Dewetting kinetics on silica substrates - three-phase contact expansion measurements for aqueous dodecylammonium chloride films
Dewetting kinetics on silica substrates - three-phase contact expansion measurements for aqueous dodecylammonium chloride films
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DOI：
10.1016/j.mineng.2005.09.026
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发表时间：
2006-05
影响因子：
4.8
通讯作者：
Anh V. Nguyen;L. Alexandrova;L. Grigorov;G. Jameson
中科院分区：
文献类型：
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作者：
Anh V. Nguyen;L. Alexandrova;L. Grigorov;G. Jameson
采用Scheludko细胞和数字高速视频显微镜研究了十二烷基氯化铵（阳离子表面活性剂）溶液中小气液界面与二氧化硅（水中带负电荷）平面之间的脱湿动力学。气液界面在电池的小硅胶毛细管底部形成，然后向硅胶平面移动。在界面间液膜破裂后，利用1000帧/秒的数字高速视频显微镜系统观察并记录了气-液-固三相接触线（TPC）的膨胀。采用垂滴法测定了表面活性剂溶液的表面张力。平衡接触角采用Scheludko-Minings法测定。TPC半径被确定为时间的函数，并与现有的流体动力学和分子动力学模型进行比较。TPC线运动的分子动力学模型很好地描述了实验数据。在三相接触膨胀开始后的短时间内，水动力模型与实验数据是一致的。建立了浮选过程中TPC线膨胀时间预测的简化模型。
The dewetting kinetics between a small air–liquid interface and a silica (negatively charged in water) planar surface in solutions of dodecylammonium chloride (cationic surfactant) has been investigated using the Scheludko cell and digital high-speed video microscopy. The gas–liquid interface was created at the bottom of a small silica capillary of the cell and then was moved towards the silica planar surface. After the rupture of the liquid films between the interfaces, the expansion of the gas–liquid–solid three-phase contact (TPC) line was observed and recorded using a digital high-speed video microscope system, operating at 1000 frames/s. The surface tension of the surfactant solution was measured using the pendant drop technique. The equilibrium contact angle was measured using the Scheludko–Minings method with a silica micro-sphere. The TPC radius was determined as a function of time and compared against the available hydrodynamic and molecular-kinetic models. The experimental data are described very well by the molecular-kinetic model for the TPC line motion. The hydrodynamic model is in agreement with the experimental data only for a short time after inception of the three-phase contact expansion. A simplified model was developed for predicting the time of the TPC line expansion in flotation.