Vapor-Triggered Mechanical Actuation in Polymer Composite Films Based on Crystalline Organic Cages
byAlimi, L.O., Fang, F., Moosa, B., Ding, Y., Khashab, N. M.
Year:2022DOI:10.1002/anie.202212596
Bibliography
138. Alimi, L.O.; Fang, F.; Moosa, B.; Ding, Y.; Khashab, N..M., Vapor-Triggered Mechanical Actuation in Polymer Composite Films Based on Crystalline Organic Cages. Angew. Chem. Int. Ed.2022
Abstract
The fabrication of smart materials, which can efficiently mimic
biological systems through the introduction of soft components, is of
great importance in the emerging fields of sensors and actuators.
However, fabricating soft and stimuli responsive materials with a
defined mechanism to tune and precisely control the triggered response
has been considerably challenging. Herein, a smart composite film that
can mechanically respond to vapors trigger then readily restores its
original shape upon the removal of the stimuli is reported. This
actuating composite film was prepared by mixing the highly elastic poly
(vinylidene fluoride) ( PVDF ) polymer with the flexible and
crystalline organic cages ( Oba-cage ) at variable concentrations. The
mechanism of the mechanical response could be accurately recorded due
to the ordered cage crystals. Interestingly, 50 wt% of the Oba-cage in
the polymer matrix (i. e. 1:1 weight ratio) shows a very fast and
reversible vapor triggered stretching and bending in less than 2
seconds. The adsorption and desorption of the organic vapors
(tetrahydropyran, tetrahydrofuran, dioxane, and ethyl acetate) by the
Oba-cage_50@PVDF film can be repeated many times with no noticeable
loss in performance. This work highlights the importance of designing
smart materials at the molecular level to precisely control the response
or reaction upon the introduction of different triggers, which can
ultimately lead to a monumental leap in the field of soft robotics.