A new approach for characterization of hydrophobization mechanisms of surfactants on muscovite surface
A new approach for characterization of hydrophobization mechanisms of surfactants on muscovite surface
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DOI：
10.1016/j.seppur.2018.09.023
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发表时间：
2019-01-31
影响因子：
8.6
通讯作者：
Hu, Yuehua
中科院分区：
文献类型：
--
作者：
Jiang, Hao;Gao, Ya;Hu, Yuehua
用动态接触角分析法研究了单一表面活性剂和混合表面活性剂在白云母表面的疏水机理。采用阴离子油酸钠(NaOL)、阳离子DDA(十二胺)和DDA/NaOL复合表面活性剂对白云母表面进行疏水处理。除了动态接触角分析外，还进行了AFM和浮选试验，以获得白云母的润湿性、气泡对白云母表面的附着能力以及单一和混合的DDA/NaOL表面活性剂在白云母表面的吸附情况。从浮选结果看，当DDA/NaOL的质量比为1：3，浓度为2×10~(-4)mol/L时，其回收率最高(~gt；90%)，动态接触角测试表明，DDA/NaOL的接触角更大，气泡更容易附着，这与浮选结果一致。AFM成像表明，与单一捕收剂相比，复合表面活性剂以块状形式均匀吸附在白云母表面，形成紧密的多层吸附。在15 nm附近，DDA/NaOL混合溶液的吸引力大于单一DDA溶液的吸引力，单一NaOL溶液有较远距离的斥力。
A new approach 'dynamic contact angle analysis' has been used in the present investigation to characterize the hydrophobization mechanisms of single and mixed surfactants on muscovite surface. The hydrophobization of muscovite surface was achieved by anionic NaOL (sodium oleate), cationic DDA (dodecylamine) and combined DDA/NaOL surfactants. Besides dynamic contact angle analysis, AFM and flotation tests were carried out to gain detail information about the wettability of muscovite, adhesion ability of bubbles towards muscovite surface and adsorption of single and mixed DDA/NaOL surfactants on the muscovite surface. From flotation results, the highest recovery ( > 90%) was obtained by the mixed DDA/NaOL when they were used at a ratio of 1:3 and the concentration of 2 x 10(-4) mol/L. The dynamic contact angle tests showed that the angles achieved by DDA/ NaOL were bigger and the bubbles were adhered more easily, which are in agreement with the flotation results. AFM imaging indicated that, as compared to single collectors, the combined surfactants adsorbed uniformly on the muscovite surface as bulks and formed a tight adsorption multilayer. The attraction in mixed DDA/NaOL was stronger than that in single DDA with the same jump-in distance at around 15 nm and the long-range repulsion was observed in single NaOL.