The formation of thick, robust, mesoporous titania films is of particular interest and the focus of this thesis has been the study and comparison of the surfactant templated formation of such materials by three methods. film structure has been studied using TEM and small angle X-ray and neutron scattering while formation was studied using Brewster angle microscopy and X-ray and neutron reflectometry. Repetitive dip-coating was used to produce films for development into dye sensitized solar cells allowing development of cells of reasonable efficiency when four depositions were used. This research showed that repetitive deposition does not necessarily lead to a linear increase in film thickness, as subsequent depositions may be thinner making the future application of this method for solar cells problematic. In contrast to dip-coating, a fluorinated surfactant was used in a largely alcohol solvent to produce mesostructured films at the air-solution interface. Film formation occurred by a surface driven mechanism via addition of individual precursors and micelles producing a lamellar structure in-situ. After removal from the interface a cubic phase developed after drying of the film. Although films are not stable to calcination the calcined material remains porous. The surfactant templated formation of ZnO films at the air-solution interface was also studied. The di-block copolymer PEPEG2250 was also used to template titania films at the air-solution interface from alcoholic solvent. Film formation occurred via a bulk driven mechanism. Although these films were found to be disordered at the interface and not stable to calcinations they were unusually robust and self supporting after removal from the interface. Studies of subphase development allowed the first time-resolved observation of surfactant templated titania particle formation.
| Identifer | oai:union.ndltd.org:bl.uk/oai:ethos.bl.uk:512325 |
| Date | January 2008 |
| Creators | Hawley, Adrian Marcus |
| Contributors | Edler, Karen |
| Publisher | University of Bath |
| Source Sets | Ethos UK |
| Detected Language | English |
| Type | Electronic Thesis or Dissertation |
Page generated in 0.0023 seconds