In the current work, an attempt has been made to investigate the effect of Graphene Nanoplatelets (GNP) reinforcement to water absorption behavior and mechanical properties of adhesive bonding with epoxy. Epoxy adhesive with various GNP content (i.e.
View Article and Find Full Text PDFThe functionality of bioactive molecules sensitively depends on their structure. For the investigation of intrinsic structural properties, molecular beam experiments combined with laser spectroscopy have proven to be a suitable tool. Herein we present an analysis of the two isolated tripeptide model systems Ac-Phe-Tyr(Me)-NHMe and Boc-Phe-Tyr(Me)-NHMe.
View Article and Find Full Text PDFIn order to investigate the influence of hydration on the backbone of a peptide or protected amino acid, the successive aggregation of water to Ac-Phe-OMe is analysed by means of IR/UV double resonance spectroscopy. To achieve meaningful results the spectra have been recorded in the region of the amide A and OH stretching vibrations as well as the amide I/II modes. Comparison with ab initio and DFT calculations leads to size-selective structural assignments.
View Article and Find Full Text PDFAs a model system for intramolecular proton/hydrogen-transfer coordinates, the structure of 2,5-dihydroxybenzoic acid is investigated for the ground, first electronically excited and also the ionic state. Combined IR/UV spectroscopy in molecular-beam experiments is applied and the experimental results are interpreted by the application of DFT and CASPT2 methods. No proton or hydrogen transfer is observed, but evidence is given for a hydrogen dislocation of the intramolecular hydrogen bond in the S(1) state and to lesser extent in the D(0) state.
View Article and Find Full Text PDFAn isolated beta-sheet model system is investigated in a molecular beam experiment by means of mass- and isomer-selective IR/R2PI double resonance spectroscopy as well as ab initio and DFT calculations. As the exclusive intermolecular assembly, a beta-sheet motif is formed by spontaneous dimerization of two isolated peptide molecules. This secondary structure is produced from the tripeptide model Ac-Val-Tyr(Me)-NHMe without any further environment to form the binding motif which is analyzed by both the characteristic amide A and I vibrations.
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