jp7b00901_si_004.mpg (1.4 MB)
Photocontrol of Clustering, Retaining, and Releasing of Microbeads Concomitant with Phototransformation of Supramolecular Architecture of Amphiphilic Diarylethene
media
posted on 2017-03-27, 00:00 authored by Akira Sakaguchi, Kenji Higashiguchi, Hajime Yotsuji, Kenji MatsudaPhotoinduced clustering of polystyrene
microbeads and photocontrol
of their diffusion was achieved in water with the assistance of photoinduced
transformation of supramolecular architecture of amphiphilic diarylethene
between sphere and fiber states. When a suspension of polystyrene
beads containing the sphere state of diarylethene was UV-irradiated
from beneath, clustering of the polystyrene beads by thermal convection
was observed. The velocity of clustering was dependent on the amount
of photogenerated nanofibers that determines the viscosity of the
water. Diffusion of the clustered polymer beads was suppressed by
the surrounding fibers, but was restored to regular Brownian motion
upon irradiation with visible light. It was suggested that the diffusion
of the microbeads was controlled by the transformation of aggregates
between the more viscous fiber state and the less viscous sphere state.
These results provide new insight into the photocontrol of particle
motion in fluidic media.