A GROWING DROP TECHNIQUE FOR MEASURING DYNAMIC INTERFACIAL-TENSION
A GROWING DROP TECHNIQUE FOR MEASURING DYNAMIC INTERFACIAL-TENSION
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DOI：
10.1006/jcis.1993.1415
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发表时间：
1993-10-15
影响因子：
9.9
通讯作者：
RADKE, CJ
中科院分区：
文献类型：
--
作者：
MACLEOD, CA;RADKE, CJ
描述了一种新的生长液滴技术，用于测量由于表面活性溶质吸附而产生的动态界面张力。该方法将膨胀液滴的瞬时压力和尺寸与界面张力联系起来，适用于测量较宽时间范围内的液/气和液/液张力，目前测量范围从10ms到几个小时。在不含表面活性剂的水/空气和水/辛醇界面上不断增长的液滴测量产生的恒定张力等于它们的已知文献值。对于含有表面活性剂的液滴，增长液滴技术捕捉单个界面的实际瞬时张力演变，而不是像经典的最大液滴压力和液滴体积张力测量那样的间隔时间。0.25m1-正十二醇溶液/空气和0.02 kg/m3 Triton X-100水溶液/十二烷界面的动态张力表现出非单调行为，表明表面活性剂的迁移相对于施加的界面膨胀速率来说是缓慢的。纯化和新鲜的6毫升十二烷基硫酸钠(十二烷基硫酸钠)溶液/空气界面的动态张力仅呈单调下降，表明相对于施加的膨胀速率，表面活性物质的传输速度很快。相反，自然含有微量十二醇杂质的陈化十二烷醇溶液表现出动态张力，反映了快速平衡的十二醇和缓慢吸附的十二醇的叠加。
A novel, growing drop technique is described for measuring dynamic interfacial tension due to sorption of surface-active solutes. The proposed method relates the instantaneous pressure and size of expanding liquid drops to the interfacial tension and is useful for measuring both liquid/gas and liquid/liquid tensions over a wide range of time scales, currently from 10 ms to several hours. Growing drop measurements on surfactant-free water/ air and water/octanol interfaces yield constant tensions equal to their known literature values. For surfactant-laden, liquid drops, the growing drop technique captures the actual transient tension evolution of a single interface, rather than interval times as with the classic maximum-drop-pressure and drop-volume tension measurements. Dynamic tensions measured for 0.25 mMaqueous 1-decanol solution/air and 0.02 kg/m3aqueous Triton X-100 solution/dodecane interfaces show nonmonotonic behavior, indicating slow surfactant transport relative to the imposed rates of interfacial dilatation. The dynamic tension of a purified and fresh 6 mMaqueous sodium dodecyl sulfate (SDS) solution/air interface shows only a monotonic decrease, indicating rapid surfactant transport relative to the imposed rates of dilatation. Conversely, an aged SDS solution, naturally containing trace dodecanol impurities, exhibits dynamic tensions which reflect a superposition of the rapidly equilibrating SDS and the slowly adsorbing dodecanol.