A comparative study of temperature dependence of induction time and oscillatory frequency in polymer‐immobilized and free catalyst Belousov‐Zhabotinsky reactions |
| |
| Authors: | Srinivasa R. Pullela Jingyi Shen Manuel Marquez Zhengdong Cheng |
| |
| Affiliation: | 1. Artie McFerrin Department of Chemical Engineering, Texas A&M University, College Station, Texas 77843;2. Harrington Department of Bioengineering, Arizona State University, Tempe, Arizona 85287;3. NIST Center for Theoretical and Computational Nanosciences, Gaithersburg, Maryland 20899;4. Center for Integrated Nanotechnologies, Los Alamos National Laboratory, Los Alamos, New Mexico 87545 |
| |
| Abstract: | Environment‐sensitive poly(N‐isopropylacrylamide) (PNIPAM) microgel particles with covalently bonded ruthenium(4‐vinyl‐4′‐methyl‐2,2′‐bipyridine) bis (2,2′‐bipyridine) [Ru(vmbipy)(bipy)2] display periodic size changes when placed in Belousov‐Zhabotinsky (BZ) reaction substrates. The temperature dependency of the induction time and oscillatory frequency of the BZ reaction in this polymer‐immobilized catalyst system were compared to the bulk BZ reaction with the catalyst in the solution phase. Prolonged induction times are observed for the immobilized catalyst, compared with free catalyst, while little difference is observed on the oscillation frequency. The Arrhenius frequency factor calculated using the induction time for the immobilized catalyst BZ reaction is about seven times smaller than that for the free catalyst Ru(bipy) case. On the other hand, the Arrhenius frequency factors calculated using the oscillatory frequency are almost the same, showing similar reaction kinetics during the BZ oscillations. The tunability of the induction time using a polymer matrix, as we observed here, while maintaining similar oscillatory behavior, should provide a new dimension to control the self‐assembling of BZ active particles. © 2009 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys 47: 847–854, 2009 |
| |
| Keywords: | activation energy Belousov‐Zhabotinsky reaction catalysts induction time microgels |
|
|
