RSUSSH 2020
IN20-111 Dynamics of oscillating Belousov-Zhabotinsky reaction in the presence of ethanol
Presenter: Ponrawit Sirisurapon
King Mongkut's University of Technology North Bangkok, Thailand
Abstract
We present a study of the effect of ethanol on the dynamics of the oscillating ferroin-catalyzed Belousov-Zhabotinsky (BZ) reaction, an oxidation of malonic acid by an acidified bromate. The color of the well-stirred BZ solution alternately changes between red and blue, corresponding to the reduced (Fe(o-phen)32+) and oxidized (Fe(o-phen)33+) states of the catalyst, respectively. The changes in color occur with a specific period. The dynamics of the oscillation are accelerated when small portion of ethanol is added. The period and amplitude of the oscillation decrease when the concentration of ethanol is increased. When the ethanol concentration reaches a threshold, the oscillation is stopped, and the solution stays blue, which correspond to the oxidized states of the catalyst. Unlike the conventional BZ reaction, NaBr is not added in our BZ preparation so the production of toxic bromine vapors is avoided. Therefore, the presented BZ reaction might serve as a quick and safe system for measuring the ethanol concentration in, e.g., beverage and food industries.
Citation format:
Sirisurapon, P., Luengviriya, C., & Luengviriya, J.. (2020). Dynamics of oscillating Belousov-Zhabotinsky reaction in the presence of ethanol. Proceeding in RSU International Research Conference, May 1, 2020. Pathum Thani, Thailand.QUESTIONS & ANSWERS
1. what is the further application of your research.
2.
What is the best percetage of ethanol for BZ reaction?
1) Why do you need to convert the coloured image to gray scale? I think you can analyze the image using one of the three colours (RGB).
2) You can have both amplitude change and oscillation frequency change to detect the effect of ethanol in BZ reaction. Which parameter will you prefer to use and why?
Dear รศ.ปัญญา มณีจักร์
Thank you for the question. The effect of ethanol on the BZ reaction can be utilized to measure the amount of ethanol in different industries. It has been demonstrated for measuring the percentage of ethanol in alcoholic beverages and gasohol. Here, we present a study on the effect of ethanol on a BZ recipe which can be prepared safer and quicker.
Dear ASSISTANT PROFESSOR DR. DUANGRUTHAI SRIDAENG
Thank you for the quesiion. Ethanol is not a component of the BZ reaction but it is added to perturb the system. The unperturbed reaction oscillates last longer. However, the study of the effect of ethanol on the BZ oscillation provides a basic knowledge for further applications, e.g., the measurement of the percentage of ethanol in alcoholic beverages and gasohol.
Dear DR. SUEJIT PECHPRASARN
1) Thank you for the questions and thank you for the good idea of using one of the three colours RGB. It might also work well. Anyway, it needs to be carefully tested which colour is the best indicator of the BZ oscillation.
2) Ethanol results in changes of both the period and amplitude of the BZ oscillation. The amplitude is the difference between the highest and the lowest of gray levels in one oscillation so that it might depend on the light intensity used to illuminate the BZ reaction. In contrast, the period is the time interval and it is independent on the illumination. Therefore, the period is more suitable variable for describing the BZ oscillations, especially for the results from different illumination.