Piidioksidipinnalle oksastettujen polyeetterien lämpötila- ja vettymisriippuvuuksien mallintaminen molekyylidynamiikkasimulaatioilla

Tunable wetting, anti-fouling, and encapsulation properties are widely present in nature, enabling phenomena such as the self-cleaning behavior of lotus leaves and controlled substance exchange across biological interfaces. These natural systems have inspired surface engineering, where polymer brushes have gained attention as functional surface coatings for biomedical and technological applications. By varying parameters such as polymer type and grafting density, brush-coated surfaces can exhibit properties ranging from water repellence to bio-resistivity. In this thesis, atomistic molecular dynamics (MD) simulations are used to study the thermal and wetting behavior of polyethylene oxide (PEO) and polyoxymethylene (POM) chains covalently grafted onto a crystalline silica substrate. The effects of chemical and structural differences on molecular-level wetting phenomena are examined by varying polymer type, temperature, and grafting density. Atomistic MD enables explicit analysis of interfacial chain conformations and the molecular-level behavior of water and brush molecules during wetting. The results reveal distinct wetting responses of PEO and POM brushes. PEO brushes increase surface hydrophilicity through flexible, disordered structures and mixing with water droplets, especially at high grafting densities, whereas POM brushes generally increase hydrophobicity through temperature-dependent in-chain ordering with a non-linear dependence on grafting density. Chain ordering and brush height were strongly influenced by grafting density and temperature. Overall, this work demonstrates that small chemical differences between polyether chains can lead to markedly different surface wetting behavior, highlighting the potential of PEO and POM brushes as tunable surface coatings for advanced surface engineering applications.