Abstract It is a big challenge to prevent the degradation of magnetic nanoparticles particularly under acid conditions. Here we demonstrated that the stability of magnetic Fe3O4 nanoparticles could be substantially improved after double coating with silica and carbon. The dense silica shell and hydrophobic porous carbon shell endowed the magnetic Fe3O4@SiO2@C nanoparticles remarkable anti-corrosion performance even under 10 M of HCl solution. More importantly, the demulsification of asphaltenes-stabilized water-in-toluene emulsion was realized with the aid of 2 wt% emulsion of our proposed double-coated magnetic particles due to their great interfacial activity. Besides, the magnetic Fe3O4@SiO2@C particles could be recycled up to six times while the magnetic Fe3O4@C particles would easily lose their interfacial activity. It is the first time to found that the inorganic shells showed a great interfacial activity. Thus, the high separation efficiency, excellent acid-anticorrosion, and easy recyclability of our proposed magnetic particles presented its great potential value in industrial application.

中文翻译：

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用于有效油水分离应用的耐酸疏水 Fe3O4@SiO2@C 磁性颗粒的制备

摘要 特别是在酸性条件下，防止磁性纳米粒子的降解是一个很大的挑战。在这里，我们证明了磁性 Fe3O4 纳米粒子的稳定性在用二氧化硅和碳进行双重涂层后可以得到显着提高。致密的二氧化硅壳和疏水性多孔碳壳赋予磁性 Fe3O4@SiO2@C 纳米粒子即使在 10 M HCl 溶液下也具有显着的防腐性能。更重要的是，沥青质稳定的甲苯包水乳液的破乳是在我们提出的双涂层磁性颗粒的 2 wt% 乳液的帮助下实现的，因为它们具有很大的界面活性。此外，磁性 Fe3O4@SiO2@C 颗粒最多可回收 6 次，而磁性 Fe3O4@C 颗粒很容易失去其界面活性。这是首次发现无机壳表现出很大的界面活性。因此，我们提出的磁性颗粒具有高分离效率、优异的耐酸腐蚀性和易回收性，在工业应用中具有巨大的潜在价值。