Controlling wettability by light : illuminating the molecular mechanism

Title data

Radüge, C. ; Papastavrou, Georg ; Kurth, Dirk G. ; Motschmann, H.:
Controlling wettability by light : illuminating the molecular mechanism.
In: The European Physical Journal E. Vol. 10 (2003) Issue 2 . - pp. 103-114.
ISSN 1292-895X
DOI: https://doi.org/10.1140/epje/e2003-00015-0

Official URL:

Abstract in another language

The functionalisation of a surface with an organic monolayer containing photoactive moieties such as the azobenzene chromophore opens an elegant route for controlling its wettability by light. In this paper we investigate the microscopic origin of the macroscopic change in wettability upon photoinduced cis-trans isomerization of a copolymeric diphenyl-diazene Langmuir-Blodgett monolayer. Polarised UV-Vis and FTIR spectroscopy have been used to monitor the orientational order of various functional groups, Atomic Force Microscopy and Imaging Ellipsometry is employed for the quantification of the surface roughness and morphology, contact angle and surface potential measurements are carried out for a characterisation of the polar ordering. The data analysis is further supported by semi-empirical and ab-initio calculations of the molecular dipole moments and the normal IR-modes of the fluorinated chromophore. The combination of all these techniques provides a detailed molecular picture. The data suggest that changes in the projection of the dipole moment onto the surface normal caused by isomerization If the azobenzene are responsible for the observed changes in the surface energy. This knowledge allowed Lis to predict guidelines for the synthesis of molecules in order to maximize the wetting contrast upon photo-irradiation.

Further data

Item Type:	Article in a journal
Refereed:	Yes
Institutions of the University:	Faculties > Faculty of Biology, Chemistry and Earth Sciences > Department of Chemistry > Chair Physical Chemistry II Faculties > Faculty of Biology, Chemistry and Earth Sciences > Department of Chemistry > Former Professors > Chair Physical Chemistry II - Univ.-Prof. Dr. Andreas Fery Faculties Faculties > Faculty of Biology, Chemistry and Earth Sciences Faculties > Faculty of Biology, Chemistry and Earth Sciences > Department of Chemistry Faculties > Faculty of Biology, Chemistry and Earth Sciences > Department of Chemistry > Chair Physical Chemistry II Faculties > Faculty of Biology, Chemistry and Earth Sciences > Department of Chemistry > Former Professors
Result of work at the UBT:	No
DDC Subjects:	500 Science > 540 Chemistry
Date Deposited:	13 Sep 2017 09:09
Last Modified:	15 Jun 2023 13:42
URI:	https://eref.uni-bayreuth.de/id/eprint/39591