Project Details
Projekt
Imaging-ellipsometer
Subject Area
Polymer Research
Term
Funded in 2023
Project identifier
Deutsche Forschungsgemeinschaft (DFG) - Project number 527112274
A device with ellipsoporosimetry function including the option to measure imaging as well as in contact with fluids under temperature control makes it possible to investigate pore size distributions, the influence of functionalisation and structure on adsorption and desorption of molecules as well as of differently polar vapours and swelling behaviour in contact with vapours or fluids on thin porous films. Due to the small amount of material, this is hardly feasible with other methods and not with simultaneous local information along the layer thickness (fit models) as well as in the area (imaging). This technique allows not only to detect pore size distribution in otherwise inaccessible samples, but also to investigate the interaction of wetting (functionalisation) or pore structure and transport or selective vapour adsorption. This is, for example necessary for the following investigations: (i) derivation of the pore size distribution in thin films/ separating layers (d ~1 µm to a few nm) also with asymmetric functionalisation and structure along the film thickness, which are just being investigated for the alignment of transport processes, and their modification by functionalisation or swelling/vapour sorption of polymers in nanoscale pores, ii) Swelling behaviour of polymer layers and mesoporous layers in contact with vapours and temperature-controlled liquids, iii) Investigation of wetting influences and nanoscale confinement on vapour adsorption and desorption, e.g. in the context of transport and separation processes. e.g. in the context of transport and separation processes. Although several departments at the TU-Darmstadt use simple ellipsometers to determine the layer thickness and refractive index of thin films, including a device that can measure in air up to high temperatures, and a few research groups also perform vapour sorption on powders, there is no possibility to investigate thin mesoporous and swellable layers and thus very small amounts of material for their pore size distribution and their vapour sorption behaviour of differently polar vapours as a function of functionalisation and structural properties. In order to measure and evaluate sorption isotherms, the extremely precise setting of the partial pressure and the automated measurement and evaluation of the measurement data obtained are crucial. If the partial pressure setting is not precise, the adsorption and desorption curves lie on top of each other and it is not possible to derive structure-property relationships. Furthermore, automated data evaluation to determine the pore size distribution is important for efficient measurements. Furthermore, temperature control for measurements in contact with fluids is crucial, especially for swellable and temperature-responsive surfaces. For example, temperature-controlled material changes and their effect on transport or release processes become accessible and thus the derivation of structure-property relationships is possible.
DFG Programme
Major Research Instrumentation
Major Instrumentation
Imaging-Ellipsometer
Instrumentation Group
5360 Meßgeräte für gestreutes und reflektiertes Licht, optische Oberflächen-Prüfgeräte
Applicant Institution
Technische Universität Darmstadt
