Diagnosing the plasma formed during acoustic cavitation in [BEPip][NTf₂] ionic liquid

Abstract

What do rovibronic temperatures tell us? Example of the sonolysis of [BePip][NTf2] ionic liquid.

Sonoluminescence Spectra in the First Tens of Seconds of Sonolysis of [BEPip][NTf2], at 20 kHz under Ar

“…They observed for [C 8 mpyrr][NTf 2 ] that increasing the sonication time led to a decrease in the intensities of the SL continuum and lines. This decrease was attributed by Pflieger et al [10] to the progressive poisoning of the plasma inside the bubbles by the sonolysis degradation products. This latter work presented the time evolution with a one-minute resolution of SL spectra of a very dry [BEPip][NTf 2 ] ionic liquid (Figure 1) under Ar and underlined that degradation of the IL had already started in the first minute of sonication.…”

“…The IL [BEPip][NTf 2 ] was prepared and characterized as described previously [10]. It was then used in its water saturated form or dried under a vacuum and stirred at 80 • C for one and a half days to keep the water content as low as possible.…”

A correlation between cavitation bubble temperature, sonoluminescence and interfacial chemistry – A minireview

“…Didenko et al [56] estimated T max of about 15,000 K in a moving single bubble case and suggested that the T max reached could be 30,000 K in stable single bubble systems. Pflieger et al [57] used molecular emissions observed in an ionic liquid and estimated rotational and vibrational temperatures in the range 4000–6000 K.…”

Multibubble Sonoluminescence from a Theoretical Perspective

“…From the spectra of MBSL, various information on the physical and chemical nature of the bubble interior can be obtained such as the bubble temperature and pressure, chemical species present inside a bubble, etc. [ 7 , 8 , 46 , 55 , 98 , 99 , 100 , 101 , 102 , 103 ]…”