A comparative sonochemical reaction that is independent of the intensity of ultrasound and the geometry of the exposure apparatus.
Sonolysis of aqueous solutions of n-alkyl anionic surfactants results in the formation of secondary carbon-centered radicals (-*CH-). The yield of -*CH- depends on the bulk surfactant concentration up to a maximum attainable radical yield (the 'plateau yield') where an increasing surfactant concentration (below the critical micelle concentration) no longer affects the -*CH- yield. In an earlier study it was found that the ratio of -*CH- detected following sonolysis of aqueous solutions of sodium pentane sulfonate (SPSo) to that of sodium dodecyl sulfate (SDS) (i.e. CH(SPSo)/CH(SDS)) depended on the frequency of sonolysis, but was independent of the ultrasound intensity, at the plateau concentrations [J.Z. Sostaric, P. Riesz, Adsorption of surfactants at the gas/solution interface of cavitation bubbles: an ultrasound intensity-independent frequency effect in sonochemistry, J. Phys. Chem. B 106 (2002) 12537-12548]. In the current study, it was found that the CH(SPSo)/CH(SDS) ratio depended only on the ultrasound frequency and did not depend on the geometry of the ultrasound exposure apparatus considered.
Sostaric
Joe Z
JZ
Radiation Biology Branch, Center for Cancer Research, National Cancer Institute, National Institutes of Health, Bethesda, MD 20892, United States. sostaric.2@osu.edu
D017738:Alkanesulfonic Acids / Q000737:chemistry; D004139:Dinitrofluorobenzene / Q000031:analogs & derivatives / Q000737:chemistry; D004578:Electron Spin Resonance Spectroscopy; D005609:Free Radicals / Q000737:chemistry; D012967:Sodium Dodecyl Sulfate / Q000737:chemistry; D012996:Solutions; D013501:Surface-Active Agents / Q000737:chemistry* / Q000528:radiation effects; D014159:Transducers; D014465:Ultrasonics
D017738:Alkanesulfonic Acids; D005609:Free Radicals; D012996:Solutions; D013501:Surface-Active Agents; C045305:2,4-dinitrofluorobenzene sulfonic acid; C086946:1-pentanesulfonic acid; D012967:Sodium Dodecyl Sulfate; D004139:Dinitrofluorobenzene