Abstract:
The use of a new block copolymer made up of poly(azobenzene methacrylate) (PMAzo) and
poly(3-O-4-vinylbenzoyl- D -glucopyranose) (PBG) is described for the solubilization of waterinsoluble
dyes such as Nile Red in aqueous solutions. This polymer, which is abbreviated as
PMAzo -b- PBG, self-assembles into spherical aggregates in water as confi rmed by atomic force
microscopy. UV irradiation of the aqueous polymer solution
destabilizes the aggregates brought about as a result of the
trans–cis isomerization of the MAzo units. Dissociated aggregates
reunite to form tubular aggregates when the solution
is irradiated with 450 nm light. Nile Red, which is a hydrophobic
dye, can be incorporated into these aggregates and
subsequently released using UV light. The encapsulation,
release, and re-encapsulation of Nile Red are studied using
fl uorescence spectroscopy.
