title: From evaporation-induced self-assembly to shear-induced alignment.
abstract: The functionality of compact nanostructured thin films depends critically on the degree of order and hence on the underlying ordering mechanisms during film formation. For dip coating of rigid nanorods the counteracting mechanisms, evaporation-induced self-assembly (EISA) and shear-induced alignment (SIA) have recently been identified as competing ordering mechanisms. Here, we show how to achieve highly ordered and homogeneous thin films by controlling EISA and SIA in dip coating. Therefore we identify the influences of the process parameters including temperature, initial volume fraction and nanorod aspect ratio on evaporation-induced convective flow and externally applied shear forces and evaluate the resulting films. The impact of evaporation and shear can be distinguished by analysing film thickness, surface order and bulk order by careful in situ SAXS, Raman and SEM-based image analysis. For the first time we derive processing guidelines for the controlled application of EISA and SIA towards highly ordered thin nematic films.
authors.affiliation: Institute of Particle Technology, Friedrich-Alexander-Universität Erlangen-Nürnberg, Cauerstraße 4, 91058 Erlangen, Germany. wolfgang.peukert@fau.de.
authors.forename: R
authors.initials: R
authors.lastname: Srikantharajah
authors.affiliation: Chair for Crystallography and Structural Physics, Friedrich-Alexander-Universität Erlangen-Nürnberg, Staudtstraße 3, 91058 Erlangen, Germany.
authors.forename: T
authors.initials: T
authors.lastname: Schindler
authors.affiliation: Fraunhofer Institute for Manufacturing Engineering and Automation IPA, Nobelstraße 12, 70569 Stuttgart, Germany.
authors.forename: I
authors.initials: I
authors.lastname: Landwehr
authors.affiliation: Institute of Particle Technology, Friedrich-Alexander-Universität Erlangen-Nürnberg, Cauerstraße 4, 91058 Erlangen, Germany. wolfgang.peukert@fau.de.
authors.forename: S
authors.initials: S
authors.lastname: Romeis
authors.affiliation: Chair for Crystallography and Structural Physics, Friedrich-Alexander-Universität Erlangen-Nürnberg, Staudtstraße 3, 91058 Erlangen, Germany.
authors.forename: T
authors.initials: T
authors.lastname: Unruh
authors.affiliation: Institute of Particle Technology, Friedrich-Alexander-Universität Erlangen-Nürnberg, Cauerstraße 4, 91058 Erlangen, Germany. wolfgang.peukert@fau.de.
authors.forename: W
authors.initials: W
authors.lastname: Peukert