27 Crawling and Bending Motions of Azobenzene Derivatives …
473
Fig. 27.9 Negative
phototactic behavior of
crystals under white light
irradiation. Optical
micrographs of crystals of 5
on a glass during irradiation
with solar-simulated light.
Images were captured after a
lapse of 0, 50, and 100 min.
The black dashed line
represents the initial position
of the crystals. Reproduced
from [18] by permission of
The Royal Society of
Chemistry
27.3 Photomechanical Bending in Polymer Film
with Photoswitchable Glass Transition Temperatures
As described earlier, the molecular design of introducing a methyl group at the 3position of azobenzene drastically enhanced the photo-induced phase transition properties in the compound 3. According to this molecular design strategy, a monomer (6),
having two methacrylate groups at the both termini, has been developed (Fig. 27.10),
and the copolymer consisting of this monomer exhibits photomechanical bending
Fig. 27.10 Molecular
structures of monomers.
Compounds 6 and 8 were
used for the synthesis of
polymer films having
photomechanical property