A measurement principle to examine the time‐of‐wetness and concentration of electrolytes using interdigitated electrode sensors and a neural network approach is discussed in this study. The electrolyte serves as a capacitive and resistive medium and changes the frequency responses of the sensor depending on its surface coverage and concentration. The measured impedance spectra are analyzed by an artificial neural network (ANN) model, which was trained by experimental and simulated data. Investigations of the performance of the ANN show a precise determination of the electrolyte concentration and present surface coverage. Furthermore, the application of this fast and easy method is discussed and tested to investigate the drying behavior of droplets from aqueous sodium chloride solution on the sensor surface in a climate chamber.

E‐coated galvanized steel sheets are widespread parts of the automotive industry. Hence, the undermining of the organic coating due to defects is a crucial issue. The delamination of an e‐coating is simulated for different cyclic climate conditions using the finite element method to predict the corrosion behavior over several weeks. A semiempirical mixed potential theory model is developed incorporating the time‐of‐wetness, the temperature, and the effect of corrosion products. Furthermore, the spatial orientation of the sheets is considered in the simulation. The trends of experimental delamination widths of corrosion tests are well described by the simulation.

We study the growth of two n-type small-molecule organic semiconductors from the perylene diimide family: N,N'-bis-(2-ethylhexyl)dicyanoperylene-3,4:9,10-bis(dicarboximide) (PDIR-CN2) and N,N'-1H,1H-perfluorobutyl-dicjyanoperylene-3,4: 9,10-bis (dicarboximide) (PDIF-CN2) whose chemical structures differ only in the imide substituents, branched alkyl chains -C8H16 and linear fluoroalkyl chains -C4F7H2, respectively. Both types of substituents introduce some degree of steric hindrance for intermolecular interactions, affecting solid-state packing during thin film formation, and thus induce specific structure-dependent optoelectronic properties in thin films. The transition from an amorphous structure to crystalline domains with strong intermolecular coupling was followed in situ and in real time during growth. We investigated the structural and morphological properties by X-ray diffraction and atomic force microscopy as a function of the substrate temperature and chemical structure. We examined the relationship between the structural properties and thin film optical signatures probed via differential reflectance spectroscopy, ellipsometry, and temperature-dependent photoluminescence. A new crystalline PDIR-CN2 polymorph at high temperatures emerges. In addition, we observed in PDIF-CN2 that the fluorinated chains contribute to crystallization inhibition because of the higher overall steric hindrance compared to the alkyl chains.