Project Details
Projekt
Structure-Property Relations and Wetting Dynamics of Organic Thin Films with Photo-Switches
Applicant
Professor Dr. Björn Braunschweig
Subject Area
Physical Chemistry of Molecules, Liquids and Interfaces, Biophysical Chemistry
Term
since 2019
Project identifier
Deutsche Forschungsgemeinschaft (DFG) - Project number 422792175
Smart surfaces that can reversibly change their wetting properties are of great interest for applications such as self-cleaning surfaces, microfluidics or microreactors just to mention a few. In this project, we propose to study dynamic wetting at photoswitchable surfaces that can undergo E/Z conformational changes triggered by light irradiation or by changes in the interfacial electric field (electrode potential). In both cases, macroscopic changes like the dynamic contact angle are coupled to the processes that occur within a single molecular layer at the solid-liquid and the solid-vapor interface, where we propose experiments from which we will gain a more complete molecular picture of the coupled substrate and drop dynamics. These are substantially influenced by the interactions of the wetting fluid with the wetted substrate and an understanding of this interaction on a molecular scale is, thus, of key importance for a description of the resulting wetting dynamics. For that reason, we will explore in this project the molecular origin of the remarkably slow switching dynamics in arylazopyrazole photo-switchable monolayers and will then address the role of surface defects and the slow self-assembly during switching on the apparent wetting dynamics. These experiments are then extended to reveal the molecular mechanism of electro dewetting and its coupling to light using photo-switchable substrates and surfactants which can be also used to tune molecular interaction and dynamics of the drop and the substrate and to remotely control wetting with two orthogonal stimuli.
DFG Programme
Priority Programmes
