Stability of Ionic Magnetic Surfactants in Aqueous Solutions: Measurement Techniques and Impact on Magnetic Processes
Stability of Ionic Magnetic Surfactants in Aqueous Solutions: Measurement Techniques and Impact on Magnetic Processes
复制标题
离子磁性表面活性剂在水溶液中的稳定性：测量技术及其对磁性过程的影响
DOI：
10.1021/acs.langmuir.9b02189
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发表时间：
2019
期刊：
影响因子：
3.9
通讯作者：
Scovazzo, Paul
中科院分区：
文献类型：
--
作者：
Fortenberry, Alex;Reed, Derek;Smith, Adam;Scovazzo, Paul
预测磁性表面活性剂在磁场中的行为对于设计磁驱动过程（如化学分离或表面张力调节）至关重要。磁场改变磁性表面活性剂溶液的界面性质的能力可能取决于表面活性剂分子的磁性和表面活性剂部分之间的缔合强度。这项研究表明，磁性表面活性剂在水性环境中的稳定性取决于含有顺磁性离子的复合物的类型，这些发现为磁性表面活性剂在水性介质中的应用设计提供了有价值的见解。研究的表面活性剂是离子型表面活性剂，其中含有顺磁性抗衡离子。本研究着眼于阴离子和阳离子表面活性剂，它利用溶液电导率，循环伏安法（CV），采样电流伏安法（SCV），和溶液pH值测量定性评估的稳定性的磁性抗衡离子在水溶液中。此外，溶液电导率被用来量化溶液中的顺磁性离子和表面活性剂胶束之间的结合程度。这些结果表明金属卤化物基阳离子表面活性剂在水溶液中是不稳定的。我们推测，这种不稳定性的结果在本研究中检查的阴离子与阳离子表面活性剂的磁响应的差异。
Predicting the behavior of magnetic surfactants in magnetic fields is critical for designing magnetically driven processes such as chemical separations or the tuning of surface tensions. The ability of magnetic fields to alter the interfacial properties of magnetic surfactant solutions may be dependent upon the strength of association between the magnetic and surfactant moieties of the surfactant molecules. This research shows that the stability of a magnetic surfactant in an aqueous environment is dependent upon the type of complex that contains the paramagnetic ion, and these findings provide valuable insight for the design of magnetic surfactants for applications in aqueous media. The surfactants investigated were ionic surfactants, which contained paramagnetic counterions. This investigation looked at both anionic and cationic surfactants; it utilized solution conductivity, cyclic voltammetry (CV), sampled current voltammetry (SCV), and solution pH measurements to qualitatively evaluate the stability of the magnetic counterions in aqueous solution. In addition, solution conductivity was used to quantify the degree of binding between the paramagnetic ions and surfactant micelles in solution. These results indicate metal halide-based cationic surfactants are unstable in aqueous solutions. We hypothesize that this instability results in the difference in the magnetic response of the anionic vs cationic surfactants examined in this study.