2009 年 34 巻 3 号 p. 465-467
Different from simple stimuli-sensitive microgels, herein, we report “self-oscillating” microgel. This microgel shows an autonomic and periodical swelling/deswelling oscillation that is synchronized with redox oscillation of the Belousov-Zhabotinsky (BZ) reaction. The cross-linked microgels were synthesized by the copolymerization of N-isopropylacrylamide (NIPAm) with ruthenium tris(2,2′-bipyridine) [Ru(bpy)3] as a catalyst for the BZ reaction by surfactant-free aqueous precipitation polymerization. The self-oscillation of the microgels was detected by changes in optical transmittance. The microgels showed not only the swelling/deswelling oscillation, which is synchronized with the redox oscillation of the Ru(bpy)3 complex immobilized in the microgels, but also flocculating/dispersing oscillation around the phase transition temperature of the microgels, with a remarkable change in optical transmittance.
