Synthesis and Structure-Property Relations of a Series of Photochromic Molecular Glasses for Controlled and Efficient Formation of Surface Relief Nanostructures

Titelangaben

Walker, Roland ; Audorff, Hubert ; Kador, Lothar ; Schmidt, Hans-Werner:
Synthesis and Structure-Property Relations of a Series of Photochromic Molecular Glasses for Controlled and Efficient Formation of Surface Relief Nanostructures.
In: Advanced Functional Materials. Bd. 19 (2009) Heft 16 . - S. 2630-2638.
ISSN 1616-3028
DOI: https://doi.org/10.1002/adfm.200900140

Volltext

Link zum Volltext (externe URL):

Abstract

This paper reports on the synthesis and properties of a new series of photochromic molecular glasses and their structure-property relations with respect to a controlled and efficient formation of surface relief nanostructures. The aim of the paper is to establish a correlation between molecular structure, optical susceptibility, and the achievable surface relief heights. The molecular
glasses consist of a triphenylamine core and three azobenzene side groups attached via an ester linkage. Structural variations are performed with respect
to the substitution at the azobenzene moiety in order to promote a formation of a stable amorphous phase and to tune absorption properties and molecular dynamics. Surface relief gratings (SRGs) and complex surface patterns can easily be inscribed via holographic techniques. The modulation heights are
determined with an equation adapted from the theory for thin gratings, and the values are confirmed with AFM measurements. Temperature-dependent
holographic measurements allow for monitoring of SRG build-up and decay and the stability at elevated temperatures, as well as determination of the
glass transition temperature. SRG modulation heights of above 600 nm are achieved. These are the highest values reported for molecular glasses to date.
The surface patterns of the molecular glasses are stable enough to be copied in a replica molding process. It is demonstrated that the replica can be used to transfer the surface pattern onto a common thermoplastic polymer.