Adiabatic implosion

We cannot mention here how the various parameters frequencies, power, gas under which the sonication takes place, pressure of the gas, etc. affect the sonochemical yield and rate. We will just mention one important parameter, the temperature. The equation of an adiabatic implosion is... 

Much of the work done in recent years on polymer mechanochemistry has made use of the high elongational strain rates observed around collapsing cavitation bubbles in sonicated solutions, as outlined in the section on mechanoluminescence [27]. In addition to the distinctive features of sonochemically-induced mechanical reactivity described above, further attention needs to be paid to the sonication conditions in the case of mechanochemical catalysis, because catalyst lifetime and turnover number are reduced by sonochemical byproducts. Implosion of cavitation bubbles is essentially an adiabatic process which leads to formation of local hotspots within the bubble in which temperature and pressure increases drastically. The content of cavitation bubbles pyrolyses under these extreme conditions and results in formation of reactive species, such as radicals and persistent secondary byproducts acidic byproducts may also form from the degradation of the substrates [75]. Chemical impurities deactivate the reactive catalyst partially if not completely. Recent studies in our group have shown that heat capacity of gas... 

When bubbles reach the resonance size range, they grow to a maximum size within one acoustic cycle and implode. Bubble implosion/collapse is a near adiabatic process. In simple thermodynamic terms, the volume of the bubble decreases instantaneously resulting in the generation of extreme heat within the bubble. Theoretical estimates predict greater than 15,000 K [44, 45]. However, experimental methods estimate about 1000-5000 K [46-50]. A number of techniques have been used to calculate the bubble temperatures. First, the bubble temperature could be theoretically calculated using Eq. (1.4). 

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