nellist, P.D. (2000). Z-contrast imaging in an aberration-corrected scanning transmission electron microscope. Microsc Microanal 6, 343352.Google Scholar
Rey, A.D. (1999). Texture dependence of the Rayleigh instability in discotic mesophase fibres. Model Simul Mater Sci Eng 7, 147155.Google Scholar
Sano, H., Usami, T. & Nakagawa, H. (1986). Lamellar morphologies of melt-crystallized polyethylene, isotactic polypropylene and ethylene-propylene copolymers by the RuO4 staining technique. Polymer 27, 14971504.Google Scholar
Santiago, P., Rendón, L., Reza-San Germán, C. & Pal, U. (2005). HAADF imaging: An effective technique for the study of nonhomogeneous nanostructures. J Nanosci Nanotechnol 5, 11721176.Google Scholar
Schaper, A., Schulz, E., Hirte, R. & Ruscher, C. (1982). The electron microscopic characterization of the morphology of partially crystalline polymers at the example of polyamide-6. Acta Polym 33, 227240 (in German).Google Scholar
Schaper, A.K., Yoshioka, T., Ogawa, T. & Tsuji, M. (2006). Electron microscopy and diffraction of radiation-sensitive nanostructured materials. J Microsc 223, 8895.Google Scholar
Seemann, R., Brinkmann, M., Kramer, E.J., Lange, F.F. & Lipowsky, R. (2005). Wetting morphologies at microstructured surfaces. Proc Natl Acad Sci USA 102, 18481852.Google Scholar
Shimizu, T., Masuda, M. & Minamikawa, H. (2005). Supramolecular nanotube architectures based on amphiphilic molecules. Chem Rev 105, 14011443.Google Scholar
Shiojiri, M. & Saijo, H. (2006). Imaging of high-angle annular dark-field scanning transmission electron microscopy and observations of GaN-based violet laser diodes. J Microsc 223, 172178.Google Scholar
Simmerer, J., Glüsen, B., Paulus, W., Kettner, A., Schuhmacher, P., Adam, D., Etzbach, K.-H., Siemensmeyer, K., Wendorff, J.H., Ringsdorf, H. & Haarer, D. (1996). Transient photoconductivity in a discotic hexagonal plastic crystal. Adv Mater 8, 815819.Google Scholar
Steinhart, M., Wendorff, J.H., Greiner, A., Wehrspohn, R.B., Nielsch, K., Schilling, J., Choi, J. & Gösele, U. (2002). Polymer nanotubes by wetting of ordered porous templates. Science 296, 1997.Google Scholar
Steinhart, M., Zimmermann, S., Schaper, A.K., Ogawa, T., Tsuji, M., Gösele, U., Weder, C. & Wendorff, J.H. (2005). Morphology of polymer/liquid crystal nanotubes: Influence of confinement. Adv Funct Mater 15, 16561664.Google Scholar
Tervoort-Engelen, Y. & van Gisbergen, J. (1991). Ruthenium tetraoxide staining for transmission electron microscopy of polypropylene/high density polyethylene blends. Polym Commun 32, 261263.Google Scholar
Trent, J.S. (1984). Ruthenium tetroxide staining of polymers: New preparative methods for electron microscopy. Macromolecules 17, 29302931.Google Scholar
Trent, J.S., Scheinbeim, J.I. & Couchman, P.R. (1983). Ruthenium tetroxide staining of polymers for electron microscopy. Macromolecules 16, 589598.Google Scholar
Vitali, R. & Montani, E. (1980). Ruthenium tetroxide as a staining agent for unsaturated and saturated polymers. Polymer 21, 12201222.Google Scholar
Walther, T. (2006). A new experimental procedure to quantify annular dark field images in scanning transmission electron microscopy. J Microsc 221, 137144.Google Scholar
Watanabe, K., Asano, E., Yamazaki, T., Kikuchi, Y. & Hashimoto, I. (2004). Symmetries in BF and HAADF STEM image calculations. Ultramicroscopy 102, 1321.Google Scholar
Wignall, G.D., Alamo, R.G., Londono, J.D., Mandelkern, L., Kim, M.H., Lin, J.S. & Brown, G.M. (2000). Morphology of blends of linear and short-chain-branched polyethylenes in the solid state by small-angle neutron and X-ray scattering, differential scanning calorimetry, and transmission electron diffraction. Macromolecules 33, 551561.Google Scholar
Winey, K.I., Laurer, J.H. & Kirkmeyer, B.P. (2000). Ionic aggregates in partially Zn-neutralized poly(ethylene-ran-methacrylic acid) ionomers: Shape, size, and size distribution. Macromolecules 33, 507513.Google Scholar