Effect of dimethyl sulfoxide addition on ultrasonic degradation of methylene blue

Abstract

The ultrasonic degradation of methylene blue was carried out in the absence and presence of dimethyl sulfoxide (DMSO) as a radical scavenger for various frequencies, and the effects of DMSO addition on the degradation rate constant estimated by assuming first-order kinetics were investigated. The degradation reaction rate decreased with DMSO addition, and hydroxyl radicals were observed to play important roles in the degradation of methylene blue. However, the degradation reaction did not stop with DMSO addition, and the degradation rate constant in the presence of DMSO was not affected by ultrasonic frequency.

Sonoluminescence and acoustic cavitation

“…The extraordinary high temperature and pressures together with the heating and cooling rates above 10 10 K=s at bubble collapse provide a high-energy reaction field. Nowadays, the area of sonochemistry extends to biological, [13][14][15][16] medical, [17][18][19] environmental, [20][21][22][23][24][25][26][27][28][29] food technologies, 30) and others.…”

Synthesis of Pd/WO3 and Pt/WO3 composite particles by sonochemical reactions and evaluation of their photocatalytic performance

“…When these cavitation bubbles expand and contract repeatedly and then collapse suddenly, hot spots of high temperature and high pressure exceeding several thousand degrees Celsius and more than a thousand atmospheres are generated locally, thereby causing chemical and physical effects. 21,22) Research is being conducted in various fields, including organic and inorganic material synthesis, [23][24][25][26] environmental conservation, 27,28) waste treatment, [29][30][31][32] and disease treatment, 33) by applying these cavitation effects induced by ultrasound (US) irradiation in liquids. For example, when an aqueous solution containing organic compounds is irradiated with US, the H 2 O molecules in the solvent are decomposed into OH radicals and H radicals,…”

Spatial distribution measurement of acoustic cavitation bubbles by laser backscattering with confocal optics

“…The temperature and pressure of the inner gas reach 5,000 K and 100 MPa in the state with greatest shrinkage because the shrinkage stage of the bubble is nearly adiabatic. The chemical effects accompanying the high-temperature and high-pressure environment are applicable to the chemical processes [1,2].…”