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

由于需要昂贵且复杂的溶剂和前体，火焰喷雾热解(FSP)的大规模应用受到阻碍。因此，FSP的应用领域可以通过使用水溶液和有机盐溶液得到很大的扩展。第一个结果表明，即使是简单的溶剂也可以在FSP中提供均匀的纳米颗粒，而不需要增强爆炸的添加剂。尽管需要大量雾化气体，但原则上可以通过气动雾化来实现如此小的液滴。在这方面，电流体雾化(EHDA或电喷雾)是一种有趣的替代方法，它可以提供尺寸从几微米到几百微米的单分散液滴，并且几乎不受压力地工作。由于静电力的作用，带电的前体液滴从电喷嘴传输到接地火焰，因此可以完全省去分散气体的使用。由于火焰和喷雾过程的分离，电喷嘴的布置和数量有很大的灵活性，大大简化了多组分材料的放大和合成。

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.