Quantification of hydroxyl radicals in photocatalysis and acoustic cavitation: Utility of coumarin as a chemical probe

Removal of single and dual ring thiophene’s from dodecane using cavitation based processes

“…The mechanism for water-based cavitation as proposed by Suryawanshi et al suggests sulphur oxidation through hydroxylation [13] , [14] . Hydroxyl radicals (OH•) may possess too short a life span (10 −9 s) [27] to significantly oxidise dual ring sulphur species in a heterogeneous set-up ( i.e . radical lifespan < OH• diffusion timescale and reaction with sulphur atoms).…”

Estimation of chemical and physical effects of cavitation by analysis of cavitating single bubble dynamics

“…Due to the extremely short lifespan of the hydroxyl radicals [9] and several uncertainties surrounding cavitation, model predictions could only be indirectly validated by inferring the associated decrease in the concentration of target chemicals. Often the non-selective nature of hydroxyl radicals led to the formation of a wide array of oxidation products especially for complex chemical species, further complicating the accurate characterisation of hydroxyl radicals [31] . Chemical reaction engineering incorporating the results from single bubble dynamics model have since been proposed to model the chemical effects of cavitation [28] , [29] , [30] .…”

Acoustic Analysis of Vortex-based Cavitation Devices: Inception and extent of cavitation

“…Various chemical methods (usually termed as dosimetry methods) use radical scavengers to quantify generated radicals (indirectly by analyzing products of reaction between selected scavenger and OH radicals) and therefore can be used for detecting cavitation. The commonly used scavengers for cavitation are salicylic acid, terephthalic acid, potassium iodide, and coumarin . Though dosimetry-based methods are useful for identifying the inception and extent of cavitation, these require expensive analytical equipment and are difficult to implement for online identification.…”

“…The commonly used scavengers for cavitation are salicylic acid, 15 terephthalic acid, 16 potassium iodide, 11 and coumarin. 17 Though dosimetry-based methods are useful for identifying the inception and extent of cavitation, these require expensive analytical equipment and are difficult to implement for online identification.…”