Research Group Prof. Dr. G. Friedrichs

Two Finished Doctorates

Riaz_SadiekOct./Nov. 2017 

Saira Riaz and Ibrahim Sadiek have successfully defended their theses in October and November 2017. Congratulations!

Saira worked in the field of functional surfaces and used sum-frequency generation (SFG) spectroscopy to investigate gold, glass, and water surfaces covered with monolayers of optical switches, consequently her thesis is entitled "Spectroscopic Investigations of Azobenzene Based Self-assembled Monolayers on Gold, SiO2, and Water". As the signal strength of SFG sensitively depends on the molecular orientation, analysis of SFG spectra helps to monitor orientational changes within the monolayer resulting from optical switching of the trans-azobenzene to its cis isomer and vice versa. Next to other findings, Saira succeeded to show that the switching efficiency of mixed monolayers (i.e., generated by co-adsorption of azozobenzene-alkylthiols and alkylthiols) depend on sterical constraints within the monolayer. Her work was funded by the SFB 677 "Function by Switching".

Ibrahim developed innovative cavity-based absorption schemes and used his newly built mid-infrared cavity ringdown spectrometer (Mid-IR-CRDS) to demonstrate the functionality and advantages of the MiD-IR-CRDS approach (using CH3I detection as an example), to provide high resolution spectroscopic data for CH2Br2 (including the presentation of a new ab initio based assignment approach for asymmetric rotor spectra), to critically assessthe working limits of a novel saturation approach (Sat-CRDS), and to put forward a proof-of-principle study of a new type of saturation based 2D spectroscopy. His dissertation " New Mid-IR-CRD Spectrometer for Organohalogen Detection and Innovative Applications of Saturation Spectroscopy" was supported by the HOSST (Helmholtz Research School for Ocean System Science and Technology) program and the Kiel cluster of excellence "Future Ocean", both aiming to promote interdisciplinary research in the field of marine sciences.