Design of a Tunable Self‐Oscillating Polymer with Ureido and Ru(bpy)₃ Moieties

Abstract

An upper critical solution temperature (UCST)-type self-oscillating polymer was designed that exhibited rhythmic soluble-insoluble changes induced by the Belousov-Zhabotinsky (BZ) reaction. The target polymers were prepared by conjugating Ru(bpy) , a catalyst for the BZ reaction, to ureido-containing poly(allylamine-co-allylurea) (PAU) copolymers. The Ru(bpy) -conjugated PAUs exhibited a UCST-type phase-transition behavior, and the solubility of the polymer changed in response to the alternation in the valency of Ru(bpy) . The ureido content influences the temperature range of self-oscillation, and the oscillation occurred at higher temperatures than conventional LCST-type self-oscillating polymers. Furthermore, the self-oscillating behavior of the Ru-PAU could be regulated by addition of urea, which is a unique tuning strategy. We envision that novel self-oscillating polymers with widely tunable soluble-insoluble behaviors can be rationally designed based these UCST-type polymers.

Bioinspired Hydrogel Interferometer for Adaptive Coloration and Chemical Sensing

“…[7,8] The polymer network of hydrogels can be readily functionalized to respond to cues like temperature, pH, and a wide range of specific molecules. [9][10][11][12][13] Furthermore, most hydrogels are transparent and stretchable, as well as low cost and environmentally friendly. [14,15] Hydrogels have been used as stimuli-responsive components in structural color systems commonly in the form of photonic crystals.…”

Dissipative Self-Assembly of Dynamic Multicompartmentalized Microsystems with Light-Responsive Behaviors

“…52 Under irradiation with light, it can produce a redox-active photoexcited state ([Ru*(bpy) 3 ] 2+ ), which then reacts with an electron acceptor (e.g., oxygen) to generate an oxidized ground state ([Ru(bpy) 3 ] 3+ ) (Figures 3E and S20). 53,54 Since Article the oxidized Ru(bpy) 3 is more hydrophilic, 55,56 the PRAFT block becomes more hydrophilic when bathed in this light. Thus, some of the Ru(bpy) 3 segments inserted in the polymer phase of the microstructure could be released into the water phase; this results in phase separation and, consequently, the reorganization of the multicompartmental structure until a new equilibrium state is reached (Figure 3F).…”

Stimuli‐Responsive Ruthenium‐Containing Polymers

“…This greatly restricts the temperature range for achieving self‐oscillating behaviors because irreversible aggregation of LCST‐type RCPs may occur when the temperature is too high . A recently developed RCP was constructed on the basis of polymers with upper critical solution temperature (UCST) and the temperature range for self‐oscillating soluble–insoluble variation was expanded to 25–42.5 °C . The UCST‐type RCP was a random copolymer containing pendant ureido groups, amino groups, and the Ru(bpy) 3 moieties.…”