Orientation control of a synthetic columnar perfluorinated supramolecular dendrimer: Surface anchoring and magnetic-field induced alignments

• Published in: Physica. B, Condensed matter Vol. 385; pp. 801 - 803
• Main Authors: Ki Yoon, Dong, Rim Lee, Su, Ho Kim, Yun, Seong, Baek-Seok, Soo Han, Young, Jung, Hee-Tae
• Format: Journal Article
• Language: English
• Published: Elsevier B.V 01.11.2006
• Subjects: Magnetic field; Orientation; Perfluorinated supramolecule; Small-angle neutron scattering; Surface anchoring; Surface anchoring; Small-angle neutron scattering; Perfluorinated supramolecule; Orientation; Magnetic field
• ISSN: 0921-4526; 1873-2135
• DOI: 10.1016/j.physb.2006.06.089

Orientation ordering of a synthetic perfluorinated supramolecule containing a hydrophilic core group and perfluorinated tails is strongly affected by the functionality, molecular shape, surface anchoring and magnetic field. Small-angle neutron scattering (SANS), synchrotron X-ray diffraction, polarized light microscopy (PLM) and transmission electron microscopy (TEM) results show that the molecule exhibits hexagonal columnar mesophase upon cooling from isotropic phase. The orientation of the columns was controlled by surface anchoring; the columnar axes were perpendicular to the hydrophobic carbon substrates, while planar alignment is favored on hydrophilic surfaces. Furthermore, the columnar domains align with the magnetic field lines, which is due to diamagnetism of these fan-shaped molecules containing aromatic rings. We show that the magnetic-induced alignment is much effective for the large-scale control of the orientation of the perfluorinated columnar mesophase.