A rapid, novel and convenient method was described in this thesis for creating nanotextured surface involving the microwave-assisted hydrothermal synthesis (MAHS) treatment of polymer films coated on surfaces. The procedure transforms the homogeneous polymer film into uniform islands of regularly shaped, micro- and nanometer-sized polymers. The regularly shaped polymer nanoislands were utilized as template for deposition of metal oxide by spin coating a metal oxide sol-gel precursor on the polymer nanotextured surface and generating regularly shaped, hollow metal oxide nanostructures after removal of the polymer template. The metal oxide nanostructures were used for the immobilization of proteins and antibacterial materials....[ Read more ]

A rapid, novel and convenient method was described in this thesis for creating nanotextured surface involving the microwave-assisted hydrothermal synthesis (MAHS) treatment of polymer films coated on surfaces. The procedure transforms the homogeneous polymer film into uniform islands of regularly shaped, micro- and nanometer-sized polymers. The regularly shaped polymer nanoislands were utilized as template for deposition of metal oxide by spin coating a metal oxide sol-gel precursor on the polymer nanotextured surface and generating regularly shaped, hollow metal oxide nanostructures after removal of the polymer template. The metal oxide nanostructures were used for the immobilization of proteins and antibacterial materials.

The polymer nanostructure was obtained by spin coating polymer solution on clean silicon wafer followed with microwave treatment in proper condition. The polymer thin film was transferred into nanoislands on the silicon wafer. The diameter, height and density of the polymer nanoislands were controlled by varying the thickness of polymer thin film. The diameter is in the range from 26 nm to 83 nm for Poly methyl methacrylate (PMMA) nanoislands created by microwave-assisted hydrothermal synthesis (MAHS). The transformation mechanism was studied via pursuing the transition and observing the formation process of the islands with atomic force microscope (AFM). The results illustrate the phenomenon could be partially explained by the mechanism of thin film spinodal dewetting from non-wettable substrate. However, there is some difference between the current theory and our experimental data. Reported spinodal dewetting often results thin film dewet from surfaces and form droplets randomly. While, microwave-assisted technique can induce not only thin film but also a film as thick as 3 μm to form uniform, ordered arrays in nano- or microscale.

Glass nanobottles were fabricated from polymer template and used as ultrasmall containers of biomolecules on a surface of the substrate. Nanobottles of different sizes were prepared by using polymer nanoislands formed by dewetting of thin polymer films. An inorganic shell was coated on the polymer template by sol-gel process and the polymer was removed to create a well defined cavity. The bottle opening could be tailored by selective etching from 14 nm to 59 nm in size sufficient for the entry of most biomolecules of interest. Proteins including bovine serum albumin conjugated to fluorescein isothiocyanate (BSA-FITC), horseradish peroxidase (HRP), glucose oxidase (GOD) were immobilized in desired glass nanobottles by simple encapsulation technology. Both HRP and GOD maintain high activity and good reproducibility in the nanobottles.

Porous TiO₂ in nanoscale was produced by using polymer nanoislands as template. The TiO₂ nanoarchitectures were produced by spin coating TiO₂ sol on the template followed by treatment with oxygen plasma, ozone or calcination to remove the polymer template. TiO₂ nanobottles formed after removal of the polymer template by calcination at 450℃ exhibit higher disinfection effect than plain titania films owing to the larger surface area.