%0 Book Section %1 statphys23_0457 %A Bagchi, D. %A Choudhury, P. Kar %A Menon, R. %B Abstract Book of the XXIII IUPAP International Conference on Statistical Physics %C Genova, Italy %D 2007 %E Pietronero, Luciano %E Loreto, Vittorio %E Zapperi, Stefano %K angle conducting polymer scattering small statphys23 structure topic-7 x-ray %T Small angle X-ray scattering investigations of conformations and organization of conducting polymer chains in various solvents %U http://st23.statphys23.org/webservices/abstract/preview_pop.php?ID_PAPER=457 %X We identify the mechanism of conformational changes and organization of conducting polymer chains in various solvents. These polymers with alternating single and double bonds are relatively less flexible than conventional polymers, and there is significant correlation among the structural and physical properties. We have used small angle X-ray scattering (SAXS) to probe the structural features of two different conducting polymers, polyethelene dioxythiophene complexed with polystyrene sulfonate (PEDOT-PSS), and poly2-methoxy-5-(2-ethyl-hexyloxy)-1,4-phenylene vinylene (MEH-PPV), in various solvents. In case of PEDOT-PSS, there is a transition from a compact coil to elongated coil structure in some solvents, which is shown to enhance the conductivity. To supplement the SAXS data, rheological data of PEDOT-PSS gels in various solvents are also analyzed, and reveal the structural changes under the influence of shear. In case of MEH-PPV, the SAXS data reveal that changes in the percentage of conjugation of chains can have can have a remarkable influence in the photoluminescence properties. These studies demonstrate that solvent assisted modification of nano-scale structure of conducting polymers can be directly probed by SAXS, which in turn can aid in controlling the properties of these polymers for technologically relevant applications. References 1. T.A. Skotheim, R.L. Elsenbaumer and J.R. Reynolds (eds.), Handbook of Conducting Polymers (2nd ed. Dekker, New York, U.S.A., 1998). 2. K. Lee, S. Cho, S. H. Park, A. J. Heeger, C.-W. Lee and S.-H. Lee, Nature, 441, 65 (2006). 3. J. Ruokolainen, R. Makinen, M. Torkkeli, M. Makela, R. Serimaa, G. ten Brinke, O. Ikkala, Science, 280, 557 (1998). 4. G. Caliskan, C. Hyeon, U. Perez-Salas, R. M. Briber, S. A. Woodson and D. Thirumalai, Phys. Rev. Lett. 95, 268303 (2005). 5. M. Knaapila, R. Stepanyan, T. Torkkeli, B. P. Lyons, T. P. Ikonen, L. Alm´asy, J. P. Foreman, R. Serimaa, R. G¨untner, U. Scherf and A. P. Monkman, Phys. Rev. E, 71 (2005) 041802. 6. R.J. Roe, Methods of X-Ray and Neutron Scattering in Polymer Science (Oxford University Press, New York, 1999). 7. O. Glatter and O. Kratky, Small-Angle X-Ray Scattering (Academic Press, London,1982). 8. W. C. Ou-Yang, C.-S. Chang, H.-L. Chen, C.-S. Tsao, K.-Y. Peng, S.-A. Chen and C. C. Han, Phys. Rev. E, 72, 031802 (2005). 9. D. Bagchi and R. Menon, Chem. Phys. Lett. 425, 114 (2006).

@incollection{statphys23_0457, abstract = {We identify the mechanism of conformational changes and organization of conducting polymer chains in various solvents. These polymers with alternating single and double bonds are relatively less flexible than conventional polymers, and there is significant correlation among the structural and physical properties. We have used small angle X-ray scattering (SAXS) to probe the structural features of two different conducting polymers, polyethelene dioxythiophene complexed with polystyrene sulfonate (PEDOT-PSS), and poly[2-methoxy-5-(2-ethyl-hexyloxy)-1,4-phenylene vinylene] (MEH-PPV), in various solvents. In case of PEDOT-PSS, there is a transition from a compact coil to elongated coil structure in some solvents, which is shown to enhance the conductivity. To supplement the SAXS data, rheological data of PEDOT-PSS gels in various solvents are also analyzed, and reveal the structural changes under the influence of shear. In case of MEH-PPV, the SAXS data reveal that changes in the percentage of conjugation of chains can have can have a remarkable influence in the photoluminescence properties. These studies demonstrate that solvent assisted modification of nano-scale structure of conducting polymers can be directly probed by SAXS, which in turn can aid in controlling the properties of these polymers for technologically relevant applications. References 1. T.A. Skotheim, R.L. Elsenbaumer and J.R. Reynolds (eds.), Handbook of Conducting Polymers (2nd ed. Dekker, New York, U.S.A., 1998). 2. K. Lee, S. Cho, S. H. Park, A. J. Heeger, C.-W. Lee and S.-H. Lee, Nature, {\bf 441}, 65 (2006). 3. J. Ruokolainen, R. Makinen, M. Torkkeli, M. Makela, R. Serimaa, G. ten Brinke, O. Ikkala, Science, {\bf 280}, 557 (1998). 4. G. Caliskan, C. Hyeon, U. Perez-Salas, R. M. Briber, S. A. Woodson and D. Thirumalai, Phys. Rev. Lett. {\bf 95}, 268303 (2005). 5. M. Knaapila, R. Stepanyan, T. Torkkeli, B. P. Lyons, T. P. Ikonen, L. Alm´asy, J. P. Foreman, R. Serimaa, R. G¨untner, U. Scherf and A. P. Monkman, Phys. Rev. E, {\bf 71} (2005) 041802. 6. R.J. Roe, Methods of X-Ray and Neutron Scattering in Polymer Science (Oxford University Press, New York, 1999). 7. O. Glatter and O. Kratky, Small-Angle X-Ray Scattering (Academic Press, London,1982). 8. W. C. Ou-Yang, C.-S. Chang, H.-L. Chen, C.-S. Tsao, K.-Y. Peng, S.-A. Chen and C. C. Han, Phys. Rev. E, {\bf 72}, 031802 (2005). 9. D. Bagchi and R. Menon, Chem. Phys. Lett. {\bf 425}, 114 (2006).}, added-at = {2007-06-20T10:16:09.000+0200}, address = {Genova, Italy}, author = {Bagchi, D. and Choudhury, P. Kar and Menon, R.}, biburl = {https://www.bibsonomy.org/bibtex/23c2041107a517a601dc61d5b331bb085/statphys23}, booktitle = {Abstract Book of the XXIII IUPAP International Conference on Statistical Physics}, editor = {Pietronero, Luciano and Loreto, Vittorio and Zapperi, Stefano}, interhash = {ff32ef81296f90eb6405f2831e4dad8d}, intrahash = {3c2041107a517a601dc61d5b331bb085}, keywords = {angle conducting polymer scattering small statphys23 structure topic-7 x-ray}, month = {9-13 July}, timestamp = {2007-06-20T10:16:20.000+0200}, title = {Small angle X-ray scattering investigations of conformations and organization of conducting polymer chains in various solvents}, url = {http://st23.statphys23.org/webservices/abstract/preview_pop.php?ID_PAPER=457}, year = 2007 }