Kovalenko Artem, Jouhannaud Julien, Polavarapu Prasad, Krafft Marie Pierre, Waton Gilles, Pourroy Geneviève
Institut Charles Sadron (ICS) CNRS - Université de Strasbourg (UPR 22), 23 rue du Loess, BP 84047, 67034 Strasbourg Cedex 2, France.
Soft Matter. 2014 Jul 28;10(28):5147-56. doi: 10.1039/c4sm00318g.
We report on the stabilization of nanoparticle-decorated microbubbles for long periods of time using a synergism between a soluble surfactant and nanoparticles. The soluble surfactant is the perfluoroalkyl phosphate C8F17(CH2)2OP(O)(OH)2 (labeled F8H2Phos) and the nanoparticles (NPs) are 20-25 nm cobalt ferrite (CoFe2O4). The NP-F8H2Phos system has been studied by dynamic light scattering, dynamic magnetic susceptibility measurements and thermal gravimetric analysis. Microbubbles with diameters in the 1-20 μm range have been stabilized in 0.1 M NaCl brine. Its presence is crucial for the long-term stabilization. The surfactant adsorbs rapidly on bubbles and slows down the bubble shrinkage. Thus, the NPs can attach to the bubble and form a hollow sphere with a rigid shell. The charge screening by NaCl favors the attachment of NPs to the bubble surface. The coverage of the bubbles by the CoFe2O4 nanoparticle layer is confirmed by thermally induced inflation-deflation experiments and the control of bubbles with a magnetic field.
我们报道了利用可溶性表面活性剂与纳米颗粒之间的协同作用，长时间稳定纳米颗粒修饰的微泡。可溶性表面活性剂是全氟烷基磷酸酯C8F17(CH2)2OP(O)(OH)2（标记为F8H2Phos），纳米颗粒（NPs）是20 - 25纳米的钴铁氧体（CoFe2O4）。通过动态光散射、动态磁化率测量和热重分析对NP - F8H2Phos系统进行了研究。直径在1 - 20微米范围内的微泡已在0.1 M NaCl盐水中稳定下来。其存在对长期稳定至关重要。表面活性剂迅速吸附在气泡上并减缓气泡收缩。因此，纳米颗粒可以附着在气泡上并形成具有刚性壳的空心球体。NaCl的电荷屏蔽有利于纳米颗粒附着在气泡表面。通过热诱导膨胀 - 收缩实验以及用磁场控制气泡，证实了CoFe2O4纳米颗粒层对气泡的覆盖。
