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论文类型：期刊论文

发表时间：2013-07-01

发表刊物：SURFACE AND INTERFACE ANALYSIS

收录刊物：SCIE、EI、Scopus

卷号：45

期号：7

页面范围：1152-1157

ISSN号：0142-2421

关键字：mass transfer; ionic surfactant; surface tension; zeta potential; Marangoni effect

摘要：This work investigated the effect of counter-ions and interfacial turbulence on oxygen transfer from gas to liquid phase containing ionic surfactant, and experiments were performed in a mechanically stirred reactor with flat gas-liquid interface. Counter-ions in terms of hydration ability and polarizability influence the interfacial coverage of ionic surfactants (i.e. cetytrimethylammonium bromide (CTAB) and cetytrimethylammonium chloride) with the same hydrocarbon chain length, producing hindrance but in different extent on oxygen transfer. The addition of electrolyte (NH4Br) substantially reduced the interfacial tension and surface charge of micelles (zeta potential) in CTAB system, and this salt effect greatly compressed interfacial double layer leading to gas transfer inhibition. The surface charge, aggregation number as well as stability of micelles formed above the critical micelle concentration could also alter interfacial configuration of surfactant layer reflected by gas absorption rate. Liquid turbulence was analyzed to decide the role of surfactant present in water on gas-liquid mass transfer, since Marangoni instability effect playing positive role should be taken into consideration under moderate liquid flow, while in turbulent system, contribution of Marangoni effect became overshadowed and consequently surfactant pose barrier' effect on gas transfer due to its surface active nature. Copyright (c) 2013 John Wiley & Sons, Ltd.