| Low-dimensional nanomaterials have sparked a worldwide interest because of their unique optical, electronic, and magnetism properties and their potential applications in nano-apparatus. The dimension, morphology and size of nanomaterials have an important effect on their properties, so how to effectively control these factors is always the hotspot and difficulty in nanometer technology research. Based on the research in phase behavior of microemulsion, several kind of nanomatherials, such as LaAlO3, Ni(OH)2 and MnO2 , were successfully synthesized in microemulsion. To control of morphology and size of nanomaterials during synthesis process have been elementarily realized. In addition, some new routes to synthesize materials were also established. The primary conclusions in this dissertation are listed as follows:Based on systemic study in phase behaviors of microemulsion, three microemulsion systems, such as TritonX-100/n-hexanol/c-hexane/water, CTAB/n-butanol/isooctane/water and Span80-Tween80/n-butano/c-hexane/water, were chosen. In Triton X-100 microemulsion system, when the mass ratio between surfactant and assistant surfactant was 3:2 and temperature was at 30℃, the biggest solubility would be attained; as for CTAB microemulsion system, when the value of S/AS was 2:3, the microemulsion system had the biggest solubility; Span80-Tween80 microemulsion system had the biggest solubility when the value of S/AS was 1:1.There were great differences in morphology and size when synthesis the same kind of nanoparticles in different microemulsion system. LaAlO3 prepared in Triton X-100 microemulsion system showed the irregular rod shape with diameter of 50nm and length of 100-200nm; LaAlO3 were regular rod shape with diameter of 12nm and length of 60nm when synthesized in CTAB microemulsion system; while in Span80-Tween80 microemulsion system, the sphere shaped with diameter of 55nm LaAlO3 were gained. In Triton X-100 microemulsion system, aged time of 12 hours and temperature at 30℃were the optimum conditions to prepare the uniform and well dispersed LaAlO3 nanoparticles. And when control the molar ratio (ω) of water and surfactant at 21-30, the irregular rod shaped with diameter of 50nm and length of 100-200nm nanoparticles were obtained. Ni(OH)2 nanoparticles with different morphologies, such as lamellar-like, rod-like, and spherical, were prepared in CTAB microemulsion system under the hydrothermal-aided conditions. The pH value at 9-10 and hydrothermal temperature at 180℃were the optimum conditions to prepare the Ni(OH)2 nanorods. Ni(OH)2 nanorods with diameter of 13nm and the length from 60 to 360nm could be gained by controlling the value ofωfrom 13 to 25. To prolong the hydrothermal reaction time could control the morphology of the products and Ni(OH)2 nanospheres were obtained by self-assembling nanorods.In the process of preparing MnO2 nanoparticles in CTAB microemulsion system under the ultrasonic-aided conditions, ultrasonic power and ultrasonic time would affect the structure, morphology and size of the products. The crystal phase of MnO2 was the amorphous phase when ultrasonic power was 50W-100W, but the crystal phase was theβphase when ultrasonic power was up to 200W. MnO2 nanorods were obtained at ultrasonic time of 10 minutes, the morphology of products were nanowires at ultrasonic time of 30minutes, and the length were longer than that of at ultrasonic time of 10 minutes. When ultrasonic time was prolonged up to 60 minutes, the morphologies of products were uniform nanobelts. Based on the hydrothermal-aided microemulsion method, the control of crystal phase(αandβ) of MnO2 were realized by changing the molar ratio of reactants between KMnO4 and MnSO4.
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