Fabrication Of Micro/Nano-Scale Organic/Inorganic Structures Templated From Ordered Polymeric Porous Films

The widely application of functional materials has become more and more important for modern society. The realization of the functionalities of many materials relies on the development of miniaturization and patterning capability. In former studies, researchers found that template-assisted fabrication approach showed enormous potential. Methods based on the desired and controllable masks and templates for fabricating versatile patterns have been more flexible and practiced among all methods for achieving ordered arrays and patterns on the desirable surfaces. In addition, the techniques for the desired arrays and patterns and their corresponding applications in the broad fields will drive the further extension and intersection between the sciences of chemistry, physics, and biology and so on.In chapter 2, we reported an alternative strategy for fabricating surface-patterned and free-standing ZnO nanobowls by using polystyrene (PS) films with spherical nanowell arrays (PFSNA) as templates. By simple dip-coating and calcination processes, isolated ZnO nanobowls can be obtained on silicon substrates directly. Subsequent wet-chemical etching generated free-standing ZnO nanobowl structures. The ability to generate surface-patterned and free-standing nanostructures offers new opportunities to synthesis more complex structures in material science. In chapter 3, we demonstrated a facile and effective method to fabricate polygonal ZnO nanobowls by using spherical poly(vinyl alcohol) (PVA) nanowell arrays as templates. Shape transition of the arrays from spherical to nonspherical was induced by thermal deformation of the PVA nanowell templates. Hexagonal, square and triangular ZnO nanobowls have been successfully prepared, and more complex polygonal structures could be prepared by easily tuning the geometry lattice of the PVA nanowell templates. This strategy can also be used for other functional materials ranging from oxides to metals. Such structures may be useful in applications of shape-dependent optical, biological, and magnetic materials and devices.In chapter 4, we studied the detail mechanism of thermal degradation of the PVA films. Thermal degradation of the polymer responds for shape transition from circular to noncircular. We can easily tune the morphology of the polymeric films by selecting thermal degradation temperature of PVA. The polymer films with special morphology can be used as templates to fabricate functional materials with transformative photonic, magnetic, and hydrophobic or hydrophilic attributes.