posted on 2021-01-11, 07:45authored byYuntian Yang, Qingqing Han, Yi-rong Pei, Shengsheng Yu, Zhegang Huang, Long Yi Jin
Self-assembled
nanomaterials composed of amphiphilic oligomers
with functional groups have been applied in the fields of biomimetic
chemistry and on-demand delivery systems. Herein, we report the assembly
behavior and unique properties of an emergent n-shaped rod–coil
molecule containing an azobenzene (AZO) group upon application of
an external stimulus (thermal, UV light). The n-shaped amphiphilic
molecules comprising an aromatic segment based on anthracene, phenyl
linked with azobenzene groups, and hydrophilic oligoether (chiral)
segments self-assemble into large strip-like sheets and perforated-nanocage
fragments in an aqueous environment, depending on the flexible oligoether
chains. Interestingly, the nano-objects formed in aqueous solution
undergo a morphological transition from sheets and nanocages to small
one-dimensional nanofibers. These molecules exhibit reversible photo-
and thermal-responsiveness, accompanied by a change in the supramolecular
chirality caused by the conformational transitions of the rod backbone.
The architecture of n-shaped amphiphilic molecules with a photosensitive
group makes them ideal candidates for intelligent materials for applications
in advanced materials science.