Online assessment of the crystalline modification of nanoparticles in the gas phase

从气相合成纳米颗粒是资源有效的和常见的。由于因果关系研究，已知颗粒性质（尺寸、形态、团聚程度、结晶度）可以通过工艺参数的变化而改变。目前，合成颗粒的性质是离线表征的，在样品提取和制备之后具有相当大的时间延迟，在DFG/AIF联合项目的第二个资助阶段-通过创新的在线测量系统（MPaC）对基于颗粒的功能材料进行多参数表征-因此，在一个新的子项目中，将开发和测试用于分析气相中颗粒结晶度的在线和原位测量方法。结晶度作为颗粒的内部结构参数与应用方式（例如活性剂的生物利用度或颗粒的导电性）具有巨大的相关性。在这个项目中，迄今未涉及的参数CRYSTALLINITY补充了其他MPaC子项目的形态、尺寸和结构分析工作。该项目的目的是开发一种新的拉曼测量方法，用于在线和原位评估气相中纳米颗粒的结晶改性，同时分析气相温度和组成。这允许研究在相应的气相颗粒工艺中变化的工艺参数对所得产品性质的影响。通过拉曼光谱，可以通过气溶胶的特征光谱特征来区分气溶胶中的多晶型物。同时，从氮气的旋转拉曼光谱确定气相温度。由于拉曼散射的相对较弱的横截面相比，并发的光-物质的相互作用，特别注意的是有效的激发和检测的拉曼信号，同时最大限度地减少并发和干扰的干扰信号（化学发光，荧光）。这将通过优化和建立一个定制的光谱仪，特别是为这个项目，和应用移位激发拉曼差光谱（SERDS）方法来实现。测量方法将基于分散在气相中的颗粒系统二氧化钛、二氧化锆和氧化铁（III）开发。

The synthesis of nanoparticles from the gas phase is resource-efficient and common. Thanks to cause and effect studies, it is known that particle properties (size, morphology, degree of agglomeration, crystallinity) can be changed by a variation of process parameters. Presently, the properties of the synthesized particles are characterized offline with considerable time delay after sample extraction and preparation, thus yielding only scarce information about the process-to-product event chain and not allowing direct influence on it. Within the second funding phase of the DFG/AIF joint project - Multi parameter characterization of particle based functional materials by means of innovative online measurement systems (MPaC) - , hereby an online and in-situ method of measurement for the analysis of the CRYSTALLINITY of particles in the gas phase is to be developed and tested in a new sub-project. The crystallinity as an internal structural parameter of particles has enormous relevance for the means of application, such as the bioavailability of active agents or the conductivity of particles. With this project, the hitherto not covered aspect of the parameter CRYSTALLINITY complements the works for the analysis of morphology, size and structure of the other MPaC sub-projects. Aim of this project is the development of a new Raman measurement process for the online and in-situ assessment of the crystalline modification of nanoparticles in the gas phase, with the simultaneous analysis of the gas phase temperature and composition. This allows investigating into the influence of varied process parameters on the resulting product properties in corresponding gas phase particle processes. By means of Raman spectroscopy, it is possible to distinguish polymorphs in aerosols by their characteristic spectral signatures. Simultaneously the gas phase temperature is ascertained from the rotational Raman spectrum of nitrogen. Due to the relatively weak cross-section of Raman scattering compared to concurring light-matter interactions, particular attention is paid to the efficient excitation and detection of the Raman signals, at the same time minimizing concurring and interfering disturbing signals (chemiluminescence, fluorescence). This will be realized by optimizing and building up a custom-made spectrometer especially for this project, and the application of the Shifted Excitation Raman Difference Spectroscopy (SERDS) method. The measurement method will be developed on the basis of the particle systems Titanium dioxide, Zirconium dioxide, and Iron(III) oxide dispersed in the gas phase.