Homogeneous coating of aerosol-nanoparticles in a cold plasma under atmospheric pressure

二氧化钛纳米颗粒在防晒霜、废水净化或自清洁涂料中有多种用途。例如，出于技术或医疗原因，相当多的此类应用需要颗粒涂层。因此，二氧化钛颗粒与二氧化硅的包覆具有重要的技术意义。不幸的是，将涂料前驱体实施到工艺链中并不是轻而易举的事情，而且大多数情况下确实需要高温。这种包覆步骤还没有被系统地研究过。在这个项目中，二氧化钛纳米颗粒将被可调节厚度的二氧化硅覆盖物覆盖。这将在集成了反应性冷等离子体(介质阻挡放电-DBD)的两步气溶胶反应器中完成。除了极具前景的技术实现之外，这种两步反应器还允许对每个工艺步骤中的所有过程和反应进行研究。到目前为止，将DBDS应用于气溶胶反应器中的纳米颗粒包覆研究很少。在这里，我们将高度复杂的表面分析技术与反应堆内的连续过程相结合。本项目的目的是阐明界面和涂层形成的基本机制，以及它们对反应器内涂层过程的反馈。

TiO2 nanoparticles are in manifold use for example in sunscreens, in wastewater purification or in self-cleaning coatings. Quite a number of these applications require a particle coating for example from technical or medical reasons. Therefore, the cladding of TiO2 particles with SiO2 is of technological relevance. Unfortunately, the implementation of the coatings precursors into the process chain is not trivial and does mostly require high temperatures. Coating steps of this kind are yet investigated systematically.Within this project TiO2 nanoparticles shall be cladded with SiO2 covers of tunable thicknesses. This will be done in a two-step aerosol reactor with integrated reactive cold plasmas (Dielectric Barrier Discharge-DBD). Beside the highly promising technical realization this two-step reactor allows for the investigations of all processes and reactions in every process step. Up to now the cladding of nanoparticles applying DBDs in aerosol reactors is barely investigated. Here we combine highly sophisticated surface analytical techniques with the continuous processes within the reactor. It is the aim of this project to elucidate the fundamental mechanisms of interface and coating formation and their feedback onto the coating processes inside the reactor.