Preparation and characterization of poly(NIPAAm-co-AMPS-co-Fe(phen)3) self-oscillating copolymers

A novel self-oscillating copolymer was prepared by utilizing Fe(phen) 3 as the catalyst of the Belousov – Zhabotinsky (BZ) reaction. In this study, 2-acrylamido-2-methylpropane sulfonic acid (AMPS) was newly introduced into the copolymer of N -isopropylacrylamide (NIPAAm) and Fe(phen) 3 as the H + providing agent for the BZ reaction. The results indicated that the copolymer solution underwent soluble–insoluble self-oscillation only in malonic acid (MA) and potassium bromate(KBrO 3 ) mixture solution, and the amplitudes were much bigger than those of poly(NIPAAm- co -Fe(phen) 3 ). That is to say, the novel copolymer succeeds in self-oscillating under acid-free conditions. Moreover, the oscillating characteristics were closely related to the content of AMPS in the copolymer.