Reactions Villermaux-Dushman

Villermaux-Dushman Reaction This method, also referred to as iodide-iodate reaction, is based on a system of two parallel competing reactions [64] ... 

On the basis of the extensive experimental results obtained for the Villermaux-Dushman reaction, Commenge and Falk [22] elaborated a protocol for estimating the characteristic mixing time in microstructured devices. They used the lEM... 

Ratio of the quantity of acid moles consumed by Villermaux-Dushman reaction, value of Yat complete segregation ... 

The present chapter aims to be complementary to the studies and reviews already published to present theoretical basis elements for the understanding of mixing principles in laminar flows, mainly developed in micromixers. Among different characterization techniques of mixing efficiency, this chapter more specifically focuses on the chemical test method, called the Villermaux-Dushman reaction, that we have developed over many years and which is named in memory of Professor Jacques Villermaux. It will be shown how to obtain the mixing time and how to relate it to operating parameters such as the Reynolds number of the flow and the specific power dissipation per unit mass of fluid. A non-exhaustive comparison of several micromixers will be presented. 

There are numerous experimental studies on micromixer characterization and, among the different methods, the well-known Villermaux-Dushman reaction is one of the most used. A few papers have proposed the comparison of the mixers performances thanks to these chemical reactions. As explained previously, mixing quality is a relative concept with regard to chemical reaction and chemical test methods... 

Several studies have been considered, particularly those with no experimental errors in the use of the Villermaux-Dushman reaction protocol and with providing important information such as mixer geometry (charmel sizes, internal volume), flow rate and pressure drop. The following studies have been analyzed ... 

Of course, the mixing quality is a very important parameter for microstructured liquid-liquid reactors. There are some approaches to characterize the mixing quality of such devices. Up to now, the most important method for characterizing the mixing quaUty of micromixers is the Villermaux-Dushman reaction [5]. This is a two-reaction system with a fast and a very fast reaction, which has been adapted for use with microstructured mixers. The better the mixing, the less product of the slower reaction is formed. This product (I3 ) is easily detected by UV spectroscopy. 

Reaction System The iodide-iodate reaction (Villermaux-Dushman reaction) is based on a system of two competing parallel reactions as described above (Equation 2.60). The neutralization reaction ri is very fast and can be considered as instantaneous. The redox reaction T2 is fast. By adding an add to a mixture of iodide and iodate in a H2B03 /H3B03 buffer, iodine will be formed only if a local proton excess exists. Therefore, the amount of iodine formed can be used to characterize the mixing time in the reactor. Best results are obtained if the mixing time is on the same order as the reaction time (t = tr2). 

Villermaux-Dushman -instantaneous neutralization and rapid redox reactions PDMS MSR Matsuyama et al. [78]... 

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