Spray introduction into FSP by means of electrohydrodynamic atomization (EHDA) of organic and aqueous precursor solutions

火焰喷雾热解（FSP）的大规模应用受到溶剂和前驱体需求的阻碍，这些溶剂和前驱体通常昂贵且复杂。因此，通过采用水溶液和有机盐溶液，FSP的应用领域可以得到很大的扩展。第一个结果表明，即使是简单的溶剂也可以在不需要爆炸增强添加剂的情况下在FSP中传递均匀的纳米颗粒。这种小液滴原则上可以通过气动雾化来实现，尽管需要大量的雾化气体。在这方面，电流体动力雾化（EHDA或电喷雾）是一种有趣的替代方案，它可以提供尺寸从几微米到几百微米的单分散液滴，并且几乎可以无压力工作。带电前驱体液滴从电喷雾喷嘴到接地火焰的传输是由于静电力发生的，因此可以完全省略分散气体的使用。由于火焰和喷雾过程的解耦，电喷雾喷嘴的布置和数量具有很大的灵活性，极大地简化了放大和多组分材料的合成。

The large-scale utilization of Flame Spray Pyrolysis (FSP) is impeded by the need for solvent and precursors, which are often costly and complex. Therefore, the field of FSP applications could largely be extended by employing aqueous and organic salt solutions. First results indicate that even simple solvent can deliver homogeneous nanoparticles in FSP without the need for explosion enhancing additives. Such small droplets can, in principle, be achieved by pneumatic atomization although requiring large amounts of nebulizing gas. In this respect, Electrohydrodynamic Atomization (EHDA or electrospray) is an interesting alternative, which can deliver monodisperse droplets with sizes ranging from a few microns up to several hundred microns and working nearly unpressurized. The transport of the electrically charged precursor droplets from the electrospray nozzle to the grounded flame occurs due to electrostatic forces so that the use of dispersion gas can completely be omitted. As a consequence of the decoupling of flame and spray processes a large flexibility exists for the arrangement and the number of electrospray nozzles strongly simplifying the scale-up and the synthesis of multi component materials.