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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.

"April 2002" / Bibliography: leaves 154-193. / ix, 198 leaves : ill. (some col.), plates (some col.) ; 30 cm. / Title page, contents and abstract only. The complete thesis in print form is available from the University Library. / Thesis (Ph.D.)--University of Adelaide, Dept. of Environmental Biology, 2002

Polymer solar cells have been attracted attention because they combine flexibility with low-cost fabrication, have been previously developed based on bulk-heterojunction. Many research groups have developed solar cells based on Poly (P3HT) and (PCBM) composites. The nanostructure morphology of P3HT: PCBM composites play an important role for affecting the device performance. Many researches propose a lot of method to improve the morphology, such as the selection of solvent in photoactive layer and the thermal annealing effect. In this research we have studied the nanostructure morphology of P3HT: PCBM composites film by blending with Cetrimoniumbromide (CTAB). We have prepared Polymer solar cells incorporating an active layer of P3HT: PCBM blended with CTAB. The short-circuit current density of the polymer solar cells improved after blend if 0.01wt% of the CTAB into P3HT: PCBM active later. The device structure of ITO/PEDOT: PSS/P3HT: PCBM: CTAB/Al was measured under AM 1.5G 100 Mw/cm2 illumination, exhibited a power conversion efficiency of 2.5%, which is a 17% improvement than the standard device. The power conversion efficiency increased from 2.13% to 2.5%. The short current density increased from 5.47mA/cm2 to 6.43mA/cm2.

In this research¡Awe used three kinds of surfactant ¡Aincluding Triton X-100(nonionic surfactant)¡ATriton QS-15 and SDS(anionic surfactant) ¡Ato study the effects of PAHs degradation bacteria on phenanthrene. In addition¡A we also discussed the treatment effects of salicylate¡A which was functioned as an inducer¡Aon degradation of phenanthrene by the microorganisms with and without the three surfactants. According to the experimental results¡Athe conclusions were as following¡G 1. Biodegradation of PAHs was interfered by species surfactant¡Awhich was affected by the experimental factor¡Aspecies of surfactant and bacteria. 2. In the low level of Triton X-100 system ¡Asalicylate could enhance the degradation of phenanthrene. 3. The effect of degrading phenanthrene was obvious by adding salicylate to the system. 4. In the system containing Aluminum oxide and Triton QS-15¡A it could not enhance the degradation effects on phenanthrene. In the future study¡A we suggest to further discuss the enhancing effects of surfactant on bioremediation of PAHs.

In this research, cetyltrimethylammonium bromide (CTAB) is used as organic template and hydrous tin chloride (SnCl4) is used as inorganic precursor to prepare mesostructured SnO2 powder. The synthesis is carried out in the room temperature using NH3(aq) as pH-modifier. The changing variables in the synthesis process include: the mixing sequence of CTAB(aq), SnCl4(aq) and NH3(aq), the molar ratio of CTAB/SnCl4 (R), the pH value of the mixture and the aging time of the mixture. The X-ray diffraction (XRD) results show that the pH value of the mixture is the determining factor for the successful synthesis of mesoporous powder. On the other hand, the mixing sequence is of no consequence on the formation of the mesostructure. For solutions of pH<1 and R=0.2, 0.5 or 1, a crystalline phase of organic-inorganic complex is found in the final products, which hinders the hydrolysis and condensation of the inorganic precursor and hence the formation of mesoporous structure. For powders derived from the solutions of pH=2~5, the diffraction peak of mesoporous structure appears and becomes more intense with increasing pH value. For solutions of pH>7, mesoporous powders are obtained constantly. As mesoporous powder is also obtained from solution of R=0.01, it is concluded that the formation of surfactant cylinders and the subsequently packed hexagonal arrays are not fulfilled during the cooperation assembly process of organic and inorganic moleculars because the concentration of CTAB is far below the critical concentration for rod micelle (~10wt0/0). On the other hand, surfactant rod micelles instead of mesoporous structure is found in the powder derived from the basic solution of R=10 (CTAB: 5 g, SnCl4: 0.5 g). This implies that in spite of the formation of CTAB rod micelles, the mesostructured SnO2 powder can not be obtained without sufficient amount of Sn-precursor . According to the model of mesostructure synthesis, in current work, surfactant ions (S+), inorganic ions (I+) and counter ions (X-) are connected in the form of S+X-I+ through the electrostatic attraction and their cooperation assembly results in mesoporous structure. As pH valueincreases instantly as NH3(aq) is added into CTAB(aq), it is concluded that CTA+OH- does not exist and X- is Br- or Cl- instead of OH-. Finally, the mesostructure obtained in this work collapse after a calcination of 5000C for two hours. Therefore, a great deal needs to be done to improve the thermal stability in the future.