Study of Phase Transitions in Supramolecular Systems Incorporated with Active Elements

点击翻译按钮获取中文摘要

We made various supramolecules based on surfactants and investigated its thermal properties in order to clarify the conditions to immobilize various active elements into supramolecules. Furthermore, for the purpose to construct the supramolecular system with the structure similar to biological supramolecules, we investigated the thermal properties of supramolecules of alpha-elastin originated from the elastic fibrous protein elastin. We determined the coexistence curve and the spinodal curve of the binary mixture, water-alpha-elastin. We concluded that critical concentration fluctuations play a important role in supramolecular ordering of alpha-elastin over a macroscopic scale. On the basis of these results, we incorporated Belousov-Zabotinskii (BZ) reaction as an active element into supramolecules. Various attractive phenomena in entrainment of a chemical oscillation were observed. These systems are sensitive to extemal perturbations, but lack stability a little.In order to improve the ability to incorporate BZ reaction, we used the cation exchange bead and silica gel bead of 100-500 mum in size. Theses beads could be regarded as chemical oscillators by micro-optically detecting the chemical waves localized on beads. Our attention is particularly focused on the coupling between two beads in no contact with each other. The results are summarized follows : (1) the synchronized frequency is higher than the natural frequency of fast oscillator, (2) there are coupled states with various frequency ratios depending on the ratio of natural frequency and (3) chaotic behaviors appear at the boundary between stable coupled states. Furthermore, a randomness was found to be induced on a limit cycle by external perturbations with a laser beam. Such random behaviors are probably chaotic, which depended on the phase of oscillator at the beginning of the perturbation.