Chiral structure formation is ubiquitous in surface self-assembly. Molecules that do not undergo chiral recognition in solution or fluid phases can do so when their configurational freedom is restricted in the two-dimensional field of a substrate. The process holds promise in the manufacture of functional materials for chiral catalysis, sensing or nonlinear optics. In this thesis, we investigate the influence of surface attraction and geometry on adsorption-induced chiral separation in several model molecules, as well as the relationships between molecular features, specifically molecular geometry and charge distribution, and chiral recognition at surface self-assembly. Simple model molecules embody the fundamental interactions involved in supramolecular structure formation in experimental systems, and allow the in-depth investigation of key parameters. Chiral pattern formation at the surface self-assembly is a complex problem, even in cases where very small organic molecules are considered. Even though the adsorption behaviour of small organic molecules on gold surfaces has been investigated extensively so far experimentally and theoretically, much of their chiral behaviour is yet to be understood at a molecular level. Theoretical investigations of chiral self-assembly of sulfur containing amino acids onto achiral and chiral gold surfaces is also presented in this thesis. By understanding chiral self-assembly on solid surfaces, one may control and direct it towards creating materials with desired functionality. / Graduate / 0494 / tp.popa@gmail.com

Surface self-assembly, the spontaneous aggregation of molecules into ordered, sta- ble, noncovalently joined structures in the presence of a surface, is of great importance to the bottom-up manufacturing of materials with desired functionality. As a bulk phenomenon informed by molecular-level interactions, surface self-assembly involves coupled processes spanning multiple length scales. Consequently, a computational ap- proach towards investigating surface self-assembled systems requires a combination of quantum-level electronic structure calculations and large-scale multi-body classical simulations. In this work we use a range of simulation approaches from quantum-based methods, to classical atomistic calculations, to mean-field approximations of bulk mixed phases, and explore the self-assembly strategies of simple dipoles and polyaromatic hydrocarbons on symmetric surfaces. / Graduate

<p>The newfound capability of creating moisture sensitive interference multilayered thin films (MLTFs) comprising microfibrillated cellulose and polymers has not previously been possible to implement on surfaces other than silicon wafer strips. Being able to incorporate interference MLTFs on fibre-based materials would introduce the possibility for new applications within authentication, sensing and customer attraction for the paper and packaging industry. By using trichloro (1H, 1H, 2H, 2H-perfluorooctyl) silane we were able to hydrophobically modify silicon substrates, enabling interference MLTF lift-off and thus the creation of free-standing MLTFs of approximately 400 nm thickness. Contact dried MLTFs approximately 250 nm thick, were successfully transferred to copy- and filter paper as well as to cellulose-based dialysis membranes. We can also report on the successful synthesis of interference MLTFs directly on a fibre composite material and on aluminium. Initial tests of a method to quantify the pull-off conditions of the MLTFs from the fluorinated surfaces using the Micro Adhesion Measurement Apparatus showed promising results.</p>

The newfound capability of creating moisture sensitive interference multilayered thin films (MLTFs) comprising microfibrillated cellulose and polymers has not previously been possible to implement on surfaces other than silicon wafer strips. Being able to incorporate interference MLTFs on fibre-based materials would introduce the possibility for new applications within authentication, sensing and customer attraction for the paper and packaging industry. By using trichloro (1H, 1H, 2H, 2H-perfluorooctyl) silane we were able to hydrophobically modify silicon substrates, enabling interference MLTF lift-off and thus the creation of free-standing MLTFs of approximately 400 nm thickness. Contact dried MLTFs approximately 250 nm thick, were successfully transferred to copy- and filter paper as well as to cellulose-based dialysis membranes. We can also report on the successful synthesis of interference MLTFs directly on a fibre composite material and on aluminium. Initial tests of a method to quantify the pull-off conditions of the MLTFs from the fluorinated surfaces using the Micro Adhesion Measurement Apparatus showed promising results.