| Summary: | 碩士 === 國立高雄大學 === 化學工程及材料工程學系碩士班 === 102 === Under the continued deterioration of the global environment and the increasingly getting more attention, reducing energy consumption and environmental protection will be an important issue in the future technological development.
In this work, we used biocompatible Poly-L-Lysine (PLL) or Poly-L-Glutamic acid (PLGA) as medium. The multilayers of PLL/PLGA were fabricated by applying Layer-by-Layer (LbL) assembly process on SiO2 substrate. The formation of gold nanoparticles and silica were both mediated by the polypeptide multilayers. After covering the nanoparticles by spin coating of sol-gel-synthesized HfO2 control oxide, Al electrode was deposited to construct a nanocrystal memory device. This study proposed a water-based all-solution process without the use of organic solvent. This process is quite simple and consistent with the recent trend of green chemistry. In this study, several issues are discussed as below: (1) the reducing ability of poly amino acid, (2) characterization of the multilayer film of poly amino acid, (3) reduction conditions of gold nanoparticles, (4) stability of gold nanoparticles, (5) memory properties of nanocrystal memory.
The experimental results showed : (1) Reducing ability of PLGA is stronger than that of PLL. And the reducing ability of carboxyl group is stronger than that of amino group by comparing the characterization of functional group in poly amino acid. The poly amino acid with a lower molecular weight induced the formation of gold particle with smaller particle size. (2) The poly amino acid with higher molecular weight assembled to a smoother film, but also depending on the solution pH value. (3) A superior reduction result of gold nanoparticles with average particle size about 4.5nm and total particle density of 1.72ⅹ1012cm-2 was obtained at solution pH value about 6. (4) The poly amino acid mediated silica can serve as protection layer, improving the thermal stability of gold nanoparticles. (5) The nanocrystal memorywith higher particle density showed better memory property.
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