| Atomic force microscopy (AFM) is employed in this thesis to probe the interfaces of pollen grains and the nanostructures of polymer films. The spontaneous microphase segregation of diblock copolymer systems into periodic morphologies make them compelling candidates for the fabrication of electronic, optical, and magnetic nanodevices. In this thesis, efforts are made to gain a deeper understanding of the dynamics of copolymer thin films, and the role played by underlying substrates in film self-assembly.; AFM, especially high-temperature AFM (HT-AFM), is a powerful tool to investigate the dynamics of domain coarsening and defect evolution of diblock copolymer thin films supported by a substrate. The domain growth behavior of polystyrene-block-poly(ethylene-alt-propylene) (SEP) films is determined to be Ostwald ripening. The isothermal propagation and annihilation of topological defects are also examined.; Substrates with micrometer-scale topographical features are determined to be crucial in the development of double gyroid microphase from cylinder-forming SEP films. Slow solvent extraction results in a gyroid morphology that exhibits a striking degree of orientational and translational order. Dependent upon the geometric pattern of the substrates, different projections of the gyroid microstructure are observed at the film surface. The influence of other experimental parameters is also discussed.; This thesis will also address the surface-assisted alignment of SEP thin films. The combination of "top-down" and "bottom-up" techniques allow for the control of the orientation and ordering of in-plane cylindrical domains in SEP thin films deposited on topographically templated substrates. Preferred orientation is achieved faster in narrow channels. Confined polymer chains can also undergo considerable elastic deformation to satisfy the channel width constraint. Furthermore, the surface roughness of channel sidewalls determines the orientation of the cylinder microdomains with respect to channel walls in tapered channels.; Lastly, in order to aid the understanding of the germination of Arabidopsis thaliana pollen grains, AFM is employed to retrieve information of not only the surface topography, but the elastic properties of heterogeneous grain surfaces. Armed with such local characterization information, it is surprising to find that the germination location shows no preference for the less stiff apertures, contrary to the classic model. |
