This title appears in the Scientific Report :
2003
Please use the identifier:
http://hdl.handle.net/2128/1322 in citations.
Please use the identifier: http://dx.doi.org/10.1021/jp035259t in citations.
X-ray Diffraction Studies of Multiple Orientation in Poly(9,9-bis(2-ethylhexyl)fluorene-2,7-diyl) Thin Films
X-ray Diffraction Studies of Multiple Orientation in Poly(9,9-bis(2-ethylhexyl)fluorene-2,7-diyl) Thin Films
The structural investigation of poly(9,9-bis(2-ethylhexyl)fluorene-2,7-diyl) (PF2/6) in aligned thin films is presented. Formation of a thickness dependent triaxial texturing is identified in thermotropically aligned films. X-ray reflectivity measurements reveal good macroscopic quality, and polariz...
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Personal Name(s): | Knaapila, M. |
---|---|
Lyons, B. P. / Kisko, K. / Foreman, J. P. / Vainio, U. / Mihaylova, M. / Seeck, O. / Pålsson, L.-O. / Serimaa, R. / Torkkeli, M. / Monkman, A. P. | |
Contributing Institute: |
Streumethoden; IFF-STM |
Published in: |
The @journal of physical chemistry |
Imprint: |
Washington, DC
Soc.
2003
|
Physical Description: |
12425 - 12430 |
DOI: |
10.1021/jp035259t |
Document Type: |
Journal Article |
Research Program: |
Kondensierte Materie |
Series Title: |
Journal of Physical Chemistry B
107 |
Subject (ZB): | |
Link: |
Get full text OpenAccess |
Publikationsportal JuSER |
Please use the identifier: http://dx.doi.org/10.1021/jp035259t in citations.
The structural investigation of poly(9,9-bis(2-ethylhexyl)fluorene-2,7-diyl) (PF2/6) in aligned thin films is presented. Formation of a thickness dependent triaxial texturing is identified in thermotropically aligned films. X-ray reflectivity measurements reveal good macroscopic quality, and polarized photoluminescence and dichroic ratios in absorption indicate clear axial alignment. Grazing-incidence X-ray diffraction shows axially aligned mesomorphic structure with a distinct arrangement of helices and large correlation lengths, indicating a high local lateral order. Theoretical models produced using molecular mechanics methods suggest 5/2-helicity. The polymer chains are parallel to the substrate in the c direction. In particular, the hexagonal-like cells are flattened in the direction of the surface normal and reveal two kinds of coexistent crystallites, a multiple orientation where the greater proportion of the crystallites have one crystal axis a perpendicular to the substrate surface, whereas a smaller proportion is aligned with the crystal axis a parallel to the surface. In thinner films the former class of orientation is usually dominant, while the proportion of the parallel orientation type increases with prolonged annealing. |