la063467h_si_002.pdf (170.04 kB)
Unique Molecular Orientation in a Smectic Liquid Crystalline Polymer Film Attained by Surface-Initiated Graft Polymerization
journal contribution
posted on 2007-04-10, 00:00 authored by Takayuki Uekusa, Shusaku Nagano, Takahiro SekiLiquid crystalline (LC) polymer brushes containing a mesogenic azobenzene (Az) moiety are synthesized on a
quartz or silicon substrate by surface-initiated atom transfer radical polymerization. The molecular orientation of the
Az units and the LC properties in the grafted chains are evaluated by UV−vis spectroscopy, polarized optical microscopy,
and grazing incidence X-ray diffraction measurements. The Az side chains of the grafted chains exhibited a smectic
LC phase in which the smectic layers are oriented perpendicular to the substrate with a parallel orientation of the
mesogens. In contrast, a spincast film of the identical LC polymer without grafting to the surface shows layer structures
parallel to the substrate. A drastic effect of tethering one end to the substrate on the LC orientation is demonstrated.