Synthesis Of Dha Derivatives, Copper Oxides, Zinc Oxides And Their Properties

Low-dimensional nanomaterials possess unique optic, electric, magnetic and mechanical properties, which have great potential in applications such as nanostructured devices, hydrogen storage, field emission and preparation of new composite materials. DHA derivative is promising high-density optical storage medium and molecular switch material which is widely used in nanotechnology, bio-medicine, electronic information. In this thesis the following aspects were studied:1. Series of ZnO nanomaterials with different morphologies were synthesized by ultrasound-microwave method, combining with solid-state thermal conversion reaction at 400℃, using Zn5(OH)8(NO3)22H2O and Zn5(OH)8(AC)22H2O as a precursor, respectively, and NaBF4 and C7H13BrN2as oriented agents. The influence of the oriented agent dosage, ultrasound time and microwave time on the morphologies of the products was studied, and the optimum reaction condition for synthesis of the ZnO materials with uniform morphology was obtained. The composition and morphology of the products were investigated by XRD and SEM, and the BET surface areas were determined by N2 adsorption-desorption experiments. Photocatalytic activities of the products on methyl orange were investigated and compared with that of the commercial TiO2 (P25). It was found that the degradation percentages of the ZnO nanobelts and nanoparticles on methyl orange are high, which may be attributed to their large BET surface areas. The surface photovoltaic property of the belt-like ZnO was studied, which shows a p-type semiconductor.2. Series of copper and copper oxide nanomaterials were synthesized by hydrothermal and microwave-assisted methods respectively in the water-l-butyl-3-methyl-imidazole tetrafluoroborate system, using Cu7Cl4(OH)10·H20 as an precursor. The influence of the ionic liquid dosage and oxygen content on the composition and morphology of the products was studied. The reaction mechanism was also analyzed. Via hydrothermal reaction route, different Cu-based products, such as polygonal CuO, CuO nanosheets, CuO/Cu2O composition and pure Cu nanoparticles can be obtained by simply changing the amount of the ionic liquid in the oxygen-starved condition. The composition and morphology of the products were controlled by the ionic liquid which functions as reductant and template. Via microwave assisted route, however, only monoclinic single crystalline CuO nanosheets with hierarchical structures were obtained even if the amount of the ionic liquid was changed accordingly, which indicates that in oxygen-rich condition the ionic liquid behaves as a template to certain extent only. The results of the SPS show that the band gap energy of the CuO and Cu2O is 2.5eV and 2.1eV, respectively.3. Series of CuO nanowires and nanosheets were synthesized without using a template by ultrasound-assisted method, combining with followed solid-state thermal conversion reaction. The influence of the ultrasound time, burning temperature and time on composition and morphology of the products was studied. Their structural characters and properties were investigated by XRD, SEM, TEM and SPS in different atmosphere. It was found that the ultrasonic time was the most important factor to the composition and morphology of the products. The CuO nanowires with hierarchical structures were obtained by 20 min ultrasonic processing,·combining with followed thermal conversion, and the direct product after no less than 30 min ultrasonic processing is CuO nanosheet. The surface photovoltaic properties of the CuO nanowires in different atmosphere demonstrate it a good potential photoelectric gas sensing material.4. The optical switching material, DHA, was synthesized successfully and the reaction condition for each step was optimized. The ring-opening reaction process of the DHA molecules was observed by UV-Vis absorption spectrum, which takes very short time,3-minute only. The routes and methods for synthesis of the DHA derivatives, containing N, S heteroatom, were explored preliminarily.