Direct Observation of Periodic Swelling and Collapse of Polymer Chain Induced by the Belousov Zhabotinsky Reaction

By utilizing a quartz crystal microbalance with dissipation (QCM-D), we directly observed the self-oscillating behavior of a polymer chain induced by the Belousov Zhabotinsky (BZ) reaction. We succeeded in measuring selfoscillations of the resonance frequency (Delta f) and dissipation (Delta D), which originate in the self-oscillating behavior of the polymer chain on a gold surface induced by the BZ reaction. We synthesized a self-oscillating polymer chain with Ru as the catalyst of the BZ reaction and a chemical adsorption site, so as to directly observe its periodic swelling and collapse on the gold surface. Distinct self-oscillation of Delta D synchronized with the selfoscillation Lf was observed. The period of the if self-oscillation was about 400 s, and the induction time was about 6.5 h. In QCM-D measurements, we found that the peaks of Delta f and Delta D oscillations did not coincide in time because the state of the Gaussian chain did not coincide with the maximum value of Delta f. Moreover, examination of the relationship between Delta f and Delta D revealed that their oscillatory waveforms were identical in frequency but differed in phase and amplitude.