Sostaric Joe Z
Radiation Biology Branch, Center for Cancer Research, National Cancer Institute, National Institutes of Health, Bethesda, MD 20892, United States.
Ultrason Sonochem. 2008 Sep;15(6):1043-8. doi: 10.1016/j.ultsonch.2008.03.007. Epub 2008 Mar 29.
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.
正烷基阴离子表面活性剂水溶液的声解作用会导致仲碳中心自由基（-*CH-）的形成。-*CH-的产率取决于表面活性剂的整体浓度，直至达到最大可达到的自由基产率（“平台产率”），此时表面活性剂浓度增加（低于临界胶束浓度）不再影响-*CH-的产率。在早期的一项研究中发现，在平台浓度下，戊烷磺酸钠（SPSo）水溶液声解后检测到的-*CH-与十二烷基硫酸钠（SDS）的-*CH-的比率（即CH(SPSo)/CH(SDS)）取决于声解频率，但与超声强度无关[J.Z.索斯塔里克，P.里斯，表面活性剂在空化气泡气/液界面的吸附：声化学中与超声强度无关的频率效应，《物理化学杂志》B 106（2002年）12537 - 12548]。在当前研究中发现，CH(SPSo)/CH(SDS)比率仅取决于超声频率，而与所考虑的超声暴露装置的几何形状无关。
