This study presents an approach to closely investigate the process of incremental layer build-up from convectively dried sessile droplets. In a droplet-by-droplet manner, three layers of sodium benzoate solution droplets are consecutively applied on a glass substrate and successively dried in a laboratory-scale drying chamber. The morphology of the simplified layer structure that incrementally forms from the individual deposits is analyzed via white-light interferometry, after every addition of a new droplet. Furthermore, complementary X-ray micro-tomography measurements of the deposits were carried out to monitor inner structure development. Recurring steps and phenomena throughout the experimental build-up process were identified and could be characterized through these methods. Moreover, these phenomena could be linked to specific combinations of droplet positioning and drying conditions. Finally, the overall influence of convective drying parameters as well as droplet properties on the layer formation process was investigated with regard to morphology and porosity.

中文翻译：

---

深入研究干燥沉积液滴的增量层积聚

本研究提出了一种方法来密切研究对流干燥的固着液滴的增量层堆积过程。以逐滴方式，将三层苯甲酸钠溶液液滴连续施加在玻璃基板上，并在实验室规模的干燥室中连续干燥。在每次添加新液滴后，通过白光干涉仪分析由单个沉积物逐渐形成的简化层结构的形态。此外，对沉积物进行了互补的 X 射线显微断层扫描测量，以监测内部结构的发展。确定了整个实验构建过程中重复出现的步骤和现象，并可以通过这些方法对其进行表征。而且，这些现象可能与液滴定位和干燥条件的特定组合有关。最后，研究了对流干燥参数以及液滴性质对层形成过程的整体影响，包括形态和孔隙率。